Comparative Overview of Inductive Output Tubes
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RF Power Generation I
RF Power Generation I Gridded Tubes and Solid-state Amplifiers Professor R.G. Carter Engineering Department, Lancaster University, U.K. and The Cockcroft Institute of Accelerator Science and Technology Overview • High power RF sources required for all accelerators > 20 MeV • Amplifiers are needed for control of amplitude and phase • RF power output – 10 kW to 2 MW cw – 100 kW to 150 MW pulsed • Frequency range – 50 MHz to 50 GHz • Capital and operating cost is affected by – Lifetime cost of the amplifier – Efficiency (electricity consumption) – Gain (number of stages in the RF amplifier chain) – Size and weight (space required) June 2010 CAS RF for Accelerators, Ebeltoft 2 General principles • RF systems – RF sources extract RF power from high charge, low energy electron bunches – RF transmission components (couplers, windows, circulators etc.) convey the RF power from the source to the accelerator – RF accelerating structures use the PRF in PP DC in RF out Heat RF power to accelerate low charge bunches to high energies PP • RF sources Efficiency RF out RF out PP P – Size must be small compared with DCin RFin DCin the distance an electron moves in one RF cycle PRF out Gain dB 10log10 – Energy not extracted as RF must be PRF in disposed of as heat June 2010 CAS RF for Accelerators, Ebeltoft 3 RF Source Technologies • Vacuum tubes • Solid state – High electron mobility – Wide band-gap materials (Si, GaAs, GaN, SiC, diamond) – Large size – Low carrier mobility – High voltage – Small size – High current • Tube types – Low voltage – Gridded -
Review of Power Sources
RF Power Generation With Klystrons amongst other things Dr. C Lingwood Includes slides by Professor R.G. Carter and A Dexter Engineering Department, Lancaster University, U.K. and The Cockcroft Institute of Accelerator Science and Technology • Basic Klystron Principals • Existing technology • Underrating • Modulation anodes • Other options – IOTS – Magnetrons June 2011 ESS Workshop June 2 IOT June 2011 ESS Workshop June 3 IOT Output gap June 2011 ESS Workshop June 4 Velocity modulation • An un-modulated electron beam passes through a cavity resonator with RF input • Electrons accelerated or retarded according to the phase of the gap voltage: Beam is velocity modulated: • As the beam drifts downstream bunches of electrons are formed as shown in the Applegate diagram • An output cavity placed downstream extracts RF power just as in an IOT • This is a simple 2-cavity klystron • Conduction angle = 180° (Class B) June 2010 CAS RF for Accelerators, Ebeltoft 5 Multi-cavity klystron • Additional cavities are used to increase gain, efficiency and bandwith • Bunches are formed by the first (N-1) cavities • Power is extracted by the Nth cavity • Electron gun is a space- charge limited diode with perveance given by I0 K 3 2 V0 • K × 106 is typically 0.5 - 2.0 • Beam is confined by an axial magnetic field Photo courtesy of Thales Electron Devices June 2010 CAS RF for Accelerators, Ebeltoft 6 Efficiency and Perveance • Second harmonic cavity used to increase bunching • Maximum possible efficiency with second harmonic cavity is approximately 6 e 0.85 -
Solid State Modulators – Efficiency Considerations Focussing on Sic Devices –
Eidgenössische Technische Hochschule Zürich Laboratory for High Swiss Federal Institute of Technology Zurich Power Electronic Systems Solid State Modulators – Efficiency Considerations focussing on SiC Devices – J. Biela, S. Stathis, M. Jaritz, and S. Blume www.hpe.ee.ethz.ch / [email protected] Typical Topology of Solid State Pulse Modulator Systems AC/DC rectifier unit DC/DC converter for charging C-bank / voltage adaption Pulse generation unit Load e.g. klystron Constant Power Pulsed Power AC DC Energy Storage Pulse Klystron Modulator Load DC DC Grid Medium Voltage ⎧⎪⎪⎪⎨⎪⎪⎪⎩ Sometimes integrated V V V V t Pulse t t t Pulse 400V or MV Intermediate Buffer Capacitor Bank Pulse Voltage