DOCUMENT RESUME Antenna Construction & Propagation Of
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Compact Bilateral Single Conductor Surface Wave Transmission Line
Compact bilateral single conductor Regarded as half mode CPW, a series of slotlines have been proposed whose characteristic impedance is easy to control [7]. The bilateral surface wave transmission line slotline with 50 ohm characteristic impedance is designed as shown in Fig. 2. The copper layers on both sides of the substrate are connected by Zhixia Xu, Shunli Li, Hongxin Zhao, Leilei Liu and the metalized via arrays, and the two via arrays can increase the perunit- Xiaoxing Yin length capacitance and decrease characteristic impedance to 50 ohm which is usually quite high for a conventional slotline. The height of via A compact bilateral single conductor surface wave transmission line h is 1.524 mm, the slot S is 0.3 mm; the space between via arrays d is (TL) is proposed, converting the quasi-transverse electromagnetic 0.4 mm; the space between neighbour vias a is 1 mm. (QTEM) mode of low characteristic impedance slotline into the As a single conductor TL, bilateral corrugated metallic strips are transverse magnetic (TM) mode of single-conductor TL. The propagation constant of the proposed TL is decided by geometric printed on both sides of the substrate and connected by via arrays the parameters of the periodic corrugated structure. Compared to configuration is shown in Fig. 3a. To excite the transverse magnetic conventional transitions between coplanar waveguide (CPW) and (TM) mode, the surface mode of the corrugated strip, from the quasi- single-conductor TLs, such as Goubau line (G-Line) and surface transverse electromagnetic (QTEM) mode, the mode of slotline, we plasmons TL, the proposed structure halves the size and this feature propose a compact bilateral transition structure, as shown in Fig. -
Numerical Modelling of VLF Radio Wave Propagation Through Earth-Ionosphere Waveguide and Its Application to Sudden Ionospheric Disturbances
Numerical Modelling of VLF Radio Wave Propagation through Earth-Ionosphere Waveguide and its application to Sudden Ionospheric istur!ances Thesis submitted for the degree of octor of Philosoph# (Science% in Ph#sics (Theoretical) of the &niversity of 'alcutta Su(a# Pal Ma#8, )*+, CERTIFICATE FROM THE SUPERVISOR This is to certify that the thesis entitled "Numerical Modelling of VLF Radio Wave Propagation through Earth-Ionosphere waveguide and its application to !udden Ionospheric Distur#ances", submitted by Mr. Sujay Pal who got his name registered on $%&$'&%$(( for the award of Ph.D. )!cience* degree of the Universit, of Calcutta. absolutely based upon his own work under the supervision of Professor !andip K. Cha0ra#arti and that neither this thesis nor any part of it has been submitted for any degree/diploma or any other academic award anywhere before. Prof. !andip K. -ha0ra#arti Senior Professor & Head Department of #strophysics & Cosmology S. N. Bose National Centre for Basic Sciences JD Block, Sector())), Salt *ake, +olkata 7---./, India TO My PARENTS i ABSTRACT Very Low Frequency (VLF) radio waves with frequency in the range 3 30 kHz ∼ propagate within the Earth-ionosphere waveguide (EIWG) for#ed $y the Earth as the %ower $oundary and the %ower ionosphere (50 100 k#) as the upper $oundary ∼ of the waveguide. These waves are generated from #an-#ade transmitters as wel% as fro# lightnings or other natura% sources( *tudy of these waves is very i#portant since they are the only tool to diagnose the %ower ionosphere( Lower part of the Earth+s ionosphere ranging &0 90 km is known as the -- ∼ region of the ionosphere( *olar Lyman-α radiation at '.'./ n# and EUV radiation in 80 '''.& n# are #ain%y responsib%e for for#ing the --region through the ∼ ionization of 123N 23O 2 during day time( The VLF propagation takes p%ace $etween the Earth+s surface and the --region at the day time. -
Long Earthquake'waves
