Dx Magazine 1/2010
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
Amateur Radio Technician Class Element 2 Course Presentation
Technician Licensing Class Antennas, feedlines T9A - T9B Valid July 1, 2018 Through June 30, 2022 Developed by Bob Bytheway, K3DIO, and 1 updated to 2018 Question Pool by NQ4K for Sterling Park Amateur Radio Club T 9 A Topics •Antennas: • vertical and horizontal polarization; • concept of gain; • common portable and mobile antennas; • relationships between resonant length and frequency; • concept of dipole antennas 2 T 9 A • A beam antenna concentrates signals in one direction. T9A01 3 T 9 A • A type of antenna loading is inserting an inductor in the radiating portion of the antenna to make it electrically longer. T9A02 4 T 9 A • A simple dipole mounted so that the conductor is parallel to the Earth’s surface is a horizontally polarized antenna. T9A03 • A disadvantage of the “rubber duck” antenna supplied with most handheld transceivers does not transmit or receive 5 as effectively as a full sized antenna. T9A04 T 9 A • To change a dipole antenna to make it resonant on a higher frequency, shorten it. T9A05 • The quad, Yagi, and dish antennas are directional antennas. T9A06 quad Yagi dish 6 T 9 A • A disadvantage of using a handheld VHF transceiver, with its integral antenna, inside a vehicle is that signals might not propagate well due to the shielding effect of the vehicle. T9A07 • The approximate length, in inches, of a quarter-wave vertical antenna for 146 MHz is 19”. T9A08 19” 7 T 9 A • The approximate length of a 6-meter, halfwave wire dipole antenna is 112 inches. T9A09 • The direction of radiation is strongest from a half-wave T9A10 dipole antenna in free space broadside to the antenna. -
Directional Or Omnidirectional Antenna?
TECHNOTE No. 1 Joe Carr's Radio Tech-Notes Directional or Omnidirectional Antenna? Joseph J. Carr Universal Radio Research 6830 Americana Parkway Reynoldsburg, Ohio 43068 1 Directional or Omnidirectional Antenna? Joseph J. Carr Do you need a directional antenna or an omnidirectional antenna? That question is basic for amateur radio operators, shortwave listeners and scanner operators. The answer is simple: It depends. I would like to give you a simple rule for all situations, but that is not possible. With radio antennas, the "global solution" is rarely the correct solution for all users. In this paper you will find a discussion of the issues involved so that you can make an informed decision on the antenna type that meets most of your needs. But first, let's take a look at what we mean by "directional" and "omnidirectional." Antenna Patterns Radio antennas produce a three dimensional radiation pattern, but for purposes of this discussion we will consider only the azimuthal pattern. This pattern is as seen from a "bird's eye" view above the antenna. In the discussions below we will assume four different signals (A, B, C, D) arriving from different directions. In actual situations, of course, the signals will arrive from any direction, but we need to keep our discussion simplified. Omnidirectional Antennas. The omnidirectional antenna radiates or receives equally well in all directions. It is also called the "non-directional" antenna because it does not favor any particular direction. Figure 1 shows the pattern for an omnidirectional antenna, with the four cardinal signals. This type of pattern is commonly associated with verticals, ground planes and other antenna types in which the radiator element is vertical with respect to the Earth's surface. -
Long-Wire Notes
Long-Wire Notes L. B. Cebik, W4RNL Published by antenneX Online Magazine http://www.antennex.com/ POB 72022 Corpus Christi, Texas 78472 USA Copyright 2006 by L. B. Cebik jointly with antenneX Online Magazine. All rights reserved. No part of this book may be reproduced or transmitted in any form, by any means (electronic, photocopying, recording, or otherwise) without the prior written permission of the author and publisher jointly. ISBN: 1-877992-77-1 Table of Contents Chapter Introduction to Long-Wire Technology.............................................5 1 Center-Fed and End-Fed Unterminated Long-Wire Antennas......19 2 Terminated End-Fed Long-Wire Directional Antennas..................57 3 V Arrays and Beams.....................................................................103 4 Rhombic Arrays and Beams.........................................................145 5 Rhombic Multiplicities ................................ ................................ ...187 Afterword: Should I or Shouldn't I.................................................233 Dedication This volume of studies of long-wire antennas is dedicated to the memory of Jean, who was my wife, my friend, my supporter, and my colleague. Her patience, understanding, and assistance gave me the confidence to retire early from academic life to undertake full-time the continuing development of my personal web site (http://www.cebik.com). The site is devoted to providing, as best I can, information of use to radio amateurs and others– both beginning and experienced–on various antenna and related topics. This volume grew out of that work–and hence, shows Jean's help at every step. Introduction to Long-Wire Technology Long wire antennas are very simple, economical, and effective directional antennas with many uses for transmitting and receiving waves in the MF (300 kHz-3 MHz) and HF (3-30 MHz) ranges. -