High Power 2 33 Electronic Systems Typical Topology of Solid State Pulse Modulator Systems Grounded klystron load I Isolation with 50Hz transformer or I Isolated DC-DC converter Typical Isolation AC DC Energy Storage Pulse Klystron Modulator Load DC DC Grid Medium Voltage V V V V t Pulse t t t Pulse 400V or MV Intermediate Buffer Capacitor Bank Pulse Voltage High Power 3 33 Electronic Systems 29 MW(35MW)/140 µs Modulator for CLIC – System Efficiency – High Power Electronic Systems CLIC System Specifications Output voltage 150:::180 kV Settling time <8 µs Output power (pulsed) 29 MW (- 35 MW) Repetition rate 50 Hz Flat-top length 140 µs Average output power 203 kW (- 245 kW) Flat-top stability (FTS) <0.85 % Pulse to pulse repeatab. <100 ppm Rise time <3 µs 819 klystrons 819 klystrons 15 MW, 142 µs circumferences 15 MW, 142 µs delay loop 73 m drive beam -
Gan Or Gaas, TWT Or Klystron - Testing High Power Amplifiers for RADAR Signals Using Peak Power Meters
Application Note GaN or GaAs, TWT or Klystron - Testing High Power Amplifiers for RADAR Signals using Peak Power Meters Vitali Penso Applications Engineer, Boonton Electronics Abstract Measuring and characterizing pulsed RF signals used in radar applications present unique challenges. Unlike communication signals, pulsed radar signals are “on” for a short time followed by a long “off” period, during “on” time the system transmits anywhere from kilowatts to megawatts of power. The high power pulsing can stress the power amplifier (PA) in a number of ways both during the on/off transitions and during prolonged “on” periods. As new PA device technologies are introduced, latest one being GaN, the behavior of the amplifier needs to be thoroughly tested and evaluated. Given the time domain nature of the pulsed RF signal, the best way to observe the performance of the amplifier is through time domain signal analysis. This article explains why the peak power meter is a must have test instrument for characterizing the behavior of pulsed RF power amplifiers (PA) used in radar systems. Radar Power Amplifier Technology Overview Peak Power Meter for Pulsed RADAR Measurements Before we look at the peak power meter and its capabilities, let’s The most critical analysis of the pulsed RF signal takes place in the look at different technologies used in high power amplifiers (HPA) time domain. Since peak power meters measure, analyze and dis- for RADAR systems, particularly GaN on SiC, and why it has grabbed play the power envelope of a RF signal in the time domain, they the attention over the past decade. -
ABBREVIATIONS EBU Technical Review
ABBREVIATIONS EBU Technical Review AbbreviationsLast updated: January 2012 720i 720 lines, interlaced scan ACATS Advisory Committee on Advanced Television 720p/50 High-definition progressively-scanned TV format Systems (USA) of 1280 x 720 pixels at 50 frames per second ACELP (MPEG-4) A Code-Excited Linear Prediction 1080i/25 High-definition interlaced TV format of ACK ACKnowledgement 1920 x 1080 pixels at 25 frames per second, i.e. ACLR Adjacent Channel Leakage Ratio 50 fields (half frames) every second ACM Adaptive Coding and Modulation 1080p/25 High-definition progressively-scanned TV format ACS Adjacent Channel Selectivity of 1920 x 1080 pixels at 25 frames per second ACT Association of Commercial Television in 1080p/50 High-definition progressively-scanned TV format Europe of 1920 x 1080 pixels at 50 frames per second http://www.acte.be 1080p/60 High-definition progressively-scanned TV format ACTS Advanced Communications Technologies and of 1920 x 1080 pixels at 60 frames per second Services AD Analogue-to-Digital AD Anno Domini (after the birth of Jesus of Nazareth) 21CN BT’s 21st Century Network AD Approved Document 2k COFDM transmission mode with around 2000 AD Audio Description carriers ADC Analogue-to-Digital Converter 3DTV 3-Dimension Television ADIP ADress In Pre-groove 3G 3rd Generation mobile communications ADM (ATM) Add/Drop Multiplexer 4G 4th Generation mobile communications ADPCM Adaptive Differential Pulse Code Modulation 3GPP 3rd Generation Partnership Project ADR Automatic Dialogue Replacement 3GPP2 3rd Generation Partnership -
