DOCSLIB.ORG

Range Considerations for RF Networks.Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Range Considerations for RF Networks.Pdf TI Technology Days 2010 Range Considerations for RF Networks Richard Wallace Abstract The antenna can be one of the most daunting components of wireless designs. Most information available relates to large antenna’s related to Amateur Radio (HAM), Cellular Applications and expensive Whip Antennas that can never be used in a low cost application. This session covers the basics that most engineers would need to know to predict the expected Range Distance between wireless devices and design parameters to achieve an optimum Range Distance. At the end of this session, the attendees should be aware of antenna requirements, the Antenna Documentation Support available and be able to select an Antenna Reference Design for their application. Agenda • Antenna Theory • Antenna Measurements • Range Estimation – Friis Basic Formula – Improved Range Estimation – Best Accuracy Estimation • Antenna Reference Designs – 2.4 GHz – 2.4 GHz & 868 MHz Dual Band – 868 / 915 / 955 MHz – 433 / 315 / 169 MHz – CC-Antenna-DK • Antenna Support Documentation – Antenna Selection Quick Guide (DN035) – Comprehensive Antenna Selection Guide (AN058) Antenna Theory – Basic Function of an Antenna • Transmit mode: Transform RF signals into electromagnetic waves, propagating into free space TX • Receive mode: Transform electromagnetic waves into RF signals RX Range OBS: The antenna is a key component for the successful design of a wireless communication system. Antenna Theory – All Monopole Antennas are Derivatives of Dipole AC current through *1: /2 Dipole an inductor lags the produces the most voltage by 90 power at the ends of degrees the antenna with little power at the feedline. Current Voltage Power /4 /4 *1 *1 All monopole antennas are derivatives of a simple dipole where one ¼ wavelength radiator is in air and one ¼ wavelength radiator is imaged into the GND and serves as the second radiator. Antenna Theory – Wavelength Calculations in Free Space Wavelength is dependent on frequency which is referenced to the speed of light (299 792 458 m / s): meters = 2.99792458E8 m/sec f (GHz) where GHz = 1E9 Wavelength for several frequency ranges, all units are in cm: λ / 4 λ / 4 λ λ Frequency air FR4 air FR4 2.4 GHz 3.1 1.5 12.5 5.9 915 MHz 8.2 3.9 32.8 15.5 868 MHz 8.6 4.1 34.6 16.3 433 MHz 17.3 8.2 69.3 32.7 315 MHz 23.8 11.2 95.2 44.9 27 MHz 277.8 130.9 1111.1 523.8 Antenna Theory – Antenna Considerations • Numerous issues to consider when selecting the antenna: – Antenna placement – Board size available for antenna layout – Operating frequency – Ground plane for ¼ wavelength antennas – Antenna mismatch (VSWR) – Objects that alter or disrupt Line of Sight (LOS) – Antenna gain characteristics – Antenna bandwidth – Antenna Radiation Efficiency Antenna Theory – Antenna Radiation Patterns – Traditional Coordinate System An Isotropic Antenna is a theoretical antenna spec in dBi and radiates equally in all directions of a sphere. Antenna Measurement Coordinate System • x-y plane (θ = 90 deg) is the azimuth plane (horizontal plane) • y-z plane (φ = 90 deg) is the elevation plane (vertical plane) Antenna Theory – Antenna Radiation Patterns – 3D OTA CTIA Measurements Example 1: 2.4 GHz Yagi Directional Antenna (DN034) Example 2: 868 MHz Meandering Monopole Antenna (Dual Band Option, 2.4 GHz, DN024, Rev E) Antenna Theory – Antenna Parameters Important parameters • WaveLength, . Antenna size for dipole relative to the c wavelength of transmission. f • Polarization the direction of the electric field to the electromagntic wave. • Impedance, Z. A measure of the total opposition to current flow in an alternating current circuit, made up of Z = R + iX two components, ohmic resistance and reactance, and usually represented in complex notation. • Bandwidth is the range of frequencies where the return BW = 100 ( (FH – FL) / FC) loss is below VSWR of 2 • Efficiency () is the ratio of power in watts actually P radiated to the power into the antenna terminals rad %100* P in Antenna Theory – Antenna Parameters Important parameters • Gain, G. is the maximum radiation beam of the highest beam. This parameter takes into account VSWR mismatch and energy losses. – Important to remember that antennas do not amplify RF. Since antennas cannot create energy, the total power radiated is the same as an isotropic antenna. Any additional energy radiated in the directions it favors is offset by equally less energy radiated