Đang tải... (xem toàn văn)
Ấn bản thứ ba của Lý thuyết ăngten được thiết kế để đáp ứng nhu cầu của sinh viên vật lý và kỹ thuật điện ở cấp đại học cao cấp và mới bắt đầu học cao học, cũng như nhu cầu của các kỹ sư thực hành. Văn bản giả định rằng sinh viên có kiến thức về lý thuyết điện từ cơ bản bậc đại học, bao gồm các phương trình Maxwell và phương trình sóng, vật lý nhập môn, phép tính vi phân và tích phân. Các kỹ thuật toán học cần thiết để hiểu một số chủ đề nâng cao trong các chương sau được kết hợp trong các chương riêng lẻ hoặc được đưa vào dưới dạng phụ lục.
ANTENNA THEORY ANALYSIS AND DESIGN THIRD EDITION Constantine A Balanis A JOHN WILEY & SONS, INC., PUBLICATION Copyright 2005 by John Wiley & Sons, Inc All rights reserved Published by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400, fax 978-646-8600, or on the web at www.copyright.com Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008 Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages For general information on our other products and services please contact our Customer Care Department within the U.S at 877-762-2974, outside the U.S at 317-572-3993 or fax 317-572-4002 Wiley also publishes its books in a variety of electronic formats Some content that appears in print, however, may not be available in electronic format Library of Congress Cataloging-in-Publication Data is available ISBN: 0-471-66782-X Printed in the United States of America 10 Preface The third edition of Antenna Theory is designed to meet the needs of electrical engineering and physics students at the senior undergraduate and beginning graduate levels, and those of practicing engineers The text presumes that the students have knowledge of basic undergraduate electromagnetic theory, including Maxwell’s equations and the wave equation, introductory physics, and differential and integral calculus Mathematical techniques required for understanding some advanced topics in the later chapters are incorporated in the individual chapters or are included as appendices The third edition has maintained all of the attractive features of the first two editions, including the three-dimensional graphs to display the radiation characteristics of antennas, especially the amplitude patterns This feature was hailed as an innovative and first of its kind addition in a textbook on antennas Additional graphs have been added to illustrate features of the radiation characteristics of some antennas However, there have been many new features added to this edition In particular, ž ž ž ž ž ž A new chapter on Smart Antennas (Chapter 16) A section on Fractal Antennas (Section 11.6) Summary tables of important equations in the respective chapters (Chapters 2, 4, 5, 6, 12–14) New figures, photos, and tables Additional end-of-the-chapter problems CD with the following Multimedia Material: ž Power Point view graphs of lecture notes for each chapter, in multicolor ž End-of-the-chapter Interactive Questionnaires for review (40–65 for each chapter) based on Java ž Animations based on Java ž Applets based on Java ž MATLAB programs translated from the FORTRAN programs of the second edition ž A number of new MATLAB programs ž FORTRAN programs from the second edition The CD is attached to the book, and it will open automatically once inserted in the computer It is highly recommended that the reader uses the Internet Explorer (IE) to open the Multimedia Material; other browsers may not perform well For additional instructions on how to open and use the material in the CD, there is a HELP file in the CD xiii xiv PREFACE The book’s main objective is to introduce, in a unified manner, the fundamental principles of antenna theory and to apply them to the analysis, design, and measurements of antennas Because there are so many methods of analysis and design and a plethora of antenna structures, applications are made to some of the most basic and practical configurations, such as linear dipoles; loops; arrays; broadband, and frequency-independent antennas; aperture antennas; horn antennas; microstrip antennas; and reflector antennas A tutorial chapter on Smart Antennas has been included to introduce the student in a technology that will advance antenna theory and design, and revolutionize wireless communications It is based on antenna theory, digital signal processing, networks and communications MATLAB simulation software has also been included, as well as a plethora of references for additional reading Introductory material on analytical methods, such as the Moment Method and Fourier transform (spectral) technique, is also included These