News from Rohde & Schwarz

Audio measurements Analysis, monitoring, data transmission

EMC test cell Favourably priced alternative to anechoic chambers

Customized radiomonitoring from 10 kHz to 18 GHz

151 Number 151 1996/II Volume 36

Audio Analyzer UPL is able to perform practically all audio measurements on analog and digital interfaces. As the “younger brother” of the internationally successful UPD, which still holds the top position in audio measurements, UPL is the solution for budget-conscious users. For more details see article on page 4. Photo 42 458 (Beethoven picture: Amadeus-Verlag, Winterthur)

Articles

Wolfgang Kernchen Analyzer UPL Audio analysis today and tomorrow ...... 4 Dr. Klaus-Dieter Göpel EMC Test Cell S-LINE Compact EMC test cell of high field homogeneity and wide frequency range ...... 7 Johann Klier Signal Generator SME06/SMT06 Analog and digital signals for receiver measurements up to 6 GHz ...... 10 Gregor Kleine Satellite Receiver CT200RS TV reception with analog and digital sound from outer space...... 13 Peter Singerl; Christian Krawinkel Audio Data Transmission System ADAS and Audio Monitoring System AMON Data transmission without data line, audio measurements without program interruption ...... 16 Reiner Ehrichs; Claus Holland; Radiomonitoring System RAMON Günther Klenner Customized radiomonitoring from VLF through SHF ...... 19 Dr. Christof Rohner BTS Antennas HF.../HK... The right antenna for every mobile-radio base station ...... 22 Thomas Rieder Paging System P2000 Flexible, multiprotocol radiopaging system...... 25

Application notes

Frank Körber Testing GSM/PCN/PCS base stations in production, installation and service with CMD54/57 ...... 28 Thomas Kneidel Container location from space ...... 30 Tilman Betz Automatic measurements on tape recorders using Audio Analyzer UPD ...... 32 Dr. Jürgen Lauterjung DVTS – video sequence for assessing MPEG encoders ...... 33 Michael Manert RF switch units simplify type-approval tests for mobile radio...... 35

Refresher topic

Peter Hatzold Digital modulation and mobile radio (II) ...... 37

2 News from Rohde & Schwarz Number 151 (1996/II) Software

Volker Janssen ESxS-K1 – attractively priced Windows software for EMC measurements ....40 Thomas Kneidel ALADIN and ARAMIS message-handling software – convenient data transmission by shortwave ...... 42 Jürgen Rauch; Karl Scalet Object-oriented software development for computer-aided, mobile data transmission ...... 44

Panorama

Dr. Andreas Waßerburger Mass Spectrometer Airsense 500 – fast gas analyzer for automobile industry ...... 46 Franz Ketterle The “lifeline” to rescuers in the air ...... 47 Leo Terneven Rohde & Schwarz FM and TV transmitters provide Greater Brussels with entertainment...... 49 Karl-Heinz Wagner A vision comes true – trunked radio for United Arab Emirates...... 50 Dr. Pekka Eskelinen R&S signal generators at Finnish Institute of Technology ...... 51 Jean-Paul Hosdain New radio stations for Belgian navy...... 53

Regular features

In short: Rohde & Schwarz now on Internet...... 9 Werner Mittermaier Test hint: Alignment of I/Q modulators by narrowband RF spectrum analysis ...... 36 Newsgrams ...... 54 Information in print...... 56 Press comments ...... 57 Wilhelm Kraemer Final article: Microwave Generator SMP – top-class performance to customer’s benefit ...... 58

Because of their low operating costs radiopaging services are becoming increasingly popular worldwide, with more and more new standards (eg ERMES, POCSAG) being established. Paging System P2000 from Rohde & Schwarz is a flexible, multiprotocol radiopaging system that meets all present and future requirements of network operators (see article on page 25). Photo 42 457/1

Imprint

Published by ROHDE & SCHWARZ GmbH & Co. KG Mühldorfstraße 15 D - 81671 Munich Telephone (0 89) 41 29-0 · international *(4989) 41 29-0 · Telex 523703 (rs d) · Editors: H. Wegener and G. Sönnichsen (German); C. B. Newberry, G. Koranyi (English) · Photos: S. Huber · Circulation 100 000 three times a year · ISSN 0028-9108 · Supply free of charge · State company or position · Printed in the Federal Republic of Germany by peschke druck, Munich · Reproduction of extracts permitted if source is stated and copy sent to R & S Munich

News from Rohde & Schwarz Number 151 (1996/II) 3 Articles

Audio Analyzer UPL far superior to instruments performing purely analog or digital measurements.

The test routines performed on analog Audio analysis today and tomorrow and digital interfaces are identical. This allows, for example, direct comparison Rohde & Schwarz has extended its range of audio analyzers by UPL, the of results obtained ahead of and after “younger brother” of UPD, which still holds the top position in audio measure- a converter. All test functions and test ments. UPL is mainly for use in production tests on digital and analog audio units signals are available both at the analog both in the consumer and professional sectors. and the digital interfaces. This makes it possible to measure at any point of a combined analog and digital transmission path. Only this ensures efficient and complete testing. The filters too are implemented digitally, resulting in an almost infinite number of filters, and this also for measurements on analog interfaces. All the user has to do is choose the type of filter (highpass, bandpass, etc), frequency and attenuation to loop a new filter into the test path (FIG 2).

The measurement speed provided by UPL is as a rule higher than that achieved with analog techniques since digital test routines can adapt their speed to the input frequency. Oper- ation is the same for the analog and the digital interfaces – a feature that should not be underestimated, especially if different types of application FIG 1 Audio Analyzer UPL, specialist for all thousand spectral lines, output of digital are to be handled. analog and digital audio signals audio signals via loudspeaker, jitter Photo 42 383/2 measurements on digital audio signals, UPL offers the following analysis func- and so on. In short, there is hardly any tions: task UPL cannot solve. And on top of • selective and broadband level this, UPL offers excellent technical data: measurements with rms, peak or analog sinewave generation with har- quasi-peak weighting, monics suppressed by typically 115 dB, • up to three filters of the integrated spectrum displays with a noise floor digital filter bank can be looped into as low as –140 dB at analog and the signal path (14 weighting filters –160 dB at digital interfaces, and fast in addition to user-programmable While audio-signal processing is no Fourier transform with maximum fre- filters), longer conceivable without the use of quency resolution of 0.05 Hz. • intermodulation measurements (total digital techniques, analog techniques harmonic distortion (THD), modula- continue to exist and undergo constant Analysis concept tion distortion, difference frequency improvement – the human ear is analog distortion); each type of intermodula- after all. A state-of-the-art audio ana- UPL performs all its measurements using tion can also be represented as a lyzer like UPL (FIG 1) must therefore digital signal processing. Analog signals bar chart, be able to handle both analog and dig- to be tested undergo extensive prepro- • wow-and-flutter measurements to ital signals. UPL is capable of fast and cessing on analog modules before they DIN/IEC, NAB, JIS or 2-sigma accurate frequency-response measure- are digitized and measured by means method with additional spectrum ments, spectrum display of demodulat- of digital routines. This concept pro- display of the demodulated signal, ed wow-and-flutter signals, generation vides an extended dynamic range and • frequency, phase and group-delay of multitone signals comprising several guarantees performance and flexibility measurements,

4 News from Rohde & Schwarz Number 151 (1996/II) Articles

• waveform function for representing • noise with a variety of amplitude dis- [1; 2] in the development lab can test signals in the time domain with tributions, be used on UPL in production, which optional smoothing of waveform • dither with adjustable level and se- substantially reduces the time for test- by interpolation and compression lectable amplitude distribution to be program generation. Long calibration of slow sequences (eg for tests on added to digital audio signals. intervals, resulting from the extensive AGC circuits), use of digital circuits, make for high • spectral analysis (FFT) with zoom UPL is able to perform amplitude and availability of the instrument. function for maximum frequency frequency sweeps for all test signals resolution of 0.05 Hz (FIG 3). and in addition interval and on-time Measurements on sweeps for bursts. digital audio interfaces The following test signals are available: Use in production UPL has balanced, unbalanced and • sinewave that can be applied to optical inputs and outputs for con- an equalizer with user-selectable UPL is particularly attractive for applica- necting consumer electronics and pro- nominal frequency response, eg tions in production. For example, it can fessional studio equipment. Additional for compensating the frequency perform all test functions simultaneously inputs and outputs allow the analyzer response of a test setup, in two channels. This feature alone re- and generator to be synchronized to the • two-tone signal for intermodulation duces the time for stereo measurements digital audio reference signal (DARS), measurements (amplitude ratios by 50% compared with most analyzers and the generator to wordclock, video and frequencies continuously ad- available on the market. Intermod- sync signals and to 1024-kHz refer- justable), ulation measurements are carried out ence clocks. The generator and the • multitone signal comprising up to using patented, digital procedures that analyzer can be driven at separate, 7400 frequencies with selectable combine high accuracy with high variable clock rates between 27 and amplitude distribution (frequency measurement speed. Fast frequency- 55 kHz. This allows the use of non- spacing can be linked to resolution response measurement using a special, standard clock rates as encountered of fast Fourier transform, thus en- FFT-coupled multitone signal affords a in sample converters, which are em- abling rapid and accurate single-shot decisive time advantage especially in ployed to an increasing extent, and in measurement of frequency response intermodulation measurements, which multimedia applications. of EUT), are often required. Digital signal pro- • arbitrary signal for generating any cessing reduces setting and transient Of course UPL is also capable of ana- trace of up to 16,384 points, times as against those achieved with lyzing additional data of the digital • sine burst and sine2 burst signal with comparable, purely analog instruments. audio signal and physical interface adjustable interval and on-time, parameters. For example, channel- An integrated program generator, which translates each manual control step into a complete IEC/IEEE-bus program line of correct syntax in the logging mode, considerably speeds up control-program FIG 3 Zoom FFT function for displaying side- FIG 2 Easy definition of filters by means of a generation. Furthermore, instrument set- bands just a few hertz from main line of audio few entries ups generated on Audio Analyzer UPD signal

News from Rohde & Schwarz Number 151 (1996/II) 5 Articles

FIG 4 Analysis of additional data of digital FIG 5 Jitter spectrum of digital audio signal audio signal coded in professional format

status data can be input and output in Future-proof investment REFERENCES binary form or coded to professional, [1] Kernchen, W.: Audio Analyzer UPD gener- consumer or any user-defined format Who can predict for sure today what ates and measures analog and digital audio signals. News from Rohde & Schwarz (FIG 4). UPL further provides display of effects growing digitization will have (1992) No. 139, pp 13 –15 jitter spectrum (FIG 5), measurement of on the audio world and what test re- [2] Hempel, J.: Automatic audio measurements jitter amplitude, generation of jittered quirements will result from this? In this with user-friendly control system of Audio output signals and is able to remove respect there will be no problems Analyzer UPD. News from Rohde & jitter from input signals. with Audio Analyzer UPL. With all test Schwarz (1993) No. 143, pp 29 – 30 functions implemented digitally, UPL Bit- and word-synchronous sync signals can be adapted to changing require- allow accurate analysis of digital audio ments by simply loading the necessary signals on an oscilloscope. The pre- software – and this also for the analog amble, eye pattern and superimposed interfaces. noise can be displayed, for example. Wolfgang Kernchen Moreover, the phase difference between the audio and the reference input can be measured, and a phase difference can be generated between the audio and the reference output. De- Condensed data of Audio Analyzer UPL lay times of equalizers, audio mixers, Analog analyzer etc can be determined by measuring Frequency range 10 Hz to 110 kHz the time difference between the output Voltage range 0.1 µV to 35 V (rms, sine) and the input signal. Common-mode Inherent distortion (THD) typ. < –115 dB signals at the balanced input (frequency, amplitude, spectrum) can be Analog generator analyzed and a common-mode signal Frequency range 10 Hz to 110 kHz can also be superimposed on the out- Voltage range 0.1 mV to 20 V (rms, sine, open-circuit) put signal. Audio Analyzer UPL further Harmonics typ. < –115 dB (< –120 dB at 1 kHz) provides measurement of input-pulse Digital analyzer and generator amplitude and sampling frequency. Clock rate 27 to 55 kHz The adjustable output level makes it Frequency range 10 Hz to 21.75 kHz possible to determine the sensitivity of Inputs and outputs XLR, BNC, optical digital audio inputs. Long cables can Inherent distortion (THD) typ. < –130 dB be simulated by means of a switchable Reader service card 151/01 cable simulator.

6 News from Rohde & Schwarz Number 151 (1996/II) Articles

EMC Test Cell S-LINE (anechoic) chamber as test environment, which must be partially fitted with absorbers to achieve the required uniform field strength (referred to as Compact EMC test cell uniform area). Since the construction and furnishing of anechoic chambers of high field homogeneity involve a lot of technology and ex- pense, cheaper alternatives have al- and wide frequency range ready appeared on the market. Exam- ples of this are TEM cells or GTEM In S-LINE, Rohde & Schwarz offers a favourably priced test cell for measuring (GHz Transverse Electromagnetic) susceptibility to electromagnetic fields in the frequency range 150 kHz to 1 GHz Cells, compact anechoic chambers and in the development phase. The test cell, which comes in two sizes, is an attractively precompliance test cells [2]. priced alternative to compact anechoic chambers. By generating the field using a symmetrical line, S-LINE offers a larger test volume than conventional cells. S-LINE, developed by Rohde & Schwarz, is a new type of EMC test cell (FIG 1) offering the user decisive With the expiry of the transitional For susceptibility measurements, signal benefits: period for the electromagnetic com- generators and power amplifiers are • substantially lower costs compared patibility law at the beginning of this needed and, like in EMI measurements, with anechoic chambers, year, all manufacturers of electrical and coupling networks or antennas in addi- electronic products in Europe are now tion. Unlike EMI measurements, electro- required to supply EMC conformity magnetic susceptibility measurements FIG 1 EMC Test Cell S-LINE, favourably priced declarations for their products and must be carried out in shielded en- alternative to anechoic chambers label them with the CE mark. Small and closures. Standards stipulate a shielded Photo 42 456 medium-sized businesses in particular have to decide which of the required measurements they can perform on their own with due consideration of their facilities and budget. Test setups and systems conforming to standards call for relatively high investment. Par- ticularly interesting, therefore, are solutions that offer low-cost EMC measurements in preliminary testing, ie precertification, prior to acceptance testing. Such measurements can further provide proof of the effectiveness of EMC measures already at the development stage, so standard-conforming measurements performed by external test houses can be reduced to a minimum.

EMC measurements are divided into electromagnetic interference (EMI) and electromagnetic immunity or susceptibility (EMS) measurements. For EMI measurements, test receivers or spectrum analyzers are required. Many users have already invested in instrumentation of this type. Rohde & Schwarz offers the budget-priced Test Receiver ESPC [1], for example, which was presented in the spring of 1995 at the EMC show in Zurich.

News from Rohde & Schwarz Number 151 (1996/II) 7 Articles

• uniform field strength throughout test Operation accordance with IEC 1000-4-3. S-LINE volume, fulfills the standard requirements over • highly compact size allowing easy Conventional test cells can be regarded an area of 50 cm x 50 cm. Practical installation in existing rooms, as widened unsymmetrical coaxial lines measurements confirm the calculations • correlation with standard-conforming with the EUT exposed to the EM field and show that the requirement for a test methods. between the inner and the outer con- uniform area is fulfilled even in a vol- ductor. By contrast, S-LINE consists of ume of 50 cm x 50 cm x 50 cm almost Mechanical design symmetrical, two-wire TEM lines pro- in the entire frequency range. vided in the electrically shielded en- S-LINE comes in two sizes. The larger closure (FIG 2). The lines are fed with model with dimensions of 1.5 m x 1 m an RF signal at one end and terminated x 1 m offers a test volume comparable with their characteristic impedance at to that of compact anechoic chambers. the other. In this case too, the EM field This small size makes S-LINE suitable generated between the lines is used for use in any development lab. Com- for determining the electromagnetic pared with conventional precompli- susceptibility of the EUT. However, ance cells, S-LINE has clear advan- due to the symmetrical arrangement, a tages with respect to radio-frequency much greater test volume is obtained characteristics. The enclosure prevents than with conventional cells of the same the emission of electromagnetic energy size. into the surroundings. It is fitted with an RF-shielded door which provides easy A theoretical assessment of the field dis- access to the inside. The EUT is taken tribution in a transverse plane of S-LINE can be made using a simple charge distribution model. The enclosure surfaces FIG 3 Field distribution in transverse plane of test cell. Coloured areas show regions of constant form the mirror lines in the transverse field strength, lines mark constant field strength in FIG 2 Electrical design of EMC Test Cell S-LINE plane. The potential field and con- steps of 3 dB. Dotted red lines indicate uniform (block diagram) sequently all other field parameters are area of approx. 50 cm x 50 cm with relative field- strength variation of less than 6 dB.

Transformer, Cell interior antenna FIG 4 shows the relative field strength splitter measured in S-LINE as a function of Line group 1 height above EUT worktop. This height

RF input is normalized to the total height of the cell. The values measured in a con- EUT Terminations ventional precompliance test cell are shown for comparison. It can clearly be seen that with a conventional cell a Line group 2 field-strength variation of almost 20 dB is to be expected, whereas with S-LINE the variation is just about 4 dB.

EMC systems and setups up by a level worktop in the cell. Since obtained by superimposing the poten- with S-LINE the EUT functions must be monitored tials of all charges. In the case of TEM during measurements in S-LINE, a transmission, this assessment can be S-LINE can be used to complement shielded window is fitted in the door applied to the E-field components. FIG 3 existing measuring equipment. Rohde & and the cell can be illuminated inside illustrates the area of the ±3-dB and Schwarz also offers complete EMC for visual monitoring. For electrical ±6-dB limits of the relative field strength test setups incorporating S-LINE. For monitoring, standard filtered feed- determined in the way described example, an EMC test system for the throughs are provided and, in addition, over the complete transverse plane frequency range 150 kHz to 1 GHz screwed-on access panels allowing the of S-LINE. This is the plane in which can be implemented with Signal cell to be configured as required. the uniform area is to be proven in Generator SMY, Power Meter NRVD,

8 News from Rohde & Schwarz Number 151 (1996/II) Articles

FIG 4 Relative field strength as function of height above cell base. Test positions are referred to total height of cell (continuous line: S-LINE Relative field strength with symmetrical lines, dotted: unsymmetrical lines).

Relative height a power amplifier and S-LINE. System Software EMS-K1 [3] allows fully auto- Condensed data of EMC Test Cell S-LINE matic tests to be performed. Frequency range 150 kHz to 1 GHz Dr. Klaus-Dieter Göpel Input power max. 100 W CW Input impedance 50 Ω VSWR of empty cell <2.5; typ. <1.5 Size of uniform area Large model approx. 50 cm x 50 cm REFERENCES Small model approx. 35 cm x 35 cm [1] Janssen, V.: EMI Test Receiver ESPC – EMC Field strength 10 V/m at 20 W input power precertification measurements for every- (large model, calculated in center of one. News from Rohde & Schwarz (1995) S-LINE) No. 149, pp 16–18 Dimensions (L x W x H) [2] Stumpf, M.; Lehmann, M.: EMC Test Systems Large model 1.5 m x 1 m x 1 m TS9977 and TS9987 – GTEM cell, the Small model 1.0 m x 0.7 m x 0.7 m favourably priced alternative to the anechoic chamber. News from Rohde & Schwarz EUT monitoring visually through shielded window, and supply electrically via access panel with (1993) No. 140, pp 8 –10 integrated filters, [3] Göpel, K.-D.: System Software EMS-K1 AC: 220 V/4 A, under Windows – Automatic measurement DC: 12 V/2 A, 5 V/4 A of electromagnetic susceptibility. News Reader service card 151/02 from Rohde & Schwarz (1995) No. 148, pp 12–15

In short Rohde & Schwarz now on Internet

Since the beginning of March, Rohde & Schwarz • The third category “Products” is the key offer has been using its own Web site, ie a server for and is arranged according to activity fields World Wide Web. The network address is: and applications. Written and display information about products can be called up. http://www.rsd.de • “Events” presents the complete Rohde & Schwarz training program in German and The offer comprises four categories of informa- English and a list of known participation in tion, mostly in English: shows for a whole year in advance.

• “What’s new” offers the latest news such as the Online information thrives on news. For this press releases of the past months in German reason our pages are continually revised so that and English. they are always right up-to-date. • “About Rohde & Schwarz” comprises general information about the company, history, tech- We recommend use of the Netscape Navigator nical milestones and international marketing as an access program (Browser). This program addresses. ensures troublefree display of data. Ba

News from Rohde & Schwarz Number 151 (1996/II) 9 Articles

Signal Generator SME06/SMT06 high-power attenuator (eg 10 or 20 dB) can be switched in. This external attenuation can be taken into account in SME and SMT as an offset, and the Analog and digital signals for signal generator then indicates the level after the attenuator. In this way mea- receiver measurements up to 6 GHz surement errors are prevented.

