Reconfigurable Metamaterial Structure for 5G Beam Tilting Antenna
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25. Antennas II
25. Antennas II Radiation patterns Beyond the Hertzian dipole - superposition Directivity and antenna gain More complicated antennas Impedance matching Reminder: Hertzian dipole The Hertzian dipole is a linear d << antenna which is much shorter than the free-space wavelength: V(t) Far field: jk0 r j t 00Id e ˆ Er,, t j sin 4 r Radiation resistance: 2 d 2 RZ rad 3 0 2 where Z 000 377 is the impedance of free space. R Radiation efficiency: rad (typically is small because d << ) RRrad Ohmic Radiation patterns Antennas do not radiate power equally in all directions. For a linear dipole, no power is radiated along the antenna’s axis ( = 0). 222 2 I 00Idsin 0 ˆ 330 30 Sr, 22 32 cr 0 300 60 We’ve seen this picture before… 270 90 Such polar plots of far-field power vs. angle 240 120 210 150 are known as ‘radiation patterns’. 180 Note that this picture is only a 2D slice of a 3D pattern. E-plane pattern: the 2D slice displaying the plane which contains the electric field vectors. H-plane pattern: the 2D slice displaying the plane which contains the magnetic field vectors. Radiation patterns – Hertzian dipole z y E-plane radiation pattern y x 3D cutaway view H-plane radiation pattern Beyond the Hertzian dipole: longer antennas All of the results we’ve derived so far apply only in the situation where the antenna is short, i.e., d << . That assumption allowed us to say that the current in the antenna was independent of position along the antenna, depending only on time: I(t) = I0 cos(t) no z dependence! For longer antennas, this is no longer true. -
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. -
Coordinate Transformations-Based Antenna Elements Embedded in a Metamaterial Shell with Scanning Capabilities
electronics Article Coordinate Transformations-Based Antenna Elements Embedded in a Metamaterial Shell with Scanning Capabilities Dipankar Mitra 1,*, Sukrith Dev 2, Monica S. Allen 2, Jeffery W. Allen 2 and Benjamin D. Braaten 1,* 1 Department of Electrical and Computer Engineering, North Dakota State University, Fargo, ND 58105, USA 2 Air Force Research Laboratory, Munitions Directorate, Eglin Air Force Base, FL 32542, USA; [email protected] (S.D.); [email protected] (M.S.A.); [email protected] (J.W.A.) * Correspondence: [email protected] (D.M.); [email protected] (B.D.B.) Abstract: In this work transformation electromagnetics/optics (TE/TO) were employed to realize a non-homogeneous, anisotropic material-embedded beam-steerer using both a single antenna element and an antenna array without phase control circuitry. Initially, through theory and validation with numerical simulations it is shown that beam-steering can be achieved in an arbitrary direction by enclosing a single antenna element within the transformation media. Then, this was followed by an array with fixed voltages and equal phases enclosed by transformation media. This enclosed array was scanned, and the proposed theory was validated through numerical simulations. Further- more, through full-wave simulations it was shown that a horizontal dipole antenna embedded in a metamaterial can be designed such that the horizontal dipole performs identically to a vertical Citation: Mitra, D.; Dev, S.; Allen, dipole in free-space. Similarly, it was also shown that a material-embedded horizontal dipole array M.S.; Allen, J.W.; Braaten, B.D. -
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. -
High-Performance Indoor VHF-UHF Antennas