techniques, together with the fundamental principles of antenna theory, can be used to analyze and design almost any antenna configuration A chapter on antenna measurements introduces state-of-theart methods used in the measurements of the most basic antenna characteristics (pattern, gain, directivity, radiation efficiency, impedance, current, and polarization) and updates progress made in antenna instrumentation, antenna range design, and scale modeling Techniques and systems used in near- to far-field measurements and transformations are also discussed A sufficient number of topics have been covered, some for the first time in an undergraduate text, so that the book will serve not only as a text but also as a reference for the practicing and design engineer and even the amateur radio buff These include design procedures, and associated computer programs, for Yagi–Uda and log-periodic arrays, horns, and microstrip patches; synthesis techniques using the Schelkunoff, Fourier transform, Woodward–Lawson, Tschebyscheff, and Taylor methods; radiation characteristics of corrugated, aperture-matched, and multimode horns; analysis and design of rectangular and circular microstrip patches; and matching techniques such as the binomial, Tschebyscheff, T-, gamma, and omega matches The text contains sufficient mathematical detail to enable the average undergraduate electrical engineering and physics students to follow, without too much difficulty, the flow of analysis and design A certain amount of analytical detail, rigor, and thoroughness allows many of the topics to be traced to their origin My experiences as a student, engineer, and teacher have shown that a text for this course must not be a book of unrelated formulas, and it must not resemble a “cookbook.” This book begins with the most elementary material, develops underlying concepts needed for sequential topics, and progresses to more advanced methods and system configurations Each chapter is subdivided into sections or subsections whose individual headings clearly identify the antenna characteristic(s) discussed, examined, or illustrated A distinguished feature of this book is its three-dimensional graphical illustrations from the first edition, which have been expanded and supplemented in the second and third editions In the past, antenna texts have displayed the three-dimensional energy radiated by an antenna by a number of separate two-dimensional patterns With the advent and revolutionary advances in digital computations and graphical displays, an additional dimension has been introduced for the first time in an undergraduate antenna text by displaying the radiated energy of a given radiator by a single threedimensional graphical illustration Such an image, formed by the graphical capabilities of the computer and available at most computational facilities, gives a clear view of PREFACE xv the energy radiated in all space surrounding the antenna It is hoped that this will lead to a better understanding of the underlying principles of radiation and provide a clearer visualization of the pattern formation in all space In addition, there is an abundance of general graphical illustrations, design data, references, and an expanded list of end-of-the chapter problems Many of the principles are illustrated with examples, graphical illustrations, and physical arguments Although students are often convinced that they understand the principles, difficulties arise when they attempt to use them An example, especially a graphical illustration, can often better illuminate those principles As they say, “a picture is worth a thousand words.” Numerical techniques and computer solutions are illustrated and encouraged A number of MATLAB computer programs are included in the CD attached to the book Each program is interactive and prompts the user to enter the data in a sequential manner Some of these programs are translations of the FORTRAN ones that were included in the first and second editions However, many new ones have been developed Every chapter, other than Chapters and 17, have at least one MATLAB computer program; some have as many as four The outputs of the MATLAB programs include graphical illustrations and tabulated results For completeness, the FORTRAN computer programs are also included, although there is not as much interest in them The computer programs can be used for analysis and design Some of them are more of the design type while some of the others are of the analysis type Associated with each program there is a READ ME file, which summarizes the respective program The purpose of the Lecture