IEEE-145-1993-R2004.pdf

IEEE Std 145-1993(R2004) (Revision of IEEE Std 145-1983) IEEE Standard Definitions of Terms for Antennas Sponsor Antenna Standards Committee of the IEEE Antennas and Propagation Society Reaffirmed 23 September 2004 Approved March 18, 1993 IEEE Standards Board Abstract: Definitions of terms in the field of antennas are provided. Keywords: antennas, definitions, propagation, terminology The Institute of Electrical and Electronics Engineers, Inc. 345 East 47th Street, New York, NY 10017-2394, USA Copyright © 1993 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 1993. Printed in the United States of America. ISBN 1-55937-317-2 No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 03:21:04 MDTNo reproduction or networking permitted without license from IHS -,-,- IEEE Standards documents are developed within the Technical Committees of the IEEE Societies and the Standards Coordinating Committees of the IEEE Standards Board. Members of the committees serve voluntarily and without compensation. They are not necessarily members of the Institute. The standards developed within IEEE represent a consensus of the broad expertise on the subject within the Institute as well as those activities outside of IEEE that have expressed an interest in partici- pating in the development of the standard. Use of an IEEE Standard is wholly voluntary. The existence of an IEEE Standard does not imply that there are no other ways to produce, test, measure, purchase, mar- ket, or provide other goods and services related to the scope of the IEEE Standard. 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Box 1331 Piscataway, NJ 08855-1331 USA IEEE Standards documents are adopted by the Institute of Electrical and Electronics Engineers without regard to whether their adoption may involve patents on articles, materials, or processes. Such adoption does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the standards documents. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 03:21:04 MDTNo reproduction or networking permitted without license from IHS -,-,- iii Introduction (This introduction is not a part of IEEE Std 145-1993, IEEE Standard Defi nitions of Terms for Antennas.) This document is a revision of IEEE Std 145-1983, IEEE Standard Defi nitions of Terms for Antennas, and corrects minor errors that appeared in that printing. The original standard was issued in 1969. The following persons were on the working group that developed this document: Donald G. Bodnar, Chair Charles C. AllenEdward JoyAntoine G. Roederer A. David BreslerWalter K. KahnAllen C. Schell Richard H. BryanFlemming H. LarsenAlan J. Simmons Robert B. DybdalRichard B. MackG. P. Tricoles William J. EnglishAllen C. NewellMichael T. Tuley E. S. GillespieH. George OltmanEdward A. Urbanik Edward HartA. David OlverA. T. Villeneuve Doren HessHarold R. RaemerJonathan D. Young The following persons were on the balloting committee that approved this document for submission to the IEEE Standards Board: Charles C. AllenDoren HessAntoine G. Roederer Donald G. BodnarEdward JoyAllen C. Schell A. David BreslerWalter K. KahnAlan J. Simmons Richard H. BryanFlemming H. LarsenG. P. Tricoles Robert B. DybdalRichard B. MackMichael T. Tuley William J. EnglishAllen C. NewellEdward A. Urbanik E. S. GillespieH. George OltmanA. T. Villeneuve Edward HartA. David OlverJonathan D. Young Harold R. Raemer When the IEEE Standards Board approved this standard on March 18, 1993 it had the following membership: Wallace S. Read, Chair Donald C. Loughry, Vice Chair Andrew G. Salem, Secretary Gilles A. BarilBen C. JohnsonDon T. Michael* Clyde R. CampWalter J. KarplusMarco W. Migliaro Donald C. FleckensteinLorraine C. KevraL. John Rankine Jay Forster*E. G. “Al” KienerArthur K. Reilly David F. FranklinIvor N. KnightRonald H. Reimer Ramiro GarciaJoseph Koepfinger*Gary S. Robinson Donald N. HeirmanD. N. “Jim” LogothetisLeonard L. Tripp Jim IsaakDonald W. Zipse *Member Emeritus Also included are the following nonvoting IEEE Standards Board liaisons: Satish K. Aggarwal James Beall Richard B. Engelman David E. Soffrin Stanley I. Warshaw Christopher J. Booth IEEE Standards Project Editor Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 03:21:04 MDTNo reproduction or networking permitted without license from IHS -,-,- iv Contents CLAUSEPAGE 1.Overview 1 1.1 Scope 1 1.2 Background 1 1.3 Reference. 3 1.4 Definition structure 3 2.Definitions 3 Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 03:21:04 MDTNo reproduction or networking permitted without license from IHS -,-,- 1 IEEE Standard Defi nitions of Terms for Antennas 1. Overview 1.1 Scope It is assumed in this standard that an antenna is a passive linear reciprocal device. Thus, where a defi nition implies the use of an antenna in a transmitting situation, its use in a receiving situation is also implicit, unless specifi cally stated otherwise. When an antenna or group of antennas is combined with circuit elements that are active, nonlinear, or nonre- ciprocal, the combination is regarded as a system that includes an antenna. Examples of such cases are an adaptive antenna system and a signal-processing antenna system; the complete conical-scanning, monopulse, and compound interferometer systems also fall in this category. For terms that are quantitative, it is understood that frequency must be specifi ed. For those in which phase or polarization is a signifi cant part of the defi nition, a coherent source of power is implied. Whenever a term is commonly used in other fi elds but has specialized signifi cance in the fi eld of antennas, this is noted in the title. When applying terms pertaining to radiation characteristics, such as gain, polarization, beamwidth, etc., to multiple-beam antennas, each port shall be considered to be that of a separate antenna with a single main beam. For polarization diversity systems that may include active devices, these terms apply to each polariza- tion state for which the antenna is adjusted. Throughout this standard, where phasors are used, or are implied, the time convention shall be taken to be exp( j t ). 