The boom in the communications sector is continuing. More and more mobile- Synthesizer concept radio networks and new radiocommunication applications are being devised. As the frequency bands below 3 GHz are already densely occupied, increasing The market success of the Rohde & use will have to be made of the region above 3 GHz. Rohde & Schwarz has Schwarz signal generators proves that responded to this trend by extending its line of signal generators by two new the right concepts were chosen. This models: SME06 and SMT06 for the frequency range up to 6 GHz. holds both for SMT, which is a budget-

FIG 1 Externally identical models SME06 and SMT06 extend signal-generator family to cover analog and digital receiver measurements up to 6 GHz. Photo 42 455

Since 1993, Rohde & Schwarz Signal With SME06 and SMT06, the mea- priced solution with a single-loop Generators SME and SMT for up to surement technology for these applica- synthesizer, and for SME, which fea- 3 GHz have been highly successful on tions is in place well ahead of time. tures direct digital multiloop frequency the market. Now this signal-generator synthesis, short settling times and family has grown by two new members: The two new models are based on their digital modulation. From the different models SME06 (FIG 1) and SMT06 lower-frequency “brothers” and were synthesizer concepts, different fields of for applications up into the 6-GHz developed using frequency doubling. application are obtained. range. Good news for customers who In other words, SME06 and SMT06 are have to meet requirements which identical to SME03 and SMT03 up to SMT covers the complete range of stipulate immunity to interference tests 3 GHz except for overvoltage protec- conventional analog receiver and EMC on electrical equipment up to 4 GHz. tion, which is not provided on the new measurements, while SME is capable SMT06 is an ideal and at the same models since it would result in a consid- of both analog and digital modulation. time cost-effective signal source for erable deterioration of the output reflec- Moreover, thanks to its fast frequency this purpose. Further applications will tion coefficient at 6 GHz. Despite this, synthesis, SME is ideal for measure- open up in the 5-GHz range, where reflected RF power up to 1 W is per- ments on frequency-hopping systems intensive R&D is under way on new missible with SME06 and SMT06. To and for tasks where every millisecond systems such as WLAN (wireless local eliminate any danger when working counts, eg tests on integrated circuits, area network), WLL (wireless local on transceivers, which often have RF since test time for the IC manufacturer is loop) and electronic road toll systems. output powers above 1 W, an external equivalent to test costs. A reduction of

10 News from Rohde & Schwarz Number 151 (1996/II) Articles

test time from 20 to a few milliseconds, standard, an LF generator can be PRBS sequences can be selected as for example, will substantially reduce fitted to SME/SMT to supply sinewave, fixed standard patterns of various manufacturing costs. With 500 µs triangular, squarewave and noise lengths or user-programmed with the settling time in the list mode, SME offers signals. The maximum frequency for aid of a list editor. Moreover, exter- an excellent prerequisite for cutting sinewaves is 500 kHz. A multifunction nally generated data sequences up to down on these costs. generator provides the same signals a length of 8 Mbits can be stored in as the LF generator over an extended SME. Such sequences are needed, for The difference between the two synthe- frequency range up to 1 MHz and, example, for propagation measure- sizer concepts can clearly be seen, for in addition, stereo multiplex and ments in GSM networks. In SME, spu- example, from the SSB phase noise VOR/ILS modulation signals. The mul- rious AM and FM can be added to (FIG 2), where SME features excellent tifunction generator makes SME/SMT the digital modulation. This allows values close to the carrier up to 10 kHz. suitable even for highly demanding receivers to be tested not only with With –115 dBc at 1 kHz from a 1-GHz measurements on FM stereo and virtually ideal signals but also with carrier, SME can compete with the very VOR/ILS navigation receivers. A pulse interference signals as encountered in best of today’s low-noise generators. generator supplies single and double practice [2]. Its favourable SSB phase-noise values pulses up to 10 MHz. It can be inter- make SME ideal for substituting a local nally or externally triggered. The pulse Ease of operation oscillator, especially when it comes to delay can be selected between 40 ns critical applications in digital trans- and 1 s. The signals generated by Despite the wealth of functions provided, mission and radar systems. SMT, on the SME/SMT are available at separate operation of SME is extremely easy other hand, shows its strength at more outputs for external applications so that thanks to a well thought-out operating than 100 kHz from the carrier. With in some cases there is no need for an concept featuring a large LCD display SSB phase noise of –150 dBc at 1 MHz external AF or pulse generator. and menu guidance. All parameters from a 1-GHz carrier, SMT is suitable and conditions selectable for a specific for blocking measurements even on Besides the analog modulation modes function are logically arranged in a high-end receivers. named above, SME06 provides virtually single display. The user can be sure of all types of digital modulation used in not overlooking any hidden criteria or Modulation today’s mobile-radio networks: GMSK, options associated with a particular GFSK, FSK, FFSK, 4FSK, QPSK, function. SME and SMT feature versatile mod- O-QPSK and π/4-DQPSK, the data of ulation modes for tests on communi- the QPSK-based modulation modes Another feature that greatly facilitates cations, navigation, telemetry and degrading in the range above 3 GHz. operation is the patented, magnetically broadcast receivers. The generators The bit rate, filters and frequency de- locking tuning knob. Although smooth- are capable of simultaneous AM, FM viation can be selected over a wide running, it provides fine stepping which (ϕM) and pulse modulation. For two- range, and a variety of combinations the user can clearly distinguish. As a tone modulation, internal and external is possible. With 4FSK and QPSK, the result, the display of SME/SMT need sources can be combined. The AM bit rate can be set in the ranges 1 to not be watched all the time, eg in step- frequency range is DC to 100 kHz, 24.3 kbit/s and 27 to 48.6 kbit/s [1]. wise tuning. Tiresome turning from one the FM range DC to 8 MHz (SMT) or 2 MHz (SME) with maximum deviation of 40 MHz (SMT) and 4 MHz (SME). A special control circuit ensures high carrier-frequency accuracy in the FM DC mode. DC coupling is possible also with phase modulation. The ϕM bandwidth is 2 MHz for SMT and 100 kHz for SME. Another valuable feature is the high-quality pulse modulation, featuring a rise/fall time shorter than 10 ns and an on/off ratio better than 80 dB.

The versatile modulation capabilities FIG 2 are backed up by a variety of modu- SSB phase noise lation sources. In addition to a fixed- of SME and SMT frequency generator incorporated as at 1 GHz

News from Rohde & Schwarz Number 151 (1996/II) 11 Articles

Future-proof investment

It is difficult to say at present what new applications lie ahead in radiocommunications. There are however two reasons pointing to a strong increase in the demand for test equipment for the 3-to-6-GHz range: first, the range up to 2.7 GHz is already densely occupied

FIG 3 so that higher frequencies will have Level frequency to be used to an increasing extent. response of SMT06 Second, the trend towards higher fre- at 0 dBm output level quencies is being speeded up through new technologies allowing the use of small, favourably priced components. With its Signal Generators SME06 and SMT06, Rohde & Schwarz takes ac- display to another, eg when operating the step time in a list, the automatic test count of this trend already now, making SME/SMT and another instrument at run can be started. sure that the right instrumentation is the same time, is a thing of the past. ready and in place. Remote control of SME/SMT is normal- Johann Klier Operator convenience is further en- ly via the IEC/IEEE-bus interface. If no hanced by a variety of useful features. IEC/IEEE-bus interface is available on Every RF specialist is aware of the prob- the external PC, the RS-232-C interface lem: the higher the operating frequency can be used instead. This is expedient, REFERENCES in a test system, the more difficult it is to for example, if a long data sequence [1] Klier, J.: Extensions to Signal Generator apply the RF signal to the EUT without has to be reprogrammed in SME and SME for testing new digital networks. News from Rohde & Schwarz (1994) No. 146, any losses or appreciable frequency SME should remain in the test system. In pp 40 –41 response occurring on the connecting such cases SME can be reprogrammed [2] Klier, J.: Simulating vector errors with lines. Here the user correction function on site via the RS-232-C interface with Signal Generator SME. News from Rohde & is helpful: level correction values for up the aid of a laptop. Schwarz (1995) No. 148, pp 32 – 33 to 160 frequency points can be stored in SME/SMT, the values between these points being determined automatically by interpolation (FIG 3). This allows the Condensed data of Signal Generator SME06/SMT06 frequency response of external cables Frequency range 5 kHz to 6 GHz to be corrected and the level at the EUT Setting time SME06/SMT06 <10 ms (<500 µs in list mode) / <15 ms to be kept constant. The user correction Spurious (f < 1.5/3/6 GHz) <–80/–74/–68 dBc function is equally valuable in EMC SSB phase noise measurements, where the frequency (f = 1 GHz, at 20 kHz from carrier) response of amplifiers, antennas or SME06/SMT06 <–126 dBc/<–116 dBc TEM cells connected after the signal Level range –144 to +13 dBm (overrange 16 dBm) generator are to be compensated. This AM/FM/ϕM SME06 DC to 100 kHz/2 MHz/100 kHz ϕ does away with complicated, external AM/FM/ M SMT06 DC to 100 kHz/8 MHz/2 MHz level controls or test routines. Digital modulation (SME only) GMSK, GFSK, FSK, FFSK, 4FSK, QPSK, O-QPSK and π/4-DQPSK Pulse modulation For frequently repeated measurement On/off ratio >80 dB series or sequences of different types Rise/fall time <10 ns of single measurements, the memory Pulse generator single pulse, double pulse, external trigger Pulse repetition period 100 ns to 85 s sequence function affords convenience Pulse width 20 ns to 1 s otherwise obtained only through pro- Pulse delay 40 ns to 1 s cessor control. Up to 50 instrument set- Multifunction generator sinewave, triangular, squarewave, noise, tings can be stored in nonvolatile mem- VOR/ILS modulation signals, stereo MPX signals ory. After programming the sequence Reader service card 151/03 of measurements (up to 256 steps) and

12 News from Rohde & Schwarz Number 151 (1996/II) Articles

Satellite Receiver CT200RS CATV Headend Equipment CT200 [1] and, like the latter, can be remotely controlled and monitored via a Windows TV reception with analog and user interface. But stand-alone opera- digital sound from outer space tion is possible too, without restrictions. Function As an extension to the CATV Headend Equipment CT200, Rohde & Schwarz now offers a satellite receiver for analog TV programs able to receive both The satellite signal arriving from the conventional two-channel analog and digital ADR programs. Thanks to the antenna on the first IF is converted in a comprehensive remote-control capabilities of the system components, a new tuner module with high image-frequency concept for broadband cable networks can be implemented. rejection to an internal (second) IF and

FIG 1 Satellite Receiver CT200RS used as fore expedient to abandon the use then frequency-demodulated (FIG 2). component of Rohde & Schwarz CATV Headend of expensive modulation lines, inter- This second satellite IF is available for Equipment CT200 or as stand-alone unit Photo 42 440 ference-prone terrestrial relay receivers monitoring and external processing. or complex microwave links for feeding An AGC (automatic gain control) circuit signals, for example, to CATV headend matches the gain in a wide input-level equipment and terrestrial transmitters range (–65 to –20 dBm). The switch- A large number of TV programs are and to utilize satellites that can be able AFC (automatic frequency correc- broadcast in Europe via the satellites received everywhere with a minimum tion) compensates frequency offsets Astra and Eutelsat. Normally, stereo of outlay. For this purpose Rohde & even in case of weak input signals (eg sound programs are also transmitted Schwarz developed the Satellite Re- signals impaired by heavy rain) and with the satellite signal. It seems there- ceiver CT200RS (FIG 1). It extends the thus ensures optimum picture quality.

News from Rohde & Schwarz Number 151 (1996/II) 13 Articles

Baseband Satellite Receiver CT200RS several

2nd IF (479.5 MHz) Synchroni- times. For this reason, one of the zation CT200RS models, Sound Subcarrier Satellite IF (920 to 2050 MHz) Demodulator CT200SS, comprises Satellite PLL Ku band Clamping Noise Video tuner demod. C band circuit trap signal only the sound section of the satellite Base- band receiver and is fed from the baseband Audio Power supply Polarity Noise AF output. Thus several subcarrier demod- signal low-noise block reduction left ulators can be operated from one

Audio baseband signal. The ADR demodula- SERBUS Noise AF signal decoder reduction right tor/decoder option may also be fitted in the subcarrier demodulator. Option ADR Demodulator/Decoder CT200DR With several satellite receivers con- Sound Subcarrier Demodulator CT200SS nected to one antenna, Active Satellite Splitter CT200A8 provides eight outputs each for horizontal and vertical FIG 2 Block diagram of Satellite Receiver may optionally be equipped with ADR polarization and covers the frequency CT200RS and Sound Subcarrier Demodulator Demodulator/Decoder CT200DR for range 920 to 2050 MHz. A low-noise CT200SS retrieving the digital ADR-modulated amplifier compensates for the distri- subcarriers (ADR = Astra Digital Radio bution loss. Redundant power supplies [2]). The option comprises the QPSK ensure optimum operational reliability. demodulator required for ADR, a CT200A8 may optionally be equipped The subsequent polarity switch makes Viterbi decoder (error protection) and with an (n+1) output giving access to Satellite Receiver CT200RS also suitable the MUSICAM decoder. Ancillary data the two types of polarization. for C-band reception (3/4 GHz) which, transmitted with ADR signals are avail- contrary to the Ku band (11/12 GHz) able for further processing, eg for an Uses commonly used in Europe, employs in- RDS coder. verted deviation. After the deemphasis CATV headends mostly handle several circuit prescribed by CCIR Rec. 405-1 Since it is common for sound pro- signals from a satellite. Active Satellite the baseband signal consisting of a grams to be transmitted in the satellite Splitter CT200A8 distributes the ver- video component (0 to 5 MHz) and signal as subcarrier pairs besides tically and horizontally polarized IF sig- subcarriers (6 to 9 MHz) is available the TV sound signals, it would seem nals from the antenna to seven channel for video and sound signal processing. appropriate to use the baseband of paths (FIG 3). The eighth output is required for the (n+1) standby channel. In the video section of the receiver the A Satellite Receiver CT200RS is con- sound subcarrier is separated and only nected to each of the two times seven the video signal is allowed to pass FIG 3 Satellite Receiver CT200RS in CATV direct outputs of CT200A8, each of through. A clamping circuit removes the headend equipment with (n+1) standby which provides a TV program consist- super-imposed energy-dispersal signal, which ensures that intermodulation products generated in the satellite transponder do not cause visible inter- FMFM ++ DSRDSR CCVS ference on the transmission link. If the Modulator path input level is too low or if no sync signal is received, a noise trap switches off CCVS Modulator the video signal at the program output. path

The monitoring output remains active Broadband DC+920 to 2050 MHz communication for measurements. CCVS network Modulator path Coupling network

The sound section of Satellite Receiver Vertical Active Satellite Splitter CT200A8 CCVS CT200RS consists of two FM subcarrier Modulator path demodulators which receive the analog sound signal accompanying the TV CCVS Modulator signal or one of the audio programs as path a mono or stereo signal. CT200RS (n+1) standby configuration

14 News from Rohde & Schwarz Number 151 (1996/II) Articles

ing of a video and stereo signal or a Satellite Receiver CT200RS and Sound shown in the example. In the case of two-channel sound signal. Each satellite Subcarrier Demodulator CT200SS may ADR subcarriers, QPSK demodulation receiver is followed by a CT200 mod- be used not only in CATV headend as well as Viterbi and MUSICAM de- ulator comprising Vision-Sound Mod- systems but also in converter systems coding are performed in the optional ulator CT200VS, Sound-2 Coder and gap-filler transmitters. Since ADR Demodulator/Decoder CT200DR. Modulator CT200S2 and Upconverter nowadays many broadcasting author- Gregor Kleine CT200UP. If additional IF inputs and ities emit their TV programs together RF outputs or higher output level are with their own sound programs via required, CATV Interface CT200CI satellite, a TV and FM converter system may be added. TV signals, FM sound or gap fillers fed from satellites can programs and possibly a DSR signal easily be set up (FIG 4). Satellite Re- are combined by passive or active ceiver CT200RS receives the signals coupling networks (eg CT200C6, from the desired satellite transponder CT200A4) and the sum signal is for- and, in addition to the video signal with warded to the broadband communica- two-channel sound, it provides a base- tion network. band signal comprising the FM pro-

DC+920 to 2050 MHz CCVS TV exciter

FM stereo transmitter Baseband FIG 4 FM stereo Example of converter transmitter FM system for one TV FM stereo program and three transmitter FM programs

REFERENCES [1] Schönberger, P.; Sturm, P.; Scheide, R.: Comprehensive monitoring and re- grams in the form of analog or digital CATV Headend System CT200 – CATV signal processing intelligent, compact, ver- mote-control capabilities of all active (ADR) subcarriers. This baseband sig- satile. News from Rohde & Schwarz (1995) CT200 components permit for the first nal is looped through Sound Subcarrier No. 148, pp 23–25 time an (n +1) standby configuration to Demodulators CT200SS, each of which [2] Kleine, G.: Astra Digital Radio – Die Technik. be implemented. The supplementary retrieves one of the three FM programs Funkschau 68 (1995) No. 10, pp 44–47 channel (satellite receiver and modulator) may replace any of the operating channels. The software used by Con- troller CT200CO holds the configura- Condensed data of Satellite Receiver CT200RS and tion of the headend equipment. The Sound Subcarrier Demodulator CT200SS controller monitors the whole headend Frequency range 920 to 2050 MHz system. If a component fails, the stand- Input sensitivity –65 to –20 dBm/50 Ω by transmitter can be remotely tuned to Image-frequency rejection >45 dB the respective satellite transponder. AFC capture range ±10 MHz CT200RS selects one of the two pola- IF bandwidth 27/32 MHz, selectable rizations with the aid of its LNB (low- Video polarity selectable for C and Ku band noise block) feed voltage and the (n+1) Video deemphasis CCIR Rec. 405-1 option in the IF satellite splitter. The Video S/N ratio >60 dB controller finally tunes the standby mod- Video output voltage 1 Vpp into 75 Ω ulator to the required output frequency Subcarrier frequency range 5.5 to 9.99 MHz and connects it through. The inopera- Stereo channel separation >80 dB tive channel path is remotely switched Unweighted S/N ratio >64 dB off and signalled defective to the con- Audio deemphasis 50 µs/75µs, J.17 trol center. The (n+1) standby configu- Audio output level +9 dBm into 600 Ω ration can be retrofitted any time in Reader service card 151/04 existing systems.

News from Rohde & Schwarz Number 151 (1996/II) 15 Articles

Audio Data Transmission System ADAS and Operation Audio Monitoring System AMON Audio Data Transmission System ADAS (FIG 1) is used for transmitting addi- Data transmission without tional data from the studio to the transmitter site via the program feed on ana- data line, audio measurements log modulation lines. Data are inserted into the program signal at the upper without program interruption end of the audio band at 14.85 kHz and use a bandwidth of 300 Hz per Broadcasting 24 hours a day leaves no time for classic transmitter measurements. sound channel at a bit rate of 400 bit/s. With Audio Monitoring System AMON it is now possible for the first time to The data are removed at the end of the monitor the quality of the supplied and transmitted television/radio program transmission link (input of sound-broad- during program time. This means programs no longer have to be interrupted to cast transmitter) by means of a steep- carry out measurements, not even for a short time. Moreover, no additional data edged lowpass filter. In addition to the lines from the studio to the transmitter are required since additional data – such data transmitted via the serial interface, as dynamic RDS data – are transmitted via modulation feed lines by AMON an 8-bit data word is available for each and/or Audio Data Transmission System ADAS. sound channel for remote-control applications. The inputs at the studio are ungrounded (optocoupler) and the outputs are floating relay contacts.

For Audio Monitoring System AMON, which includes the functions of ADAS, the audio signal is subjected to an FFT analysis at the beginning and end of a transmission link to obtain its audio spectral components. To reduce the volume of measured data, the signal is distributed in 14 frequency bands, for which the corresponding rms level is determined and transmitted to the decoder (FIG 2). The phase difference of the two channels is transmitted to the decoder to determine any polarity errors for stereo signals. The decoder also analyzes the incoming signal and compares it with the data of the source. The characteristics of the transmission link are obtained by sub- traction. Each measurement, carried out once per second, generates 15 values.