in all other directions. – IEEE Gain Definition: GIEEE = Radiated Power / Delivered Power = D • Directivity, D. Antenna directivity is usually measured in dBi, or decibels above isotropic sphere antenna. – The directional antenna has a maximum directivity greater than 0dB. • Resonance Frequency is the electrical resonance is related to the electrical length of the antenna. Antenna Theory – Antenna Q and Bandwidth Properly designed antenna’s should cover the range of frequencies over which the antenna can operate correctly with sufficient bandwidth. TI defines the antenna’s bandwidth in Hertz when VSWR less than 2:1, or return loss of greater than -9.5dB • Bandwidth (BW) can be defined in percentage of the operating frequency: BW = 100 ( (FH – FL) / FC) • There is a direct relationship between Q and bandwidth f f Q HL fc Antenna Theory – Antenna Categories • Two fundamental types of antennas – Single ended antennas • Usually matched to 50 ohm • Needs a balun if the chip has a differential output • Easy to characterize with a network analyzer – Differential antennas • Can be matched directly to the impedance of the radio • Can be used to reduce the number of external components • Complicated to make good design • Difficult to measure the impedance and to characterize. Antenna Theory – Resonant Antennas • Resonant antennas are often used – Monopole: λ/4 – Bent Monopole: λ/4 – Inverted F: λ/4 – Dipole: λ/2 – Folded dipole: λ/2 Antenna Theory – Frequency “v” Size • Lower frequency increases the range – Theoretically, reducing the frequency by a factor of two doubles the range (line of sight) • Lower frequency requires a larger antenna – λ/4 at 433 MHz is 17.3 cm (6.77 in) – λ/4 at 915 MHz is 8.2 cm (3.22 in) – λ/4 at 2.4 GHz is 3.1 cm (1.20 in) • A meandered structure is a compact dipole with inductive loading - λ/4 at 2.4 GHz feedline Antenna Theory – Max. Power Transfer (VSWR) Moritz Von Jacobi’s maximum power theory states that maximum power transfer happens when the source resistance equals the load resistance. As impedances are mis-matched, part of the transmitted signal is reflected back into the source which is the Voltage Standing Wave Ratio (VSWR); the ratio of the reflected waveform to the transmitted waveform. With antenna design: VSWR is a measure of how well the input impedance of the antenna matches the characteristic impedance of the output from the RF network. Impedance mismatch will reduce performance ! Antenna Theory – Antenna Types - Commonly Used antennas • Commonly used antennas – PCB antennas • No extra cost • Size demanding at sub 433 MHz • Good performance at > 868 MHz – Whip antennas • Expensive solutions for high volume • Good performance • Hard to fit in many applications – Chip antennas • Medium cost • Good performance at 2.4 GHz • OK performance at 868-955 MHz • Poor performance at 433-136 MHz – Wire / Helical antennas • Low cost • Ideal at sub 433 MHz Antenna Measurements - Done in Lab • S-parameter measurements – Q and Bandwidth – Matching - Mismatch – Return Loss • Spectrum Analyzer – Power Delivered to Antenna – Bandwidth – Relative Measurements of Radiated Power • TI Tools – Receive Signal Strength Indicator (RSSI) SmartRF studio – Frequency Sweep Function (Ideal for bandwidth measurements) Antenna Measurements - Impedance Magnitude of mismatch in dB with respect to frequency. The smith chart shows how the impedance varies with No exact impedance can be obtained from this format. frequency. Useful tool to find the values of the antenna matching component values. VSWR circles can be used to see how well the antenna is matched. Question: The dashed red line is shown at 14dB. What is the VSWR ? S11 S11 Antenna Measurements - Impedance - Smith Chart Short circuit Match Open circuit parallel L series L Inductive parallel C series C Capacitive Antenna Measurements - Impedance Matching Mismatch between the antenna and the feed line results in losses and will reduce the radiated power from the antenna. Inductors and capacitors in shunt and series can be used to achieve the desired impedance matching. Antenna Measurements - Characterization How to characterize antennas: 1. Measure the reflected power at the feed point of the antenna 2. Measure the radiated power across the bandwidth of interest 3. Measure the radiation pattern in an Anechoic Chamber 1. 2. 