EN 61580-9-1996 en Methods of Measurement for Waveguides Part 9 Reflection Coefficient at Rectangular Waveguide Interfaces《波导测量方法 第9部分 矩形波导管接口的反射系数 IEC 1580-9 1996》.pdf

《EN 61580-9-1996 en Methods of Measurement for Waveguides Part 9 Reflection Coefficient at Rectangular Waveguide Interfaces《波导测量方法 第9部分 矩形波导管接口的反射系数 IEC 1580-9 1996》.pdf》由会员分享，可在线阅读，更多相关《EN 61580-9-1996 en Methods of Measurement for Waveguides Part 9 Reflection Coefficient at Rectangular Waveguide Interfaces《波导测量方法 第9部分 矩形波导管接口的反射系数 IEC 1580-9 1996》.pdf（16页珍藏版）》请在麦多课文档分享上搜索。

1、STD-BSI BS EN b1580-9-ENGL 1777 m 1b2qbb7 0587230 703 BRITISH STANDARD . . . . . . . -. . . - . . . . -. . -. . I Methods of measurement for waveguides Part 9. Reflection coefficient at retangular waveguide interfaces * * m The European Standard EN 61580-9 : 1996 has the status of a British Standard

2、 ICs 33.120.10 m BS EN 61580-9 : 1997 IEC 1580-9 : I1996 STD-BSI BS EN bL580-9-ENGL I997 3b2VbbS 0587233 8liT M AmdNo. Date BS EN 61580-9 : 1997 Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EPU46, Cables,

3、 wires and waveguides, RF connectors and accessories for communication and signalling, to Subcommittee EPU46/2, RF connectors and waveguides, on which the following bodies were represented: AEA Technology BEAMA Electrical Cable and Conductor Accessory Manufacturers British Non-Ferrous Metals Federat

4、ion British Telecommunications plc Federation of the Eleclmnics Industry Ministry of Defence National Supervisory inspectorate Society of Cable Television Engineers This British Standard, having been prepared under the direction of the Electrotechnid Sector Board, was published under the authority o

5、f the Standards Board and comes into effect on 15 February 1997 O BSI 1997 The following BSI references relate to the work on this standard Committee reference EPU42 Draft for comment 96203429 DC ISBN O 580 26941 8 I STD-BSI BS EN bL580-7-ENGL 1777 m Lb29bb7 058FZ12 78b m - BS EN 61580-9 : 1997 _ Co

6、ntents Committees responsible Page Inside fmnt cover National foreword ii Foreword 2 Text of EN 61580-9 3 O BSI 1997 i STD-BSI BS EN bL58KGNGL 1797 Lb24bbTO5872L3 bL2 = BS EN 61680-9 : 1997 National foreword This British Stanard has been prepared by Subcommittee EPL/46/2 and is the English language

7、version of EN 61580-9 : 1996 MeuLods of measurement for waveguides - Part 9: b) lateral displacement between the waveguide axes in either the H or E plane; c) angular misalignment between the waveguide axes. 2 Normative reference The following normative document contains provisions which, through re

8、ference in this text, constitute provisions of this part of IEC 1580. At the time of publication, the edition indicated was valid. All normative documents are subject to revision, and parties to agreements based on this part of IEC 1580 are encouraged to investigate the possibility of applying the m

9、ost recent edition of the normative document indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IEC 154: Flanges for waveguides 3 List of symbols Let: a = basic inside width of the waveguide; b = basic inside height of the waveguide; hc = cut-off w

10、avelength; Aal Ab = deviations from the basic internal waveguide dimensions; AaO, Abe = linear displacements between the waveguide axes. = waveguide wavelength; hg The above symbols are illustrated in figure 1. In addition, let: Pa = reflection coefficient due to changes in waveguide width; Pb = ref

11、lection coefficient due to changes in waveguide height; PH = reflection coefficient due to H-plane displacement; PE = reflection coefficient due to E-plane displacement. e STD-BSI BS EN b158-p7TENL 1777 m 1b2bbT0587218 LT4 m Page 5 EN 61580-9 : 1996 4 Effect of dimensional changes and axial dlspacem

12、ent 4.1 Combination of mismatches For small dimensional changes, pa and Pb are due to the resistive mismatches between the waveguides, the shunt susceptances being negligible. lhe reflection coefficients due to displacements, pH and pE, are due to shunt susceptances and consequently in phase quadrat

13、ure with (pa + Pb). The total mismatch due to the combination of dimensional changes and axial displacement is therefore: NOTES 1 lhe highest value of reflection coefficient for axially aligned waveguides is when a and b are at extreme tolerances and a waveguide with dimensions (a + Aa), (b - Ab) ma

14、tes with a waveguide with dimensions (a - Aa), (b + Ab)- 2 susceptance. p and PE have opposite signs, p being due to an inductlve susceptance and PE to a capacitive 4.2 Theoretical considerations In the IEC 154 series of standards, the following formula is given for the maximum reflection due to the

15、 combination of dimensional changes and lateral displacement for rectangular waveguides: 1 R = lolog, 4,9348 kg X 7,8957 x Av2 - a3 where R is the reflection loss. Equation (2) can be re-written in terms of reflection coefficients as follows: 1 R= 10 log,o - P2 i Ag2 x Aa 4,9348 hg X Aae2 7,8957 x A