FIG 1 Audio Data Transmission System ADAS and Audio Monitoring System AMON for quality control of audio transmission equipment without program interruption Photo 42 442

16 News from Rohde & Schwarz Number 151 (1996/II) Articles

Source analysis Transmission link Reception analysis design, which allows upgrading of Program+data External data External data Audio Data Transmission System ADAS AMON AMON Measured values Program (coder) (decoder) Program to a full-featured Audio Monitoring System AMON at any time. The Level Level Level AMON/ADAS hardware with high- Data carrier resolution sigma-delta A/D converters in the audio paths provides for high Frequency Frequency Frequency quality without comprehensive analog signal pre- and postprocessing being required. Customer requirements can easily be met thanks to digital signal

Level ime Level ime T T processors that are used for filtering, modulation, demodulation and FFT.

Frequency Frequency FIG 2 Principle of A separate process controller serving FFT analysis, FFT analysis, audio monitoring the serial and parallel interfaces as well data conditioning, data reception, by means of data transmission data conditioning, comparison of source with reception analysis program signal as the IEC/IEEE bus and the display (FIG 3) controls communication with external units. The two units can also be conveniently integrated into a test and monitoring system via IEC/IEEE This enables the following transmission ment according to CCITT 0.33 allows bus. The complete test and monitoring parameters to be determined depend- measurements to be made on audio values can be queried and displayed ing on the program signal: transmission equipment during pro- via IEC/IEEE bus. Software updates • level error, gram breaks. This option can be used can easily be carried out via the • frequency response, both in the AMON coder and AMON RS-232-C interface from the front panel • S/N ratio, decoder and enables separate mea- using flash EPROMs without any re- • polarity (phase L/R), surements of the transmission line and moval or replacement of units being • channel interchange, the sound-broadcast transmitter. required. • program interchange.

An additional stereo test input at the AMON decoder serves for monitoring transmission equipment located at the same site. The signal at this input is Audio filter Modulator FFT directly compared with the program input, through which the quality of (only with AMON) a sound-broadcast transmitter can be R checked. If a data channel with a L Analog input R Controller defined delay to the program signal L Analog output Control logic R Test input IEC/ Remote FIG 3 IEEE RS-232-C is available, the system can also be L (only with AMON) control Block diagram of bus used for digitally coded audio links. AMON and ADAS The signals are compared in the analog domain.

The test results are compared with selectable tolerance tables. Inner and Configuration Uses outer tolerance limits are determined for each test parameter. If any of the Although these two units offer a variety Continuous quality control of the mod- limit values is exceeded, a message will of functions, they only require a mini- ulation-line network and the broadcast be sent via a relay contact. Each limit mum of space. The standard configura- transmitters during the ongoing pro- value has a hysteresis to avoid frequent tion is a 19-inch desktop (1 height unit, gram is indispensable to ensure high messages being issued if a measured approx. 44 mm), which is also suitable program availability. This is state of value fluctuates around a tolerance for installation into system racks. This the art for picture transmission with use limit. An optional automatic measure- compact size is due to modern modular of the test-signal-insertion technique [1].

News from Rohde & Schwarz Number 151 (1996/II) 17 Articles

With Audio Monitoring System AMON Video program it is now also possible to monitor the TV transmitter Audio quality of audio transmissions while program the program is on the air. Thanks to its RF integrated monitoring functions (inde- Video program + test lines pendent limit monitoring of measured values for program and test input, monitoring of program identification, time- Audio Audio AMON coder Audio program AMON decoder controlled start of a CCITT 0.33 se- program + data quence) issuing warnings via relay con- Audio monitoring Audio monitoring of transmission link of transmitting equipment tacts AMON is an optimized, independent monitoring system. Even higher functionality (operation, statistics, etc) FIG 4 Monitoring of transmission link and TV Audio Monitoring System AMON is transmitter by means of test-signal-insertion tech- can be achieved by integration into a also equipped with these functions. The nique and Audio Monitoring System AMON monitoring system such as TS6100 [2]. capacity of the data channel is partly FIG 4 gives an example for a favour- utilized for transmitting the measure- ably priced vision/sound monitoring ment data. system including program-feed check at Transmitter remote control is also pos- Peter Singerl; Christian Krawinkel the transmitter site in combination with sible. Multilevel addressability allows Video Measurement System VSA with access to individual units or unit groups,

Studio Modulation line Transmitter site FIG 5 REFERENCES Data-line Data-line Monitoring of tele- [1] Bichlmaier, T; Finkenzeller, R.: Video Mea- coder decoder Word 9 vision sound with surement System VSA – Four TV measuring Audio Monitoring instruments plus controller in one compact Field RS-232-C Field RS-232-C pulse pulse System AMON and unit. News from Rohde & Schwarz (1995) transmission of No. 147, pp 18–21 source data in data [2] Lehmann, M.; Strauss, G.: TV Monitoring AMON AMON line (line 329, (coder) (decoder) and Test Systems TS6100 – Video and audio word 9) parameters of TV transmitters all under control. News from Rohde & Schwarz (1996) No. 150, pp 16 –18 [3] Finkenzeller, R.; Polz, E.: Measuring all TV built-in Test Receiver option VSA-B10 ie all the decoders of a program, all RF and video parameters for the first time [3], which may, in the simplest case, the decoders of a site or individual in a compact unit. News from Rohde & use the integrated PC to control the decoders. Schwarz (1996) No. 150, pp 44–45 whole monitoring system. If data-carrier insertion into the sound channel is not possible or not desired, the source data Condensed data of Audio Data Transmission System ADAS can be transmitted via an external data and Audio Monitoring System AMON channel. This may be done in the data ADAS and AMON line while monitoring the television Data transmission program signal path 4DPSK sound (FIG 5). Frequency response (40 Hz to 14.5 kHz) +0.1/–0.2 dB Stopband attenuation above 14.71 kHz >70 dB Audio Data Transmission System ADAS AMON only is employed wherever data have to be Analyzer level range +9 to –74 dB transmitted to a transmitter site. These Monitoring measurement time approx. 200 ms data can be program identification or Measurement speed approx. one measurement/s transparent serial data such as RDS Measurement parameters level error, frequency response, data or remote-control data for con- S/N ratio, channel interchange, trolling any functions at the transmitter program interchange site. Thus, for example, the stereocoder Optional measurement functions CCITT 0.33, program no. 01 can be controlled or traffic announce- Reader service card 151/05 ment identification can be activated.

18 News from Rohde & Schwarz Number 151 (1996/II) Articles

Radiomonitoring System RAMON Modular design

To permit the great variety of tasks Customized radiomonitoring to be performed, Radiomonitoring System RAMON is of modular design. from VLF through SHF The number of modules used and their associated tasks vary depending on Radiomonitoring System RAMON from Rohde & Schwarz detects and monitors application. RAMON may be con- emissions in the frequency range 10 kHz to 18 GHz. Made up of tried and figured as required from a compact tested standard components, it allows comprehensive radiomonitoring systems system with only one operator position to be set up to customer requirements. A graphics user interface ensures easy- through to a hierarchical system with to-learn and convenient operation. an appropriate number of operator positions (FIG 1). Thus each system can be optimally adapted to the desired application and reliability is ensured through the use of tried and tested modules. The following modules are available:

• RAMON-supervise, • RAMON-search, • RAMON-monitor, • RAMON-analyze, • RAMON-locate, • RAMON-compact.

Each module is a configurable unit comprising radiomonitoring equipment, a controller and software tailored to the particular application and complement. Operators of the individual modules exchange data within the FIG 1 Radiomonitoring System RAMON- • preparation of reports, system via LAN for sending messages, search with application-specific add-ons as • evaluation and comparison of ob- giving orders or storing reports. The desktop Photo 42 134/2 tained data, variety of systems that can be set up • setting up and updating of a data- with the aid of these modules ranges The purpose of interception and moni- base, from single-position systems (RAMON- toring is to provide information about • preparation of statistics. compact) through medium-sized systems radiocommunications for the determination of a scenario (systems, positions, movements, distribution, concentrations, intentions). A few typical activities of Order, Report, radiomonitoring are: basic information scenario • searching for known and unknown Report signals, Search order • monitoring of radiocommunication activities and alarm frequencies, • identification, detection or recognition of transmitters, • direction finding and location of

radio stations, Monitoring order Monitoring order Monitoring order • aural monitoring and recording of FIG 2 radio messages, Block diagram of • analysis under technical and textual medium-sized radio- aspects, monitoring system Report

News from Rohde & Schwarz Number 151 (1996/II) 19 Articles

mation obtained to control monitoring activities. Based on this information and his specialist knowledge and experience he prepares reports for the superordinate level, which is his con- tribution to fixing the scenario. All his activities are supported by the graphics user interface of RAMON-supervise, permitting fast acquisition of results.

RAMON-search (FIG 4) comprises a FIG 3 Evaluation of reports Search Receiver ESMA [1] and one or using database more Compact Receivers ESMC [2]. The module permits a fast search through frequency bands and rapid signal identification. The search opera- (FIG 2) to large, hierarchically orga- visor is the interface with the superordi- nized systems made up of several sub- nate level, from where he receives or- systems. ders and further information. The supervisor prepares search and monitoring The operator position RAMON-super- orders and passes them on to the oper- vise offers functions allowing the super- ators. Results obtained by the operators visor to control radiomonitoring and are stored as reports in a database. If prepare reports. Thus assignments can the results are not post-processed, the be issued, their handling checked, re- supervisor carries out evaluation with ports or results examined and allocated the aid of the database and supporting to individual radio stations. The super- functions (FIG 3). He utilizes the infor-

Overview mode in search operation The figure shows a snapshot of a search receiver operating in overview mode. Single frequencies and frequency bands are combined to a scan sequence of up to 10,000 channels. Known signals or unwanted bands may

FIG 4 Single-rack operator position RAMON- search

tor scans specified frequency bands for active transmitters with his receiver in the overview mode (see box). In this mode the search receiver scans the defined range at maximum speed. Detected signals are shown in a panoramic display. Frequencies of interest are marked in the display and sent at a click to the compact receiver, where they are aurally identified and measured. If a signal is to be further monitored and analyzed, he sends an auto- be suppressed. The overview provides tools permitting signals to be measured matically prepared order to the moni- or the display to be zoomed or frozen. Recommended search receivers are toring operator by a single keystroke. ESMA and ESMC. Supported by RAMON-search the operator is able to respond quickly to

20 News from Rohde & Schwarz Number 151 (1996/II) Articles

new signals, identify a multitude of emissions and execute a great number of search orders.

RAMON-monitor (FIG 5) contains several aural-monitoring receivers and at least one recorder. The software of the position guarantees efficient monitoring performance. The monitoring operator receives an order from the supervisor or search operator and the system immediately tunes a receiver to the frequency to be monitored. He records the detected signal and notes down important information in a report in which receiver settings are automati-

FIG 6 Direction finding and radiolocation in monitoring mode with map (R&S MapView software)

aural-monitoring receiver and a re- RAMON-locate. This allows systems in corder. The software includes all main use to be upgraded and improved by functions of RAMON-supervise, -search updates. Thanks to the modular design, and -monitor. The tasks normally per- upgrading may be carried out in steps formed at the supervisor, search and so that even a small installation can be monitoring positions are concentrated expanded to an increasingly powerful in one position. Procedures are similar radiomonitoring system. to those performed at the separate Reiner Ehrichs; Claus Holland; positions but the individual tasks are Günther Klenner carried out at a less detailed level. This makes system software support so particularly important. With RAMON- compact a single operator is able to obtain all essential information by

FIG 5 Rack layout of RAMON-monitor means of radiomonitoring and to add REFERENCES this information to the scenario. [1] Oberbuchner, E.: Search Receiver ESMA – The ideal frontend for VHF-UHF monitoring systems. News from Rohde & Schwarz Optimization and upgrading (1995) No. 149, pp 7–9 cally included. The operator locates the [2] Boguslawski, R.; Egert, H.-J.: VHF-UHF Com- transmitter with the aid of direction find- Rohde & Schwarz continuously enhances pact Receiver ESMC – Easy radio detection ers and is able to view the position on existing modules and is developing in VHF-UHF range. News from Rohde & his map (FIG 6). Detected emissions are new ones like RAMON-analyze and Schwarz (1994) No. 143, pp 11–13 recorded on tape for subsequent evaluation. Depending on the technical facilities of his position, the operator may carry out detailed signal measurements. Modules of Radiomonitoring System RAMON The results are also noted down in RAMON-supervise coordinator position the report. RAMON-monitor allows the RAMON-search search and identification position operator to monitor several frequencies RAMON-monitor monitoring position simultaneously and speedily prepare RAMON-analyze analyzer position (in development) detailed reports. RAMON-locate radiolocation position (in development) RAMON-compact compact single-position system The single-position system RAMON- Reader service card 151/06 compact includes a search receiver, an

News from Rohde & Schwarz Number 151 (1996/II) 21 Articles

BTS Antennas HF.../HK... stations (base transceiver stations) must fulfill stringent requirements. Further criteria of interest to network operators The right antenna are reliability and – last but not least – economy. Based on these requirements, for every mobile-radio base station Rohde & Schwarz has developed two families of antennas for the 900-MHz Besides offering the complete range of test equipment required for radio networks, and 1800-MHz bands. These omni- Rohde & Schwarz supplies antennas for base stations providing radio coverage for directional (HK...) and directional assigned areas. Directional and omnidirectional antennas from Rohde & Schwarz (HF...) antennas come in a variety of can be used in all networks operating in the 900-MHz or 1800-MHz band: GSM, types of various gain levels, allowing DCS1800 (PCN), TACS, Qualcomm, NMT900, NTT etc, thus opening up a virtually for all conceivable applications of net- unlimited range of customers. work operators (FIG 1).

FIG 1 Examples from Rohde & Schwarz BTS Malaysia and Germany, and intro- Design antenna program: sector antennas providing duction is imminent in another 15 coun- coverage in mobile-radio networks Photo 41 835/7 tries. Basically, BTS antennas are made up of vertically stacked dipoles [1]. If Standards GSM and DCS1800 differ coverage is to be provided not for basically in their frequency band (GSM: the whole surrounding area but only for 900 MHz, DCS1800: 1800 MHz) and a sector of it, the dipoles are mounted the transmitting power of base stations in front of a reflector. Antennas of this Mobile-radio networks are spreading at and terminals. In DCS1800 networks, type are commonly classified by the breakneck speed, meeting the growing which are mainly intended for commu- horizontal half-power beamwidth of demand worldwide for speech and nication via hand-held phones, trans- their directional patterns. For example, data communication that is afford- mitting power is lower and coverage one speaks of 65° antennas (FIG 2). able and possible for everyone and area smaller than in GSM networks. Another parameter determining the everywhere using small, favourably Modern mobile-radio networks are characteristics of a BTS antenna is its priced terminals. Standards GSM and organized in cells of varying size gain. The gain is proportional to the DCS1800 for digital modulation are depending on the topography of the number of stacked dipoles and thus to becoming more and more popular. area in question and the traffic volume the total length of the antenna. The gain GSM networks are in operation in to be handled. and half-power beamwidth to be select- well over 50 countries, often several ed for a specific coverage area mainly networks are installed in a country, To reliably eliminate coverage gaps depend on the topography and on the and there is a strong upward trend. and thus prevent the interruption of expected traffic volume (see table in DCS1800 networks are already in use radio links for an area, the directional blue box). Omnidirectional antennas in Great Britain, Switzerland, Thailand, patterns of antennas installed at BTS are mainly used in areas with low traf-

22 News from Rohde & Schwarz Number 151 (1996/II) Articles

lobe of the antenna electrically (down tennas (beam forming, beam shaping). tilt) to achieve better illumination of It is generally true that not only gain the coverage area and reduce the risk increases with the number of stacked of interference with an adjacent cell dipoles but also the number of side (FIG 3). The down tilt is usually between lobes and minima (nulls). The side lobes 1° and 6°. In practice, sector antennas above the main lobe provide no cover- often use a combination of electrical age but increase the risk of interference and mechanical down tilt. The latter with adjacent cells; it is therefore ad- is implemented by means of a swivel visable to suppress them as far as pos- holder, which is of course included sible, which may afford higher gain at in the Rohde & Schwarz range of the same time. By contrast, the minima accessories. located between the side lobes below

FIG 2 65° Sector Antenna HF065E1 for 1800-MHz band Photo 41 835/5

fic volume and often replaced by directional antennas (sector antennas) as the number of subscribers increases.

Radiation patterns FIG 4 Null fill-in and The vertical pattern of a BTS antenna is side-lobe suppression shaped by the type of feed used for the (schematic) vertically stacked dipoles. If all dipoles are fed with signals of the same amplitude and phase, maximum gain will be obtained. But this is not always the Apart from down-tilting, further mea- the radiation peak result in coverage optimum solution. For example, it is sures are recommended for optimizing gaps especially in the vicinity of the often an advantage to lower the main the radiation characteristics of BTS an- base station, which may cause break- down of links even in digital networks. Therefore, BTS antennas are required not only to feature side-lobe suppression but also a certain amount of null fill-in (FIG 4). Carefully designed null fill-in contributes considerably towards reliable coverage, which has been verified not only in theory FIG 3 but also by numerous mobile tests [2] Electrical down tilt (FIG 5). (bottom) focuses energy to coverage area (schematic) It goes without saying that Rohde & Schwarz antennas meet the standard requirements of network operators with regard to null fill-in and side-lobe sup- Half-power beamwidth Topographical conditions Traffic volume pression. In most cases much better Omnidirectional antennas rural low specifications are achieved than those 160° and 120° antennas mountains, national borders random 120° and 90° antennas rural high stipulated. Omnidirectional Antenna 65° antennas urban high HK612, for example, fulfills particularly 33° antennas traffic routes random stringent requirements with respect

News from Rohde & Schwarz Number 151 (1996/II) 23 Articles

to environmental stresses that plays a decisive role for network operators. Accommodated in a weatherproof radome, all parts of the antenna are perfectly protected against environmental effects. Due to their very slim design, the antennas resist wind speeds up to 200 km/h without any appreciable impairment of their radiation patterns and thus of coverage (for example, a hurricane of wind force 12 has a speed of about 125 km/h). And, last but not least, the high quality standard main- FIG 5 Received signal level in vicinity of mobile- low-loss feed of the dipoles and was tained at Rohde & Schwarz – certified radio base station (right with and left without null therefore given preference over the to ISO 9001 – guarantees not only the fill-in on BTS antenna) commonly used method of depositing electrical and mechanical data but also the stripline directly on a dielectric as a long service life for all BTS antennas. in the case of PCBs. Another advan- Dr. Christof Rohner tage of this feed concept is the small parameter spread of the antennas in to vertical radiation pattern shaping. production. Generally it can be said that all BTS antennas from Rohde & Schwarz are Characteristics the result of elaborate optimization [3] and meet all of the described require- Through complete simulation of all pa- ments. rameters relevant to antenna characteristics, including dipoles, reflectors and Antenna feed distribution networks, the following features and benefits were achieved The antenna dipoles are fed with volt- in all BTS antennas from Rohde & ages of defined amplitude and phase Schwarz: via a power distribution network de- • modularity, allowing application- signed as a stripline. The stripline is an specific gain figures to be imple- integral part including all junctions, mented, phasing lines, transformers and match- • effective suppression of radiation in REFERENCES ing pads required, doing away with unwanted directions, [1] Stark, A.; Nielsen, L.; Rohner, C.: Favourably priced omnidirectional and sector antennas error-prone adjustments and alignments • compact size, for PCN base stations. News from Rohde & and allowing high manufacturing pre- • pattern shaping to avoid coverage Schwarz (1993) No. 143, p 35 cision to be maintained throughout a gaps, [2] Schmitz, U.: Zwei Tage Stress an den Schalt- batch. Only a single solder joint is • extremely high reliability, knöpfen der mobilen Kommunikation – Unter- required between the antenna input • favourable price/performance ratio. wegs im Funk-Messmobil. VDI-Nachrichten No. 3 (21.1.1994), p 11 and the stripline. This and the use of [3] Stark, A.; Rohner, C.: Optimizing the Cover- snap-in connections have drastically Finally it should be emphasized that it age of DCS1800 Base Stations by Radiation reduced the failure rate in production is not only the electrical data of the BTS Pattern Forming. Microwave Engineering and increased MTBF by a factor of antennas but also their high resistance Europe (Oct. 1994), p 59 80 compared with antennas featuring conventional coaxial-line connectors. Another essential advantage afforded Condensed data of BTS Antennas HF.../HK... by this concept is the extremely low Frequency band 860 to 960 MHz, intermodulation. 1710 to 1880 MHz VSWR ≤1.3 The stripline is fitted between two metal Max. permissible wind speed 200 km/h plates and fixed in position by dielectric MTBF 40,000,000 hrs supports. This design, which is known Reader service card 151/07 as a triplate line, makes for extremely

24 News from Rohde & Schwarz Number 151 (1996/II) Articles

Paging System P2000 Flexible, multiprotocol radiopaging system

Radiopaging services are becoming more and more popular worldwide. System operators are continuously expanding their existing networks and installing new facilities. R & S BICK Mobilfunk offers a complete service package covering planning, installation, training and maintenance. A new generation of radiopaging systems meets world-market requirements for a multiprotocol infrastructure.