~ LONG EARTHQUAKE'WAVES Seisllloloo-istsLl are tuning their instnlments to record earth 1l10tiollS with periods of one Jninute to an hour and mllplitudes of less than .01 inch. These,,~aycs tell llluch about the earth's crust and HHltltle by Jack Oliver "lhe hi-H enthusiast who hitS strug· per cycle. A reI.ltlvely shorr earthquake earth'luake waves tmvel at .9 to 1.S 1 gled to ImprO\'e tlIe re;pollse of wave has a duration of 10 seconds. At miles per second, they lange in length hI:; e'jlllpment In the bass range at present the most infornl.1tive long waves from 10 mile" up to the 8,OOO-mde length .11 oUlld 10 c~'d(-s per ;econd wIll ha VI" a h,\v€ periods of 15 to 75 seconds from of the earth's ,hamete... TheIr amplitude, fellow-feeling for the selsmologi;t \vho CfEst to crest. \Vith more advanced in however, is of an entirely di/lerent 01 de.. : IS ,attempting to tune hiS installments to ,,11 uments seismologists hope sooo to one of these waves displaces a point on the longest earth'luake \\".\\'es. But where study 450-second waves. The longest so the sudace of the eal th at some dislil1lce IIl-n deals in cITIes per second, seisll1OIo" f.tr detected had ., penod of :3,400 sec from the shock by no more than a hun· gy measures its fre<luencle; 111 seconds onds-·nearly an hour! Since these long dredth of an inch, even when eXCited by t/) ~ ~ SUBTERRANEAN TOPOGRAPHY of the North American con· at which the depth of the boundary was established. -
Atmospheric Anisotrophy and Its Effect on the Delay Power Spectra of Tropospheric Scatter Radio Signals Hosny Mohammed Ibrahim Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1982 Atmospheric anisotrophy and its effect on the delay power spectra of tropospheric scatter radio signals Hosny Mohammed Ibrahim Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Electrical and Electronics Commons Recommended Citation Ibrahim, Hosny Mohammed, "Atmospheric anisotrophy and its effect on the delay power spectra of tropospheric scatter radio signals " (1982). Retrospective Theses and Dissertations. 7507. https://lib.dr.iastate.edu/rtd/7507 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help clarify markings or notations which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure complete continuity. -
Surface Waves: What Are They? Why Are They Interesting?
SURFACE WAVES: WHAT ARE THEY? WHY ARE THEY INTERESTING? Janice Hendry Roke Manor Research Limited, Old Salisbury Lane, Romsey, SO51 0ZN, UK [email protected] ABSTRACT Surface waves have been known about for many decades and quite in-depth research took place up until ~1960s . Since then, little work has been done in this area. It is unclear why, however today we have more powerful modelling methods which may enable us to understand their use better. It is known that high frequency (HF) surface waves follow the terrain and this has been utilised in some cases such as Raytheon's HF surface wave radar (HFSWR) for detecting ships over-the-horizon. It is thought with some more insight and knowledge of this phenomenon, surface waves could be extremely useful for both military and civil use, from communications to agriculture. WHAT ARE SURFACE WAVES? Over the many decades that surface waves have been researched, some confusion has built up over exactly what constitutes a surface wave. This was discussed by James Wait in an IEE Transaction in 1965 1 and was even a matter of discussion at the General Assembly of International Union of Radio Science (URSI) held in London in 1960. It was concluded that “there is no neat definition which would encompass all forms of wave which could glide or be guided along an interface”. However, the definitions which have been settled upon for this paper are as follows: Surface Wave Region : The region of interest in which the surface wave propagates. Surface Wave : A surface wave is one that propagates along an interface between two different media without radiation; such radiation being construed to mean energy converted from the surface wave field to some other form. -
A Simplified Mathematical Model to Calculate the Maximum Usable Frequencies Over Iraqi Territory Khalid A