16、b#2 - a3 v therefore p = J 4a3 +% + (3) .e. Equation (3a) is identical to equation (1). STD-BSI BS EN bL580-7-ENGL 1977 LbZqbb9 0587237 O30 Page 6 EN 61580-9 : 1996 The separate factors in equation (3a) can be expressed as follows: Ab b Pb =- 4,9348 hg x Aa.2 “s (*J (6) =x - a3 2a kc PH - 4.3 Determ

17、ination of reflection coefficients These may be determined either by use of equations (4) to (7) or by means of the graphs shown in figure 2 where the reflection coefficients are expressed as percentages. For Pb the ordinate of figure 2 may be used directly as pb is independent of frequency. For pa,

18、 pH and pE the ordinate takes into account the frequency of operation. NOTES 1 mid-band values for pa and pH. For mid-band operation of a waveguide kcA, approximates to unity and the ordinate gives the approximate Ao Io 2 For waveguides with a 2:1 aspect ratio -I - and the ordinate gives the approxi

19、mate mid-band value of pE, 4.4 Summary Equation (2) has been accepted by the IEC for the determination of reflection loss (.e. return loss) between two rectangular waveguide flanges in the IEC 154 series of flange standards. These standards contain tables of reflection loss based. on the criterion t

20、hat the maximum allowable displacement between waveguide flanges should not degrade the inherent return loss due to waveguide dimensional tolerances by more than 1 dB. This leads to a maximum value for Aa, of 0,0175a for a waveguide tolerance of 1d500. For the larger sizes of waveguide this gives a

21、worst-case value of return loss of approximately 40 dB. STD-BSI BS-EN bL580-9-ENGL 1777 Lb2Vbb 0587220 852 Page 7 EN 61580-9 : 1996 5 Angular misalignment between waveguide flanges For a rotation of 4“ between the flanges of two identical rectangular waveguides, with aspect ratios of 2:1, the follow

22、ing approximate expression may be used to determine the mid-band value of reflection coefficient: pt = 0,5 sin2 9 (8) where pt is due to the effect of an inductive susceptance. Equation (8) may be used for values of 9 up to 45“ but p, varies with aspect ratio and also varies inversely with frequency

23、. STD-BSI BS EN bL580-9-ENGL 1777 Lb24bb7 0587223 777 Page 8 EN 61580-9 : 1996 Aa Guide Balde n 1 waveguideN1 - Guide Bande no 2 waveguide N 2 b a I, J Fig la - Variations des dimensions intrieureslchange internal dimensiais plan WH piane Plan OE plane fig 1 b - piacement latrai des axes des guidesl

24、lateral displacement beivuwn weguides axes fig lc - caiage angulaire des axes des guidedAngular msaligiment betwen waveguides Figure 1 - Illustration des discontinuits dans la section Illustration of section discontinuities 100 10 1 Page 9 EN 61580-9 : 1996 0,001 0,Ol 1 Figure 2 - Graphiques pour dt

25、erminer le coefficient de rflexion Graphs for determination of reflection coefficient STD-BSI BS EN bL5O-7-ENL 1777 W LbELibb7 057223 561 Page 10 EN 61580-9 : 1996 Annex ZA (normative) Normative references to international publications with their corresponding European publications This European sta

26、ndard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed herealter. For dated references, subsequent amendments to or revisions of any of these publications apply t

27、o this European Standard oniy when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). NOTE. When an international publication has been modified by common modifications, indicated by (mod), the relevant

28、 EN/HD applies. Publication Year Title EC 154 series finges for waveguides EN/ED Year EN 60154-1 1994 HD 129 series O BSI 1997 BS EN 61580-9 : 1997 List of references See national foreword. * * m O BSI 1997 BS EN 61580-9 : 1997 IEC 1580-9 : 1996 BSI 389 Chiswick High Road London w4 4AL BSI - British

29、 Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Contract requirements A British Standard does not purport to include all the ne

30、cessary provisions of a contract. Users of British Standards are responsible for their correct application. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure tha they possess the latest amendments or editions. It is the constant aim of BSI

31、to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the responsible technical committee, the identity of which can be found on the inside front cover. Tel 0181 996 9000;

32、 Fax: O181 996 7400. BSI offers members an individual up- service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services, Sales D

33、epartment at Chiswick Tel 0181 996 7000; Fax: 0181 996 7001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested. Information on standards BSI provides a wide range of

34、information on national, European and international standards through its Library, the Standardline Database, the BSI Information Technology Service (BITS) and its Technical Help to Exporters Service. Contact the Information Department at Chiswick Tel O181 996 7111; Fax: O181 996 7048. Subscribing m

35、embers of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Customer Services, Membership at Chiswick Tel O181 996 7002; Fax: 0181 996 7001. Copyright Copyright subsists in all BSI

36、 publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means - elect

37、ronic, photocopying, recording or otherwise - without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained If permission is granted, the tem may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copynght Manager, BSI, 389 Chiswick High Road, London W4 4AL ISBN O 680 26941 8 EPii462