High‐Performance Indoor VHF‐UHF Antennas: Technology Update Report 15 May 2010 (Revised 16 August, 2010) M. W. Cross, P.E. (Principal Investigator) Emanuel Merulla, M.S.E.E. Richard Formato, Ph.D. Prepared for: National Association of Broadcasters Science and Technology Department 1771 N Street NW Washington, DC 20036 Mr. Kelly Williams, Senior Director Prepared by: MegaWave Corporation 100 Jackson Road Devens, MA 01434 Contents: Section Title Page 1. Introduction and Summary of Findings……………………………………………..3 2. Specific Design Methods and Technologies Investigated…………………..7 2.1 Advanced Computational Methods…………………………………………………..7 2.2 Fragmented Antennas……………………………………………………………………..22 2.3 Non‐Foster Impedance Matching…………………………………………………….26 2.4 Active RF Noise Cancelling……………………………………………………………….35 2.5 Automatic Antenna Matching Systems……………………………………………37 2.6 Physically Reconfigurable Antenna Elements………………………………….58 2.7 Use of Metamaterials in Antenna Systems……………………………………..75 2.8 Electronic Band‐Gap and High Impedance Surfaces………………………..98 2.9 Fractal and Self‐Similar Antennas………………………………………………….104 2.10 Retrodirective Arrays…………………………………………………………………….112 3. Conclusions and Design Recommendations………………………………….128 2 1.0 Introduction and Summary of Findings In 1995 MegaWave Corporation, under an NAB sponsored project, developed a broadband VHF/UHF set‐top antenna using the continuously resistively loaded printed thin‐film bow‐tie shown in Figure 1‐1. It featured a low VSWR (< 3:1) and a constant dipole‐like azimuthal pattern across both the VHF and UHF television bands. Figure 1‐1: MegaWave 54‐806 MHz Set Top TV Antenna, 1995 In the 15 years since then much technical progress has been made in the area of broadband and low‐profile antenna design methods and actual designs. -
VLF Radio Observations and Modeling
INDIAN CENTRE FOR SPACE PHYSICS ANNUAL REPORT (2013-2014) TABLE OF CONTENTS Report of the Governing Body 3 Governing Body of the Centre 4 Members of the Research Advisory Council 4 Academic Council Members 4 In-Charge, Academic Affairs 4 Dean (Academic) and Finance Officer 4 Administrative Officer 4 Public Information Officer 5 In Charge of the Departments 5 Faculty Members 5 Honorary Faculty Members 5 Project Scientists 5 Post-Doctoral Fellows 5 Senior Research Fellows 5 Junior Research Fellows 6 ICTP Senior Research Fellow 6 Visiting Research Scholars 6 Engineers / Laboratory Staff 6 Office Staff 6 Security Staff 6 Research Facilities at the Head Quarter 7 Facilities at other branches of the Centre 7 Brief Profiles of the Scientists of the Centre 7 Research Work Published or Accepted for Publication 10 Books and In Books 14 Members of Scientific Societies/Committees 15 Ph.D. degree Received 15 Ph.D. Thesis Submitted 15 Course of lectures offered by ICSP members 15 Participation in National/International Conferences & Symposia 16 Workshops / Seminars / Conferences etc. organized 17 Visits abroad from the Centre 17 Major Visitors to the Centre 17 Collaborative Research and Project Work 17 M.Sc. projects guided by ICSP members 18 Summary of the Research Activities of the Scientists at the Centre 19 The ionospheric and earthquake research centre (IERC) 38 Activities of the Indian Centre for Space Physics, Malda Branch 40 Auditors Report to the Members 42 Published by: Indian Centre for Space Physics, Chalantika 43, Garia Station Road, Garia, Kolkata 700084 EPABX +91-33-2436-6003 and +91-33-2462-2153 Extension Numbers: Department of Ionospheric Science: 21 Department of Astrochemistry/Astrobiology: 22 Accounts: 23 Seminar Room: 24 Computer room: 25 Department of High Energy Radiation: 26 X-ray Laboratory: 27 Fax: +91-33-2462-2153 E-mail: [email protected] Website: http://csp.res.in Front Cover: Superposed photos of the earth taken from a camera on board a balloon borne mission and the sky at Ionospheric and Earthquake Research Center of ICSP taken by Mr. -
Ground-To-Air Antennas and Antenna Line Products Information About KATHREIN Broadcast
BROADCAST CATALOGUE Ground-to-Air Antennas and Antenna Line Products Information about KATHREIN Broadcast As of 1st June 2019, KATHREIN SE's (formerly KATHREIN-Werke KG) business unit "BROADCAST" will be transferred to KATHREIN Broadcast GmbH (limited liability company). From 1st June 2019, the new company data are: KATHREIN Broadcast GmbH Ing.