3. Antenna Measurements - Anechoic Chamber z + = y x • Patterns give directivity and gain of the antenna. • Radiated power is also measured. • Done in an anechoic chamber to eliminate multi-paths for accurate plots. • Done through contracted 3rd party companies. Antenna Measurements - andwidthB With a Spectrum Analyzer With a Network Analyzer BWVSWR2 fHL f Antenna Measurements - Reflection ZZ 1 l 0 VSWR ZZl 0 1 VSWR 1 20S11 log( ) 20 log dB VSWR 1 VSWR S11dB Reflected Delivered power % power % 1 -∞ 0 100 1.1 -27 0.2 99.8 1.2 -21 0.8 99.2 1.5 -14 4 96 2 -9.5 11.1 89.9 3 -6 25 75 4 -4.4 36 64 5 -3.5 44.4 55.6 5.8 -3 50 50 10 -1.7 66.9 33.1 Antenna Measurements - Mounting of Cable for S11 Measurements Tip: It is invaluable to have semi-rigid cables in the lab for debugging RF. Solder first shielding onto an earth plane and then solder the 50ohm connection. Minimize risk for riping off tracks when connecting to the semi- rigid cable. Supplier: AMSKA (www.amska.se) Ready made semi-rigid cables are A50451229, ASC047-PSMAf-0,3-200, Cable Assembly, with SMA-f and quite expensive but can be re-used 3mm stripped, 20cm again.
Load more

Recommended publications
  • W5GI MYSTERY ANTENNA (Pdf)
    W5GI Mystery Antenna A multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software Article by W5GI ( SK ) The design of the Mystery antenna was inspired by an article written by James E. Taylor, W2OZH, in which he described a low profile collinear coaxial array. This antenna covers 80 to 6 meters with low feed point impedance and will work with most radios, with or without an antenna tuner. It is approximately 100 feet long, can handle the legal limit, and is easy and inexpensive to build. It’s similar to a G5RV but a much better performer especially on 20 meters. The W5GI Mystery antenna, erected at various heights and configurations, is currently being used by thousands of amateurs throughout the world. Feedback from users indicates that the antenna has met or exceeded all performance criteria. The “mystery”! part of the antenna comes from the fact that it is difficult, if not impossible, to model and explain why the antenna works as well as it does. The antenna is especially well suited to hams who are unable to erect towers and rotating arrays. All that’s needed is two vertical supports (trees work well) about 130 feet apart to permit installation of wire antennas at about 25 feet above ground. The W5GI Multi-band Mystery Antenna is a fundamentally a collinear antenna comprising three half waves in-phase on 20 meters with a half-wave 20 meter line transformer. It may sound and look like a G5RV but it is a substantially different antenna on 20 meters.
    [Show full text]
  • California State University, Northridge
    CALIFORNIA STATE UNIVERSITY, NORTHRIDGE Design of a 5.8 GHz Two-Stage Low Noise Amplifier A graduate project submitted in partial fulfillment of the requirements For the degree of Master of Science in Electrical Engineering By Yashika Parwath August 2020 The graduate project of Yashika Parwath is approved: Dr. John Valdovinos Date Dr. Jack Ou Date Dr. Brad Jackson, Chair Date California State University, Northridge ii Acknowledgement I would like to express my sincere gratitude to Dr. Brad Jackson for his unwavering support and mentorship that aided me to finish my master’s project. With his deep understanding of the subject and valuable inputs this design project has been quite a learning wheel expanding my knowledge horizons. I would also like to thank Dr. John Valdovinos and Dr. Jack Ou for being the esteemed members of the committee. iii Table of Contents Signature page ii Acknowledgement iii List of Figures v List of Tables vii Abstract viii Chapter 1: Introduction 1 1.1 Communication System 1 1.2 Low Noise Amplifier 2 1.3 Design Goals 2 Chapter 2: LNA Theory and Background 4 2.1 Introduction 4 2.2 Terminology 4 2.3 Design Procedure 10 Chapter 3: LNA Design Procedure 12 3.1 Transistor 12 3.2 S-Parameters 12 3.3 Stability 13 3.4 Noise and Noise Figure 16 3.5 Cascaded Noise Figure 16 3.6 Noise Circles 17 3.7 Unilateral Figure of Merit 18 3.8 Gain 20 Chapter 4: Source and Load Reflection Coefficient 23 4.1 Reflection Coefficient 23 4.2 Source Reflection Coefficient 24 4.3 Load Reflection Coefficient 26 Chapter 5: Impedance Matching
    [Show full text]
  • Circuit and Method for Balun Compensation