Doctors, fire brigades and business trol center with access controller and a people too want to be or have to be paging base station. A public national available at all times and wherever radiopaging system comprises a mul- they may be. This is made possible tiple of these individual elements. The by modern mobile-radio systems. The aim of optimizing the network topology advantages of a radiopaging system is to minimize the investment and oper- are relatively low costs for the user in ational costs of radio coverage and the comparison with a cordless phone for network. example, small size and light weight and very long operating times of the R & S BICK Mobilfunk is the right partner battery-operated pagers. The beepers, for the network operator as it not only as they are usually called, come in a provides complete radiopaging infra- variety of models. There are even structures but also individual compo- watch-integrated beepers. The required nents such as paging base stations or system infrastructure generally remains paging centers for the professional net- hidden to the public. work operator. The compliance of the systems with all important paging FIG 1 shows the structure of a simple standards allows their integration in paging system with which a city can be already existing networks. In addition covered from a high antenna site, for to the hardware Rohde & Schwarz also example. It consists of a network con- offers accompanying services such as planning and optimization of the system concept and radio coverage, site acquisition as well as training and maintenance.

Paging System P2000 (FIG 2) is the first model of a new generation of multi- FIG 2 Base station of Paging System P2000 protocol radiopaging systems covering Photo 42 441 current paging standards in the frequency bands commonly used for mobile radio. The most widespread standard in Europe for the air interface Radio Messaging Standard (ERMES) in is the POCSAG code (Post Office Code 1992. This standard specifies not only Standardization Advisory Group), a the air interface with a data rate of standard that was already recommend- 6250 Baud but also the used frequen- ed in 1982 by ITU and allows data cies and the interfaces between the in- rates of up to 2400 Baud. The Euro- dividual system components with the pean Telecommunications Standards aim of implementing a European-wide FIG 1 Structure of simple paging system Institute (ETSI) passed the European paging-system network.

News from Rohde & Schwarz Number 151 (1996/II) 25 Articles

Elements of radiopaging system

The professional Paging System P2000 consists of four basic elements (FIG 3): • access systems, • network control center including Distribution system operation administration and maintenance accesses, • distribution system between network control center and base stations, • paging base stations ensuring defined radio coverage.

Access systems Access systems Network control center Paging base station The call requests are routed to the system via different accesses. The network operator can select any combi- FIG 3 Structure of complex radiopaging network Paging base stations nation from a large variety of different The number and sites of paging base access systems. stations depend on area coverage planning. Well over 1000 paging base Distribution systems stations can be installed according to Network control center Different distribution media and net- the configuration level of the paging The basic software package supports works can be used according to net- system. the standard functions of a public radio- work operator requirements to distrib- paging system. Extending the number ute calls from the control center to the The connection of the access systems of subscribers is optional just as addi- transmitters and to route back opera- to the network control center and the tional features. All the system elements tional and maintenance messages from distribution system is via industrial com- are integrated into a general operation the base stations. puter networking in cooperation with administration and maintenance con- ATM of Constance, Germany. The prin- cept. Subscriber handling and billing ciple of distributed processing can thus systems are incorporated into the FIG 4 National satellite-supported radiopaging also be fully utilized in paging systems. system via open interfaces. network Moreover, a distributed information system is a convenient platform for the static and dynamic division of the functionality of a complex system into several principally independent system

Uplink Downlink units. The capacity of the access Uplink controller systems, the network control center as POCSAG Paging well as the distribution system can be service controller extended in economical stages so that Uplink SAT SAT controller modem modem the requirements of national network ERMES operators using several radiopaging

Other networks Downlink frequencies on which different paging eg GSM OAM PSDN controller (SMS) etc standards are possible can be fully met Access systems Paging without causing capacity bottlenecks. base station POCSAG Characteristics

Maintenance Subscriber In addition to basic features such as system handling Access systems high availability and operation on all international frequencies in the VHF Remote Router LANs and UHF band, features minimizing the

Decentralized access PCs X terminals cost of ownership for the network oper-

26 News from Rohde & Schwarz Number 151 (1996/II) Articles

ator are major highlights of Paging is of course available and allows mes- All the services including cascading of System P2000: sages to be sent either via an ERMES, different functions are basically avail- • market-oriented scaling from less POCSAG or another high-speed pag- able to any subscriber. Which of the than 100 to more than 5 million ing system. A further interface is pro- services may be used by the individual subscribers, vided for external and cost-effective subscriber depends on authorization • linking of different accesses via satellite uplink. The interface between by the system operator and the tech- open interfaces, the downlink controller and the radio- nical facilities of the pager itself. The • traffic-load distribution and redun- paging transmitter is configured so that paging call is converted into the format dancy through decentralized, dis- existing transmitters from other manu- required prior to sending the call via tributed call-data processing, facturers can easily be connected to the one or several paging transmitters in • distribution networking both terres- new infrastructure. the downlink controller. The necessary trial and via satellite, transmission bandwidth of the satellite • support of different paging protocols FIG 4 illustrates the structure of a na- link is thus drastically reduced, which and baud rates by software down- tional paging system for standards substantially cuts the operating costs of load, POCSAG and ERMES with satellite the whole paging system. • cost-optimized and unobtrusive out- uplink of the individual paging base Thomas Rieder door installation of base stations, stations for call distribution as well as • requirement-oriented solutions for in- a terrestrial communication channel for house coverage and on-site paging, operation administration and mainte- • intelligent and comprehensive oper- nance. Thanks to consistent use of the ation administration and mainte- distributed data-processing principle, nance concept down to component any access system such as an operator level, workstation, Internet access or speech- • easy servicing of base stations by recognition system can accept paging electricians. calls for any subscriber authorized in the paging system and forward them Standardized interfaces between cer- in the system. Prior to call-acceptance tain system units allow for flexible up- acknowledgement to the calling parts, grading or retrofitting of units. An inter- the subscriber number and the type of face between different paging systems pager is checked for validity.

Combinations and functional scope of Paging System P2000

Access system Network control center Distribution network Paging base station

Voice access Services Satellite Frequency bands Operator High calling-rate subscriber VSat VHF Phone (DTMF) Calling party pays SCPC UHF Voice box Calling party contributes Data networks Output power Data access Receiving party pays HDLC 25 W Modem Info call/news TCP/IP 200 W (400 W) X.25 Call diversion Leased lines Paging standards X.400 Paging standards CCITT M.1020 ERMES Internet / WWW ERMES ISDN POCSAG T-online POCSAG Dial-up lines High-speed paging Fax access High-speed paging Analog Mechanical design Fax box Operation administration ISDN Rack Fax → text and maintenance (OAM) Microwave links Unobtrusive outdoor cabinet SW download/parametrization Compact cabinet for indoor coverage Remote control/service Service concept Subscriber handling Continuous built-in test Authorization Service by electricians Billing data

Reader service card 151/08

News from Rohde & Schwarz Number 151 (1996/II) 27 Application notes

Testing GSM/PCN/PCS base stations in production, installation and service with CMD54/57

The following parameters of the base station (BTS = base transceiver station) can be measured with the radiocommunication tester:

Transmitter • Transmitter power to an accuracy of ± 0.6 dB with integrated peak- power meter • Power ramping at full dynamic range (72 dB) using the zoom function • Phase and frequency errors with graphic and numeric display • Modulation spectrum in only 60 s for 500 bursts on 23 frequencies (FIG 2) FIG 1 • Switching spectrum Digital Radiocom- munication Tester CMD57, ideal com- Receiver pact tester for pro- • Bit error rate (BER) (single or con- duction, installation tinuous) with various evaluation and and service of connection capabilities, eg loop- GSM/PCN/PCS base stations back in CMD, loopback in BTS, Photo 42 362/1 Abis monitoring, IEC/IEEE-bus or RS-232-C interface • Bit pattern to CCITT standard Base stations for digital mobile radio for this application, measurements are • Transmitter level with high accuracy must function reliably at all times. To in compliance with current GSM specifi- (eg error <1 dB at –104 dBm). guarantee this, the transceivers are cations. subjected to stringent quality tests at all Use in module production stages of production from the individu- The following features make CMD54/57 al module to the ready-made product, ideal for measurements in the applica- Important aspects for selecting test and key RF parameters are measured tions outlined above: equipment in production are easy inte- during on-site installation and during • flexibility for production, gration into existing production lines service. However different the measure- • Abis control for installation and final and measurement speed. Thanks to a ment tasks may be, they can all be testing in production and, great variety of synchronization and performed with a single compact test • unique worldwide, uninterrupted trigger facilities and a number of system – Digital Radiocommunication operation while checking or retro- analog measurement functions, CMD Tester CMD54/57 (FIG 1)*. It covers fitting transceiver modules during can be matched optimally to the DUT. the frequency ranges for GSM, PCN servicing. The SCPI-compatible IEC/IEEE bus (DCS1800) and optionally also PCS (DCS1900). With the aid of an option the two models can also be used in the field of European train radio. Since signalling has not yet been defined

* Schindlmeier, R.: Digital Radiocommunication FIG 2 Tester CMD54/57 – GSM/PCN base-station testers Modulation spectrum for production, installation and service. News from of base-station Rohde & Schwarz (1994) No. 146, pp 16 –18 transmitter

28 News from Rohde & Schwarz Number 151 (1996/II) Application notes

ensures fast remote control (FIG 3). Radio network DUT Abis Transmitter measurements are possible control without signalling – an indispensable feature in module testing – with trigger- Base-station controller ing to pulsed and non-pulsed signals.

The built-in RF signal generator allows Abis monitoring measurements to be carried out on receiver modules. The DC ammeter and voltmeter of CMD are optimized for measuring pulsed signals and an FIG 5 CMD54/57 optional AF generator/analyzer is pro- Transmitter test servicing base vided for AF measurements including station on the air Receiver test frequency measurements.

and outgoing calls, location update, Abis control comes in two variants, call cleardown, frequency hopping, either for control via an external con- Manufacturer-specific control bus, channel and time-slot changing. With troller or by CMD alone (FIG 4). With eg RS-232-C, IEC/IEEE bus RS-484 the realtime speech encoder/decoder variant 1, CMD executes Abis appli- option (CMD-B5) integrated, the cation programs remotely controlled, audio quality of the base station can eg from a notebook. The application Trigger signals be tested. programs serve for controlling the BTS.

DUT If special measurement tasks are to be

Receiver test CMD offers an interesting concept for carried out, the user may modify in any

Transmitter test Abis control for final testing in produc- way the application program supplied tion and installation. The Abis interface by Rohde & Schwarz. Once the pro- FIG 3 Typical test setup in module production is a digital interface with a data rate of gram on the external controller matches 2048 kbit/s capable of handling up to the user’s requirements, it can be 120 voice channels of 16 kbit/s each loaded into CMD for controlling the and two 64-kbit/s signalling channels. BTS from CMD (variant 2). The menus

Equipped with an Abis plug-in card and of the external controller will be dis- Use in final testing in a BTS-specific control software, CMD played on CMD. The supplied software production and installation comprises an application program for variants 1 and 2 for manual BTS con-

Main tasks of CMD54/57 for final tests trol. Switchover between Abis control in production and on-site installation of and RF measurement is possible by a BTS are measurements with signal- Variant 1 DUT means of a softkey. An application Abis ling, call setup for signalling tests, control program permitting fully automatic BTS audio check, control of the complete RS-232-C/ measurements is supplied in addition. IEC/IEEE BTS system via the Abis interface and bus automatic testing. Variant 2 Use in service

In final testing measurements on active Receiver test Once a base station has been put into base stations have to be carried out, Transmitter test operation, it should only be switched ie stations which, driven by external off in cases of emergency. This means FIG 4 Abis control with external notebook or equipment, emit RF carriers with signal- CMD54/57 that any service work is to be per- ling information. Even the CMD basic formed with the transceiver in full oper- model evaluates and indicates impor- ation. CMD is worldwide the first tant network codes, permits synchron- compact radio tester to carry out trans- ization to the C0 carrier (broadcast mitter and receiver measurements on carrier) and gives an overview of RF performs the following functions via base stations in operation. CMD per- parameters. Optionally, software per- the Abis interface: BTS reset, BTS con- mits even transmitter and receiver mod- mitting complete call setup with signal- figuration, software download, BTS ules to be retrofitted without interrupting ling to the RF interface can be loaded reconfiguration as well as transmitter/ the operation. For this application CMD into CMD. Supported are incoming receiver activation and deactivation. has been upgraded by a number of

News from Rohde & Schwarz Number 151 (1996/II) 29 Application notes

important functions making it a test card. The required SIM-card reader In the GSM network up to 16 RF car- mobile phone. CMD is connected to is fitted below the instrument without riers with a channel spacing of 600 kHz the RF interface of the base station, a enlarging the size of the basic unit. may be on the air simultaneously. One call is set up and then all RF parameters of these carriers is assigned to the test are measured (FIG 5). After call setup CMD allows Abis moni- mobile phone CMD54/57 and has to toring. To do so it feeds RF signals be measured selectively. For this reason The signalling software performs call modulated with a CCITT bit pattern to all other channels are suppressed setup, holding (even under adverse the base-station receiver. Depending by means of a special SAW (surface conditions) and cleardown. It also sup- on the quality and sensitivity of the acoustic wave) filter so that they ports, for instance, a change of channel receiver, the bits are received correctly cannot impair measurement results. and time slot as well as authentication. or with errors. The BTS forwards the Frank Körber

Signalling protocols complying with received bits via the Abis interface to the OSI reference model required the base-station controller and then to for the measurements are implemented the network. CMD connected with high in CMD. impedance to this line measures the received bits at the respective time slot. Like a real telephone, the test mobile Errors detected between the transmitted phone CMD54/57 obtains access to and received bits are displayed as bit Reader service card 151/09 for further informa- the network only via a registered SIM error rate on CMD. tion on CMD54/57

Container location from space

FIG 1 Container terminal of Hamburger Hafen- und Lagerhaus AG Photo: Author

make the Hamburger Hafen- und La- gerhaus AG (HHLA = Hamburg port and warehouse company) Hamburg’s leading port and transport enterprise.

At the container terminal of the HHLA, where around 1.5 million standardized containers are handled per year, and in ports of comparable size, additional costs incurred in the search for misplaced containers are considerable. Expenses for a single day of lay-off per ship amount to around 100,000 DM, which makes searching for a misplaced In COLOS (Container Location System) based position location system of this container a costly business. A search Rohde & Schwarz offers one of the type in a container terminal, situated at becomes necessary every time a most advanced and powerful systems the Buchard quay in Hamburg, with straddle carrier operator fails to depos- for locating straddle carriers. Rohde & turnover of around 15 million tons of it a container at the assigned location. Schwarz is the first company world- goods and space for 35,000 standard- At a terminal where 70 vehicles are wide to install an automatic, satellite- ized containers (FIG 1). These figures used around the clock, this happens on

30 News from Rohde & Schwarz Number 151 (1996/II) Application notes

operational data link. Here the position and other data of all containers are handled and all actions relating to these data are coordinated. Converse- ly, the carrier operators are informed via this channel of where to move next.

As the positions of the straddle carriers are dynamically determined with pinpoint accuracy, these data can basically also be used to ward off collisions. This is of particular interest at terminals using unmanned carriers. Dynamic positioning of the vehicles is also a prerequisite for effective fleet management. This means that the movement of empty carriers is reduced to a minimum, dis- tances to be covered are optimized and capacities are used as required. The utilization of available transport capacities is thus increased.

Use of the DGPS location system is FIG 2 Principle of container location with COLOS Container Location System COLOS is not limited to container positioning. It is based on the Global Positioning suitable for all applications requiring System (GPS). This satellite-based loca- dynamic and highly accurate location tion system allows positioning on the such as, for instance, piloting of vehi- ground within a circle with a radius of cles at airports, locating well holes on the average twice a day. The HHLA 100 m around the actual position. The oil fields or positioning bucket-wheel came to the conclusion that looking Differential Global Positioning System excavators in brown-coal open-pit for containers occurs too often and is (DGPS)*, evolved from GPS, ensures mining. too expensive. So it ordered the satel- considerably better positioning accu- lite-based Container Location System racy (uncertainty less than 1 m). It is Rohde & Schwarz offers a series of COLOS from Rohde & Schwarz. due to this development that the system satellite-based location systems with COLOS automatically identifies the can now fulfill the stringent requirements various degrees of positioning accu- position of the containers and provides of container positioning at a terminal. racy. COLOS offering pinpoint accu- information on weight, length and racy to within 1 m is the most accurate stacking level whenever a container is DGPS corrects the received GPS posi- DGPS system from Rohde & Schwarz. deposited or picked up at the terminal. tion data by using correction data Thomas Kneidel obtained from a reference station. The Another benefit of knowing the exact correction data are transmitted from the position of all containers is that storage reference station to the mobile units capacity can be increased. So far the (at 9600 Baud) via a telemetry link top level of the terminal had to remain (FIG 2). The carrier vehicles can thus empty so as not to obstruct access by improve their GPS position data. Posi- carriers. If a container were to be lifted tion and other data of the containers over two vertically stacked containers, deposited at the terminal are trans- the third level had to be left free for mitted to the control center via an manoeuvring. With all container positions and the loading sequence known, an intelligent storage management system can also use the top level for * Krüger, G.; Springer, R.: Highly precise storage. In the described example this localization on land, at sea and in the air with corresponds to an increase in storage GPS and DGPS. News from Rohde & Schwarz capacity of 50% in the ideal case. (1993) No. 140, pp 26–27 Reader service card 151/10

News from Rohde & Schwarz Number 151 (1996/II) 31 Application notes

Automatic measurements on tape recorders using Audio Analyzer UPD

Live transmission of sound and TV pro- as a great number of measuring instru- and documentation of the recording grams tends to be the exception. Nor- ments and a PC were required, they and reproduction quality of tape re- mally programs are stored on magnetic could only be used in a stationary role. corders and of the sound section of tapes and replayed whenever required video tape recorders with the aid of or when broadcast. Sound and TV pro- In Audio Analyzer UPD an instrument industrial standard reference tapes, grams are also filed away on magnetic is available which is able to carry out custom recordings or custom test tapes. It must be ensured, of course, practically all necessary audio mea- tapes. that this conservation does not impair surements [1]. Whole test sequences audio or video quality. In large broad- can be performed automatically with The control program TAPE.BAS com- casting stations several hundred of these the aid of the optional Universal prises the following selectable menus: tape recorders and video recorders Sequence Controller UPD-K1 [2]. The • Measure with reference tape may be in permanent use. They are application software “Automatic mea- • Record with tape monitoring subject to wear and tear, so they re- surements on tape recorders” makes • Record without measurement quire regular maintenance to preserve use of this capability and allows even • Measure with recorded tape the quality of reproduction. Depending custom program functions to be • Read stored test data on the complexity of the equipment, included in the automatic sequence. • Manual single measurements manual measurements on a recorder The large numbers of Sony Betacam may take several hours and in the recorders used in broadcasting stations For measurements with reference case of regular maintenance of a great can thus be remotely controlled by tapes no manual action of any kind number of units this may lead to ca- UPD and measurements are carried out is required. In the case of a Betacam pacity problems – not to speak of the fully automatically. No other measuring recorder with remote control and a costs involved for the service personnel. instruments or an additional PC are reference tape with time code, the In the past a number of computer pro- required. Tape recorders can thus be necessary testpoints on the tape are grams were available for automatic measured directly on site (FIG 1). The automatically selected in CUE-UP measurements on tape recorders but, program allows automatic checking mode. Without remote control, the reference tape has to be rewound and started at the beginning. The required testpoints on the tape are automatically selected and the measurement is performed.

Recording with simultaneous tape monitoring is possible with a user- defined sequence and usually done without remote control. Remote control is required however for measuring erasure attenuation, as in this case the particular tape section has to be tracked several times.

Recording without simultaneous measurement with a user-definable sequence allows the generation of a test tape for recorders without tape monitoring. FIG 1 Automatic measure- The “Measure with recorded tape” ment on tape menu is called up for testing reproduc- recorder with Audio Analyzer UPD tion with a previously recorded tape Photo 42 400/2 (eg a custom reference tape).