1.2 Background The defi nitions of terms contained herein, for the most part, stand alone and are easily understood out of context. The terms pertaining to gain, directivity and polarization, however, are interrelated and hence require some elaboration. The viewpoint taken for polarization is that this term can be used in three related meanings. It can apply a) To a fi eld vector at some point in space b)To a plane wave c)To an antenna The polarization of a fi eld vector specifi es the shape, orientation, and sense of the ellipse that the extremity of the fi eld vector describes as a function of time. This applies to any fi eld vector: electric fi eld, magnetic fi eld, velocity fi eld in a plasma, displacement fi eld in a solid, etc. In a single-frequency plane wave, a speci- fi ed fi eld vector has the same polarization at every point in space. This is taken as the polarization of the plane wave. Conventionally, in electromagnetics, the electric fi eld is considered rather than the magnetic fi eld. However, in a nonisotropic medium, the polarization state of the plane wave requires consideration of all its vector components. The third application of the term polarization is to antennas. The polarization of Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 03:21:04 MDTNo reproduction or networking permitted without license from IHS -,-,- IEEE Std 145-1993IEEE STANDARD DEFINITIONS 2 an antenna in a given direction is that of the plane wave it radiates at large distances in that direction. By rec- iprocity, a plane wave coming from that direction whose polarization ellipse has the same axial ratio, orien- tation, and sense will yield the maximum response for a given power fl ux density. For best understanding, the three related defi nitions of polarization should be read in the above order. One departure from previous usage should be noted. The defi nition of the tilt angle of the polarization ellipse now requires that it be measured according to the right-hand rule with the thumb pointing in a reference direction. For a plane wave, the reference direction is the direction of propagation. This is advantageous, since it removes any ambiguity about the specifi cation of the orientation of the polarization ellipse. It should be noted, however, that the polarization of the antenna is defi ned as that of the wave it radiates, whether it is used for transmitting or receiving. This means that for the receive case, the coordinate system used to describe the polarization of the antenna and the incoming wave are oriented in opposite directions. (See IEEE Std 149-1979, IEEE Standard Test Procedures for Antennas, clause 11, Polarization. 1 ) There are two ways to handle this situation. One is to transform the polarization of the wave into the antennas coordinate system; the second is to defi ne a receiving polarization for the antenna, which is that of the wave to which the antenna is polarization matched. The latter was chosen both here and in IEEE Std 149-1979. This should not be taken to mean that one cannot use the antennas coordinate system, but rather that if it is done, it should be clearly specifi ed as the polarization of the incoming wave referred to the antennas (transmitting) polarization. The term receiving polarization can also be applied to a nonreciprocal antenna that may receive only. The interdependence of gain, polarization, and impedance has led to the inclusion of several terms, including partial gain, partial directivity, and partial realized gain. The interrelationships of these terms and the basic terms gain, directivity and realized gain are best visualized by referring to the fl ow chart shown in fi gure 1. A similar fl ow chart can be constructed for a receiving antenna. 1 Information on the reference can be found in 1.3. PA = power available from the generator PM = power to matched transmission line PO = power accepted by the antenna PR = power radiated by the antenna I = radiation intensity In = partial radiation intensity M1 = impedance mismatch factor 1 M2 = impedance mismatch factor 2 = radiation effi ciency GR = realized gain G = gain D = directivity gR = partial realized gain g = partial gain d = partial directivity p = polarization effi ciency Figure 1Gain and directivity fl ow chart 4In GGD R PAPMPOPRp ggd R M1M2 4I Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 03:21:04 MDTNo reproduction or networking permitted without license from IHS -,-,- IEEE OF TERMS FOR ANTENNASStd 145-1993 3 1.3 Reference This standard shall be used in conjunction with the following publication: IEEE Std 149-1979 (Reaff 1990), IEEE Standard Test Procedures for Antennas (ANSI). 2 1.4 Defi nition structure In these defi nitions, words or phrases in parentheses that are part of the term can be omitted when the term is used, provided they are understood from context. Those words or phrases in brackets can replace the words or phrases that immediately precede them. If bracketed words or phrases appear in several places in the defi - nition, then all bracketed words or phrases must be used together in the defi nitions. For those cases where two or more terms are synonyms, the preferred term will be defi ned; the other terms will refer to the pre- ferred term and be listed after the defi nition. Abbreviations appear after the term and are enclosed in paren- theses. Terms that are no longer recommended for use are indicated as being deprecated. Synonyms for a term are listed at the end of the defi nition. 2. Defi nitions 2.1 absolute gain (of an antenna). See: gain (in a given direction). 2.2 active array antenna system. An array in which all or part of the elements are equipped with their own transmitter or receiver, or both. NOTES 1Ideally, for the transmitting case, amplitudes and phases of the output signals of the various transmitters are control- lable and can be coordinated in order to provide the desired aperture distributi