1、IEEE Std 1128-1998(R2012) IEEE Recommended Practice for Radio-Frequency (RF) Absorber Evaluation in the Range of 30 MHz to 5 GHz Sponsor Standards Committee of the IEEE Electromagnetic Compatibility Society Reaffirmed 8 June 2012 Approved 13 January 1998 IEEE Standards Board Abstract: Realistic and
2、repeatable criteria, as well as recommended test methods, for characteriz- ing the absorption properties of typical anechoic chamber linings applied to a metallic surface are described. Parameters and test procedures are described for the evaluation of RF absorbers to be used for radiated emissions
3、and radiated susceptibility testing of electronic products, in the ab- sorber manufacturer and/or absorber user environment, over the frequency range of 30 MHz to 5 GHz. Keywords: anechoic chamber, radiated emissions, RF absorber, semianechoic chamber The Institute of Electrical and Electronics Engi
4、neers, Inc. 345 East 47th Street, New York, NY 10017-2394, USA Copyright 1998 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 1998. Printed in the United States of America. ISBN 1-55937-986-3 No part of this publication may be reproduced in any form, in
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17、that are brought to its attention.Copyright 1998 IEEE. All rights reserved. iiiIntroductionThis introduction is not part of IEEE Std 1128-1998, IEEE Recommended Practice for Radio-Frequency (RF) AbsorberEvaluation in the Range of 30 MHz to 5 GHz.Interest in materials that absorb radio-frequency ener
18、gy has existed for many years. The recent increasedregulation of sources of radio waves and equipment immunity levels has led to the need for a more accuratedetermination of electromagnetic field intensity. As modern measuring antennas and receivers haveincreased measurement accuracy, the problem of
19、 making accurate measurements in less than optimum open-area test sites has become a more important part of the overall measurement procedures. The practice ofplacing absorbing materials on the walls and ceilings of measuring sites to reduce reflections from these sur-faces has become common. Claims
20、 for the efficacy of various absorbing materials, however, have led toconflicting reports in the literature, which confuse many potential purchasers of absorbing material. Aneffort to end that confusion led to the development of a draft recommended practice in 1986. Following sev-eral years of work,
21、 the current recommended practice was developed.At the time this recommended practice was completed, the working group had the following membership:Jose Perini, ChairAnatoly Tsailovich, Vice Chair Ferdy Mayer, SecretaryThe following individuals have contributed reviews and comments and have attended
22、 meetings:The following persons were on the balloting committee:Paul AndersonEdwin L. BronaughFrederic J. BroydeDonald E. ClarkLarry S. CohenWilliam E. CoryHeinrich GarnDavid GiangiulliFranz GisinDiethard HansenH. R. HofmannMotohisa KandaKeneth K. KimuraJames C. KloudaBrian F. LawrenceMing-Chiang Li
23、Kefeng LiuL. Van De LooverboschAtsuya MaedaLuc MartensWilliam H. McGinnisWalter D. McKercharFernando MendozaJohn D. OsburnBarry PateGhery S. PetitHugo PuesScott RolesonGabriel A. SanchezVerner SchaeferJames R. StidmanRandy AndersonJ. P. ChaumatTim DArcangelisHugh W. DennyMichael FoegelleTim Harringt
24、onGrahme HarveyuDonald N. HeirmanJohn HowardEdward F. KuesterRobert MartensD. Mc NultyMonika NeufingeriDetlef RistanM. SekimotoShrish ShahK. ShinadaJames RoyalGary F. E. VroomanDonald A. WeberStephen H. BergerEdwin L. BronaughFrederic J. BroydeJoseph E. ButlerDonald E. ClarkWilliam E. CoryHugh W. De
25、nnyHeinrich GarnDonald N. HeirmanDaniel D. HoolihanAtsuya MaedaFerdy MayerJohn D. OsburnJose PeriniGhery PettitA. PiperJ. H. PluckScott RolesonDavid SeaburyRalph M. ShowersDonald L. SweeneyDavid L. TraverGraham Wilsoniv Copyright 1998 IEEE. All rights reserved.The final conditions for approval of th
26、is recommended paractice were met on 13 January 1998. This recom-mended practice was conditionally approved by the IEEE Standards Board on 9 December 1997, with thefollowing membership:Donald C. Loughry, Chair Richard J. Holleman, Vice ChairAndrew G. Salem, Secretary*Member EmeritusAlso included are
27、 the following nonvoting IEEE Standards Board liaisons:Satish K. AggarwalAlan H. CooksonClyde R. CampStephen L. DiamondHarold E. EpsteinDonald C. FleckensteinJay Forster*Thomas F. GarrityDonald N. HeirmanJim IsaakBen C. JohnsonLowell JohnsonRobert KennellyE. G. “Al” KienerJoseph L. Koepfinger*Stephe
28、n R. LambertLawrence V. McCallL. Bruce McClungMarco W. MigliaroLoius-Franois PauGerald H. PetersonJohn W. PopeJose R. RamosRonald H. ReimerIngo RschJohn S. RyanChee Kiow TanHoward L. WolfmanCopyright 1998 IEEE. All rights reserved. vContents1. Introduction 11.1 Scope 11.2 Applications . 12. Referenc
29、es 23. Definitions and acronyms 23.1 Definitions . 23.2 Acronyms. 44. Measurement instrumentation 54.1 Spectrum analyzers 54.2 Spectrum analyzer and tracking generator. 84.3 Electromagnetic interference (EMI) receiver 114.4 Vector network analyzers 134.5 Scaler network analyzers . 134.6 Vector voltm
30、eter 144.7 Time-domain reflectometer . 154.8 EMC antennas 165. Test environment parameter guidelines. 176. Material bulk-parameter evaluation. 176.1 Background 186.2 Bulk-parameter measurement procedures . 217. Evaluation of the reflectivity of RF absorbers. 267.1 Background 267.2 RF absorber reflec
31、tivity measurement procedures 288. RF absorber performance in ATS, ALC, and semianechoic absorber-lined chambers (SALC) . 498.1 Background 498.2 ATS and ALC measurement procedure. 508.3 Semianechoic chamber measurement procedure. 559. Test reports 579.1 Test report content . 579.2 Test report dispos
