Iec 62153 4 10 2015

I E C 62 53 -4-1 ® Edition 2.0 201 5-1 I N TE RN ATI ON AL S TAN D ARD colour i n sid e M etal l i c com m u n i cati on cabl e tes t m eth od s – P art 4-1 : E l ectrom ag n e ti c com pati bi l i ty (E M C ) – Tran s fe r i m ped an ce an d s creen i n g atten u ati on of fe ed -th rou g h s an d el e ctrom ag n eti c g as kets – D ou bl e IEC 621 53-4-1 0:201 5-1 (en) coaxi al tes t m e th od T H I S P U B L I C AT I O N I S C O P YRI G H T P RO T E C T E D C o p yri g h t © I E C , G e n e v a , S wi tz e rl a n d All rights reserved Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IEC's member National Committee in the country of the requester If you have any questions about I EC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local I EC member National Committee for further information IEC Central Office 3, rue de Varembé CH-1 21 Geneva 20 Switzerland Tel.: +41 22 91 02 1 Fax: +41 22 91 03 00 info@iec.ch www.iec.ch Ab ou t th e I E C The I nternational Electrotechnical Commission (I EC) is the leading global organization that prepares and publishes I nternational Standards for all electrical, electronic and related technologies Ab o u t I E C p u b l i ca ti o n s The technical content of IEC publications is kept under constant review by the IEC Please make sure that you have the latest edition, a corrigenda or an amendment might have been published I E C Catal og u e - webstore i ec ch /catal og u e The stand-alone application for consulting the entire bibliographical information on IEC International Standards, Technical Specifications, Technical Reports and other documents Available for PC, Mac OS, Android Tablets and iPad I E C pu bl i cati on s s earch - www i ec ch /search pu b The advanced search enables to find IEC publications by a variety of criteria (reference number, text, technical committee,…) It also gives information on projects, replaced and withdrawn publications E l ectroped i a - www el ectroped i a org The world's leading online dictionary of electronic and electrical terms containing more than 30 000 terms and definitions in English and French, with equivalent terms in additional languages Also known as the International Electrotechnical Vocabulary (IEV) online I E C G l os sary - s td i ec ch /g l oss ary More than 60 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002 Some entries have been collected from earlier publications of IEC TC 37, 77, 86 and CISPR I E C J u st Pu bl i s h ed - webstore i ec ch /j u stpu bl i sh ed Stay up to date on all new IEC publications Just Published details all new publications released Available online and also once a month by email I E C C u stom er S ervi ce C en tre - webstore i ec ch /csc If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csc@iec.ch I E C 62 53 -4-1 ® Edition 2.0 201 5-1 I N TE RN ATI ON AL S TAN D ARD colour i n sid e M etal l i c com m u n i cati on cabl e tes t m eth od s – P art 4-1 : E l ectrom ag n e ti c com pati bi l i ty (E M C ) – Tran s fer i m pe d an ce an d s creen i n g atten u ati on of fe ed -th rou g h s an d el e ctrom ag n eti c g as kets – D ou bl e coaxi al tes t m e th od INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 33.1 00; 33.1 20.1 ISBN 978-2-8322-2993-4 Warn i n g ! M ake su re th a t you obtai n ed th i s pu bl i cati on from an au th ori zed d i s tri bu tor ® Registered trademark of the International Electrotechnical Commission –2– I EC 621 53-4-1 0:201  I EC 201 CONTENTS FOREWORD Scope Norm ative references Terms and definitions Principle of the test method Procedure Equipm ent Dynamic range Verification of the test set-up Sam ple preparation Measurem ent General Screening attenuation Transfer impedance Expression of results Transfer impedance Screening attenuation Requirements An nex A (informative) Background for the measurem ent of the shielding effectiveness of feed-throughs and electrom agnetic gaskets A General A Theoretical model of the test procedure A Perform ing m easurem ents A 3.1 Characteristic impedance uniform ity of the test fixture A 3.2 Measuring EMI -gaskets by using a NWA A 3.3 Pictures and m easurement results An nex B (inform ative) Reference device for verification m easurement 23 B General 23 B Design of the reference device 23 B Verification m easurement result 24 An nex C (informative) I mpact of ground loops on low frequency measurem ents 25 C General 25 C Analysis of the test set-up 25 Bibliograph y 28 Figure – A two-port Figure – Equivalent circuit of the test set-up and definition of ZT Figure – Cross-section of a typical feed-through configuration Figure – Cross-section