32 News from Rohde & Schwarz Number 151 (1996/II) Application notes

• frequency response long (31.5/40/ (FIG 2), postprocessing or comparison. 63/125/250/500 Hz /1/2/4/ Results can also be subjected to an 6.3/8/10/12.5/14/15/16/17/ automatic tolerance check with the 18/19/20/22 kHz), aid of a user-defined tolerance mask. • S/N ratio (weighted and unweight- Values within the tolerances are ed), marked and will not be shown in the • FM S/N ratio (60 Hz/–20 dB with printout. This allows a very fast go/ 400-Hz highpass filter), nogo test or a short test report to be • distortion d3 (1 kHz or depending made. FIG 2 Result of frequency-response measure- on reference tape), ment • crosstalk 1 > 2 ( 1 kHz), The test program considerably simpli- • crosstalk 2 > 1 ( 1 kHz), fies the maintenance of tape recorders • crosstalk 1 > 2 (10 kHz), and therefore improves performance • crosstalk 2 > 1 (10 kHz), reliability while at the same time reduc- Loading and reading of stored mea- • wow & flutter CCIR and unweighted ing workload. Users of UPD may surement data is required for display (3150 Hz), obtain the respective Application Note or comparison with current measure- • pitch error (3150 Hz), (1GPAN19) together with the program ments. • channel selection (mono) free of charge from their local Rohde & • channel selection (channels 1+2) Schwarz representative. Manual measurements are required, • channel selection (channels 3+4) Tilman Betz for instance, for service settings or ad- • distortion d3 (1 kHz) at nominal justments. level +3 dB • erasure attenuation + output level at REFERENCES The following single measurements 1 kHz. [1] Kernchen, W.: Audio Analyzer UPD gener- can be combined into any sequence: ates and measures analog and digital audio signals. News from Rohde & Schwarz • output level, After the selection of mode and se- (1992) No. 139, pp 13 –15 • azimuth (10 kHz), quence the measurement is started au- [2] Hempel, J.: Automatic audio measurements • reference level for frequency-re- tomatically. If the recorder is remotely with user-friendly control system of Audio sponse measurement, controlled, no further action is required. Analyzer UPD. News from Rohde & Schwarz • frequency response with reference Without remote control the operator is (1993) No. 143, pp 29 –30 tape (definition acc. to reference requested to rewind the tape and press tape table), Play or Rec+Play. Measurement results • frequency response short (63 Hz/ can be stored together with the test 1/2/4/10/12.5/15/20 kHz), report information for documentation Reader service card 151/11

DVTS – video sequence for assessing MPEG encoders

What is picture quality? How do you allowed reliable conclusions to be every detail. And this future has al- define TV picture quality? Up to now drawn. That was the world of analog ready started. For Rohde & Schwarz as things were relatively simple. The pic- TV. a manufacturer of TV test and measur- ture quality determined in subjective ing instruments the question is: how can tests with large groups of viewers on The TV pictures of the future will be dig- the quality of TV pictures be assessed representative examples was closely itally coded. They will be data-reduced under these new conditions? To tackle correlated with a number of measure- and compressed and show character- this question a number of problems ment results, the assessment of which istics that cannot yet be assessed in have to be defined and solved first.

News from Rohde & Schwarz Number 151 (1996/II) 33 Application notes

• quantization error for moving objects; at high compression factors, in particular the artefacts moving in front of a background which corresponds to a noise signal can be clearly distinguished, • prediction errors; they allow conclusions to be drawn on the sequence of I, P and B frames (intracoded, predicted and bidirectionally predicted picture elements).

Information on preprocessing is pro- DVTS test pattern vided in addition: • subsampling of luminance and/or chrominance components in the An initial step towards finding an developed a product in close coopera- vertical direction, answer is to assess the influence of the tion with the communications institute of • subsampling of luminance and/or encoder on the picture components. Braunschweig Technical University as a chrominance components with pre- first attempt to solve these problems. filtering with/without separation The type of coding entailed by MPEG-2 of picture elements, [1] is mainly based on the reduction of The Encoder Test Sequence DVTS (FIG) • discarding of luminance and/or redundant and irrelevant information consists of stationary and moving chrominance components. contained in consecutive TV pictures, picture elements that stringently test for instance, on the minimum resolution the various capabilities of an encoder. With the Encoder Test Sequence DVTS required for the human eye to discern It allows assessment with the aid of the the first of many steps has been taken moving elements on the screen. By elim- artefacts typical for this kind of hybrid towards objective assessment of picture inating these redundant and irrelevant coding. The test sequence in line with quality for heavily compressed video components, and particularly by an CCIR 601 is stored on tape in the D1 or signals. Updates will be regularly intelligent combination of different Betacam SP format. The test sequence issued to include the latest findings data-reduction methods, compression is used as an input signal to the en- of experts and users alike. Through factors of the order of 50:1 to 100:1 coder. The encoded signal is then de- cooperation with its customers Rohde & are obtained depending on the source coded and displayed on a monitor. By Schwarz would like to find a solution material and the desired picture quality using the same decoder the differences to the problem of objective assessment of the coded signal. This means, for between different encoders can be of TV picture quality. example, that a TV signal to CCIR 601 determined. Theoretically the decoder Dr. Jürgen Lauterjung of 216 Mbit/s is compressed to around should have no influence on signal 4 to 2 Mbit/s. Since different reduction quality, so even different decoders may and compression methods are com- be used. bined in this case, greatly varying results are obtained after encoding The following parameters can be as- REFERENCES depending on the individual parame- sessed in this way: [1] ISO/IEC 13818-2: Information Technology ters selected. • global quantization factor (for JPEG, – Generic coding of moving pictures and associated audio information, Part 2: Video MPEG-1 [2], MPEG-2) indicated [2] ISO/IEC 11172-2: Information Technology The tools that can be used in the en- as a relative quantity (0 to 31) on a – Coding of moving pictures and associated coder are described in detail in the scaled bar display, audio for digital storage media at up to MPEG-2 standard. The efficiency of the • quantization error at grey-scaled, about 1.5 Mbit/s, Part 2: Video combined tools for the source material neutral wedges; the block artefacts can be globally assessed by visually examined in this case permit conclu- examining the encoded signal, but a sions to be drawn on DCT (digital differentiated evaluation was so far cosine transform) parameters, doomed to failure because of the con- • quantization error at edges; this siderable effort involved in a statistical- error is to be assessed separately ly sound, subjective quality assessment. for the luminance and chrominance For this reason Rohde & Schwarz has components, Reader service card 151/12

34 News from Rohde & Schwarz Number 151 (1996/II) Application notes

RF switch units simplify type-approval tests for mobile radio

A variety of measurements are stipu- be illustrated by two typical tasks of of 200 kHz a signal/noise ratio of lated for type-approval tests of mobile type-approval test systems: measure- >170 dBc is obtained. Even given the radios and base stations. The specifi- ment of receiver RFI immunity and best generators, this is only possible cations of the European Telecommuni- transmitter spurious emissions. with the use of filters. Three filters are re- cation Standards Institute (ETSI) define quired for the large frequency range measurements of RF parameters and from 100 kHz to 12.75 GHz: a low- measurements at different layers. These pass filter and a highpass filter for fre- can be carried out fully automatically quencies outside the receiving range by systems for mobile-radio type-ap- and a notch filter for frequencies within proval testing from Rohde & Schwarz. the receiving range. As the receive fre- Protocol tester Base station FIG 1 shows a configuration based on (DUT) quency of the DUT has to be variable, Test System TS8510 for base stations a tunable notch filter is used for measur- RF switch unit [1]. The DUT is integrated into the test ing blocking signals in its vicinity. To en- procedure via three different interfaces: sure accurate stimulation of the wanted a digital interface with 2.048 Mbit/s signal to within ±1 dB, it is adjusted

(Abis) and two RF interfaces for DUT at a high level with a precision power FIG 1 Block diagram of Test System TS8510 transmitter and receiver. The two RF for base stations meter and then reduced to the required interfaces and the digital interface are level of –104 dBm via an attenuator. operated by separate units – in TS8510 by Digital Radiocommunication Test Set The spurious emissions of base sta- CRTP04 from Rohde & Schwarz [2] In testing the RFI immunity of base tions have to be measured in the fre- for the RF interfaces and a Siemens pro- stations a wanted signal of very low quency range 100 kHz to 12.75 GHz. tocol tester for the Abis interface. This level (eg –104 dBm) is applied to the Their level must not exceed –36 dBm configuration meets all the require- DUT and at the same time an unwanted in this range (–30 dBm from 1 GHz). ments for RF tests with standard accu- signal of very high level (eg +8 dBm) The base stations are operated at full racy and for classic protocol tests. in the range 100 kHz to 12.75 GHz. power level – for TS8510 this means With a receiver input bandwidth output power up to +43 dBm, which In addition to protocol tests, ETSI corresponds to a dynamic range of specifications also stipulate paramet- 79 dB. Testing is made difficult (as far rical RF measurements with partly very as the spectrum analyzer is concerned) high demands on DUT and test system. FIG 2 Block diagram of RF switch unit for by the fact that ETSI standards stipulate These parametrical RF measurements type-approval test systems test bandwidths of up to 3 MHz. This comprise: • receiver dynamic range from –104 to –15 dBm, • susceptibility of receiver: intermodulation suppression, adjacent-channel suppression, co-channel suppression, Filter bank blocking, Blocking adjust uplink signal spurious response, Downlink signal

• spurious emission of transmitter, Base • intermodulation attenuation of trans- Uplink signal station ( -104 dBm) mitter.

Fading Filter bank In many of these cases, RF signals from simulator different sources are to be applied to the DUT very accurately or the test Signal generator signal or sections of it have to be measured and detected precisely. This will RF switch unit

News from Rohde & Schwarz Number 151 (1996/II) 35 Application notes

cannot be managed by the spectrum compensation of the individual paths. REFERENCES analyzer without filters, which is why Moreover, the setups have to be docu- [1] Tiwald, W.: Type-approval tests on GSM/ three filters are required for each re- mented very precisely for type-approv- PCN base stations with Test System TS8510. News from Rohde & Schwarz (1993) ceiving range (a lowpass and highpass al testing so that measurements may be No. 143, p 28 filter each as well as a notch filter), ie repeated under the same conditions [2] Schubert, W.: Digital Radiocommunication a total of six filters for GSM and PCN. any time. An RF switch unit offers an Test Set CRTP04 – Test set for base stations As GSM and PCN signals have the alternative: measurements are carried to new PCN/DCS1800 mobile-phone same coding apart from the frequency, out fully automatically and can be standard. News from Rohde & Schwarz (1993) No. 143, pp 8–10 the spurious emissions of GSM stations repeated and verified any time under in the PCN band and those of PCN exactly the same conditions – even in base stations in the GSM band must other labs. FIG 2 illustrates the principle not exceed –98 dBm at full output of such a switch unit used by Rohde & power. The required dynamic range of Schwarz in its GSM Simulator, ITA >140 dB can only be produced using Test System TS8910, PCN Simulators a special duplex filter and an amplifier. TS8920 and TS8925, DECT Test System TS8930 as well as in Test For manual switching, all these mea- System TS8510 for base stations men- surements require a lot of hardware tioned above. for the test setup, measurement and Michael Manert Reader service card 151/13

Alignment of I/Q modulators Test hint by narrowband RF spectrum analysis

Rohde & Schwarz offers a narrowband RF spectrum analyzer (option CMD-K43) for the GSM/ PCN/PCS test sets of the CMD family. With a frequency span of ±130 kHz and selectable resolution filters, spectral lines can be measured in a dynamic range of up to 60 dB. This analyzer is especially suitable for the alignment of I/Q modulators. For a GSM modulator, for example, the RF After alignment compli- signal to be tested is modulated with +67.7 kHz ance with specifications frequency offset. By adjusting the gain, offset and of I/Q modulator can quadrature, signal components at –67.7 kHz and be verified using two at the carrier center can be reduced to minimum. measured values and two difference markers.

DUT CMD For this purpose Digital Radiocommunication Tester CMD has three additional markers that also oper- I/Q modulator ate as difference markers. The quality of alignment can thus be checked very easily. Reader service card 151/14 for further information on Werner Mittermaier CMD-K43

36 News from Rohde & Schwarz Number 151 (1996/II) Refresher topic

Digital modulation and mobile radio (II)

2 Basic modulation out that these two time-domain signals data sequence is a random, uniformly techniques are identical to the real and imaginary distributed sequence of 1s and 0s, a parts of the complex, equivalent base- good assumption for actual data trans- The amplitude, frequency and/or phase band signal to within the sign of missions, the discrete spectrum tends of the RF or baseband signal described the imaginary part. Modulation is then to a continuous spectrum in the limit. by equations (2) to (6) are modified by essentially a process of mapping the Again there is a DC component of A/2 the data signal so that the information it data sequence a(n) to be transmitted and zeroes at multiples of the bit rate. represent is impressed on the RF signal. onto the complex envelope of the mod- This signal is fed to the modulator. The terms M-ary amplitude, frequency ulated RF signal. or phase modulation are used to indi- It is easy to see that the carrier is, in ef- cate which parameter is varied to rep- fect, turned on and off when it is multi- resent the information. The term keying plied by the unipolar NRZ signal. If 2.1 Amplitude-shift keying is used for digital modulation. The modulation is taken to be the assign- abbreviations ASK for amplitude-shift Amplitude-shift keying (ASK) is the ment of a symbol ai from an alphabet keying, FSK for frequency-shift keying simplest way of modulating digital comprising N symbols to a signal and PSK for phase-shift keying are information onto a carrier. Even si from a set of N signals (in this case π widely used internationally. though on/off keying (OOK), the N = 2), the signal s1 = cos(2 fct) is original version of ASK, is no longer assigned to the symbol 1 and the

Straight ASK has ceased to have any commonly used, it is the key to under- signal s2 = 0 to the symbol 0. significance in practice, but FSK and standing the fundamentals of digital PSK are widely used in their binary and modulation. As the carrier signal and the baseband M-ary forms. With M-ary PSK, the signal are multiplied together, it follows upper limit for M is 8 because noise sus- To simplify the discussion, we shall from the shift theorem for Fourier trans- ceptibility rises disproportionally as M assume that the data stream which forms that the spectrum of the modulat- π increases. A combination of ASK and modulates the (real) carrier A · cos(2 fct) ed RF signal is PSK is used for M >8. This leads to is a sequence a(n) with a ∈ {0, 1} com- M-ary quadrature amplitude modula- prising an alternating sequence of 1s 1 π s(t) = -– A · ΄cos(2 fc t) tion (QAM). In this case the carrier can and 0s, ie a(n) = 1, 0, 1, 0, 1, 0, ...... 2 assume M states or, as has already This sequence is converted into a uni- been explained, there exists a set of polar NRZ signal by a digital interpo- 1 π 1 + -– · cos 2 fc ± -– f bit t M time-domain signals, each of which lation filter with π [ [ 2 ] ] represents a digital word ld(M) bits in 1 T T –– for – –– ≤ t ≤ –– 1 3 length (ld = logs to base 2). h(t) = ͭ T 2 2 – ––– · cos 2π f ± -– f t +… (8) π [ [c bi]t ] ΅ 0 elsewhere 3 2 The actual modulation process involves multiplying an RF carrier of the form After D/A conversion, a signal with the for the sequence a(n) = 1, 0, 1, 0, 1, 0 π ϕ A · cos[(2 fct + (t)], which can Fourier series ...... and a continuous spectrum in the also be expressed in complex form as form of a symmetrical mapping of the π ϕ 1 2 1 A · exp(j2 fct) · exp[j (t)], by the u(t) = -– A · 1+ -– · cos 2π -– f t baseband spectrum into the RF band ΄ π bit baseband signal. A simple ring mixer 2 [ [2 ] ] for a random sequence a(n). In both can be used to perform straightforward cases the carrier frequency is present 2 π 3 types of modulation like binary ASK or – ––– · cos 2 -–fbit t +… (7) in the spectrum but at half its original 3π [ [2 ]] ΅ PSK. The data sequence is converted amplitude. The spectrum has zeroes at into a unipolar (ASK) or bipolar (binary is obtained. the frequencies fc ± nfbit (FIG 3). PSK) NRZ signal. With M-ary PSK and QAM, the signal to be modulated must The DC component is half the ampli- Equation (8) shows that both halves of be split into its I and Q components. tude (A/2) and there are spectral lines the spectrum centered on the carrier Both components are modulated by at odd half-integer multiples of the bit frequency would, in theory, be infinitely two different time-domain signals cI(t) rate, ie (2n +1)fbit/2. There are no wide. Therefore, to ensure efficient and cQ(t), which are derived from the spectral lines at whole integer multiples use of the RF band, the spectrum must ≠ data sequence a(n). However, it turns of the bit rate n · fbit (n 0). If the be bandlimited. This is best done in the

News from Rohde & Schwarz Number 151 (1996/II) 37 Refresher topic

baseband. Specifically, all frequencies in the baseband signal up to at least fbit/2 must be allowed through. This is equivalent to limiting the bandwidth of Baseband signal 0.5 f the RF signal to fc ± fbit/2, in other bit words to fbit.

f bit Abrupt limiting of the baseband at fbit/2 is counterproductive because large signal delays are introduced. The filter that is used should, therefore, have RF signal a continuous transition from the pass- band to the stopband which follows a cosine function for example. FIG 4 Time-domain signals and spectra with for ASK, is bipolar (binary phase-shift binary phase-shift keying keying, BPSK). If the NRZ signal is used to modulate a carrier of the form π A · cos(2 fct), an RF signal which (1– α) 1 for 0 ≤ f ≤ ———— is phase-shifted by 180° as compared 2T to the modulating signal is obtained. 1 π(2fT –1) (1– α) (1– α) This means that s1(t) = –s2(t) and H(f) = —ͭ1– sin΄——————΅ for ————< f ≤ ———— (9) ͭ 2 2α 2T 2T this type of modulation is called antipodal. (1– α) 0 for ————< f 2T The (real) spectrum of the baseband signal is given by

4 π 1 u(t) = A ·΄-– · cos 2 -– f bit t This filter replaces the sin x/x lowpass be transmitted. The theoretical upper π [ [2 ]] which was mentioned previously. The limit for ASK is 1 bit/s/Hz, but in RF signal now has a bandwidth B practice efficiencies between 0.65 and 4 π 3 – -—–– · cos 2 -– fbit t +…΅. (10) which is a function of the roll-off factor 0.8 bit/s/Hz are encountered. 3π [ [2 ]] α α and in fact when = 0, B = fbit and when α = 1, B = 2f . In practice and has no DC component. bit 2.2 Binary phase-shift keying roll-off factors between 0.35 and 0.5 are widely used; this corresponds to If the data sequence a(n) is mapped The spectrum of the modulated carrier

RF bandwidths between 1.35fbit and to a sequence of delta functions 1.5f . It is then possible to define a a(n) · δ (nT) ∈ {+1;–1}, an NRZ signal bit 2 π 1 s(t)= A ·΄-– · cos 2 fc ± -– f bit t bandwidth efficiency which indicates is output by the sin x/x lowpass. This π [ [ 2 ]] what bit rate per Hz of bandwidth can signal, unlike the modulation signal 2 π 3 – -—– · cos 2 fc ± -– f bit t +…΅, (11) 3π [ [ 2 ]]

is obtained by multiplying the baseband signal and the carrier together. The spectrum does not contain the car-

Baseband signal rier frequency (FIG 4). The occupied bandwidth is the same as that for ASK 0.5 f bit and has been limited by passing the

f bit baseband signal through a lowpass filter with a cos roll-off before modulation. Consequently, ASK and BPSK have the same theoretical maximum bandwidth RF signal efficiency of 1 bit/s/Hz and a bandwidth efficiency between 0.65 and FIG 3 Time functions and spectra with amplitude-shift keying 0.8 bit/s/Hz in practice.