Arecibo 430 Mhz Radar System
file: 430txman 12-98 draft Aug. 31, 2005 Arecibo 430 MHz Radar System Operation and Maintenance Manual Written by Jon Hagen April 2001, 2nd ed. May 2005 1 NOTE With its high-voltage and high-power, and high places, this transmitter is potentially lethal. Proper precautions must be taken to avoid electrical shock, RF exposure, and X-ray exposure. (See Section 22). Emergency Procedure: ELECTRIC SHOCK Neutralize power 1. De-energize the circuit by means of switch or circuit breaker or cut the line by an insulated cutter. 2. Safely remove the victim from contact with the energy source by using dry wood stick, plastic rope, leather belt, blanket or any other non-conductive materials. Call for help 1. Others can help you administer first aid 2. Others can call professional medical help and/or arrange transfer facilities Cardio Pulmonary Resuscitation (CPR) 1. Check victim's ABC A - airway: Clear and open airway by head tilt - chin lift maneuver B - breathing: Check and restore breathing by rescue breathing C- circulation: Check and restore circulation by external chest compression 2. If pulse is present, but not breathing, maintain one rescue breathing (mouth to mouth resuscitation) as long as necessary. 3. If pulse and breathing are absent, give external chest compressions (CPR). 4. If pulse and breathing are present, stop CPR, stabilize the victim. 5. Caution: Only properly trained personnel should administer CPR to avoid further harm to 2 the victim. Administer first aid for shock 1. Keep the victim lying down, warm and comfortable to maintain body heat until medical assistance arrive. -
Ampleon Company Presentation
Microwave Journal Educational Webinar Ampleon Brings RF Power Innovations towards Industrial Heating Market Gerrit Huisman Robin Wesson Klaus Werner Nov, 17, 2016 Amplify the future | 1 Ampleon at a Glance Our Company Our Businesses • European Company / Headquarters in • Building transistors and other RF Power products Nijmegen/Netherlands for over 50 years • 1,250 employees globally in 18 sites • Industry Leader for 35 years, addressing • Worldwide Sales, Application and R&D – Mobile Broadband – Broadcast • Own manufacturing facility – Aerospace & Defense • Partnering with leading external manufacturers – ISM – RF Energy Technologies & Products Customers • Broad LDMOSTaco and GaN technology portfolio Reinier Zwemstra Beltman • Comprehensive package line-up • Chief Operations Head of Sales OutstandingOfficer product consistency Amplify the future | 2 Ampleon and RF Energy • Recognized as thought leader • Co-founder of RF Energy Alliance • Working with the leaders in new application domains Amplify the future | 3 RF Power Industrial market dominated by vacuum tubes • Current solutions mainly based on ‘old’ vacuum tube principles • Somewhat fragmented market with large and many small vendors – TWT (Traveling Wave Tubes) – Klystron – Magnetrons – CFA (Crossed Field Amplifiers) – Gyrotrons Amplify the future | 4 2020 TAM VED’s about ~$1B $1.2B in 2014 TAM VEDS Source ABI research TWT 63% Klystron 17% Gyrotron 3% magnetron Cross Field 15% 2% Not included: domestic magnetrons, Aerospace market Amplify the future | 5 Solid state penetrates the -
Klystron Gun Arcing and Modulator Protection
SLAC-PUB-10435 KLYSTRON GUN ARCING AND MODULATOR PROTECTION S.L. Gold Stanford Linear Accelerator Center (SLAC), Menlo Park, CA USA Abstract The demand for 500 kV and 265 amperes peak to power an X-Band klystron brings up protection issues for klystron faults and the energy dumped into the arc from the modulator. This situation is made worse when more than one klystron will be driven from a single modulator, such as the existing schemes for running two and eight klystrons. High power pulsed klystrons have traditionally be powered by line type modulators which match the driving impedance with the load impedance and