1、BRITISH STANDARD BS EN 61580-7:1997 IEC 1580-7: 1996 Methods of measurement for waveguides Part 7: Graphical method for the determination of waveguide performance The European Standard EN61580-7:1996 has the status of a British Standard ICS33.120.10BSEN61580-7:1997 This British Standard, having been
2、 prepared under the directionof the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 February1997 BSI 12-1998 The following BSI references relate to the work on this standard: Committee reference EPL/46/2 Draft announced in BSI Updat
3、e October 1996 ISBN 0 580 26939 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EPL/46, Cables, wires and waveguides, RF connectors and accessories for communication and signalling, to Subcommittee EPL/46/2, RFconnector
4、s and waveguides, upon which the following bodies were represented: AEA Technology BEAMA Electrical Cable and Conductor Accessory Manufacturers British Non-Ferrous Metals Federation British Telecommunications plc Federation of the Electronics Industry Ministry of Defence National Supervisory Inspect
5、orate Society of Cable Television Engineers Amendments issued since publication Amd. No. Date CommentsBSEN61580-7:1997 BSI 12-1998 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 61580-7 3BSEN61580-7:1997 ii BSI 12-1998 National foreword This Brit
6、ish Standard has been prepared by Subcommittee EPL/46/2 and is the English language version of EN61580-7:1996 Methods of measurement for waveguides Part7: Graphical method for the determination of waveguide performance published by the European Committee for Electrotechnical Standardization (CENELEC
7、). It is identical with IEC1580-7:1996 published by the International Electrotechnical Commission (IEC). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Stan
8、dard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 8 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated
9、. This will be indicated in the amendment table on theinside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61580-7 August 1996 ICS33.120.10 Descriptors: Waveguides, graphical method for the determination of performance English version Methods of measurement for waveguides Part 7:
10、Graphical method for the determination of waveguide performance (IEC1580-7:1996) Mthodes de mesure appliques aux guides dondes Partie 7: Mthode graphique pour dterminer les performances dun guide dondes (CEI1580-7:1996) Meverfahren fr Hohlleiter Teil 7: Graphisches Verfahren zur Bestimmung der Hohll
11、eiter-eigenschaften (IEC1580-7:1996) This European Standard was approved by CENELEC on1996-07-02. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. U
12、p-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translatio
13、n under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, It
14、aly, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1
15、050 Brussels 1996 Copyright reserved to CENELEC members Ref. No. EN 61580-7:1996 EEN61580-7:1996 BSI 12-1998 2 Foreword The text of document46B/208/FDIS, future edition1 of IEC1580-7, prepared by SC46B, Waveguides and their accessories, of IEC TC46, Cables, wires, waveguides, R.F. connectors, and ac
16、cessories for communication and signalling, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN61580-7 on1996-07-02. The following dates were fixed: Contents Page Foreword 2 1 Scope 3 2 Form of presentation 3 3 Examples 3 3.1 Ordinary rectangular waveguides 3 3.2 Medium
17、flat rectangular waveguides 3 3.3 Square waveguides 3 3.4 Circular waveguides 3 4 Formulae for cut-off wavelengths 3 4.1 Rectangular waveguides 3 4.2 Circular waveguides 4 Figure 1 5 Figure 2 6 Figure 3 7 Figure 4 8 Table 1 Roots of Bessel function for TE mnmodes 4 Table 2 Roots of Bessel function f
18、or TM mnmodes 4 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1997-04-01 latest date by which the national standards conflicting with the EN haveto be withdrawn (dow) 1997-04-01EN61580-7:1996 BSI 12-1998 3
19、 1 Scope This part of IEC1580 is applicable to waveguide performance. The objective is to provide a means for determining the cut-off frequencies for the dominant and higher order modes in waveguides of various types over the frequency range from1GHz to27GHz. It is only intended to be used as an app