38 News from Rohde & Schwarz Number 151 (1996/II) Refresher topic

2.3 M-ary quadrature Pulse shaping

amplitude modulation Digital filter

To increase bandwidth efficiency, two, Digital three or in general k consecutive bits filter from a data sequence a(n) can be combined to form a new symbol b(m) by means of serial/parallel conversion. As a result, the symbol rate is reduced to fbit/k. The new symbols are referred to as dibits, tribits, quadbits or k-bit 16 QAM words in general. The modulation process requires M = 2k RF signals, each with a different phase and/or amplitude. The M = 2k possible symbols b(m) are mapped onto these signals. FIG 5 M-ary quadrature amplitude modulation An I/Q modulator is the best type of modulator to use. First of all, it splits the unmodulated RF signal into two compo- Bit sequence nents. The quadrature or Q component is phase-shifted by 90° with respect to the in-phase or I component. There- RF time-domain signal fore the unmodulated I component 0.5 f π bit is described by cos(2 fct) and the unmodulated Q component by π –sin(2 fct). Both components are fed to mixers, where they are multiplied Time-domain signal in baseband RF spectrum with the modulating signals cI(t) and Unmodulated cQ(t); cI(t) and cQ(t) are derived from carrier Modulated the symbol sequence b(m) and to carrier within the sign of the Q component are identical to the real and imaginary parts of the complex envelope of the I/Q modulator Phase state modulated RF signal. The products diagram π π cI(t) · cos(2 fct) and cQ(t) · [–sin(2 fct)] are added together to give the mod- FIG 6 Quadrature phase-shift keying ulated RF signal. The modulation process is reduced to mapping the symbol ϕ sequence b(m) onto the two baseband bits are combined to form a dibit Bit Dibit cI(t) cQ(t) sequence components. In the case of unfiltered which can represent one out of quadrature amplitude modulation M = 22 = 4 symbols. These symbols 00 I 1 1 45° ϕ ∈ 10 II –1 1 135° (QAM), staircase signals in the time are mapped onto the phases i {45°, 11 III –1 –1 225° domain with M/2 possible values are 135°, 225°, 315°} of the RF signal 01 IV 1 –1 315° produced (FIG 5). or onto the four time-domain signals π π si(t) = A · cos[2 fct + (2i + 1) · /4] TABLE 1 Modulation parameter assignments By passing the baseband signal with i ∈ {0, 1, 2, 3}. TABLE 1 shows through a filter with a cutoff frequency how the bit sequences, the dibits, the equal to half the symbol rate, the band- modulation signals and the phases of Theoretically, the bandwidth efficiency width of the RF signal is limited to the the RF signal are related. FIG 6 shows can be increased to 2 bit/s/Hz and so symbol rate = bit rate/k, which means the signals in the time domain, in the is twice the maximum bandwidth effi- that the bandwidth efficiency is k times frequency domain and by means of a ciency for ASK and BPSK. In practice, better than for BPSK. Quadrature phase state diagram. It should be noted values between 1 and 1.5 bit/s/Hz phase-shift keying (QPSK) is the first that in this case too there is no carrier- can be obtained. step in this direction. Two consecutive frequency component in the spectrum. To be continued Peter Hatzold

News from Rohde & Schwarz Number 151 (1996/II) 39 Software

ESxS-K1 – attractively priced Windows software for EMC measurements

FIG 1 Fully automatic RFI test system with Test Receiver ESHS, V-Network ESH3-Z5 and computer with EMI Software ESxS-K1 Photo 42 219

The automation of EMC measurements Software Package ESxS-K1 supports • graphic display of results and scan in development and production has both Rohde & Schwarz compliance- data, become a topic of interest since the class Test Receivers ESHS/ESVS/ESS • comparison of limit lines with peak coming into force of the electromag- and Test Receivers ESVD/ESVB/ESN/ and average detection, netic compatibility law (European EMC ESVN, which measure useful signals • standard-conforming evaluation with Directive 89/336/EEC) this year. in line with the EN standard [2]. The quasi-peak and average detector, Labelling electrical and electronic prod- dialogs and masks for defining test • data reduction by subranging and/ ucts with the CE mark is now stipulated setups, scan modes, measurements, or acceptance margin selection, by law to indicate compliance with inter- evaluation and report generation are • peak-list edit function, peak list can national standards for electromagnetic straightforward and simple, making it be modified for automatic and semi- interference and susceptibility. Rohde & easy to get acquainted with the pro- automatic measurements, Schwarz, a leading enterprise in the gram even for those working with it • marker functions and zoom func- field of EMC, offers – in addition to for the first time. In addition, EMI Soft- tion. advanced EMI/EMS Software Package ware ESxS-K1 offers measurement ES-K1 [1] with modular, flexible and ex- and evaluation functions frequently Frequency sweeps can be stopped, a tendable architecture under Windows – needed by experienced EMC users facility that is often needed in prac- a budget-priced EMI software intended including: tice. Sweeps can be restarted at the in the first place for small and medium- • measurements at a keystroke (con- marker frequency, the current receive sized enterprises to provide fast, reliable figuration and loading of setups, frequency or at the point they were and reproducible EMC measurements. scan start), stopped.

40 News from Rohde & Schwarz Number 151 (1996/II) Software

After completion of a frequency sweep, can be transferred via DDE (dynamic selected subranges can be examined in data exchange) to other Windows detail using the zoom function. For this, applications such as Winword or the Find Worst Case function offers the Excel, allowing the user to generate current and the maximum level values, reports in any desired form. Moreover, while the user performs fine-tuning of detailed online help is available in the receiver, determines the EUT posi- English and German for all software tion for the Worst Case mode and, at a functions. keystroke, initiates final measurement with quasi-peak and average detec- EMI Software ESxS-K1 can be installed tion. The final result is automatically on any Windows-compatible computer added to the frequency list. with 80386 processor or higher with IEC/IEEE-Bus Interface Card PS-B4 Three options are available for final from Rohde & Schwarz or PCII/IIA or measurement: AT-GPIB from National Instruments. • automatic measurement; this means cycling with a defined test setup The software package is available through the frequency list obtained for precertification Test Receiver ESPC from peak measurements, (9 kHz to 2.5 GHz) [3] under the • semiautomatic measurement; same FIG 3 Final measurement with Find Worst Case designation EMI Software ESPC-K1 as automatic measurement but with function activated and measurement using quasi- (supplied as accessory with ESPC). The peak and average detectors Find Worst Case function activated, functions and features of this software • manual measurement; maximum are identical to those of ESxS-K1, but level indication is obtained through ESPC-K1 only supports Test Receiver fine-tuning of receiver and position- ESPC. ing of EUT. trolled by R&S receivers via the user Volker Janssen port, allowing the phase and PE wire ESxS-K1 of course allows complete set- setting to be recorded along with the ups to be loaded into the receiver and frequency and level information. current setups to be stored in the PC REFERENCES under ’Receiver Setup‘. Using editable The reports generated have the same [1] Wolle, J.: EMI Software ES-K1 – Windows limit lines and tables with correction layout as receiver reports, including for EMI measurements. News from Rohde & values for frequency-dependent trans- all settings relevant to measurement re- Schwarz (1993) No. 142, pp 22–23 ducer factors, reproducible, standard- producibility. Reports can be displayed [2] Rohde & Schwarz: Test & Measurement Products (Catalog 96/97) conforming measurements can be before they are printed using the Print [3] Janssen, V.: EMI Test Receiver ESPC – EMC made. It is also possible to integrate Preview function. Reports can be output precertification measurements for every- V-Networks ESH3-Z5 (two-line) and to any printer or plotter supported by one. News from Rohde & Schwarz (1995) ESH2-Z5 (four-line), which are con- Windows™ 3.1. Individual report fields No. 149, pp 16 –18

FIG 2 Curves measured with peak and average detectors, with limit lines conforming to EN55022 and associated frequency list Reader service card 151/15

News from Rohde & Schwarz Number 151 (1996/II) 41 Software

ALADIN and ARAMIS message-handling software – convenient data transmission by shortwave

It is a popular fallacy that data trans- example, many foreign ministries com- To prevent data losses during transmission by shortwave is unreliable, municate with their representations all mission, ALADIN and ARAMIS use the complicated and out of date. With the over the world via shortwave, indepen- software-implemented Z-modem proto- aid of Message-Handling Software dent of service providers [1], and re- col in addition to data-link protocols Packages ALADIN (Automatic Link search institutes use this medium to FEC (forward error correction) and And Data Interchange Network) and keep in touch with their remote field ARQ (automatic repeat request) imple- ARAMIS (Automatic Radio Message bases [2]. mented in the hardware components. If Interchange System), shortwave be- a link breaks down or is disturbed, data comes increasingly attractive in the ALADIN and ARAMIS automatically transmission will be continued from modern communications world. ALADIN transmit and receive messages so that the point of disturbance. Successfully and ARAMIS provide reliable, loss-free the user requires no in-depth knowl- transmitted data will not be sent again. and free-of-charge data transmission edge of the shortwave medium. When Encryption algorithms are available no matter whether in a building or over the user issues an addressed message, to provide increased security against thousands of kilometers. Besides con- link setup and data transmission to the the interception of sensitive data. ventional text files, fax messages and counterstation will be performed auto- video stills can be produced and trans- matically. The two software packages The two software packages ALADIN mitted. The menu-controlled user inter- provide a modern workstation (FIG 2) and ARAMIS make it possible to imple- face makes it easy to get familiarized with a clear-cut, menu-controlled user ment communication networks where with the system (FIG 1). interface for the generation, editing each station can communicate with any other station. Alternatively, any user- defined organization structure, eg a star configuration, can be implemented (FIG 2).

ARAMISARAMIS ARAMIS was designed especially for the FIG 1 User interface requirements of small and medium- of ARAMIS software Message Handling Software sized networks. It is the simpler of Version 3.1 26.3.96 the two systems and restricted to the shortwave medium. In an ARAMIS station, the antenna is automatically aligned in the direction of the station called to make the maximum use of transmitted and received power.

ALADIN was designed for the implementation of worldwide communication networks. In addition to shortwave, it allows alternative transmission media to be integrated such as Satcom terminals [3], telephone networks or LANs. If a communication link is dis- If no cable connection exists between and transmission of ASCII texts, fax files turbed, switchover can be made to an- parties located at a large distance from and video stills. Basically any binary other medium without interrupting the each other or if communication inde- files can be transmitted. The user is sup- transmission – a unique and so far unri- pendent of a network operator or tele- ported especially in the management, valled feature of ALADIN. Successfully phone company is desired, this is storage and archiving of large quan- transmitted data will not be sent again. where shortwave comes into its own. In tities of incoming and outgoing mes- In addition, for each medium, alterna- the frequency range 1.5 to 30 MHz, sages. Possible I/O devices include tive communication paths between the communication links can be set up camcorders, fax machines, printers sender and the addressee (eg via a worldwide at low operating costs. For and teletypewriters. relay station) are offered to which

42 News from Rohde & Schwarz Number 151 (1996/II) Software

FIG 2 Modern shortwave workstation ALADIN and ARAMIS are based on an REFERENCES Photo 42 295 operating system with multitasking [1] Ofer, K. H.: Crisis-proof communication by capability. This means that a large shortwave in German diplomatic service. News from Rohde & Schwarz (1991) number of automatic processes can No. 135, pp 18–21 be performed simultaneously. For ex- [2] Kohnen, H.: Reliable shortwave commu- switchover is made automatically in the ample, while a received message is out- nications – a matter of life and death in event of a failure. put to a fax machine, a text file can be the Antarctic winter. News from Rohde & transmitted to another station and at Schwarz (1993) No. 141, pp 41–43 For shortwave transmission, the core of the same time a picture recorded with [3] Böhler, U.: Shortwave radio or satellite communication? News from Rohde & the system is formed by a special HF a camcorder. The software packages Schwarz (1995) No. 149, pp 57– 59 data modem [4]. The 2700-bit/s mo- run on System Processor MERLIN [5] [4] Hackl, H.: Secure data transmission with dem provides an effective throughput or a standard PC meeting specific 2700 bit/s on shortwave links. News rate of up to 2150 bit/s at 100% data environmental requirements (shock and from Rohde & Schwarz (1994) No. 146, transmission reliability (corresponding vibration resistance, EMC). pp 29–31 to 2690 bit/s at an asynchronous PC [5] Maurer, P.; Völker, K.: Multimedia com- interface with a start and a stop bit). Message-Handling Software Packages munication with MERLIN system processor. News from Rohde & Schwarz (1993) ALADIN and ARAMIS make long-dis- No. 142, pp 27–28 tance shortwave links as reliable as wired phone and fax connections but are far more economical.

FIG 3 Typical structure of shortwave network Thomas Kneidel

Reader service card 151/16

News from Rohde & Schwarz Number 151 (1996/II) 43 Software

Object-oriented software development for computer-aided, mobile data transmission

Object-oriented software development is in part based on concepts already FIG 2 Typical inter- known for some time; it is however task communication via message dis- only in the past five years that it has patcher (O2 sends become a topic of general interest. message to O4) There are various definitions as to when an approach can be regarded as object-oriented. In contrast to the common- 2. use of reliable system software that lowing are four examples from the ship ly employed function- or data-oriented automatically responds to disturbance communication system: approaches, object-oriented software or interference from the environment “StartSupercycle” starts the super cycle, development combines data and func- not only by changing the frequency but ie the central sequencing control for tions in such a way that they reflect also by effecting handover between radio data transmission. as closely as possible the concrete and the HF and VHF Tx/Rx components. “StopSupercycle” stops the super cycle abstract objects of the real world. The software design is based on object- and allows radiotelephone communi- oriented software engineering accord- cation. Rohde & Schwarz has, for a customer- ing to Jacobson [3], since this method “MakeLink” starts the procedure for a specific project, systematically and enables a smooth transition from de- X.25 link setup. consistently implemented an object- sign to implementation. “SendMessage” starts radio data trans- oriented concept. The result is a flex- mission. ible, easy-to-service ship communica- Design steps tion system for the exchange of radar Step 2: Finding objects data, electronic mail and files of virtu- Object-oriented software development In this step you determine what objects ally any size [1]. The whole system is is implemented in several steps. are necessary for system operation and extremely immune to interference for what relationships exist between these two reasons: Step 1: Definition of functions objects. As a result the software archi- Based on the customer’s requirements tecture is obtained, ie the organization 1. use of high-quality Tx/Rx compo- and the resulting specifications, all de- of the software into tasks and components such as VHF-UHF Transceiver sired system functions – referred to as nents (FIG 1). For example, the mes- XT452 and HF Transceiver XK855 with use cases – are recorded. The objective sage dispatcher developed by Rohde & integrated FSK modem and ALIS pro- is to describe as completely as possible Schwarz plays an important role in the cessor [2], all functions required in a system. Fol- system because it extends the multitasking capability of the operating system (multi-user DOS) by simulated multitasking at the application level. While the major tasks are handled by the multitasking function of the operating system, the message dispatcher man- ages the objects within the tasks. For this the objects must register with all their methods (messages) at the message dispatcher during runtime. This procedure is employed not only for inter- but also for intra-task communication and for communication with device drivers (FIG 2).

Step 3: Description of interaction between objects FIG 1 Software architecture for com- Object-oriented programs are based on munication system the exchange of messages between ob-

44 News from Rohde & Schwarz Number 151 (1996/II) Software

jects. A commonly employed method of Precondition and postcondition illustrating the message flow is by means checks of message sequence charts (interac- Each object ensures as far as possible tion diagrams). The message sequence that its data are consistent by checking charts enable the functional interfaces them during runtime. Checking is per- of the objects to be defined (FIG 3). formed twice, ie on entering a method (precondition check) and on leaving Step 4: Specification of objects a method (postcondition check). The The majority of the objects used in the concept is simple [4] but it markedly ship communication system were imple- enhances quality and productivity as it mented in the form of status automatons requires developers to specify classes as is common practice in communi- accurately to be able to define the cations engineering. State transition conditions (invariants) for these checks. diagrams are used for the specification This makes codes maintainable and of the objects. The diagrams allow a also extends component testing, which smooth transition from design to imple- substantially reduces the probability of mentation (FIG 4). runtime errors. FIG 4 Detail of state transition diagram (object: RSX25Group; state transition: linking → init) Coding and quality Exception handling Exception handling causes the pro- About 20 new objects (classes) were gram to go to a recovery routine in defined for the above communication the event of an error. This feature of out reason is the object-oriented ap- system. Part of the objects was later im- C++ is another powerful tool for the proach regarded as a quantum leap plemented from C++ using inheritance. determination of runtime errors. It is in terms of productivity and maintain- Most of the objects can be re-used, eg used for cushioning protocol errors, ability in professional software devel- the message dispatcher, as well as for example. opment. Exception handling as well as classes employed for system configu- pre- and postcondition checks have ration and a timer class for time moni- Trace mechanism been incorporated into modern pro- toring, to name just the most important Each object of a task writes messages gramming languages [5] and make ones. But not only have new classes into a file during runtime. The messages for considerably increased reliability, been generated, old ones were used as are classified according to contents stability and testability. well. The latter mainly included con- and can be filtered as required. System Jürgen Rauch; Karl Scalet tainer classes and classes for the con- operation is recorded in this way, and figuration of the user interface and any malfunctions are traceable. This were taken from the Borland library of feature can be disabled for reasons of classes. system performance. REFERENCES [1] Jungherz, M.; Maurer, P.: Radiocommunica- High-quality software is characterized, Through the use of object-oriented tech- tion system helps Italian customs authorities in coastal monitoring. News from Rohde & among other features, by stability, niques in conjunction with measures Schwarz (1996) No. 150, pp 46 –47 maintainability and testability. Rohde & aimed at the improvement of software [2] Greiner, G.: Reliable shortwave with ALIS. Schwarz created high quality in its ship quality, Rohde & Schwarz has devel- News from Rohde & Schwarz (1988) communication system by following a oped a product that meets even the No. 116, pp 47– 50 strategy based on three mainstays: most exacting requirements. Not with- [3] Jacobson, I.: Object-Oriented Software En- gineering – A Use Case Driven Approach. Addison-Wesley (1993) [4] Porat, S.; Fertig, P.: Class Assertions in C++. Journal of Object-Oriented Programming. SIGS Publications (May 1995) volume 8, No. 2, pp 30–37 [5] Meyer, B.: Eiffel: The Language. Prentice Hall (1992)

FIG 3 Message sequence chart for MakeLink system function Reader service card 151/17

News from Rohde & Schwarz Number 151 (1996/II) 45 Panorama

Mass Spectrometer Airsense 500 – fast gas analyzer for automobile industry

Airsense 500 (FIG 1) is an extremely fast, selective and highly sensitive gas- analysis system for use in the automobile industry. Modern motorcar engines should have low fuel consumption and minimum exhaust emission. Moreover, drivers expect their cars to have a long service life and adequate engine performance. These requirements can be met by optimizing the combustion processes in the engine and by the use of a catalytic converter. For this, appropriate geometry of the combustion chamber, correct ignition timing and the right combustion mixture are required. Com- bustion processes today are micro- computer-controlled, which necessitates a thorough knowledge of the complex FIG 1 Multicompo- chemical and physical processes taking nent gas analyzer place in the engine and in the catalytic Airsense 500: sturdy, turnkey system con- converter. figurable to customer requirements Any variation of engine load has an Photo 42 459 immediate effect on the composition of the exhaust gases. For example, in a diesel engine more benzene can be detailed analysis of the composition of are generated in an ion source from a produced with than without a catalytic exhaust gases and its variation with sample gas. The ions are separated in converter if the engine is idling. As the time. Mass Spectrometer Airsense 500 an analyzer according to their mass composition of gases is highly complex meets the exacting requirements as and charge and recorded by means of and the processes take place at high to selectivity, speed and sensitivity a detector. In classical mass spectrome- speeds, just a few exhaust-gas com- involved in an analysis of this kind. try, ions are generated through the col- ponents (eg NOx, CO, SO2, total lision of fast electrons with the sample. hydrocarbons) have been analyzed A mass spectrometer is an analysis This takes place in small chambers in so far. The processes taking place in system that identifies substances by which electrons emitted from a cathode the engine can be optimized through their mass. To this end, gaseous ions are accelerated towards the anode, ionizing gas particles on their way. Often, more energy is transmitted in this process than required for ionization, with the result that the ions break up into smaller, likewise charged particles (fragmentation). A large number of different ions of equal mass is thus obtained in a mixture of gases, which makes qualitative and quantitative analysis impossible, ie the process is not very selective.

Airsense 500 avoids fragmentation by FIG 2 Basic design of Mass Spectrometer employing a special ionization method. Airsense 500 A gas sample is ionized through the

46 News from Rohde & Schwarz Number 151 (1996/II) Panorama

ondary-ion multiplier (Channeltron), a fast preamplifier and an electronic GHz counter. This special system affords detection limits far below one ppb (part per billion) and measurement times below 100 ms. This allows even extremely small changes in the concen- tration of a substance to be detected online (FIG 3). Using different ionization FIG 3 gases in rapid succession, it is possible Exhaust-gas concen- to extend the spectrum of measurable tration as function of engine load components.