Notes is to provide the instructors a copy of the text figures and some of the most important equations of each chapter They can be used by the instructors in their lectures but need to be supplemented with additional narratives The students can use them to listen to the instructors’ lectures, without having to take detailed notes, but can supplement them in the margins with annotations from the lectures Each instructor will use the notes in a different way The Interactive Questionnaires are intended as reviews of the material in each chapter The student can use them to review for tests, exams, and so on For each question, there are three possible answers, but only one is correct If the reader chooses one of them and it the correct answer, it will so indicate However, if the chosen answer is the wrong one, the program will automatically indicate the correct answer An explanation button is provided, which gives a short narrative on the correct answer or indicates where in the book the correct answer can be found The Animations can be used to illustrate some of the radiation characteristics, such as amplitude patterns, of some antenna types, like line sources, dipoles, loops, arrays, and horns The Applets cover more chapters and can be used to examine some of the radiation characteristics (such as amplitude patterns, impedance, bandwidth, etc.) of some of the antennas This can be accomplished very rapidly without having to resort to the MATLAB programs, which are more detailed For course use, the text is intended primarily for a two-semester (or two- or threequarter) sequence in antenna theory The first course should be given at the senior undergraduate level, and should cover most of the material in Chapters through 7, and Chapters 16 and 17 The material in Chapters through 16 should be covered in a beginning graduate-level course Selected chapters and sections from the book can be covered in a single semester, without loss of continuity However, it is almost essential that most of the material in Chapters through be covered in the first course and before proceeding to any more advanced topics To cover all the material of the text xvi PREFACE in the proposed time frame would be, in some cases, a very ambitious task Sufficient topics have been included, however, to make the text complete and to give the teacher the flexibility to emphasize, deemphasize, or omit sections or chapters Some of the chapters and sections can be omitted without loss of continuity In the entire book, an ej ωt time variation is assumed, and it is suppressed The International System of Units, which is an expanded form of the rationalized MKS system, is used in the text In some cases, the units of length are in meters (or centimeters) and in feet (or inches) Numbers in parentheses () refer to equations, whereas those in brackets [] refer to references For emphasis, the most important equations, once they are derived, are boxed In some of the basic chapters, the most important equations are summarized in tables I would like to acknowledge the invaluable suggestions from all those that contributed to the first and second editions, too numerous to mention here Their names and contributions are stated in the respective editions It is a pleasure to acknowledge the invaluable suggestions and constructive criticisms of the reviewers of the third edition: Dr Stuart A Long of University of Houston, Dr Christos Christodoulou of University of New Mexico, Dr Leo Kempel of Michigan State, and Dr Sergey N Makarov of Worcester Polytechnic University There have been many other contributors to this edition, and their contributions are valued and acknowledged Many graduate and undergraduate students from Arizona State University who have written many of the MATLAB computer programs Some of these programs were translated from the FORTRAN ones, which appeared in the first and second editions However a number of entirely new MATLAB programs have been created, which are included for the first time, and not have a FORTRAN counterpart The name(s) of the individual contributors to each program is included in the respective program The author acknowledges Dr Sava V Savov of Technical University of Varna, Bulgaria, for the valuable discussions, contributions and figures related to the integration of equation (5-59) in closed form in terms of Bessel functions; Dr Yahya RahmatSamii and Dr John P Gianvittorio of UCLA for the figures on Fractal antennas I would like to thank Craig R Birtcher of Arizona State University for proofreading part of the manuscript; Bo Yang of Arizona State University for