    Europaisches Patentamt J European Patent Office © Publication number: 0 644 605 A1 Office europeen des brevets EUROPEAN PATENT APPLICATION © Application number: 94112882.9 int. CI 6: H01P 5/10 @ Date of filing: 18.08.94 © Priority: 22.09.93 US 124875 © Applicant: MOTOROLA, INC. 1303 East Algonquin Road @ Date of publication of application: Schaumburg, IL 60196 (US) 22.03.95 Bulletin 95/12 @ Inventor: Kaltenecker, Robert S. © Designated Contracting States: 2719 S. Estrella Circle DE FR GB Mesa, Arizona 85202 (US) Inventor: Pfizenmayer, Henry L. 3318 E. Turquiose Avenue Phoenix, Arizona 85028 (US) Inventor: Wernett, Frederick C. 492 Kweo Trail Flagstaff, Arizona 86001 (US) © Representative: Hudson, Peter David et al Motorola European Intellectual Property Midpoint Alencon Link Basingstoke, Hampshire RG21 1PL (GB) © Circuit and method for balun compensation. 10 © A novel circuit and method for providing am- 14 plitude and phase compensation for a balun in order P1 P2 7o,Eo | Ox to provide first and second voltage signals that are 12 1 16 balanced has been provided. The compensation is I rrm < ^ achieved by an amplitude and phase com- adding P3 pensation circuit such as a transmission line (14) or 1 mm 18 o inductive (20) and capacitive (22) lumped elements CO in series with one of the ports of the balun on the balanced side. The and amplitude phase compensa- FIG. 1 tion circuit includes a characteristic impedance CO pa- rameter (Zo) and an electrical length parameter (Eo) that are optimized such that the amplitude difference between first and second voltage signals is mini- mized, while the magnitude of the phase difference between first and second voltage signals is maxi- mized.
    [Show full text]
  • Design and Application of a New Planar Balun
    DESIGN AND APPLICATION OF A NEW PLANAR BALUN Younes Mohamed Thesis Prepared for the Degree of MASTER OF SCIENCE UNIVERSITY OF NORTH TEXAS May 2014 APPROVED: Shengli Fu, Major Professor and Interim Chair of the Department of Electrical Engineering Hualiang Zhang, Co-Major Professor Hyoung Soo Kim, Committee Member Costas Tsatsoulis, Dean of the College of Engineering Mark Wardell, Dean of the Toulouse Graduate School Mohamed, Younes. Design and Application of a New Planar Balun. Master of Science (Electrical Engineering), May 2014, 41 pp., 2 tables, 29 figures, references, 21 titles. The baluns are the key components in balanced circuits such balanced mixers, frequency multipliers, push–pull amplifiers, and antennas. Most of these applications have become more integrated which demands the baluns to be in compact size and low cost. In this thesis, a new approach about the design of planar balun is presented where the 4-port symmetrical network with one port terminated by open circuit is first analyzed by using even- and odd-mode excitations. With full design equations, the proposed balun presents perfect balanced output and good input matching and the measurement results make a good agreement with the simulations. Second, Yagi-Uda antenna is also introduced as an entry to fully understand the quasi-Yagi antenna. Both of the antennas have the same design requirements and present the radiation properties. The arrangement of the antenna’s elements and the end-fire radiation property of the antenna have been presented. Finally, the quasi-Yagi antenna is used as an application of the balun where the proposed balun is employed to feed a quasi-Yagi antenna.
    [Show full text]
  • University of Cincinnati
    UNIVERSITY OF CINCINNATI _____________ , 20 _____ I,______________________________________________, hereby submit this as part of the requirements for the degree of: ________________________________________________ in: ________________________________________________ It is entitled: ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ Approved by: ________________________ ________________________ ________________________ ________________________ ________________________ Digital Direction Finding System Design and Analysis A thesis submitted to the Division of Graduate Studies and Research of the University of Cincinnati in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE (M.S.) in the Department of Electrical & Computer Engineering and Computer Science of the College of Engineering 2003 by Huazhou Liu B.E., Xi’an Jiaotong University P. R. China, 2000 Committee Chair: Professor Howard Fan ABSTRACT Direction Finding (DF) system is used in many military and civilian operations such as surveillance, reconnaissance, and rescue, etc. In the past years, direction finding system is implemented usually using analog RF techniques such as Butler matrix and analog beamforming. Analog direction finding systems have drawbacks inherent from their analog properties such as expensive implementation, inflexibility to adjust or change functionality, intensive calibration procedures and
    [Show full text]
  • 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.