-Anton-Kathrein-Str. 1, 3, 5, 7 83101 Rohrdorf, Germany Tax Payer's ID No.: 156/117/31113 VAT Reg. No.: DE 323 189 785 Commercial Register Traunstein: HRB 27745 Catalogue Issue 06/2019 All data published in previous catalogue issues hereby becomes invalid. We reserve the right to make alterations in accordance with the requirements of our customers, therefore for binding data please check valid data sheets on our homepage: www.kathrein.com Please also see additional information on inside back cover. Our quality assurance system and our Our products are compliant to the EU environmental management system apply Directive RoHS as well as to other to the entire company and are certified RoHS environmentally relevant regulations by TÜV according to EN ISO 9001 and (e.g. REACH). EN ISO 14001. Antennas for Communication Antennas for Communication Antennas for Navigation Antennas for Navigation Electrical Accessories Electrical Accessories Mechanical Accessories Mechanical Accessories Services Services Summary of Types The articles are listed by type number in numerical order. Type No. Page Type No. Page Type No. Page Type No. Page 711 ... 727 ... 792 ... K63 ... 711329 50, 51 727463 28, 29 792008 75 K637011 601825 73 727728 34, 35 792246 76 713 ... K64 ... 713316B 56, 57 729 ... 800 ... K6421351 601704 66, 67 713645 83 729803 28, 29 80010228 49 K6421361 601686 68, 69 K6421371 601687 68, 69 714 .. -
UHF VHF Dipole Antenna
A.H. Systems Model TDS-536 Tuned Dipole Set TDS-536 TV Dipole Set Operation Manual A.H. Systems inc. – May 2014 1 REV B A.H. Systems Model TDS-536 Tuned Dipole Set TABLE OF CONTENTS INTRODUCTION 3 GENERAL INFORMATION 5 OPERATING INSTRUCTIONS 6 FORMULAS 7 MAINTENANCE 10 WARRANTY 11 A.H. Systems inc. – May 2014 2 REV B A.H. Systems Model TDS-536 Tuned Dipole Set INTRODUCTION CONTENTS – TUNED DIPOLE SET, TV Model Part QTY Number Number Description 1 TSC-536 2573 Transit Storage Case 2 N/A N/A Keys 1 TV-1 2572 Tuned Dipole Antenna (50 MHz – 220 MHz) 2 N/A N/A 17” Extension Elements 2 N/A 2337-2 Telescoping Elements 1 TV-2 2580 Tuned Dipole Antenna (325 MHz – 1000 MHz) 1 SAC-213 2111 3 Meter Cable, N(m) to N(m) 1 ABC-TD 2332-1 Clamp 1 N/A 2346 Tape Measurer A.H. Systems inc. – May 2014 3 REV B A.H. Systems Model TDS-536 Tuned Dipole Set INTENDED PURPOSES This equipment is intended for indoor and outdoor use in a wide variety of industrial and scientific applications, and designed to be used in the process of generating, controlling and measuring high levels of electromagnetic Radio Frequency (RF) energy. It is the responsibility of the user to assure that the device is operated in a location which will control the radiated energy such that it will not cause injury and will not violate regulatory levels of electromagnetic interference. RANGE OF ENVIRONMENTAL CONDITIONS This equipment is designed to be safe under the following environmental conditions: Indoor use Altitude up to 2000M Temperature of 5C to 40C Maximum relative humidity 80 % for temperatures up to 31C. -
Adding an Input Balun in AAA-1 in Dipole Mode to Reduce 2 Nd Order IMD Distortions When Asymmetric Signal Source (Antenna) Is Used
Adding Input Balun in the Dipole Amplifier ……. Rev.1.1 © LZ1AQ Adding an Input Balun in AAA-1 in Dipole Mode to Reduce 2 nd Order IMD Distortions when Asymmetric Signal Source (antenna) is Used When using large loops as dipole arms with AAA-1 active antenna amplifier or totally asymmetric electric antennas such as ground plane (GP), some 2-nd order IMD distortion might occur due to asymmetric signal source combined with the strong signals. The vertical dipole is partially asymmetric antenna – the lower arm has higher capacitance to ground than the upper one. Also nearby conducting objects can influence the dipole symmetry additionally. The dipole amplifier itself has very high OIP2 to symmetric signal sources – in order of +90 dBm but it can not be accomplished since the signals in the two arms of the amplifier might have different amplitudes due to input asymmetry. How to localize 2 nd order IMD distortions? The easiest way is to check the 2 nd order products (F1+F2 and 2F ) which might exist as a spurious signals in 14.400 – 15.200 MHz band as result of action of strong broadcasting stations on 41 m band with frequencies 7.200-7.600 MHz. Night time is most suitable for this experiment. The RX must have good dynamic range and a good input band pass filter which must stop the fundamental signals at 41 m band to avoid generation of 2 nd order products in the RX itself. All candidate spurious frequencies in 14-15MHz zone should be multiples of 5 KHz since this is the distance between broadcasting frequencies. -
HF Radio Propagation
