1、 IEC 62431 Edition 1.0 2008-07 INTERNATIONAL STANDARD Reflectivity of electromagnetic wave absorbers in millimetre wave frequency Measurement methods IEC 62431:2008(E) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2008 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no
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8、ustserv If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service Centre FAQ or contact us: Email: csciec.ch Tel.: +41 22 919 02 11 Fax: +41 22 919 03 00 IEC 62431 Edition 1.0 2008-07 INTERNATIONAL STANDARD Reflectivity of electromagnetic
9、wave absorbers in millimetre wave frequency Measurement methods INTERNATIONAL ELECTROTECHNICAL COMMISSION XA ICS 19.080; 17.120; 29.120.10 PRICE CODE ISBN 2-8318-9895-1 Registered trademark of the International Electrotechnical Commission 2 62431 IEC:2008(E) CONTENTS FOREWORD.5 1 Scope.7 2 Normative
10、 references .7 3 Terms, definitions and acronyms 7 3.1 Terms and definitions 7 3.2 Acronyms and symbols10 4 Specimen .12 4.1 Specimen specification12 4.2 Reference metal plate .12 4.2.1 Material and thickness.12 4.2.2 Surface roughness 12 4.2.3 Flatness 12 4.2.4 Size and shape12 4.3 Reference specim
11、en for calibration .12 5 Specimen holder 13 6 Measurement equipment 13 6.1 Type of network analyzer 13 6.2 Antenna 13 6.2.1 Horn antenna.13 6.2.2 Lens antenna.13 6.3 Amplifier13 6.4 Cable 14 7 Measurement condition 14 7.1 Temperature and environment.14 7.2 Warming up of measurement equipment14 7.3 E
12、lectromagnetic environment 14 8 Calibration of measurement system and measurement conditions 14 8.1 Calibration of measurement system.14 8.2 Measurement conditions14 8.2.1 Dynamic range 14 8.2.2 Setting up of the network analyzer for keeping adequate dynamic range.14 9 Horn antenna method .15 9.1 Me
13、asurement system 15 9.1.1 Configuration of the measurement system .15 9.1.2 Horn antenna.16 9.1.3 Specimen holder16 9.1.4 Mounting of the specimen18 9.1.5 Antenna stand .18 9.2 Measurement conditions18 9.2.1 Measurement environment 18 9.2.2 Measuring distance .18 9.2.3 Size of specimen .18 9.3 Measu
14、rement procedures 19 10 Dielectric lens antenna method focused beam method 20 10.1 Outline 20 62431 IEC:2008(E) 3 10.2 Measurement system 20 10.2.1 Transmitting and receiving antennas .20 10.2.2 Focused beam horn antenna .21 10.2.3 Specimen size .22 10.2.4 Reference metal plate size 22 10.2.5 Specim
15、en holder22 10.2.6 Method of fixing the specimen and the reference metal plate.23 10.3 Measurement procedures 23 11 Dielectric lens antenna method parallel beam method .25 11.1 Principle25 11.1.1 Outline 25 11.1.2 Parallel EM wave beam formed using a EM wave lens.25 11.2 Measurement system 26 11.2.1
16、 Composition of measurement system 26 11.2.2 Dielectric lens antenna 29 11.3 Specimen 29 11.3.1 General .29 11.3.2 Reference metal plate .29 11.3.3 Size of specimen .30 11.4 Measurement procedures 30 11.4.1 Normal incidence.30 11.4.2 Oblique Incidence30 12 Test report31 Annex A (informative) Reflect
17、ion and scattering from metal plate Horn antenna method .33 Annex B (informative) Reflectivity of reference specimens using horn antenna method38 Annex C (informative) Specifications of commercially available antennas 39 Annex D (normative) Calibration using VNA.42 Annex E (informative) Dynamic rang
18、e and measurement errors .51 Annex F (informative) Enlargement of dynamic range Calibration by isolation.53 Annex G (informative) Relative permittivity of styrofoam and foamed polyethylene based on foam ratio 54 Annex H (informative) Calculation of Fraunhofer region Horn antenna method.55 Figure 1 D
19、efinition of reflectivity.10 Figure 2 Configuration of the measurement system normal incidence (S 11 ).15 Figure 3 Configuration of the measurement system oblique incidence (S 21 ) 16 Figure 4 Mounting method of specimen17 Figure 5 The mechanism of adjusting azimuth and elevation17 Figure 6 Measurem
20、ent system for normal incidence (side view).20 Figure 7 Measurement system for oblique incidence (top view)21 Figure 8 Structure of a dielectric lens antenna .22 Figure 9 Structure of specimen holder23 Figure 10 EM wave propagation using a horn antenna and a dielectric lens.26 Figure 11 Block diagra
21、m of the measurement system 27 Figure 12 A measurement system for normal incidence .28 4 62431 IEC:2008(E) Figure 13 Measurement system for oblique incidence 28 Figure 14 Position of a shielding plate .29 Figure 15 Items to be mentioned in a test report 32 Figure A.1 Reflection from the reference me
22、tal plate versus measurement distance between the antenna and the metal plate33 Figure A.2 Reflectivity of reference metal plate versus size34 Figure A.3 Reflectivity of reference metal plate at 40 GHz .35 Figure A.4 Reflectivity of reference metal plate with cross section of 200 mm 200 mm at 40 GHz