A Simplified Mathematical Model to Calculate the Maximum Usable Frequencies Over Iraqi Territory Khalid A. Hadi*, Loay E. Goerge** A Simplified Mathematical Model to Calculate the Maximum Usable Frequencies Over Iraqi Territory Khalid A. Hadi*, Loay E. Goerge** * Department of Astronomy & Space, College of Science, University of Baghdad ** Department of Computer Science, College of Science, University of Baghdad Receiving Date: 25-02-2011 - Accept Date: 13-06-2011 Abstract In this project, the spatial and temporal variation of maximum usable frequency (MUF) parameter is investigated and modeled. The values of MUF for Baghdad station links, with other stations distributed over Iraq territory, where determined using the international reference model (RECF533) for HF propagation. The determined MUF dataset reflected that the spatial distribution of this parameter for Baghdad station shows circular symmetry, which stimulated the possibility of using a two dimensional second order polynomial in order to describe MUF variation. The main feature of this adopted mathematical model is its low complexity. The results of conducted analysis indicated that the spatial variation of MUF is simple while its temporal variation is more complicated and needs more sophisticated mathematical description than the polynomial description. The test results showed that the accuracy of proposed simple model lies within the tolerance of REC533 reference model. Key words: Ionosphere, HF communication prediction, MUF Vol 7 No: 4, October 2011 1 20 ISSN: 2222-8373 A Simplified Mathematical Model to Calculate the Maximum Usable Frequencies Over Iraqi Territory 1. INTRODUCTION The Maximum Usable Frequency, denoted by MUF, is an important ionospheric parameter. It is defined as the highest frequency that allows reliable long-range high frequency (HF) radio communication between two points due to ion-ospheric refraction. -
Applications of 2-D Moiré Deflectometry to Atmospheric Turbulence
Journal of Applied Fluid Mechanics, Vol. 7, No. 4, pp. 651-657, 2014. Available online at www.jafmonline.net, ISSN 1735-3572, EISSN 1735-3645. DOI: 10.36884/jafm.7.04.21420 Applications of 2-D Moiré Deflectometry to Atmospheric Turbulence S. Rasouli1, 2†, M. D. Niry1, Y. Rajabi1, A. A. Panahi1 and J. J. Niemela3 1 Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran 2 Optics Research Center, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran 3The Abdus Salam ICTP, Strada Costiera 11, 34151 Trieste, Italy †Corresponding Author Email: [email protected] (Received August 23, 2013; accepted December 1, 2013) ABSTRACT We report on applications of a moiré deflectometry to observations of anisotropy in the statistical properties of atmospheric turbulence. Specifically, combining the use of a telescope with moiré deflectometry allows enhanced sensitivity to fluctuations in the wave-front phase, which reflect fluctuations in the fluid density. Such phase fluctuations in the aperture of the telescope are imaged on the first grating of the moiré deflectometer, giving high spatial resolution. In particular, we have measured the covariance of the angle of arrival (AA) between pairs of points displaced spatially on the telescope aperture which allows a quantitative measure of anisotropy in the atmospheric surface layer. Importantly, the telescope-based moiré deflectometry measures directly in the spatial domain and, besides being a non-intrusive method for studying turbulent flows, has the advantage of being relatively simple and inexpensive. Keywords: Boundary layers: turbulence; Electromagnetic waves: atmospheric propagation; Turbulence: atmospheric; Diffraction gratings: optical; Interferometers. -
CRIRES User Manual