    [Show full text]
  • 3.1Loop Antennas All Antennas Used Radiating Elements That Were Linear Conductors
    SECX1029 ANTENNAS AND WAVE PROPAGATION UNIT III SPECIAL PURPOSE ANTENNAS PREPARED BY: MS.L.MAGTHELIN THERASE 3.1Loop Antennas All antennas used radiating elements that were linear conductors. It is also possible to make antennas from conductors formed into closed loops. Thereare two broad categories of loop antennas: 1. Small loops which contain no morethan 0.086λ wavelength,s of wire 2. Large loops, which contain approximately 1 wavelength of wire. Loop antennas have the same desirable characteristics as dipoles and monopoles in that they areinexpensive and simple to construct. Loop antennas come in a variety of shapes (circular,rectangular, elliptical, etc.) but the fundamental characteristics of the loop antenna radiationpattern (far field) are largely independent of the loop shape.Just as the electrical length of the dipoles and monopoles effect the efficiency of these antennas,the electrical size of the loop (circumference) determines the efficiency of the loop antenna.Loop antennas are usually classified as either electrically small or electrically large based on thecircumference of the loop. electrically small loop = circumference λ/10 electrically large loop - circumference λ The electrically small loop antenna is the dual antenna to the electrically short dipole antenna. That is, the far-field electric field of a small loop antenna isidentical to the far-field magnetic Page 1 of 17 SECX1029 ANTENNAS AND WAVE PROPAGATION UNIT III SPECIAL PURPOSE ANTENNAS PREPARED BY: MS.L.MAGTHELIN THERASE field of the short dipole antenna and the far-field magneticfield of a small loop antenna is identical to the far-field electric field of the short dipole antenna.
    [Show full text]
  • Development of Electric and Magnetic Near-Field Probes
    National Bureau of Standards Library. £-01 Admin. Bldg. OCT 6 1981 191108 ~&h /CO sm 8 NBS TECHNICAL NOTE 658 6 $ , a £i "ffAU O* U.S. DEPARTMENT OF COMMERCE/National Bureau of Standards Development of Electric and Magnetic Near-Field Probes tx NATIONAL BUREAU OF STANDARDS 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 (he 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. (3) a technical basis for equity in trade, and (4) technical services to promote 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, and the Office for Information Programs. THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and consistent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of a Center for Radiation Research, an Office of Meas- urement Services and the following divisions: Applied Mathematics — Electricity — Mechanics
    [Show full text]
  • A Portable Twin-Lead 20-Meter Dipole
    By Rich Wadsworth, KF6QKI A Portable Twin-Lead 20-Meter Dipole With its relatively low loss and no need for a tuner, this resonant portable dipole for 14.060 MHz is perfect for portable QRP. first attempt at a portable problem is that its 300 ohm impedance to 70 ohms, a feed line that is an electri- dipole was using 20 AWG normally requires a tuner or 4:1 balun at cal half wave long will also measure 50 My speaker wire, with the leads the rig end. to 70 ohms at the transceiver end, elimi- simply pulled apart for the length re- But, since I want approximately a half nating the need for a tuner or 4:1 balun. 1 quired for a /2 wavelength top and the wavelength of feed line anyway, I decided To determine the electrical length of rest used for the feed line. The simplic- to experiment with the concept of mak- a wire, you must adjust for the velocity ity of no connections, no tuner and mini- ing it an exact electrical half wavelength factor (VF), the ratio of the speed of the mal bulk was compelling. And it worked long. Any feed line will reflect the im- signal in the wire compared to the speed (I made contacts)! pedance of its load at points along the of light in free space. For twin lead, it is Jim Duffey’s antenna presentation at the feed line that are multiples of a half wave- 0.82. This means the signal will travel at 1999 PacifiCon QRP Symposium made me length.