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. -
Iii © ABDELRAHMAN ELSIR MOHAMED 2017
© ABDELRAHMAN ELSIR MOHAMED 2017 iii Dedication This humbled work is dedicated to My great lovely PARENTS who instilled in me the passion of learning and who were my first teachers in this life and the scarified everything for my sake My sisters who inspired and supported me forever My brother, Abdelraheem iv ACKNOWLEDGMENTS I would like to express my sincere and deep gratitude for my great respected Professor, Mohmmad Sharawi, for the intensive knowledge and extreme support that I had while working with him. Moreover, I would like to acknowledge the valuable comments of Dr. Sharif Iqbal and Dr. Hussein Attia as examiners for this thesis. Finally, I like to express my profound gratitude for my family: my parents, my brother and my sisters for supporting me throughout the entire process. I also would like to thank all my friends especially Mr. Hussein Abdellatif. v TABLE OF CONTENTS ACKNOWLEDGMENTS ............................................................................................................. V TABLE OF CONTENTS ............................................................................................................. VI LIST OF TABLES ........................................................................................................................ IX LIST OF FIGURES ....................................................................................................................... X LIST OF ABBREVIATIONS .................................................................................................... XII ABSTRACT -
Antenna Theory (Sc: 25C)
SUBCOURSE EDITION SS0131 A US ARMY SIGNAL CENTER AND FORT GORDON ANTENNA THEORY (SC: 25C) EDITION DATE: FEBRUARY 2005 ANTENNA THEORY Subcourse Number SS0131 EDITION A United States Army Signal Center and Fort Gordon Fort Gordon, Georgia 30905-5000 5 Credit Hours Edition Date: February 2005 SUBCOURSE OVERVIEW This subcourse is designed to teach the theory, characteristic, and capabilities of the various types of tactical combat net radio, high frequency, ultra high frequency, very high frequency, and field expedient antennas. The prerequisites for this subcourse is that you are a graduate of the Signal Office Basic Course or its equivalent. This subcourse reflects the doctrine which was current at the time it was prepared. In your own work situation, always refer to the latest official publications. Unless otherwise stated, the masculine gender of singular pronouns is used to refer to both men and women. TERMINAL LEARNING OBJECTIVE ACTION: Explain the basic antenna theory and operations of combat net radio, high frequency, ultra high frequency, very high frequency, and field expedient antennas. CONDITION: Given this subcourse. STANDARD: To demonstrate competency of this subcourse, you must achieve a minimum of 70 percent on the subcourse examination. i SS0131 TABLE OF CONTENTS Section Page Subcourse Overview .................................................................................................................................... i Lesson 1: Antenna Principles and Characteristics ............................................................................ -
Antenna Catalog. Volume 3. Ship Antennas
UNCLASSIFIED AD NUMBER AD323191 CLASSIFICATION CHANGES TO: unclassified FROM: confidential LIMITATION CHANGES TO: Approved for public release, distribution unlimited FROM: Distribution authorized to U.S. Gov't. agencies and their contractors; Administrative/Operational use; Oct 1960. Other requests shall be referred to Ari Force Cambridge Research Labs, Hansom AFB MA. AUTHORITY AFCRL Ltr, 13 Nov 1961.; AFCRL Ltr, 30 Oct 1974. THIS PAGE IS UNCLASSIFIED AD~ ~~~~~~O WIR1L_•_._,m,_, ANTENNA CATALOG Volume m UNCLASSIFIED SHIP ANTENN October 1960 Electronics Research Directorate AIR FORCE CAMBRIDGE RESEARCH LABORATORIES Can+rftc AT I9(6N4,4 101 by GEORGIA INSTITUTE OF TECHNOLOGY Engineering Experiment Station •o•log NOTIC 11ý4 Sadoqh amd P4is4,ej ww~aI~.. 