EUROPEAN SOUTHERN OBSERVATORY Organisation Europ´eene pour des Recherches Astronomiques dans l’H´emisph`ere Austral Europ¨aische Organisation f¨urastronomische Forschung in der s¨udlichen Hemisph¨are ESO - European Southern Observatory Karl-Schwarzschild Str. 2, D-85748 Garching bei M¨unchen Instrumentation Division CRIRES User Manual Doc. No. VLT-MAN-ESO-14500-3486 Issue 1, Date 06/01/2006 Prepared for Review - INTERNAL USE ONLY Ralf Siebenmorgen 06.01.2006 Prepared .......................................... Date Signature CRIRES User Manual VLT-MAN-ESO-14500-3486 ii Change Record Issue/Rev. Date Section/Parag. affected Reason/Initiation/Documents/Remarks Issue 0.5 06/12/04 RSI First draft CRIRES User Manual VLT-MAN-ESO-14500-3486 iii Abbreviations and Acronyms AO Adaptive optics APD Avalanche photo-diode CRIRES High-resolution infrared echelle spectrometer of the VLT DM Deformable mirror DMD Data management division ESO European Southern Observatory ETC Exposure time calculator FC Finding chart FoV Field of view FWHM Full width at half maximum NIR Near infrared OB Observing block P2PP Phase II proposal preparation PSF Point spread function QC Quality control RTC Real time computer SM Service mode SR Strehl ratio TIO Telescope and instrument operator USG User support group VLT Very large telescope VM Visitor mode WF Wave front WFS Wave front sensor CRIRES User Manual VLT-MAN-ESO-14500-3486 iv Wavelength range 1 − 5µm Resolving power (2 pixels) 105 Slit width 0.200 − 100 Slit length 5000 Pixel scale 0.100 Adaptive optics 60 actuator curvature -
Using High Frequency Propagation to Calculate Basic Maximum Usable Frequency
Using High Frequency Propagation to Calculate Basic Maximum Usable Frequency Israa Abdualqassim Mohammed Ali* * University of Baghdad, College of Science, Baghdad, Iraq Received: XX 20XX / Accepted: XX 20XX / Published online: ABSTRACT A comparison between observed (obs.) digital ionospheric sounding data and predicted (pre.) using International Reference Ionosphere (IRI) model for critical frequency (foF2) and Basic Maximum Usable Frequency (BMUF) of ionospheric F2-Layer has been made. A mid-latitude region selected for this research work by using data from station Wakkanai (45.38o N, 141.66o E). This study included 12 monthly median data from year (2001, R12=111) selected for high Sunspot number (SSN) and years for low SSN (2004, R12=44) and (2005, R12=29). Frequency parameters foF2 reveals that there is a good correlation between observed and predicted except for January of years 2001 and 2004, and BMUF revealed that there is a good correlation between observed and predicted for years of low SSN and all months except in month 1, 9 and 12 of year 2004, for year 2001 of high SSN there is a bad correlation. A correction factor as a function of time used from fitting technique to correct the predicted value with observed value of BMUF for year 2001. Keywords: Ionosphere; foF2; M3000F2; BMUF Author Correspondence, e-mail: [email protected] 1. INTRODUCTION The maximum usable frequency (MUF) is important ionospheric parameter for radio users because of its role in radio frequency management and for providing a good communication 1 link between two locations (Athieno et al., 2015; Suparta et al., 2018). -
Propagation Analysis of a 900 Mhz Spread Spectrum Centralized Traffic Signal Control System
PROPAGATION ANALYSIS OF A 900 MH Z SPREAD SPECTRUM CENTRALIZED TRAFFIC SIGNAL CONTROL SYSTEM Brian L. Urban, AS, BS, EIT Thesis Prepared for the Degree of MASTER OF SCIENCE UNIVERSITY OF NORTH TEXAS May 2006 APPROVED: Perry McNeill, Major Professor Michael Kozak, Committee Member Shuping Wang, Committee Member Bernard Vokoun, Committee Member Vijay Vaidyanathan, Departmental Program Coordinator Albert B. Grubbs, Chair of the Department of Engineering Technology Oscar Garcia, Dean of the College of Engineering Sandra L. Terrell, Dean of the Robert B. Toulouse School of Graduate Studies Urban, Brian L., Propagation analysis of a 900 MHz spread spectrum centralized traffic signal control system. Master of Science (Engineering Technology), May 2006, 88 pp., 20 tables, 27 illustrations, references, 25 titles. The objective of this research is to investigate different propagation models to determine if specified models accurately predict