    [Show full text]
  • Wireless Sensing and Identification of Passive Electromagnetic Sensors Based on Millimetre-Wave FMCW RADAR
    Wireless Sensing and Identification of Passive Electromagnetic Sensors based on Millimetre-wave FMCW RADAR Hervé Aubert, Franck Chebila, Mohamed Mehdi Jatlaoui, Trang Thai, Hamida Hallil, Anya Traille, Sofiene Bouaziz, Ayoub Rifai, Patrick Pons, Philippe Menini, et al. To cite this version: Hervé Aubert, Franck Chebila, Mohamed Mehdi Jatlaoui, Trang Thai, Hamida Hallil, et al.. Wire- less Sensing and Identification of Passive Electromagnetic Sensors based on Millimetre-wave FMCW RADAR. IEEE RFID Technology & Applications, Nov 2012, Nice, France. 5p. hal-00796002 HAL Id: hal-00796002 https://hal.archives-ouvertes.fr/hal-00796002 Submitted on 1 Mar 2013 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Wireless Sensing and Identification of Passive Electromagnetic Sensors based on Millimetre-wave FMCW RADAR H. AUBERT, Senior Member, IEEE , F. CHEBILA, M. JATLAOUI, T. THAI, H. HALLIL, A. TRAILLE, S. BOUAZIZ, A. RIFAÏ , P. PONS, P. MENINI , M. TENTZERIS, Fellow, IEEE Abstract — The wireless measurement of various physical spectrum synthesized by the FMCW RADAR [12]. The quantities from the analysis of the RADAR Cross Sections wireless identification of sensors may then be based on variability of passive electromagnetic sensors is presented.
    [Show full text]
  • Multiband RF Circuits and Techniques for Wireless Transmitters Multiband RF Circuits and Techniques for Wireless Transmitters Wenhua Chen • Karun Rawat Fadhel M
    Wenhua Chen · Karun Rawat Fadhel M. Ghannouchi Multiband RF Circuits and Techniques for Wireless Transmitters Multiband RF Circuits and Techniques for Wireless Transmitters Wenhua Chen • Karun Rawat Fadhel M. Ghannouchi Multiband RF Circuits and Techniques for Wireless Transmitters 123 Wenhua Chen Fadhel M. Ghannouchi Tsinghua University University of Calgary Beijing Calgary, AB China Canada Karun Rawat Indian Institute of Technology Roorkee Roorkee India ISBN 978-3-662-50438-3 ISBN 978-3-662-50440-6 (eBook) DOI 10.1007/978-3-662-50440-6 Library of Congress Control Number: 2016940120 © Springer-Verlag Berlin Heidelberg 2016 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made.
    [Show full text]
  • Wideband UHF Antenna for Partial Discharge Detection
    applied sciences Article Wideband UHF Antenna for Partial Discharge Detection Zhen Cui 1, Seungyong Park 1, Hosung Choo 2 and Kyung-Young Jung 1,* 1 Department of Electronics Computer Engineering, Hanyang University, Seoul 04763, Korea; [email protected] (Z.C.); [email protected] (S.P.) 2 School of Electronic and Electrical Engineering, Hongik University, Seoul 04066, Korea; [email protected] * Correspondence: [email protected]; Tel.: +82-2-2220-2320 Received: 29 January 2020; Accepted: 27 February 2020; Published: 2 March 2020 Abstract: This paper presents a ultra-high frequency (UHF) antenna for partial discharge (PD) detection and the antenna sensor can be used near a conducting ground wire. The proposed UHF antenna has advantages of easy setup and higher-frequency detection over the high-frequency current transformer (HFCT) sensor. First, a variety of loop-shaped antennas are designed to compare each near field coupling capability. Then, a new UHF antenna is designed based on the loop-shaped antenna, which has the best near field coupling capability. Finally, the proposed UHF antenna is fabricated and measured. It provides a wide impedance bandwidth of 760 MHz (740–1500 MHz). Its simple setup configuration and wide bandwidth frequency response in the UHF band can provide a more efficient means for PD detection. Keywords: partial discharge; ultra-high frequency (UHF) antenna 1. Introduction With the significant increase in electric power consumption, power equipment is currently being developed towards large capacity, ultra-high voltage, and unmanned control. If such large capacity power equipment fails to work, in general, it takes considerable time to repair the entire system and resume electric power supply.
    [Show full text]