23、35 Figure A.5 Analysis of reflection from a metal plate37 Figure B.1 Reflectivity of a 200 mm 200 mm silica-glass plate in millimetre wave frequency38 Figure C.1 Representative specifications of a horn antenna.39 Figure C.2 Structure of cylindrical horn antenna with dielectric lens in Table C.2, A u
24、sed at 50 GHz - 75 GHz40 Figure C.3 A structure of dielectric lens and horn antenna in Table C.2, D.41 Figure D.1 Measurement configuration for the case of normal incidence with a directional coupler connected directly to the horn antenna42 Figure D.2 Configuration for response calibration using a r
25、eference metal plate in the case of normal incidence 43 Figure D.3 Configuration for response calibration using a reference metal plate in the case of oblique incidence44 Figure D.4 Configuration for response and isolation calibration in the case of normal incidence 45 Figure D.5a Response calibrati
26、on Figure D.5b Isolation calibration.45 Figure D.5 Configuration for response and isolation calibration in the case of oblique incidence 45 Figure D.6 Configuration for S 111-port full calibration in the case of normal incidence 47 Figure D.7 Precision antenna positioner configuration48 Figure D.8 T
27、RL calibration procedure.49 Figure D.9 Measurement and TRL calibration of transmission line .50 Figure E.1 An example of receiving level of a reference metal plate and that without a specimen .51 Figure E.2 Dynamic range and measurement error of reflectivity52 Figure F.1 A method to remove spurious
28、waves.53 Figure H.1 Fraunhofer region and antenna gain .55 Table 1 Acronyms 11 Table 2 Symbols 11 Table C.1 Antenna gain 24 dB (example A)39 Table C.2 Some specifications of antennas with dielectric lenses 40 Table G.1 Relative permittivity and foam ratio of styrofoam54 Table G.2 Relative permittivi
29、ty and foam ratio of foamed polyethylene.54 62431 IEC:2008(E) 5 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ REFLECTIVITY OF ELECTROMAGNETIC WAVE ABSORBERS IN MILLIMETRE WAVE FREQUENCY MEASUREMENT METHODS FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for
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39、e for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 62431 has bee
40、n prepared by subcommittee SC46F: RF and microwave passive components, of IEC technical committee 46: Cables, wires, waveguides, R.F. connectors, R.F. and microwave passive components and accessories. IEC 62431 replaces and cancels IEC/PAS 62431 with corrections of obvious errors as noted in 46F/29A
41、/RVN. The text of this standard is based on the following documents: CDV Report on voting 46F/65/CDV 46F/72/RVC Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the
42、 ISO/IEC Directives, Part 2. 6 62431 IEC:2008(E) The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch” in the data related to the specific publication. At this date, the publ
43、ication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. A bilingual version of this publication may be issued at a later date. 62431 IEC:2008(E) 7 REFLECTIVITY OF ELECTROMAGNETIC WAVE ABSORBERS IN MILLIMETRE WAVE FREQUENCY MEASUREMENT METHODS 1 Scope This International Sta
44、ndard specifies the measurement methods for the reflectivity of electromagnetic wave absorbers (EMA) for the normal incident, oblique incident and each polarized wave in the millimetre-wave range. In addition, these methods are also equally effective for the reflectivity measurement of other materia
45、ls: measurement frequency range: 30 GHz to 300 GHz; reflectivity: 0 dB to 50 dB; incident angle: 0 to 80. NOTE This standard is applicable not only to those EMA which are widely used as counter-measures against communication faults, radio interference etc. , but also to those used in an anechoic cha
46、mber in some cases. EMAs may be any kind of material, and may have any arbitrary shape, configuration, or layered structure as pointed out below. Material: Conductive material, dielectric material, magnetic material. Shape: planar-, pyramidal-, wedge-type, or other specific shapes. Layer structure:
47、single layer, multi layers, or graded-index material. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (includi
48、ng any amendments) applies. ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories 3 Terms, definitions and acronyms For the purposes of this document, the following terms and definitions apply. 3.1 Terms and definitions 3.1.1 ambient level the value of radiat
49、ion power or noise which exists when no measurement is being carried out at the experiment site 3.1.2 associated equipment an apparatus or product connected for convenience or operation of the equipment 3.1.3 beam diameter the diameter where the electric field strength decreases by 3 dB from the centre of the focused beam 8 62431 IEC:2008(E) 3.1.4 beam waist the portion at which the diameter