received signal levels for short path 900 MHz spread spectrum radio systems. The City of Denton, Texas provided data and physical facilities used in the course of this study. The literature review indicates that propagation models have not been studied specifically for short path spread spectrum radio systems. This work should provide guidelines and be a useful example for planning and implementing such radio systems. The propagation model involves the following considerations: analysis of intervening terrain, path length, and fixed system gains and losses. Copyright 2006 by Brian L. Urban ii ACKNOWLEDGEMENTS I acknowledge the following people for their efforts and contributions to my thesis. It would not have been completed without them. Special thanks to the author’s thesis advisor, Dr. -
Recommendation ITU-R V.573-4
Rec. ITU-R V.573-5 1 RECOMMENDATION ITU-R V.573-5* Radiocommunication vocabulary (1978-1982-1986-1990-2000-2007) Scope This Recommendation provides the main vocabulary reference, giving synonymous terms in three languages and the associated definitions. It includes terms given in Article 1 of the Radio Regulations (RR) and extends the list to technical terms defined in texts of the ITU-R. The ITU Radiocommunication Assembly, considering a) that Article 1 of the Radio Regulations (RR) contains the definitions of terms for regulatory purposes; b) that the Radiocommunication Study Groups have a need to establish new and amended definitions for technical terms that do not appear in RR Article 1 or that are so defined as to be unsuitable for Radiocommunication Study Group purposes; c) that it would be desirable for some of these terms and definitions established by the Radiocommunication Study Groups to be more widely used within the ITU-R, recommends that the terms listed in RR Article 1 and in Annex 1 below should be used as far as possible with the meaning ascribed to them in the corresponding definition. NOTE 1 – Study Groups are invited, where there is a difficulty in using any of the terms with the meaning given in the corresponding definition, to forward to the Coordination Committee for Vocabulary (CCV) a proposal for revision or alternative application, accompanied by substantiating argument. NOTE 2 – A number of terms in this Recommendation appear also in RR Article 1 with a different definition. These terms are identified by (RR . ., MOD) or (RR . .(MOD)) if the modifications consist only of editorial changes. -
7.3 ANTENNAS and WAVE PROPAGATION 7.3.1 Objectives
7.3 ANTENNAS AND WAVE PROPAGATION 7.3.1 Objectives and Relevance 7.3.2 Scope 7.3.3 Prerequisites 7.3.4 Syllabus i. JNTU ii. GATE iii. IES 7.3.5 Suggested Books 7.3.6 Websites 7.3.7 Experts’ Details 7.3.8 Journals 7.3.9 Findings and Developments 7.3.10 Session Plan 7.3.11 Question Bank i. JNTU ii. GATE iii. IES 7.3.1 OBJECTIVES AND RELEVANCE Through this subject, Students can understand the physical concept of Radiation and they can relate real- world situations. They can learn about various types of antennas, its working principle and design. Since Hertz and Marconi, antennas have become increasingly important to our society until now they are indispensable. They are everywhere: at our homes and workplaces, on our cars and aircrafts. While our ships, satellites and spacecrafts bristle with them, even as pedestrians we carry them. “With mankind’s activities expanding into space, the need for antennas will grow to an unprecedented degree. Antennas will provide the vital links to and from everything out there. 7.3.2 SCOPE It gives about the basic concepts of the antenna parameters and also about the various antenna theorems in detail. Antennas are the basic components of any electric systems and are connecting links between the transmeter and free space and the receiver. Antenna place a vital role in finding the characteristics of the system in which antennas are employed. It gives in detail about the various types of microwave, VHF, and UHF antennas, their characteristics and the various applications.