20、endix to the measuring method published by SC46B. 2 Form of presentation 2.1 Information is presented in the form of nomograms (seeFigure 1 toFigure 3) for the following waveguide types: ordinary rectangular waveguide (aspect ratio2 : 1); medium flat rectangular waveguide (aspect ratio3 : 1); square
21、 waveguide; circular waveguide. 2.2 To determine waveguide performance, project a line horizontally corresponding to a specified mode to cut the a/l axis. Draw a line from this point through the “a” (mm) line to cut the frequency axis. 2.3 If greater accuracy is required, the cut-off frequencies can
22、 be calculated using the relationships listed in clause 4 for the cut-off wavelengths (lc). Cut-off frequency is then given by fc = c/lc, where “c” is the velocity of light. 2.4 Examples are given below to illustrate the use of the nomograms. 3 Examples 3.1 Ordinary rectangular waveguides 3.1.1 For
23、ordinary rectangular waveguides the recommended frequency range extends from25% above the dominant mode cut-off to 5% below the cut-off for the next higher order mode. 3.1.2 To determine the normal operating frequency band for, say, R48 waveguide, proceed as follows using the nomogram shown asFigure
24、 2: a) project the TE 10and TE 20lines horizontally to cut the a/l axis at 0,5 and1,0 respectively; b) draw a line from the points0,5 and1,0 through the point a =47,55mm to cut the frequency axis at the points corresponding to the required cut-off frequencies; c) read off the values3,15GHz for the T
25、E 10mode and6,31GHz for the TE 20mode. 3.1.3 The normal operating band for R48 is therefore: (3,15 + 25 %) = 3,94 GHz to (6,31 5 %) =5,99GHz 3.2 Medium flat rectangular waveguides For these waveguides, suppression of the TE 20mode results in a nominal 1,5 : 0,5 =3 : 1 bandwidth compared with2 : 1 fo
26、r ordinary rectangular waveguides. The TE 20mode is an odd mode which can easily be suppressed by filtering. 3.3 Square waveguides To determine the common cut-off frequency for the TE 11and TM 11modes for a square waveguide with a =34mm proceed as follows: a) project the common TE 11 , TM 11line hor
27、izontally to cut the a/l axis at the point A (seeFigure 4); b) draw a line from A through a =34mm to cut the frequency axis at B, corresponding to the cut-off frequency of6,24GHz. 3.4 Circular waveguides To determine the diameter “a” and the cut-off frequency for a circular waveguide operating up to
28、11GHz in the dominant (TE 11 ) mode only, proceed as follows: a) project the TE 11and TM 01lines horizontally to cut the a/l axis at the points C and D respectively (see Figure 4); b) allowing for a safety factor of approximately1%, draw a line from point D to the point corresponding to11,1GHz on th
29、e frequency axis. This cuts the “a” line at E corresponding to a value a =20,7mm; c) draw a line from C through E to cut the frequency axis at the point F, corresponding to the cut-off frequency of8,5GHz. 4 Formulae for cut-off wavelengths 4.1 Rectangular waveguides For the TE mnand TM mnmodes: wher
30、e a = broad dimension of the wave guide; b = narrow dimension of the waveguide. l c 2 ab m 2 b a -n 2 a b - + - =EN61580-7:1996 4 BSI 12-1998 4.2 Circular waveguides where a = diameter of the guide; x mn = roots of a Bessel function. The first14 roots of the appropriate Bessel functions are tabulate
31、d below for the TE mn(Table 1) and TM mn(Table 2) modes. NOTEm and n can be interchanged to give an orthogonal set of modes for square waveguides. Table 1 Roots of Bessel function for TE mnmodes Table 2 Roots of Bessel function for TM mnmodes l c p a x mn - = m n 0 1 2 3 4 5 6 1 3,832 1,841 3,054 4,
32、201 5,317 6,416 7,501 2 7,016 5,331 6,706 8,015 9,282 10,520 11,735 m n 0 1 2 3 4 5 6 1 2,405 3,832 5,136 6,380 7,588 8,771 9,936 2 5,520 7,016 8,417 9,761 11,065 12,339 13,589EN61580-7:1996 BSI 12-1998 5 Figure 1EN61580-7:1996 6 BSI 12-1998 Figure 2EN61580-7:1996 BSI 12-1998 7 Figure 3EN61580-7:199
33、6 8 BSI 12-1998 Figure 49 blankBSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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