proofreading part of the manuscript, revising a number of the MATLAB programs, and developing the flow chart for accessing the CD Multimedia material; and Razib S Shishir of Arizona State University for developing all of the Java-based software, including the Interactive Questionnaires, Applets, and Animations Special thanks to the many companies (Motorola, Inc., Northrop Grumman Corporation, March Microwave Systems, B.V., Ball Aerospace & Technologies Corporation, Samsung, Midland Radio Corporation, Winegard Company, Antenna Research Associates, Inc., Seavey Engineering Associates, Inc., and TCI, A Dielectric Company) for providing photos, illustrations, and copyright permissions The author acknowledges the long-term friendship and support from Dennis DeCarlo, George C Barber, Dr Karl Moeller, Dr Brian McCabe, Dr W Dev Palmer, Michael C Miller, Frank A Cansler, and the entire AHE Program membership, too long to be included here The friendship and collaborative arrangements with Prof Thodoros D Tsiboukis and Prof John N Sahalos, both from the Aristotle University of Thessaloniki, Greece, are recognized and appreciated The loyalty and friendship of my graduate students is acknowledged and valued To all my teachers, thank you You have been my role models and inspiration PREFACE xvii I am also grateful to the staff of John Wiley & Sons, Inc., especially George Telecki, Associate Publisher, Wiley-Interscience, for his interest, support, cooperation, and production of the third edition; Danielle Lacourciere, Associate Managing Editor, for the production of the book; and Rachel Witmer, Editorial Assistant, for managing the production of the cover Finally, I must pay tribute to my family (Helen, Renie, and Stephanie) for their support, patience, sacrifice, and understanding for the many hours of neglect during the completion of the first, second, and third editions of this book It has been a pleasant but daunting task Constantine A Balanis Arizona State University Tempe, AZ Contents Preface xiii Antennas 1.1 1.2 1.3 1.4 1.5 1.6 Introduction Types of Antennas Radiation Mechanism Current Distribution on a Thin Wire Antenna Historical Advancement Multimedia References Fundamental Parameters of Antennas 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 Introduction Radiation Pattern Radiation Power Density Radiation Intensity Beamwidth Directivity Numerical Techniques Antenna Efficiency Gain Beam Efficiency Bandwidth Polarization Input Impedance Antenna Radiation Efficiency Antenna Vector Effective Length and Equivalent Areas Maximum Directivity and Maximum Effective Area Friis Transmission Equation and Radar Range Equation Antenna Temperature Multimedia References Problems 1 17 20 24 24 27 27 27 38 40 42 44 58 64 65 69 70 70 80 85 87 92 94 104 108 112 114 vii viii CONTENTS Radiation Integrals and Auxiliary Potential Functions 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Introduction The Vector Potential A for an Electric Current Source J The Vector Potential F for a Magnetic Current Source M Electric and Magnetic Fields for Electric (J) and Magnetic (M) Current Sources Solution of the Inhomogeneous Vector Potential Wave Equation Far-Field Radiation Duality Theorem Reciprocity and Reaction Theorems References Problems Linear Wire Antennas 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 Introduction Infinitesimal Dipole Small Dipole Region Separation Finite Length Dipole Half-Wavelength Dipole Linear Elements Near or on Infinite Perfect Conductors Ground Effects Computer Codes Multimedia References Problems Loop Antennas 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 Introduction Small Circular Loop Circular Loop of Constant Current Circular Loop with Nonuniform Current Ground and Earth Curvature Effects for Circular Loops Polygonal Loop Antennas Ferrite Loop Mobile Communication Systems Applications Multimedia References Problems Arrays: Linear, Planar, and Circular 6.1 6.2 6.3 6.4 Introduction Two-Element Array N -Element Linear Array: Uniform Amplitude and Spacing N -Element Linear Array: Directivity 133 133 135 137 138 139 142 144 144 150 150 151 151 151 162 165 170 182 184 205 214 217 218 219 231 231 232 246 255 261 263 266 268 269 273 275 283 283 284 290 313 Index Terms Polarization Links 70 See also Circular polarization elliptical 576 helical antenna 570 long-wire antenna 558 of a radiated wave 71 source antenna 1024 spiral slot antennas 618 Polarization efficiency 76 Polarization ellipse Polarization loss factor (PLF) Polarization measurements 97 1041 76 1040 1038 “Polarization mismatch,” 76 77 Polarization pattern 72 1041 