therefore current limit at twice the operating current. Multiple klystrons have the added problems of a lower modulator source impedance and added stray capacitance, which converts into appreciable energy at high voltages like 500kV. SLAC has measured the energy dumped into klystron arcs in a single and dual klystron configuration at the 400 to 450kV level and found interesting characteristics in the arc formation. The author will present measured data from klystron arcs powered from line-type modulators in several configurations. The questions arise as to how the newly designed solid-state modulators, running multiple tubes, will react to a klystron arc and how much energy will be dumped into the arc. 1. INTRODUCTION The amount of protection required for a gun arc or a defocused beam in a microwave tube is a continual source of controversy and debate. Historically, tube companies have set protection requirements by their own experience in test. Body current interception was thought to be limited to 10 joules maximum and shutdown within 10 microseconds. -
The Free Electron Laser Klystron Amplifier Concept
E.L. Saldin et al. / Proceedings of the 2004 FEL Conference, 143-146 143 THE FREE ELECTRON LASER KLYSTRON AMPLIFIER CONCEPT E.L. Saldin, E.A. Schneidmiller, and M.V. Yurkov Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany Abstract as short as 10-100 µm have never been measured and are challenging to predict. We consider optical klystron with a high gain per cas- The situation is quite different for klystron amplifier cade pass. In order to achieve high gain at short wave- scheme described in our paper. A distinguishing feature of lengths, conventional FEL amplifiers require electron beam the klystron amplifier is the absence of apparent limitations peak current of a few kA. This is achieved by applying which would prevent operation without bunch compression longitudinal compression using a magnetic chicane. In in the injector linac. As we will see, the gain per cas- the case of klystron things are quite different and gain of cade pass is proportional to the peak current and inversely klystron does not depend on the bunch compression in the proportional to the energy spread of the beam. Since the injector linac. A distinguishing feature of the klystron am- bunch length and energy spread are related to each other plifier is that maximum of gain per cascade pass at high through Liouville’s theorem, the peak current and energy beam peak current is the same as at low beam peak cur- spread cannot vary independently of each other in the injec- rent without compression. Second important feature of the tor linac. To extent that local energy spead is proportional klystron configuration is that there are no requirements on to the peak current, which is usually the case for bunch the alignment of the cascade undulators and dispersion sec- compression, the gain will be independent of the actual tions. -
3D Modeling, Analysis, and Design of a Traveling-Wave Tube
3D MODELING, ANALYSIS, AND DESIGN OF A TRAVELING-WAVE TUBE USING A MODIFIED RING-BAR STRUCTURE WITH RECTANGULAR TRANSMISSION LINES GEOMETRY by SADIQ ALI ALHUWAIDI B.S., University of Colorado, Boulder, 2011 M.S., University of Colorado, Colorado Springs, 2014 A dissertation submitted to the Graduate Faculty of the University of Colorado Colorado Springs in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Electrical and Computer Engineering 2017 © 2017 SADIQ ALI ALHUWAIDI ALL RIGHTS RESERVED This dissertation for the Doctor of Philosophy degree by Sadiq Ali Alhuwaidi has been approved for the Department of Electrical and Computer Engineering by Heather Song, Chair T.S. Kalkur Charlie Wang John Lindsey Zbigniew Celinski Date 12/05/2017 ii Alhuwaidi, Sadiq Ali (Ph.D. Engineering - Electrical Engineering) 3D Modeling, Analysis, and Design of a Traveling-Wave Tube Using a Modified Ring- Bar Structure with Rectangular Transmission Lines Geometry Dissertation directed by Associate Professor Heather Song. ABSTRACT A novel