1! d' ths, . 'to0 t,UL .. -+~~~~~-L#..-•...T... -w 0 I tdin #" "•: ..."- C UNCLASSIFIED AFCRC-TR-60-134(111) ANTENNA CATALOG Volume III SHIP ANTENNAS (Title UOwlnIied) October 1960 Appeoved: Mmurice W. Long, Electronics Division Submitteds A oed: Technical Information Section k Jeme,. L d, Directot Esis..ielng Expe•immnt Station Prepared by GEORGIA INSTITUTE OF TECHNOLOGY Engineering Experiment Station DOWNGRADED A-r 3 YEAR INTERVAIS. DECL~IFED AFTER 12 YEA&RS. DOD DIR 5200.10 UNC-LASSIFIED. , ~K-11. 574-1 ." TABLE OF CONTENTS Page INTRODUCTION . 1 EQUIPMENT FUNCTION ................ .................. ... 3 ANTENNA TYPE . 7 ANTENNA DATA AB Antennas ......... ................. .............. ...................... ... 15 AN Antennas ............................ ...................................... -
Wideband Rectenna System for Microwave Power Transfer
Wideband Rectenna System for Microwave Power Transfer by Mohammed Aldosari A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master of Applied Science in Electrical and Computer Engineering Waterloo, Ontario, Canada, 2018 ©Mohammed Aldosari 2018 AUTHOR'S DECLARATION I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract One of the fundamental devices in Microwave Power Transfer (MPT) is the rectenna or rectifying antenna, which collects the electromagnetic energy from the free space and convert it directly to a useful DC power. Although many designs of rectenna systems have been proposed, most of them operate in a narrowband frequency and/or a certain level of incident power, which limits the output DC power and the uses of the rectenna. In this work, three novel designs of the rectenna that operate in broadband frequency and wide range of received power are developed. The design methodology for such critical characteristics for the rectenna has been discussed in details. Furthermore, the presented wideband rectennas have the best results comparing to the literature in terms of frequency bandwidth and power range, which indicates great achievement in terms of increasing the output DC power significantly as a result of decreasing the effect of the variation of the frequency and incident power and the ability of harvesting multiple frequencies simultaneously. Furthermore, the wideband rectenna can be considered as an approach to minimize the number of the used rectennas by having a single rectenna that operates in a wide frequency bandwidth and wide range of incident power. -
Highlights of Antenna History
~~ IEEE COMMUNICATIONS MAGAZINE HlOHLlOHTS OF ANTENNA HISTORY JACK RAMSAY A look at the major events in the development of antennas. wires. Antenna systems similar to Edison’s were used by A. E. Dolbear in 1882 when he successfully and somewhat mysteriously succeeded in transmitting code and even speech to significant ranges, allegedly by groundconduction. NINETEENTH CENTURY WIRE ANTENNAS However, in one experiment he actually flew the first kite T is not surprising that wire antennas were inaugurated antenna.About the same time, the Irish professor, in 1842 by theinventor of wire telegraphy,Joseph C. F. Fitzgerald, calculated that a loop would radiate and that Henry, Professor’ of Natural Philosophy at Princeton, a capacitance connected to a resistor would radiate at VHF NJ. By “throwing a spark” to a circuit of wire in an (undoubtedly due to radiation from the wire connecting leads). Iupper room,Henry found that thecurrent received in a In Hertz launched,processed, and received radio 1887 H. parallel circuit in a cellar 30 ft below codd.magnetize needies. waves systematically. He used a balanced or dipole antenna With a vertical wire from his study to the roof of his house, he attachedto ’ an induction coilas a transmitter, and a detected lightning flashes 7-8 mi distant. Henry also sparked one-turn loop (rectangular) containing a sparkgap as a to a telegraph wire running from his laboratory to his house, receiver. He obtained “sympathetic resonance” by tuning the and magnetized needles in a coil attached to a parailel wire dipole with sliding spheres, and the loop by adding series 220 ft away. -
A Multi-Tone Rectenna System for Wireless Power Transfer