The gas-analysis system Airsense 500 exchange of charges between charged The source-gas ion current is focussed has proved its value under adverse source-gas ions (eg Xe+) and the mole- in the first octopole (FIG 2) using high- conditions such as exist on engine cules under examination (secondary- frequency fields in an ultra-high vacuum test stands as well as in garbage-incin- ion mass spectrometer). Each type of and transported to a chamber where erating plants, coal-fired power stations source-gas ion has its characteristic charge exchange takes place, ie the gas and in the food-processing industry. energy. Using suitable source gases, sample is ionized. The ions obtained Dr. Andreas Waßerburger the ionization energy can be exactly are focussed in a second octopole. The determined and fragmentation avoided. ion streams are separated according to Airsense 500 in this way provides inter- their masses in a quadrupole filter using ference-free analysis of complex gas crystal-stabilized high-frequency fields. mixtures. The particle detector consists of a sec- Reader service card 151/18

The “lifeline” to rescuers in the air

In summer 1995 Rohde & Schwarz won the order to supply a blanket radio network for the SAR service (search and rescue) of the German Air Force. This organization of the Federal Armed Forces is primarily a service to support military operations. And as part of FIG 1 the national search and rescue service SAR helicopter of German Air Force of the Federal Republic of Germany, it on duty helps any aircraft and – in cooperation Photo: Armed with Deutsche Gesellschaft zur Rettung Forces Office Schiffbrüchiger (German society for rescuing shipwrecked persons) – any vessel in an emergency situation. In The Federal Republic of Germany is di- Holstein. This belongs to the SAR area addition to these tasks it supports the vided into SAR areas (FIG 2). Search of Glücksburg and comes under the civil rescue service in case of acute and rescue activities are managed jurisdiction of the German Navy, which emergencies (FIG 1), provided there is by the rescue coordination center. This has its own radio network. no conflict of interest with the military center of the German Air Force is tasks and requirements of the SAR responsible for the whole of Germany More than 30 air-control radio stations service [1]. except for its northern state Schleswig- are set up to ensure blanket VHF-UHF

News from Rohde & Schwarz Number 151 (1996/II) 47 Panorama

of all the air-control radio stations are normally operated on a common frequency. However, the frequency can be changed by remote control to deal with major incidents.

The semipermanent lines of all the air- control radio stations are linked to the rescue coordination center. Moreover, ADS links are set up between the rescue coordination center and the nearest switching center. The control of radios including all the required device settings as well as the output of device FIG 2 SAR areas messages is via three independent of German Armed data-processing workstations. The whole Forces (asterisk = radio system can be accessed from rescue coordination center, triangle = any of these workstations. The radio SAR helicopter, network can be divided into subnet- red circle = SAR works. Access to the primary unit of helicopter with an air-control radio station is computer- doctor on call) controlled, ie access is possible by clicking the selected air-control radio station on the graphic display of the radio network. The secondary unit is radio coverage for the operation area rescue coordination center operates, selected by means of the direct access of the German Air Force. These stations monitors and controls the radio network key. comprise two radio systems based on via a central system. equipment of series 400 (FIG 3) [2]. Project planning provides for step-by- They can be operated in the VHF or One of the radios of the air-control step implementation and startup of the UHF aeronautics band and allow data radio stations is linked to the monitoring radio network. The complete system is transmission in both frequency bands and control system in the rescue coor- intended to be available in 1998. Thus, from an air-control radio station. Sta- dination center via a semipermanent SAR will receive a tool that consider- tions already operating VHF-UHF radio line. Communication with such radios ably facilitates and speeds up operat- services are provided with separate is thus always possible on the set fre- ing routines in radiocommunication, im- transmitters and receivers with asso- quency. The second radio is elected as proves availability and last but not least ciated antennas. This is usually the an ADS (automatic direct subscriber) reduces operating costs. case with local military ATC centers via the German Air Force Automated Franz Ketterle and air-defense radar stations. Stations Communications System so that a sec- of the German Air Force Automated ond frequency in the VHF-UHF band Communications System are normally can be used at the same time. The equipped with transceivers only. The operational equipment (primary units)

REFERENCES [1] Günther, H.-J.; Ketterle, F.: Funk – das Fern- meldemittel der dritten Dimension. Elektronik Report 95, pp 20–24 [2] Krüger, G.: Communication equipment for air-traffic control and airports. News from FIG 3 Transceiver Rohde & Schwarz (1991) No. 134, pp 4–7 of Rohde & Schwarz radio equipment series 400 Photo 40 903 Reader service card 151/19

48 News from Rohde & Schwarz Number 151 (1996/II) Panorama

Rohde & Schwarz FM and TV transmitters provide Greater Brussels with entertainment

It can hardly be overlooked, the 300-m operated in turns, ie in passive standby. high tower in a rural area around In contrast to the transmitters for TV1, Leeuw-Saint-Pierre, directly located on those for TV2 have klystron tubes and the route to Pepingen in the heartland are extremely reliable. of Flemish Brabant (FIG). Extremely powerful sound-broadcast and TV trans- Rohde & Schwarz, which is firmly mitters from Rohde & Schwarz are established in Belgium’s FM network, operated in this tower. The whole story won the order in the face of competition began because of an accident. In from four other well-known European autumn 1983 a heavy storm destroyed transmitter producers. “It was the most the antenna mast of BRTN (Belgian TV favourable offer for BRTN”, confirms and broadcasting company of the Flemish community) and RTBF (Belgian TV and broadcasting company of the French community) at the Wavre broadcast station. BRTN chose Leeuw-Saint- Pierre to set up a new mast now providing Greater Brussels with the FM programs Radio 1, Radio 2, Radio 3, Studio Brussels and Radio Donna and with the two TV programs TV1 and Broadcasting tower of TV2. Belgium’s BRTN at Leeuw- Saint-Pierre in Flemish Brabant and view of hall The transmitters are located in a huge with TV transmitters from hall on the second platform of the Rohde & Schwarz tower at the base of the antenna mast. Photos: BRTN The FM transmitters have a power of 10 kW each and a common standby transmitter. Radio Donna, the fifth program, transmits with 2.5 kW and has a standby transmitter of the same power. The different radio programs are taken via a transmitter-combining filter and emitted from a common antenna. The FM transmitters are solid-state throughout, which keeps operating costs at a minimum. The transmitters are air- cooled and the recovered heat is used to warm the rooms in winter.

The transmitter for TV1, the most modern in Europe according to Paul Desmet, advisor to the head of program services, consists of two 10-kW solid-state Paul Desmond. The high-quality systems transmitters that are used together. The are in compliance with all standard system thus corresponds to a 20-kW specifications and completely meet user transmitter operating with integrated requirements, especially with regard to active standby. The system for TV2 con- price, ease of maintenance and repair sists of two identical transmitters yield- as well as safety regulations. Reader service card 151/20 for further informa- ing a total power of 40 kW. These are Leo Terneven (BRTN) tion on FM and TV transmitters

News from Rohde & Schwarz Number 151 (1996/II) 49 Panorama

A vision comes true – trunked radio for United Arab Emirates

The United Arab Emirates (UAE) with At the end of 1993 Rohde & Schwarz approx. 2.2 million inhabitants are received an order to install a national, a federation of seven emirates (Abu blanket turnkey trunked-radio system Dhabi, Dubai, Sharjah, Ras Al Khai- based on ACCESSNET® [1]. The first mah, Fujairah, Um Al Qaiwain, Ajman) planning stage was successfully im- that were united in a common state plemented in close cooperation with in 1971. The Emirates stretch over an the UAE Ministry of the Interior within area of 90,600 km2. Since the foun- six months. Another stage was com- dation of the state, Sheikh Zayed bin pleted half a year later so that com- Sultan Al Nahyan (head of state, presi- plete coverage of all the important re- dent and also sovereign of Abu Dhabi) gions/cities stretching from Abu Dhabi, has been transforming the country at a Ras Al Khaimah to Fujairah, where breathtaking speed together with the 90% of the people live, was ensured heads of all the other emirates from (FIG 1). a barren desert landscape into a pros- perous, modern state thanks to im- The graduated, modular and hierarchi- mense technological and infrastructural cal switching concept of ACCESSNET® investments. with its outstanding software functions FIG 2 Example of ACCESSNET ® radio base (signalling standard MPT 1327/1343) station in United Arab Emirates Photo: Author Current investments include the updat- is the ideal key technology to meet ing of telecommunication facilities. In all the operational requirements of se- early 1990 it was recognized that curity organizations, coastguard, civil lation of a master system controller investment spent on different, incom- defence, police, customs, immigration which, as a central switching unit, is patible radio systems with limited authorities, fire brigades, ambulances, networked with five regional trunked coverage and of different performance etc. Thanks to ACCESSNET ® these site controllers via wired lines. Twenty data for daily use coupled with the user groups can now effectively carry “dislocated” radio base stations (FIG 2) special demands in emergency situa- out their specific tasks independently controlled by the trunked site controllers tions would be absolutely unsuitable. or, if required, together for the benefit via terrestrial lines ensure full cellular Trunked-radio systems were winning of the inhabitants or maintaining inter- coverage and provide excellent grade through more and more and finally nal security. of service and high traffic capacity turned out to be the ideal solution for with a large number of radio channels. the realization of the vision of one radio An optimum, decentralized switching The whole network infrastructure can of system for all parties concerned. concept was implemented by the instal- course be monitored by a central maintenance computer system or by regional maintenance terminals. 100% availability is thus guaranteed.

The users have powerful trunked-radio sets, which are installed in vehicles and ships (FIG 3) and can also be used as desktop units in local centers of operation. Hand-held radios with special accessories are for use in and outside vehicles. About 2000 trunked-radio FIG 1 System design of sets are currently used by the different trunked-radio net- organizations and are not only used work ACCESSNET® for speech communication but also in United Arab for data transmission. A sophisticated Emirates (red: locations of phase 1, scheme for call numbers and task- blue: phase 2) oriented release of certain functions for

50 News from Rohde & Schwarz Number 151 (1996/II) Panorama

particular subscribers/subscriber groups optimize the deployment of people and material in day-to-day and emergency situations. Dispatcher terminals in regional centers allow rapid task allo- cation to operational units.

ACCESSNET® is in operation around FIG 3 Patrol boats the clock and the network will be of coastguard of extended successively. The tactical United Arab Emirates demands of coastguards and other Photo: Gulf News security organizations will thus be met by equipping all the present and additional sites along the coast and on the islands with digital switching and trunked-radio system will not only REFERENCES radio technology to allow encrypted, master today’s needs but also those [1] Wagner, K.-H.: Trunked-radio systems suc- ie absolutely intercept-proof, end-to-end of tomorrow and the day after. As the cessful all along the line. News from Rohde & Schwarz (1994) No. 146, p 55 communication. A new generation of operator of ACCESSNET® the UAE [2] Schinke, U.; Klier, W.: Radiocommunication digital shipboard radios with inte- Ministry of the Interior has undoubtedly System ACCESSNET ®-D – Trunked radio grated encryption is also part of the set a notable example and received goes digital. News from Rohde & Schwarz extension. ACCESSNET® thus follows attention and won recognition. Con- (1995) No. 149, pp 28–31 the trend from purely analog to fully sequently, the trunked-radio system digital technology with application- ACCESSNET® is offered at low cost to tailored speech and data encryption all national organizations with a view [2]: an indispensable precondition for to becoming independent user groups. organizations with security tasks. A large number of these organizations are expected to take advantage of the ® ACCESSNET fulfills the vision of the attractive offer in the near future. Reader service card 151/21 for further informa- United Arab Emirates: this powerful Karl-Heinz Wagner tion on ACCESSNET ®

R& S signal generators at Finnish Institute of Technology

In the field of RF design, manufacture mechanical and electrical stability at an setup with Signal Generator SMT [1] or maintenance, talented and well- adequate price, as the instruments must and Spectrum Analyzer FSEA [2] for educated engineers are the most valu- frequently be transported between labs general measurement tasks. But it was able resource of any company or public and test sites and students often lack found that the more favourably priced institution. For creating such resources, experience on how to deal with mea- Signal Generators SMX and SMY extensive laboratory exercises have suring equipment. [3; 4] also maintain their specifications been included in the training program even in harsh environments, are of technical institutes and universities. The Kotka Institute of Technology in well-protected against accidentally The teaching environment sets specific Finland decided to use Rohde & applied external voltages and ex- demands on the laboratory equipment Schwarz equipment for many of their tremely rugged thanks to their sturdy in terms of RF specifications as well as measurements. FIG 1 shows a test metal cabinets.

News from Rohde & Schwarz Number 151 (1996/II) 51 Panorama

Another advantage of R&S signal generators is their simple operation – an important aspect in university applications, as many students are afraid of making operating errors and, after all, the main focus of learning is some- where else. If the student must first read FIG 1 High-quality and learn for several hours about how test setup comprising Signal Generator to tune the instrument to the right fre- SMT and Spectrum quency, he will be distracted. Happily Analyzer FSEA used enough, there is test gear with a better for measuring anten- design approach. Take Signal Genera- na radiation patterns Photo: Huurrekorpi tor SMY: via a large spinwheel the student has immediate control of carrier frequency and level. Changing steps or units is performed by hardkeys below of hand-held phones, are very tight. On tained within reasonably tight limits if the display, and activating modulation the other hand it is not advisable to pur- financial limits demand, and instruments is also very easy. And if, according to chase the most expensive and luxurious be chosen that can be upgraded at a Murphy’s law, the student pushes the instruments for a teaching lab. Besides later date. wrong button anyhow, he simply gets the financial risks in maintenance, cali- a clearly indicated error message. The bration and repair, there is the fact that All the mentioned aspects demonstrate plastic guide card below Signal Gen- these devices are simply overspecified that Signal Generator SMY is a good erators SMX and SMY is a valuable and have a lot of features which are solution for measurements in training aid for the average student (FIG 2) never used. When dealing with RF, one institutes. Its excellent features and mod- and normally no handbook is needed way to save is to set a suitable frequen- ulation variety show that the instrument because IEC/IEEE-bus commands are cy limit. The benefit is felt in costs, and is intended for the professional market, also included. most of the phenomena encountered in but it is nevertheless within the means of radio engineering can be still demon- the not-so-wealthy customer – like most Test equipment used for teaching strated and measured. For many pur- of the academic teaching branch tend should be of a high quality standard. poses Signal Generator SMY is a suit- to be nowadays. Many facts of modern telecommuni- able choice with its upper frequency Dr. Pekka Eskelinen cations and RF engineering cannot of 2 GHz instead of a microwave unit, (Kotka Institute of Technology, Finland) be demonstrated or tested with simple which would cost at least three times as instruments because power level, fre- much. In a normal teaching environment quency and modulation tolerances, eg basic specifications should be main- REFERENCES [1] Lüttich, F.; Klier, J.: Signal Generator SMT – The signal source for receiver and EMS measurements up to 3 GHz. News from Rohde & Schwarz (1993) No. 142, pp 13 –15 [2] Wolf, J.: Spectrum Analyzer FSEA/FSEB – New dimensions in spectral analysis. News from Rohde & Schwarz (1995) No. 148, pp 4–8 [3] Lüttich, F.: SMX, a cost-effective signal generator for 100 kHz to 1000 MHz. News from Rohde & Schwarz (1986) No. 115, pp 13–15 [4] Klier, J.: Signal Generator SMY – The signal source within everybody’s means. News from Rohde & Schwarz (1994) No. 144, pp 8–10 FIG 2 Signal Generator SMX with plastic guide card – so normally no handbook is needed Reader service card 151/22 for further informa- Photo 42 445 tion on SMY

52 News from Rohde & Schwarz Number 151 (1996/II) Panorama

New radio stations for Belgian Navy

The new radio stations installed by ciated transmitting/receiving anten- Rohde & Schwarz onboard the na is installed on the vessel platform Belgian ships Zinnia and Godetia are (FIG 2). used to ensure a permanent link between national authorities and Teletype signals from a receiver are naval forces as well as other vessels, routed through a matrix in one of the search and rescue organizations, air- three MERLIN system processors, high- craft and helicopters. These two end terminals for RTTY networks to command vessels of the Belgian NATO standard, and then output on a naval forces, which also perform printer or teleprinter. In the other direc- logistic tasks, are named after the tion, the messages coded by MERLIN two escort planes of the British Flower are sent via the transmitters. It is also Class. The two giant vessels that possible to pass on messages received were used to transport the Belgian from another vessel via MERLIN. troops of the British Royal Navy and offered to Belgium at the end The system has plenty more to offer. of WW2 are also in operation as Thanks to an automatic alarm receiving minehunters and minesweepers and system operating on the international proved to be very successful during frequency 2.182 kHz, Godetia has FIG 2 Antenna system of maritime radio station the Iraq-Iran conflict, the Gulf War an automatic distress signal. PSTN Photos: Force Navale and during a mission in Somalia. hookup is also possible so that mem- “Thanks to the excellent technical bers of the crew can ring home. Ves- equipment and a very competent sel-to-vessel communication by means crew we succeeded in finding and of this system is carried out by three- radio operator Guy Corvelijn con- destroying about 270 mines without member teams taking turns every six firms: “With this installation, we have any accidents or casualties,” says the hours. The communication system a very fast and reliable system. This in- Belgian Navy. proved its reliability during an exer- vestment in a communication system cise in the Mediterranean in which that is extremely secure and thus indis- It is obvious that an extremely high- Italian, Spanish, English, French and pensable for navigation is completely performance radio station is a pre- German units participated. Second justified.” requisite for such missions. Rohde & Jean-Paul Hosdain Schwarz was thus asked to replace a (Capitaine de Corvette, large part of the outdated equipment Force Navale Zeebruges) installed at the end of the 60s. The new radio station (FIG 1) comprises six receivers and four transceivers as well as a number of radio sets spe- cially designed for mobile land and maritime radio services. It also contains a microprocessor for controlling data exchange between the modules. The most powerful transceiver onboard the vessels (1 kW) allows long-distance links over continents and also automatic setup of shortwave links and maintains them in case of interference. The other three transceivers are mainly used for vessel-to-vessel or vessel-to- land links. All the transceivers operate in the frequency range from 1.5 to

30 MHz. The six receivers cover the FIG 1 Communication system onboard Belgian Reader service card 151/23 for further informa- range 10 kHz to 30 MHz. The asso- vessel Godetia tion on maritime radio systems

News from Rohde & Schwarz Number 151 (1996/II) 53 Newsgrams

varia, the German government and accompany product development, Rohde & Schwarz. It will enable in- compliance test sets and what Rohde vestigations of the quality of digital & Schwarz offers in the way of train- radiocommunication when influenced ing. Particular interest focused on the by different kinds of interference, compact S-LINE test cell for measur- and the possibilities for correction ing susceptibility to interference (see offered by various coding systems. also page 7 in this issue). There were The laboratory will be equipped with PC information terminals on the several differently configured trans- stand to present a diskette demon- mitters with digital modulation, a strating Rohde & Schwarz’s compe- fading simulator and a number of tence in EMI and EMS solutions, and units for analyzing the spectral width also giving new customers an over- of signals, the impulse response of view of CE certification, standards, transmission channels and trans- accredited offices and R&S refer- mission errors. Beside high-speed ence customers. (If you are interest- digital signal processors, six SUN- ed, ask your local R&S represen- Sparc and Ultra workstations will be tative for the diskette.) As in previous Photo: Holthaus in use for coding and decoding. years, Rohde & Schwarz invited There is sufficient capacity in the visitors to its traditional weisswurst laboratory for six academic theses party with beer and pretzels on the CeBIT 96 with extremely shortness of the show there were to be worked on at the same time. second day of the event. This was satisfied exhibitors more customer contacts, also spread This makes it a highly specialized again very popular, and 350 guests At the world’s biggest showgrounds across the weekend. At the focus of training facility for engineers in enjoyed the Bavarian specialities in Hanover, information and com- interest were mobile radio and EMC what is the fastest growing field of while consulting the company’s team munication technology was again engineering, followed by trunked communications technology. The of EMC experts. the order of the day from 14 through radio. Overall, corporate sales rates laboratory will also conduct joint 20 March this year. There were two the results of CeBIT 96 as very posi- research with industry and network Because of the increased number of major differences compared to one tive, which is in tune with the ma- operators. PI exhibitors and visitors, the 6th EMC year earlier. First of all the show was jority of exhibitors. 89.7% have fair and congress in two years’ time shortened by one day and did not already announced their intention is moving to Düsseldorf. Rohde & commence until the Thursday. And to attend CeBIT 97. C. Rockrohr Schwarz will again be attending. secondly the number of visitors V. Janssen dropped from 755,300 to about 600,000. The number of exhibitors on the other hand rose from 6111 5th international EMC to 6507. trade fair and congress This three-day event at the Karlsruhe The decrease in the number of visi- Rohde & Schwarz equips congress center in February 1996 tors was planned because, accord- mobile-radio laboratory was the biggest trade fair staged to ing to the show’s organizers, its ca- of Munich Technical University date on electromagnetic compatibil- pacity had more than been reached In a special laboratory of the faculty ity. With 246 exhibitors attending, the year before. The new concept of of communications engineering at some 50 more than in 1994, the a “profi CeBIT”, accompanied by a Munich Technical University (Prof. 4554 registered visitors (approx. drastic increase in entrance prices J. Hagenauer), a development and 3900 in 1994) were offered a wide and consequently one third fewer test facility is being set up for mobile view of the market, new products, private visitors than a year earlier, radio. Rohde & Schwarz, as the the latest research results, new was seen by show committee mem- world’s leading company in the field or changed standards. Rohde & Photo: Müller ber Hubert-H. Lange as a “precision of digital radiocommunication test- Schwarz attended sporting a motto landing en route to professionalism”. ing, was awarded an order to equip of “The Sure Way to CE”, ie the EU’s As far as shifting the opening day to the laboratory. The facility is being conformity mark, and informed the a Thursday is concerned, this creat- financed by Munich Technical Uni- numerous visitors to its stand (photo ed enormous scheduling programs versity itself, the Free State of Ba- below) about test equipment to for the trade and business press, Rohde & Schwarz faculty because there were countless press prize 1995 in Jena Photo: Janssen conferences to be attended in just The faculty prize for excellent scien- two days, and so visits to the stands tific achievement at Jena University – of the exhibitors had to be neglected. donated by Rohde & Schwarz – was The federal information technology awarded at the beginning of the association would like the show to year as part of a colloquium con- run from Monday through Saturday, vened by Prof. Wolfgang Richter, and we shall have to wait and see the dean of the physico-astronomy how the organizers respond. faculty. Wolf-Rüdiger Lange, Execu- tive Vice President of Rohde & Rohde & Schwarz was present as Schwarz, presented the prize for usual in hall 17 with an exhibition the best dissertation in 1995 to area of 192 sqm. The motto this year Dr Andreas Kleinwächter and for was “Rohde & Schwarz – Com- the best thesis to Jens Stäbe, petence in Radiocommunication” Dipl.-Ing. (in the photo from left: (photo above). In relation to the Richter, Lange, Kleinwächter, Stäbe).