32、ition . 5710. Bibliography 57Copyright 1998 IEEE. All rights reserved. 1IEEE Recommended Practice for Radio-Frequency (RF) Absorber Evaluation in the Range of 30 MHz to 5 GHz1. Introduction1.1 ScopeThe purpose of this recommended practice is to recommend realistic and repeatable criteria, as well as
33、 rec-ommended test methods, to characterize the absorption properties of typical anechoic chamber liningsapplied to a metallic surface. This recommended practice covers the parameters and test procedures for theevaluation of radio-frequency (RF) absorbers to be used for radiated emissions and radiat
34、ed susceptibilitytesting of electronic products, in the absorber manufacturer and/or absorber user environment, over the fre-quency range of 30 MHz to 5 GHz.The recommended methods approach the RF absorber evaluation at three levels:a) RF absorber materials bulk parametersb) Arrays of commercially a
35、vailable RF absorbersc) RF absorbers in actual applications, as in anechoic or semianechoic chambers and lined open-areatest sites.The evaluation measurements can be performed in frequency and/or time domain. This recommendedpratice, however, does not address the accuracy and limitations of the diff
36、erent evaluation methods. Theseissues will be addressed in future revisions of this recommended pratice.1.2 ApplicationsWith the proliferation of RF absorber-lined shielded rooms, and their wide utilization for testing equipmentfor radiated emissions and radiated susceptibility, there is a need to p
37、rovide repeatable and realistic perfor-mance figures of such RF absorbers in the frequency range of 30 MHz to 5 GHz and higher.Up until now, the data provided by many manufacturers usually has been for normal incidence only. Thisdata eliminates the effect of polarization on the RF absorber performan
38、ce. For RF absorbers that use a pyra-midal structure, the reflection coefficient is also a function of the alignment of the incident wave with thepyramidal structure, especially for high frequencies and for large angles of incidence. Furthermore, only themagnitude of the reflection coefficient typic
39、ally is provided by the manufacturers. The lack of these kinds ofdata precludes the accurate calculation of the performance of RF absorber materials in the great majority ofapplications.IEEEStd 1128-1998 IEEE RECOMMENDED PRACTICE FOR RADIO-FREQUENCY (RF)2 Copyright 1998 IEEE. All rights reserved.Thi
40、s recommended practice is intended as an aid to RF absorber users and manufacturers. It indicates thetype of data that is required by the design engineer and the various methods that may be used to obtain suchdata. It is hoped that, in the future, both manufacturers and users will utilize the same o
41、r accepted equivalentmethods to estimate the performance of RF absorbers.2. ReferencesThis recommended practice should be used in conjunction with the following documents:ANSI C63.2-1996, American National Standard for Electromagnetic Noise and Field Strength Instumenta-tion, 10 kHz to 40 GHz Specif
42、ications.1ANSI C63.4-1992, American National Standard for Methods of Measurement of Radio-Noise Emissionsfrom Low-Voltage Electrical and Electronic Equipment in the Range of 9 kHz to 40 GHz.IEC/CISPR 16-1 (1993-08), Specifications for radio disturbance and immunity measuring apparatus andmethodsPart
43、 1: Radio disturbance and immunity measuring apparatus.23. Definitions and acronyms3.1 DefinitionsFor the purposes of this recommended practice, the following terms and definitions shall apply.3.1.1 absorber-lined chamber (ALC): A room or enclosure (either shielded or unshielded) with all of itssurf
44、aces lined with radio-frequency (RF) absorber material. Commonly referred to as an anechoic chamber.3.1.2 absorber-lined open-area test site (ATS): An open-area test site (OATS) in which the ground planeis covered with radio-frequency (RF) absorber to suppress ground reflections. See also: open-area
45、 test site(OATS).3.1.3 angle of incidence: At a point on a surface, the acute angle between the normal to this surface and thedirection of propagation of an incident wave.3.1.4 antenna factor: a) Quantity relating the strength of the field in which an antenna is immersed to theoutput voltage across
46、the load connected to the antenna. b) A factor that, when properly applied to the volt-age meter reading of the measuring instrument, yields the electric field strength in volts/meter or the mag-netic field strength in amperes/meter. NOTES1This factor includes the effects of antenna effective length
47、 and mismatch and may include transmission line loss.2The factor for the electric field strength is not necessarily the same as the factor for the magnetic field strength.3The antenna factor, as determined in ANSI C63.5-1988, is very nearly equal to the free-space antenna factor.3.1.5 bistatic refle
48、ctivity: The reflectivity when the reflected wave is in any specified direction other thanback toward the transmit antenna. The transmit and receive antennas are at different locations. 1ANSI C63 publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane, P.
49、O. Box 1331, Piscat-away, NJ 08855-1331, USA; or from the Sales Department, American National Standards Institute, 11 West 42nd Street, 13th Floor,New York, NY 10036, USA.2CISPR documents are available from the International Electrotechnical Commission, 3, rue de Varemb, Case Postale 131, CH 1211,Genve 20, Switzerland/Suisse. They are also available in the United States from the Sales Department, American National StandardsInstitute, 11 West 42nd Street, 13th Floor, New York, NY 10036, USA.IEEEABSORBER EVALU