Introduction to HF Radio Propagation 1. The Ionosphere 1.1 The Regions of the Ionosphere In a region extending from a height of about 50 km to over 500 km, most of the molecules of the atmosphere are ionised by radiation from the Sun. This region is called the ionosphere (see Figure 1.1). Ionisation is the process in which electrons, which are negatively charged, are removed from neutral atoms or molecules to leave positively charged ions and free electrons. It is the ions that give their name to the ionosphere, but it is the much lighter and more freely moving electrons which are important in terms of HF (high frequency) radio propagation. The free electrons in the ionosphere cause HF radio waves to be refracted (bent) and eventually reflected back to earth. The greater the density of electrons, the higher the frequencies that can be reflected. During the day there may be four regions present called the D, E, F1 and F2 regions. Their approximate height ranges are: • D region 50 to 90 km; • E region 90 to 140 km; • F1 region 140 to 210 km; • F2 region over 210 km. At certain times during the solar cycle the F1 region may not be distinct from the F2 region with the two merging to form an F region. At night the D, E and F1 regions become very much depleted of free electrons, leaving only the F2 region available for communications. Only the E, F1 and F2 regions refract HF waves. The D region is very important though, because while it does not refract HF radio waves, it does absorb or attenuate them (see Section 1.5). -
Time and Frequency Users' Manual
,>'.)*• r>rJfl HKra mitt* >\ « i If I * I IT I . Ip I * .aference nbs Publi- cations / % ^m \ NBS TECHNICAL NOTE 695 U.S. DEPARTMENT OF COMMERCE/National Bureau of Standards Time and Frequency Users' Manual 100 .U5753 No. 695 1977 NATIONAL BUREAU OF STANDARDS 1 The National Bureau of Standards was established by an act of Congress March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, a technical (3) basis for equity in trade, and (4) technical services to pro- mote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materials Research the Institute for Applied Technology, the Institute for Computer Sciences and Technology, the Office for Information Programs, and the Office of Experimental Technology Incentives Program. THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and consist- ent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essen- tial services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of the Office of Measurement Services, and the following center and divisions: Applied Mathematics -
Identifying and Locating Cable TV Interference Application Note
Application Note Identifying and Locating Cable TV Interference A Primer for Public Safety Engineers and Cellular Operators Introduction In the early days of cable TV systems, the signals being sent over the cables were the same signals that were transmitted over the air. This minimized the extent of interference problems. Problems in those days would often manifest as ghosting and would look like a multipath reflection. However as cable TV systems offered more and more TV channels and other services, signals transmitted over the cables covered virtually the entire spectrum from 7 MHz to over 1 GHz. See table 1. There are many different services that operate over the air in that frequency range. All those services can be subject to interfering signals radiating from cable TV systems and in turn over the air signals can leak into the cable TV plant and cause interference. As cable TV systems began to expand the frequency range in the cable, interference started to be experienced by aeronautical users in the 100 to 140 MHz range and amateur radio operators in the 50 MHz to 54 MHz, 144 to 148 MHz, 220 to 225 MHz, and the 440 to 450 MHz bands. First responders could also experience interference when operating near a leaky cable plant. Problems in the 700 and 850 MHz cellular bands emerged as the frequencies in the cables were pushed higher and higher to provide more channels for cable TV customers. As the 600 MHz frequency range begins to be used by cellular operators, problems are likely to be seen there as well.