54 News from Rohde & Schwarz Number 151 (1996/II) Newsgrams

RSE success continues representatives with the biggest Rohde & Schwarz Engineering and growth and the biggest order book. Sales GmbH (RSE) was able to re- The highest turnover in Europe was port a 30% leap in orders received, achieved by England, in Germany compared to one year earlier, at for the third time by Cologne, and in its third international sales meeting the Middle East by Saudi Arabia. in autumn 1995. In addition to all Cups for the biggest percent growth European representatives, the coun- went to the representatives from tries Russia, Turkey, Egypt, Saudi Denmark and Russia as well as to the Arabia and the United Arab Emir- Nuremberg office. To conclude the ates attended the annual meeting meeting, as a small thankyou for the for the first time, held in Schwangau good results in the past business at the foot of Neuschwanstein Castle year, the group undertook a white- to mark the 150th birthday of water trip in five dinghies through Bavaria’s King Ludwig II. Similarly Imster Gorge. This was mastered to King Ludwig in his day, who was with great bravura thanks to the Whereas Andreas Kleinwächter’s CTD55 – go/nogo tester for very open to innovative engineering, splendid team spirit, most of the subject “Investigation of rotating GSM, PCN and PCS phones the participants were presented with participants managing to avoid disks in the general theory of Beside Go/Nogo tester CTD52 for the latest RSE product lines during contact with the 6°C cold water relativity” was expressly theoretical GSM mobile phones, Rohde & their three-day stay. At this meeting (photo below). in nature, Jens Stäbe’s work “Inves- Schwarz is now offering a small, too there were trophies for the W. Schmittseifer tigation of the effect of vehicle lightweight and low-cost unit – pitch oscillations on the distribu- CTD55 – that can test PCN Photo: Leonardi tion of dip beams”, carried out (DCS1800) and PCS (DCS1900) for automobile producer BMW, is phones in addition (photo above). of immediate practical benefit. In The tests, with a clear go/nogo re- awarding the prize for 1995, Rohde sult, run automatically, and the user & Schwarz continued a five-year needs no knowledge at all of radio- tradition. Company co-founder communications testing. Optionally Dr Hermann Schwarz instituted the CTD55 will allow more in-depth tests prize to honour the university that that it logs on a connected printer. both he and Dr Lothar Rohde at- The functions include call setup tended, and to demonstrate the and cleardown in both directions, company’s interest in high stan- change of power and channel, dards of education for engineers measurement of power ramping, an and physicists. echo test and checking of receiver K.-O. Müller sensitivity. W. Mittermaier

Reader service card 151/41

40-kW high-power signal generator from Rohde & Schwarz, a “technical monument” Feedback

Karl-Eduard Knaf, president, and Friedmar Kerbe, The following is taken from this brochure: “The In the chapter “History” a meeting between the vice-president of the association for regional association for regional and technical history senior engineer of HESCHO at that time, Hans and technical history in the Thuringian town of succeeded in adding the 40-kW high-power Handrek, and Dr Rohde and Dr Schwarz is Hermsdorf wrote to us: “As regular readers of signal generator of the ceramics company as a described. We already mentioned this event in your magazine “News from Rohde & Schwarz” technical monument to the list of protected objects. “News from Rohde & Schwarz” about 13 years and especially after seeing your report “100 years The signal generator was last operated in 1989 ago in our jubilee issue on the 50th anniversary of of radiocommunications – Rohde & Schwarz has for product testing. One of the aims of the asso- the company (issue 103). We take this opportunity been shaping it for more than 60 years” we would ciation is to maintain the generator operational to thank Mr. Knaf and Mr. Kerbe for their letter. All like to draw your attention to a monument in and to provide the public at large access to it. The readers who require further information or wish to Hermsdorf: our 40-kW high-power signal gener- installation was developed by the Munich-based see the technical monument in Hermsdorf may ator developed by Rohde & Schwarz and put into company Rohde & Schwarz and put into opera- contact Mr. Knaf or Mr. Kerbe under the following operation at HESCHO (Hermsdorf-Schomburg tion at HESCHO in July 1941, the result of an address and phone number: Insulator Company) in 1941. For more detailed interesting technical development accompanied information refer to the enclosed brochure.” by many personal contacts.” Verein für Regional- und Technikgeschichte e.V. Hermsdorf, Industriegelände PF 2153 D-07621 Hermsdorf ຜ: (+49 03 66 01) 6 23 72/6 49 08

News from Rohde & Schwarz Number 151 (1996/II) 55 Information in print

Digital Radio Analyzer PCSD is adapted by Digital Monitoring Direction Finders DDF0xM Spectrum Display EPZ513 The updated data software options either for channel impulse re- (0.3 to 3000 MHz) feature digital correlative sheet describes the RF panoramic display (max. sponse (CIR) analysis in radio networks or for operation according to Watson-Watt; monopulse 650 MHz) when EPZ513 is used together with general interference analysis and C/I analysis; processing and direction finding of GSM signals; Compact Receiver ESMC. 8-inch colour display (VGA), for external monitors DF error < 1 ° RMS, minimum signal duration HF Data sheet PD 757.9451.22 enter 151/33 1024 x 768 pixels; PCMIA interface. ≤ 5 ms, VHF/UHF ≤ 500 µs; AC and DC supply; Data sheet PD 757.2150.21 enter 151/24 antennas for stationary and mobile use, internal Base station antennas for GSM and PCN PC with colour LCD available. networks (860 to 960/1710 to 1889 MHz) are Digital Radiocommunication Testers CMD50, Data sheet PD 757.1854.21 enter 151/30 available as omnidirectional and directional an- CMD53 (GSM, PCN/PCS) are equivalent to tennas with different gain levels, MTBF 40 million CMD52 and CMD55 when equipped with options, Multichannel Communications System 400U hours thanks to completely new stripline technique, but are intended for service purposes. (100 to 163/225 to 400 MHz) is based on the electrical and mechanical main-lobe down tilt, Data sheet PD 757.2209.21 enter 151/25 successful Series 400 from R&S, but features easy-to-use snap-in connections. enhanced flexibility and serviceability. Info PD 757.1931.21 enter 151/07 Vector Signal Analyzer Option FSE-B7 demod- Data sheet PD 757.1583.21 enter 151/19 ulates, analyzes and documents all digital mobile- TACAN Receiver ETS200 Specifications have been radio signals with Spectrum Analyzers FSEA and FSEB. Multichannel Communications System 400U redefined (R&S Cologne Plant). Data sheet PD 757.2167.21 enter 151/26 (100 to 163/225 to 400 MHz) Information leaflet Data sheet PD 757.1754.22 enter 151/34 giving an overview of standard models of this tried Antenna Preamplifier ESMI-Z7 (20 MHz to 7 GHz) and tested modular program. reduces the noise figure of systems by 8 dB; Info PD 757.1383.21 enter 151/31 New application notes 50 Ω, VSWR (> 60 MHz): < 1.7; power supply (115 or 230 V) included. Log-Periodic Dipole Antenna HL040 (400 to C/I EMI analysis in digital radio networks Data sheet PD 757.2215.21 enter 151/27 3000 MHz) for transmission and reception in Appl. 1CMAN26E enter 151/35 mobile and stationary use, linearly polarized Calibration System Family TS9000 for measuring broadband field-strength and EMI measurements; Test signals for DAB and DVB Ω instruments is of modular design to allow cali- 50 , VSWR typ. < 2, gain 5 to 7 dBi; input power Appl. 1GPAN27E enter 151/36 bration to various standards and offers fully auto- max. 50 W (cw). matic operation in dialog; complete system con- Data sheet PD 757.1919.21 enter 151/32 Frequency hopping for GSM base station tests figurations are available for specific tasks. with Signal Generator SME Data sheet PD 757.2309.21 enter 151/28 Container Location System COLOS, based on Appl. 1GPAN28E enter 151/37 GPS, enables three-dimensional positioning of Spectrum Analyzers FSEA, FSEB, FSEM The data containers with a pinpoint accuracy to within 1 m, Measurement of clicking noise on audio lines sheet now also covers models FSEM20 (9 kHz to thus optimizing container management and using Audio Analyzer UPD 26.5 GHz) and FSEM30 (20 Hz to 26.5 GHz) transport. Appl. 1GPAN31E enter 151/38 Data sheet PD 757.1519.23 enter 151/29 Data sheet PD 757.2180.21 enter 151/10 Schz

New catalogs

The Test & Measurement Products Catalog 96/97, The new Test & Measurement Products Catalog has just published in German and English, replaces the been completely revised and is a compact reference Measuring Equipment Catalog 93/94 as well as the medium containing all essential information. New Products Supplement 94/95. On 360 pages this catalog provides a comprehensive overview of Test & Measurement Products Catalog 96/97 Rohde & Schwarz activities in the field of mobile PD 756.3501.25 enter 151/39 radio, EMC, spectrum and network analysis, signal generators and analyzers, voltage and power measurements as well as general laboratory measurements. In line with business developments at There is another new publication: the EMC Test & Rohde & Schwarz, the fields of mobile radio, EMC Measurement Products Catalog. Since the begin- and test systems are given the main emphasis. ning of this year it has become mandatory for all manufacturers and importers of electrical equip- The new catalog no longer covers sound and TV ment to ensure the electromagnetic compatibility of broadcasting since a separate catalog is available their products. On 64 pages the catalog presents for this. New additions to the catalog include opti- the whole range of EMC test and measurement cal measurements as well as a number of spectrum products available from Rohde & Schwarz and and network analyzers from Advantest, for whom gives some EMC background information. Rohde & Schwarz is the representative in Europe, Africa, Australia and Brazil. For reasons of sales EMC Test & Measurement Products Catalog rights, there is also an English version of the catalog PD 757.2350.21 enter 151/40 without the Advantest products. Kr

56 News from Rohde & Schwarz Number 151 (1996/II) Press comments

Digitally monitored The French magazine “Electronique”, no. 54/95, showed a few examples from the wide selection Edition 6/95 of the defence magazine “armada of systems and aids that Rohde & Schwarz offers international”, published in Switzerland, looked for measuring emission of and susceptibility to at modern surveillance direction finding from HF electromagnetic interference. through UHF and highlighted Digital Direction Finder DDF0xM:

The growing spread of time compression and frequency hopping makes it increasingly difficult Journey to the heart to intercept an opponent’s radiocommunications. of the chart Realizing that the necessary search and DF receiver performance exceeds the capabilities of This was the headline chosen in edition 7/96 most military surveillance receivers in use, Rohde of “Markt & Technik”, the Munich weekly for & Schwarz has developed a new surveillance electronics and information technology, for its system working with digital signal processing report on the presentation of Vector Network for fast Fourier transform, linear filtering, etc. Analyzer ZVR at a press conference during the One result of this development activity is the Productronica 95 show: recently presented compact DF receivers of the DDF0xM series. Rohde & Schwarz is trying to put a new family of test instruments in place on the booming telecommunications market. The ZVR line stands for extremely fast, highly precise and yet user-friendly Where Bavaria is tops Plain-clothes man vector network analysis, one of the company’s showpiece activities. … Modular design, Rohde & Under this headline “Bayernkurier” presented “Highly recommended” was the judgement of Schwarz has realized this too, is increasingly im- Rohde & Schwarz of Munich in its edition of a plain-clothes participant in courses on the portant at a time when the unbounded investment 21 October 1995: subject of GSM/PCN at the Rohde & Schwarz of earlier years is giving way to modest restraint training center in Munich. The editor of “Mobil- and customers have to work with strictly limited One of the outstanding companies in Bavaria is funk News” in issue 1/96: budgets. undoubtedly Rohde & Schwarz of Munich, a producer of equipment for radiocommunications, The courses last three days, two days for test and measurement, and an enterprise true to “GSM/PCN – digital mobile telephones” and the motto “Where Bavaria is tops”. There is hardly one day on “GSM/PCN – testing mobile sta- Top Products of 1995 and a TV transmitter or radio station that can manage tions”. The material is put over in a pleasantly The Best in Test without its products. In many sectors Rohde & relaxed and interesting way. Whether retailer or Schwarz is the market leader in Germany, in design engineer, everyone gets their money’s As Top Product of October 1995 the editors Europe and even in the world. … At Rohde & worth. The presenter gives you basic and back- of the US magazine “Microwave & RF” chose Schwarz the manufacturing depth is characteristic. ground knowledge in masterly fashion, and his Digital Radiocommunication Tester CMD80 in A whole number of pace-setting machine tools and observations of the scene make you sit up. Even edition 12/95, and the jury of “Test & Measure- production systems have been designed and built though the price of 1790 and 920 DM may seem ment World”, issue 12/95, was also unanimous to the company’s specifications. “We vouch for high, the participant can be sure straight after- in placing this Rohde & Schwarz instrument each of our services with our good name”. wards that the investment will soon pay off. among the Top 11 Test Products.

Vector Network Analyzer ZVR drew a lot of interest in the press, nationally and internationally. Edition 206 of France’s “Electronique International” awarded this top product from Rohde & Schwarz space on its title page. “Elektronik Praxis” (issue 3/96), “hf-praxis” (1-2/96) and “ntz” (2/96) also gave ZVR the pole position on their cover spreads.

News from Rohde & Schwarz Number 151 (1996/II) 57 Final article

Microwave Generator SMP – top-class performance to customer’s benefit

No need to consult a manual. It is ob- got it made. They need no expensive vious that designers were at work here booster amplifiers. The modules shown who knew all about practical opera- in FIG 3 guarantee high output power tion. All functions have been packed and a wide frequency range. into clear-cut, straightforward menus. Multifunction keys and cryptic special And yet, what would the user-friend- functions are really a thing of the past. liest and most powerful signal genera- And should the user some time or other tor be without a high-quality frequency wish additional information: help texts synthesizer? SMP users need not worry are available at a keystroke. The bene- about this. The state-of-the-art concept fits for the user are evident. The feeling of SMP based on direct digital synthe- when working with SMP can best be sis with a resolution of 0.1 Hz up into described by the – slightly modified – the 40-GHz range, excellent frequency slogan of a Bavarian automobile man- stability, fast settling and extremely low ufacturer: measure with pleasure. SSB phase noise (FIG 4) leaves nothing to be desired. But the merits of SMP are not restricted to its outside. Just take a look at FIG 2, Naturally, the modulation characteris- which shows the typical output power tics are every bit as good as the other versus frequency for the various SMP data offered by generators of the SMP models. Levels of +16 dBm at 27 GHz family. For example, AM ranges from (SMP03) and +11 dBm at 40 GHz DC to 100 kHz. Scan modulation with (SMP04) are unparalleled on the mar- a wide dynamic range is possible for ket. Not to forget SMP22, which with simulating antenna rotation in radar FIG 1 Microwave Generator SMP, successful symbiosis of superb microwave technology and about +29 dBm at 2 GHz and notable applications and for similar effects. FM ergonomic computer design Photo 42 447 +23 dBm at 20 GHz puts quite a few ranges from DC to 5 MHz (typ. 7 MHz) competitors in their places. The advan- for max. 10 MHz deviation and carrier tages for the customer are obvious here frequencies up to 20 GHz (or max. too: the high output power makes all 20 MHz deviation for frequencies They have been on the market for SMP models ideal for use in automatic above 20 GHz). On top of this, SMP about two years now – the microwave test systems. “Power killers” such as is the first microwave generator world- generators of the SMP family for the long connecting cables, waveguide wide to provide phase modulation from frequency range up to 40 GHz. adapters, power dividers or relay DC to 100 kHz. And not to forget pulse Thanks to their excellent technical matrices become harmless even at modulation, the classic type of modula- characteristics such as high output 40 GHz. In short, SMP users have tion performed by microwave genera- power, extremely high spectral purity, an intelligent operating concept and, last but not least, an especially attractive purchase price, the generators established themselves in this critical market segment straight away.

The qualities of SMP are reflected by its external design (FIG 1): a large-size LCD display normally provided only on high-grade notebook computers is simply an invitation for you to make an FIG 2 Typical entry. Next you discover that operation maximum output is just as easy as it looks: all settings power of Microwave can be made with a few keystrokes. Generators SMP

58 News from Rohde & Schwarz Number 151 (1996/II) Final article

At this point the inclined reader may be wondering if so much high tech is affordable. Well, the SMP family was designed not only for excellent technical performance but for high economy and future-proofness too. The result is an instrument the user can tailor to his requirements by choosing from a wide range of options the components FIG 3 The YFO (YIG filter oscillator), he really needs. Should a subsequent the core of SMP extension or adaptation be necessary (background), fea- to handle new measurement tasks – no tures space-tested problem, SMP can easily be retrofitted technology for high output power, ex- as required. Built-in diagnostic func- tremely high spectral tions and computer-aided measurement purity and reliability. functions ensure fast and uncompli- In the 40-GHz cated servicing. Calibration is required frequency doubler (front), patented every three years at the earliest. The thin-film technology unit need not be opened for calibra- does the trick: tion, nor do any mechanical adjust- output power that ments have to be made. sets new standards worldwide. Photo 42 444

tors, where SMP features rise and fall 1. User correction to obtain a user- times typically shorter than 5ns, pulse selectable frequency-response charac- widths below 10 ns and an on/off ratio teristic of the RF level. Correction values better than 80 dB. can be entered manually or via the IEC/IEEE bus. With an external power One problem frequently encountered meter (NRVS or NRVD) connected, SMP in microwave measurements is that determines correction values automati- signal sources and EUTs have to be cally at a keystroke. FIG 4 SSB phase noise of Microwave Genera- connected to one another via cables 2. Memory sequence, programmable tors SMP at 10 GHz that are long compared with the wave- sequence with complete instrument length, which means high attenuation setups. as well as high frequency response. 3. List mode, programmable se- So it is difficult to feed the EUT with de- quence with up to 2003 frequency Which member of the SMP family is the fined RF power. The signal generators and level pairs. right one for you? Take your choice of the SMP family offer four functions 4. External level control using exter- from the versions listed in the blue box. to solve this problem: nal level meter. Wilhelm Kraemer

Model Frequency range Output power

SMP02 10 MHz/2 to 20 GHz >+11.5 dBm SMP22 10 MHz/2 to 20 GHz >+20 dBm SMP03 10 MHz/2 to 27 GHz >+13 dBm SMP04 10 MHz/2 to 40 GHz >+10 dBm Reader service card 151/42

News from Rohde & Schwarz Number 151 (1996/II) 59 21 . 2244 . 7 1 · PD 75 5 1 News from Rohde & Schwarz

ROHDE& SCHWARZ GmbH & Co. KG · Mühldorfstraße 15 · D-81671 München P. O. B. 8014 69 · D-81614 München · Tel. (+49 89) 41 29-0 · Fax (+49 89) 41 29-21 64