Polar plots 1025 Polygonal loop antennas 263 Potential functions 133 138 95 97 Power density constant-current circular loop 249 half-wavelength dipole 182 small loop 237 parabolic reflector 911 Power pattern Power Point (PPT) viewgraphs 913 27 28 491 636 38 39 154 177 See also Multimedia resources Poynting vector dipole Poynting vector method Primary polarization Principal patterns Principal term 154 173 434 1035 33 368 This page has been reformatted by Knovel to provide easier navigation Index Terms Printed-circuit technology Probe compensation technique Proceedings of IRE Proceedings of the IEEE Links 521 1015 578 Propagating waves 707 Propagation constant 705 Propagation factor 704 Protocol 978 MANET 578 980 “Pseudoperiodic” field strength 892 Pulse basis point-matching 456 “Pulse” functions 437 452 Pyramidal horn 769 782 constructing 772 Pyramidal Horn-Analysis program 780 802 Pyramidal Horn-Design program 781 802 Q Q method 239 “Quad” antenna 599 Quadratic distribution 419 Quadratic phase error 784 Quadratic phase term 741 Quadrature Phase Shift Keying (QPSK) 991 Quality factors, microstrip antennas 852 Quarter-wavelength monopole 191 Quarter-wavelength transformer 523 Quarterwave program 531 541 Quasistationary fields 158 241 “Quiet zone,” 1003 1008 Quiet-zone fields 1010 Quiet-zone ripple 1008 742 783 195 1010 This page has been reformatted by Knovel to provide easier navigation Index Terms Q values electrically small antennas Links 646 639 R Radar cross section(RCS) methods of predicting Radar IEEE band designations Radar Range Equation Radial waveguide Radian 96 97 98 99 1097 94 96 740 756 36 37 Radian distance 156 Radian sphere 157 Radiated fields 151 asymptotic evaluation of 707 biconical antenna 501 constant-current circular loop 246 E-plane sectoral horn 743 H-plane sectoral horn 757 loop antenna 233 pyramidal horn 772 rectangular aperture 677 171 703 168 Radiated power circular patch antenna 849 horizontal electric dipole 201 vertical electric dipole 190 Radiated wave, polarization of 71 Radiating near-field (Fresnel) region 34 165 833 835 Radiating slots Radiation characteristics for circular apertures and circular planar arrays 422t corrugated horn 791f helical antenna 567 This page has been reformatted by Knovel to provide easier navigation Index Terms Links Radiation characteristics (Cont.) loop antennas 269 parabolic reflector 899 rhombic antenna 565 two-element loop array 599 Radiation efficiency 97 See also Efficiency measurements of 1036 of small circular loops 240 small loop 239 Radiation energy, optimizing Radiation equations 660 Radiation fields circular aperture 686 rectangular apertures 666 688t Radiation intensity 40 broadside array 314 constant-current circular loop 252 dipole 173 end-fire array 316 half-wavelength dipole 182 Hansen-Woodyard end-fire array 310 317 horizontal electric dipole 201 203 paraboloidal reflector 901 small loop 242 vertical electric dipole 190 Radiation intensity patterns, three-dimensional Radiation mechanism, aperture-matched horns 46 54 160 47f 793 Radiation pattern lobes 30 Radiation patterns 17 cylindrical dipole antennas 511 electromagnetic horns 797 This page has been reformatted by Knovel to provide easier navigation Index Terms Links Radiation patterns (Cont.) measuring 1021 polygonal loop antennas 266 reciprocity for 148 Radiation power density 1035 38 See also Power density Radiation problems, computer animation-visualization of 15 Radiation resistance biconical antenna 503 computing 180 constant-current circular loop 252 dipole 179 ferrite loop 266 half-wavelength dipole 184 horizontal electric dipole 201 long wire antenna 559 loop antenna 231 small loop 238 vertical electric dipole 191 Radiators, polarization state of 1041 Radio frequency spectrums 1096 Radio systems, cellular 947 Random error efficiency 913 Random fractals 642 Range maps 956 Ray tracing 900 Reaction Reactive near-field region 161 165 177 259f 203 258 192f 1005 Rayleigh fading RCS control methods 155 992 99 146 34 165 170 This page has been reformatted by Knovel to provide easier navigation Index Terms Reactive power density Receiving antenna, polarization of Links 155 1040 Receiving field pattern 149 Receiving loop, ferrite-loaded 267 Receiving mode 79 coupling in 481 Reciprocal network 469 Reciprocity for antenna radiation patterns 148 theorems 144 for two antennas 147 Recording equipment 1025 Rectangular anechoic chambers 1005 1006f 420 663 Rectangular apertures design considerations for 693 on an infinite electric ground plane 665 712 TE10-mode distribution on an infinite ground plane uniform distribution in