energies Article A Multi-Tone Rectenna System for Wireless Power Transfer Simone Ciccia 1,* , Alberto Scionti 1, Giuseppe Franco 1, Giorgio Giordanengo 1 , Olivier Terzo 1 and Giuseppe Vecchi 2 1 Advanced Computing and Application, LINKS Foundation, 10138 Torino, Italy; [email protected] (A.S.); [email protected] (G.F.); [email protected] (G.G.); [email protected] (O.T.) 2 Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Torino, Italy; [email protected] * Correspondence: [email protected] Received: 3 April 2020; Accepted: 4 May 2020; Published: 9 May 2020 Abstract: Battery-less sensors need a fast and stable wireless charging mechanism to ensure that they are being correctly activated and properly working. The major drawback of state-of-the-art wireless power transfer solutions stands in the maximum Equivalent Isotropic Radiated Power (EIRP) established from local regulations, even using directional antennas. Indeed, the maximum transferred power to the load is limited, making the charging process slow. To overcome such limitation, a novel method for implementing an effective wireless charging system is described. The proposed solution is designed to guarantee many independent charging contributions, i.e., multiple tones are used to distribute power along transmitted carriers. The proposed rectenna system is composed by a set of narrow-band rectifiers resonating at specific target frequencies, while combining at DC. Such orthogonal frequency schema, providing independent charging contributions, is not affected by the phase shift of incident signals (i.e., each carrier is independently rectified). The design of the proposed wireless-powered system is presented. -
Antennas and Power Products for Wireless Communications Devices
global solutions : local support 25 YEARS OF TECHNOLOGY LEADERSHIP Centurion Wireless Technologies, a Laird Technologies company, is a designer and manufacturer of antennas and power products for wireless communications devices. For over 25 years, industry leading manufacturers and installers of mobile phones, handheld devices, in-building wireless systems, PDAs, professional business radios and automobiles have relied on the quality and reliability of Centurion's products. Centurion offers in-house cus- tomer design, tooling, mold fitting and production to provide a complete turnkey solution to fit any customer-spe- cific need. With eight design, manufacturing and sales facilities around the globe, Centurion has one of the largest and most talented R&D and sales support teams in the industry. A UNIT OF LAIRD TECHNOLOGIES Centurion's parent, Laird Technologies, manufactures a wide range of EMI shielding materials and related prod- ucts for the computer, telecommunications, aerospace, defense, medical, automotive and general electronics industries. These products include engineered board level shields, fingerstock, conductive elastomers in extrud- ed profiles, molded shapes and form-in-place gaskets, fabric-over-foam and a full range of shielded windows, cus- tom metal stampings, knitted wire mesh and ventilation panels. Also offered are microwave absorber products, thermal interface materials, integrated metal printed circuit boards and thermally conductive circuit board lami- nation adhesives, and a complete EMC and product engineering and testing service. COMMITMENT TO QUALITY Centurion has the ISO 9001:2000 quality assurance program in place at all phases of design and development in their Westminster, Akersberga and Beijing facilities. Centurion is one of the only antenna manufacturers in the world to have received QS-9000 certification for its automotive antennas — a mark of unprecedented quality set by the automotive industry — at their Lincoln, Penang and Shanghai locations. -
Locked out of the Action? I I I 117 O 3 932 6 8
Volume 14, Number 7 July 1995 U.S. $3.95 Can. $6.25 Printed in the United States \ 1 DD SPECIAL REPORT: Radio FD o After the OKC Bomb A Publication of Boss on Grove Enterprises, Inc. Air Wheels: Have Tower will Travel Will Your Scanner Be Locked Out of the Action? i i i 117 o 3 932 6 8 www.americanradiohistory.com You Miss a Thing With SCOUT'" The SCOUT" Has Taken Tuning Your Receiver To a New Dimension Featuring Automatic Tuning of your AR8000 and AR2700 with the Optoelectronics Exclusive, Reaction Tune (rat.Pend). Any frequen- cy captured by the Scout will instantly tune the receiver. Imagine the possibilities! End the frus- tration of seeing two -way communications with- out being able to pick up the frequency on your portable scanner. Attach the Scout and AR8000/2700 to your belt and capture up to 400 frequencies and 255 hits per frequency. Or mount the Scout and AR8000/2700 in your car and cruise your way into the future of scan A simple interface cable will connect u to a whole new dimension of scanning. The Scout's unique Memory Tune (Pat.Pend.) 'Scanner not included feature allows you to capture frequencies, log into memory and tune your AR8000 /2700 at a Features later time. A distinctive double beep will inform Automatically tunes these receivers with Reaction Tune you when the Scout has captured a new frequen- (Pat Pend .)CI -V receivers (ICOM's R7000, R7100, and R9000), (Pro 2005/2006 equipped with OS456, Pro 2035 cy, while a single beep indicates a frequency that equipped with 0S535) or AOR models (AR2700 and been recorded.