slow-wave structure of the traveling-wave tube consisting of rings and rectangular coupled transmission lines is modeled, analyzed, and designed in the frequency range of 1.89-2.72 GHz. The dispersion and interaction impedance characteristics are investigated using High Frequency Structure Simulator, HFSS, and a power run is carried out using Finite-Difference Time-Domain (FDTD) code, VSim. The performance of the design providing a better output power, gain, bandwidth, and efficiency is compared to the conventional and existing designs by implementing cold- and hot-test simulations. In addition, an electron gun and periodic permanent magnet, PPM, is designed using EGUN code and ANSYS Maxwell, respectively. -
Progress of the Klystron and Cavity Test Stand for the Fair Proton Linac
WEPMA022 Proceedings of IPAC2015, Richmond, VA, USA PROGRESS OF THE KLYSTRON AND CAVITY TEST STAND FOR THE FAIR PROTON LINAC A. Schnase#, E. Plechov, J. Salvatore, G. Schreiber, W. Vinzenz, GSI, Darmstadt, Germany C. Joly, J. Lesrel, IPN Orsay, CNRS-IN2P3 Université Paris Sud, France Abstract types. This allowed us to use a 3 phase standard CEE plug, which simplifies changing of the test setup. The In collaboration between the FAIR project, GSI, and firmware was adjusted to the expected pulsed modes. In CNRS, the IPNO lab provided the high power RF operation, we need a repetition rate of 4 Hz; with some components for a cavity and klystron test stand [1]. For margin the amplifier should work at 5 Hz and actually the initial operation of the 3 MW Thales TH2181 klystron at amplifier can handle repetition rates of 10 Hz and higher. 325.224 MHz we received a high voltage modulator from The required pulse length is 0.2 ms. For testing, we used CERN Linac 4 as a loan. Here we report, how we 0.4 ms long pulses. Such pulse pattern is shown in Fig. 2. integrated the combination of klystron, high voltage The amplifier bias (yellow trace) is activated 1 ms before modulator, and auxiliaries to accumulate operating the RF is applied. The falling edge of the green trace experience. Klystron RF operation started on a water triggers the power measurement. The light blue trace cooled load, soon the circulator will be included and then shows the RF output. the prototype CH cavity in the radiation shielded area will be powered. -
Gan Class F Power Amplifier for Klystron Replacement
GaN Class F Power Amplifier for Klystron Replacement HV DC: 50 V Phase II HV DC: 11.6 kV RF CW: 6.1 kW RF CW: 8 kW, 33% =63% completed ~02/10/2018 Principal investigator: aveguide Alexei V W Smirnov PM: Michelle Shinn Topic 24b: NUCLEAR PHYSICS ACCELERATOR TECHNOLOGY (Radio Frequency Power Sources) 1 Nuclear Physics SBIR/STTR Exchange Meeting August 7-8, 2018 The GOAL To develop a prototype and test a CW, all-solid-state, 1.497 GHz power amplifier specialized as space- compatible replacement of the VKL7811 klystron with ~16”16” footprint (and ~19” height) at >60% efficiency and ~1.5-2 W drive power. 33% >60% efficiency 19” 14.5” 2 Nuclear Physics SBIR/STTR Exchange Meeting August 7-8, 2018 NPT2024 & Pallets: Testing & Tweaking 25 NPT2024 MACOM transistors were purchased and tested using different boards. Tweaking method is developed to maximize efficiency and minimize harmonics Nuclear Physics SBIR/STTR Exchange Meeting August 7-8, 2018 NPT2024 Pallet Tweaking 2nd harmonic is suppressed below -30 dB, and 3rd harmonic below -70 dB Power increase: ~10% Efficiency: by ~3% Nuclear Physics SBIR/STTR Exchange Meeting August 7-8, 2018 4 NPT2024: Power droop @ Pin0.5% Power droop: 15% for 2hrs 40 min 5 Nuclear Physics SBIR/STTR Exchange Meeting August 7-8, 2018 Thermal instability Nuclear Physics SBIR/STTR Exchange Meeting August 7-8, 2018 6 Conclusion on NPT2024 • Low power, gain and efficiency; • Poor reproducibility and degradation; • High failure rate (>25% failed); • Performance spread (15% saturated power stdev) • Thermal instability. Available GaN power MOSFETS are not sufficient for the CW application Better CW power transistors are required.