space Rectangular array Rectangular coordinates 679 676 351 352 1084 Rectangular loop antennas 265 Rectangular microstrip antennas 819 843 Rectangular patch antenna 816 864 Rectangular patch arrangements 860f Rectangular pyramidal horn 797 Rectangular-to-cylindrical transformations 1079 Rectangular-to-polar graphical solution 322 Rectangular-to-spherical transformations 661 Reference aperture voltage 716 Reference terminals 983 1083 65f This page has been reformatted by Knovel to provide easier navigation Index Terms Links Reflection from flat and spherical surfaces 210f law of 186 Reflection coefficient 205 magnitude of 485f variations of 490 Reflection point, determination of Reflection ranges corner reflector 884 multimedia resources 936 parabolic reflector 893 plane reflector 883 software package for 926 spherical reflector 934 Reflector edge treatments 1009 Reflector efficiencies, maximum 920 Reflector program 937 Reflectors See also Reflector antennas feed for 800 579 Reflector systems, geometrical configuration for 884f Region separation 165 827 Request-To-Send (RTS) signal 980 580 85 Residuals 368 Resistive sheet problem 485 Resolution capability 883 66 Repulsive mechanism Reradiated power 1037 1003 Relative gain 837 213 Reflector antennas Yagi-Uda antenna 207 456 43 Resonance, cylindrical dipole antennas 510 Resonance forms 269 Resonant antenna 550 This page has been reformatted by Knovel to provide easier navigation Index Terms Resonant frequencies, microstrip antennas Links 819 830 845 Resonant input resistance circular patch antenna 851 microstrip antennas 822 Resonant wire antennas 559 Retractable/telescopic monopole 195 Return loss 983 RF absorbers 1005 Rhombic antenna 565 Rhombic loop antennas 265 Right-hand polarization 72 Root-matching method 388 Root-MUSIC algorithm 964 Rotational mounts 1025 Rough surface statistics 212 Rumsey’s equation 612 RXTRN training packet 980 1027 S Safety factor 348 Scalar horn 787 Scalar potential 136 Scale modeling 611 1029 Scale model measurements 208 1044 Scaling factor, Taylor design 407 Scalloping 189 788f 926 201 Scan angle array impedance and 483 versus normalized element impedance 487f Scan angular volume 866 Scan blindness 491 Scanning, principle of 304 489f 866 867 This page has been reformatted by Knovel to provide easier navigation Index Terms Links Scanning arrays 300 Scanning surfaces, near-field to far-field methods Scattered (reradiated) power 362 1015 85 Scattered electric field 443 444 Scattered fields 100 908 Scattered power density Scattering Scattering area 97 434 90 Schelkunoff polynomial method 388 498 Sectoral array 196 284 Sectoral pattern 394 398 Sectoring 949 950f Self And Mutual Impedances program 472 Self-impedance 433 Self-reactance 466f Self-resistance 466f Sense of rotation 1039 Sensitivity factor 346 Series-feed network 865 Series type resonance 195 Shadowing 927 Shannon sampling theorem 400 Shaped reflectors 895 Shaping method 99 458 1036 1040 1042 269 Short-circuited stub 523 Short dipole, impedances of 488 Side-by-side configuration 472 475f circular aperture 687 688t rectangular apertures 672t 674 476f Side lobe level Side lobe reduction 677 680 795 This page has been reformatted by Knovel to provide easier navigation Index Terms Sidelobes Links 31 Hansen-Woodyard end-fire array 319 relation to amplitude distribution 417 Taylor (One-Parameter) design 411 32 triangular, cosine, and cosine-squared distributions 418t Sierpinski gasket 643 Signal fading 956 See also Fading entries Signal propagation, smart antennas 954 Signals-not-of-interest (SNOIs) 947 951 952 955 959 981 952 955 959 990 990 Signals-of-interest (SOIs) 947 951 Signal-to-interference ratio (SIR) 957 987 Signal-to-noise ratio (SNR) 957 Sine integrals Single hop connectivity 1053 977 Single parabolic-cylinder reflector system 1013 Single paraboloidal reflector CATR design 1010 Single-Plane Collimating Range (SPCR) 1013 Single section quarter-wavelength transformer 523 Single-slot directivity, microstrip antennas 840 Single wire radiation mechanism Sinusoidal current distribution 463 Slant ranges 1005 Slaw wave 551 Slightly rough surface 212 Slot antennas 699 linearly polarized, flush-mounted, log-periodic 623 spiral 617 718 Small antennas See Electrically small antennas Small circular loop antenna 232 This page has been reformatted by Knovel to provide easier navigation Index Terms Small dipole current distribution of Links 162 163 Small loop design procedure for 260 infinitesimal magnetic dipole and 237 maximum effective aperture of 243 power density and radiation resistance of 237 radiation efficiency of 240 Small loop approximation 252 Smart antennas 22 24 945 See also Smart antenna systems antenna beamforming 962 antenna elements 958 beamforming, diversity combining, Rayleigh-fading, and trellis-coded modulation 990 benefits and drawbacks of 957 cellular radio systems evolution 947 geometries 993 MANETs 977 multimedia resources 994 signal propagation 954 system design and simulation 982 Smart-antenna systems capacity of 949 954 Smart program 973 Smith chart 537 Snell’s law of reflection 898 Snell’s law of refraction 206 Soft/hard surfaces 23 Solid angle 36 995 207 This page has been reformatted by Knovel to provide easier navigation Index Terms Links Source antennas 1024 Source modeling 447 Source node (SRC) 980 Space-attenuation 1008 Space Division Multiple Access (SDMA) 952 978 Space factor 171 386 circular aperture 421 line-source distribution 393 rectangular distribution 420 Taylor (One-Parameter) design 406 411 triangular, cosine, and cosine-squared distributions two-dimensional distribution 418t 666 Spatial Division Multiple Access (SDMA) 952 Spatial processing 945 Spectral techniques 703 711 Spherical aberration 934 936 Spherical coordinates 1085 Spherical phase term 742 783 Spherical reflector 894 934 Spherical surface near-field measurements 1017 Spherical-to-cylindrical transformations 1082 Spherical-to-rectangular transformations 1083 Spherical vector waves (modes) 637 Spillover efficiency 913 Spiral slot antennas 617 Spiral wire antennas 615 Square aperture 683 Square loop antennas 264 Square patch 861 Standard gain horn 780 Standing wave antennas 550 915 920 863 864f 921f This page has been reformatted by Knovel to provide easier navigation Index Terms Links Standing waves Stationary phase method 707 Stationary points 708 Steradian 36 Structural scattering term 102 Stub-matching 523 Subdomain functions 452 Subroutines of Directivity program integral computer 64 438 Subspace DOA estimation methods 964 Superdirective arrays 326 Superdirectivity 345 Super gain 346 Surface geometry, paraboloidal reflector 896 Surface reactance, corrugated surface 789 Surface roughness effects 924 Surface wave antenna 551 Swept-frequency instrumentation 1030f Switched-beam systems 950 Switched-line phase shifter 301 Symmetrical loading 799 Symmetrical planar folded dipoles 521 Synthesis 385 See also Antenna synthesis Synthesis program 417 System noise power 107 System noise temperature 108 423 T Tai & Pereira formula Tapered anechoic chambers 54 1005 This page has been reformatted by Knovel to provide easier navigation Index Terms Links Tapered antenna 498f Taper efficiency 913 Taylor design, procedure for 408 Taylor Line-Source (One-Parameter) design 362 410 Taylor Line-Source (Tschebyscheff-Error) design 362 363 916 920 921f 923 406 TE10-mode distribution, on an infinite ground plane TE11-mode distribution on an infinite ground plane 679 796 690 Tee program 533 Te_horn program 802 Television frequency spectrums 542 1095 TE mode, parabolic reflector 926 Temperature, antenna 104 Terminal voltage 482 Terminated V antennas 560 Terminating impedance 481 562f See also Aperture admittance Termination, long wire antenna 557 Termination (load) impedance 636 Termination resistance, long wire antenna 557 Test antenna Testing functions Theorem of similitude Thevenin equivalent circuit 1001 455 1045 83 Thick dipoles 508 Thin dipoles 508 amplitude patterns for Thin wire antenna, current distribution on 1033 84f 174f 17 Three-antenna absolute polarization method 1043 Three-antenna gain measurement technique 1031 This page has been reformatted by Knovel to provide easier navigation Index Terms Links Three-dimensional amplitude patterns 298f Three-dimensional array factor 297 Three-dimensional field pattern, rectangular aperture 667 669f Three-dimensional programs 48 3-D Spherical program 48 109 Throughput 959 978 Time-average power density 158 249 long wire antenna 982 987 553 Time delays 962 963 Time DivisionMultiple Access (TDMA) 978 980 Time-phase quadrature 569 T-match 530f TM mode, parabolic reflector 926 Tolerance errors 348 Top-hat-loaded antennas 151 Total directivity 981 531 45 1035 Total electric field 159 206 Total phase error 935 Total radiated power 40 long wire antenna 554 Total tangential electric field 446 Training packets 980 Transformers 538 Transmission-line analysis method 815 Transmission-line current 517 Transmission-line method 434 Transmission-line mode 516 rectangular patch 816 Transmission-line model 519 Transmission lines, log-periodic dipole array 636 443 41 This page has been reformatted by Knovel to provide easier navigation 988