of the test fixture with a connector Figure – Cross-section of the test fixture with an electromagnetic gasket 1 Figure A – Cross-section of a typical feed-through configuration Figure A – Cross-section of the test fixture with a connector Figure A – Equivalent circuit of the test setup with the shunt admittance y of the feed-through I EC 621 53-4-1 0: 201  I EC 201 –3– Figure A – TDR step response at input-port of test fixture Figure A – View of the test fixture connected to a network anal yzer Figure A – Top view of the test fixture Figure A – Detailed view of the contact area Figure A – Detailed view of the captivation for the conductive O-ring test Figure A – I solation of the network anal yzer 20 Figure A – I solation of the test fixture when characterizing an ideal short (m etal plate) 20 Figure A 1 – Measured operational screening transmission when characterizing a typical conductive O-ring 21 Figure A – Transfer im pedance Z T of a typical conductive O-ring 21 Figure A – Screening attenuation a s of a typical conductive O-ring 22 Figure B – Reference device, e g resistors soldered onto a PCB 23 Figure B – Typical verification m easurement result 24 Figure C.1 – Double coaxial test set-up 25 Figure C.2 – Equivalent circuits of the double coaxial test set-up 26 Figure C.3 – Results obtained with (green) and without ferrites on the test leads (blue) 27 –4– I EC 621 53-4-1 0:201  I EC 201 INTERNATI ONAL ELECTROTECHNI CAL COMMISSI ON M E T AL L I C C O M M U N I C AT I O N P a rt -1 : C AB L E T E S T M E T H O D S – E l e c tro m a g n e t i c c o m p a ti b i l i t y ( E M C ) – T n s fe r i m p e d a n c e a n d s c re e n i n g a t te n u a t i o n o f fe e d - th ro u g h s a n d e l e c tro m a g n e t i c g a s ke ts – D o u b l e c o a x i a l te s t m e th o d FOREWORD ) The I nternati on al Electrotechni cal Comm ission (I EC) is a worl d wid e organization for stan dardization com prisin g all n ation al el ectrotechnical comm ittees (I EC National Comm ittees) The object of I EC is to prom ote internati onal co-operation on all q uestions concerni ng stand ardi zati on in the el ectrical an d electronic fi elds To this en d and in additi on to other acti vities, I EC pu blish es I nternational Stan dards, Techn ical Specificati ons, Technical Reports, Publicl y Avail abl e Specificati ons (PAS) an d Gu ides (h ereafter referred to as “I EC Publication(s)”) Th ei r preparation is entrusted to tech nical comm ittees; any I EC N ational Comm ittee interested in the subj ect dealt with m ay partici pate in this preparatory work I nternational, governm ental an d n on governm ental organ izations l iaising with th e I EC also participate i n this preparation I EC collaborates closel y with the I ntern ational Organi zation for Stand ardization (I SO) in accordance with ditions determ ined by agreem ent between th e two organi zati ons 2) The form al decisions or ag reem ents of I EC on tech nical m atters express, as n early as possible, an i nternati onal consensus of opi nion on the rel evant subjects since each technical com m ittee has representati on from all interested I EC N ational Com m ittees 3) I EC Publications have the form of recom m endations for intern ational use an d are accepted by I EC National Com m ittees in that sense While all reasonable efforts are m ade to ensure that the tech nical content of I EC Publications is accu rate, I EC cann ot be h eld responsi ble for th e way in which th ey are used or for an y m isinterpretation by an y en d u ser 4) I n order to prom ote intern ational u niform ity, I EC National Com m ittees und ertake to apply I EC Publications transparentl y to the m axim um extent possible i n their national an d regi on al publicati ons Any divergence between an y I EC Publication and the correspondi ng national or regi on al publicati on sh all be clearl y in dicated in the latter 5) I EC itself d oes n ot provi de an y attestation of conform ity I n depend ent certificati on bodies provi de conform ity assessm ent services and, in som e areas, access to I EC m arks of conform ity I EC is not responsi ble for any services carri ed out by ind ependent certification bodi es 6) All users shou ld ensure that th ey have the l atest editi on of thi s publicati on 7) No liability shall attach to I EC or its directors, em ployees, servants or ag ents inclu din g in divi dual experts an d m em bers of its technical com m ittees and I EC Nati on al Com m ittees for any person al i njury, property d am age or other dam age of any nature whatsoever, wheth er di rect or indirect, or for costs (includ i ng leg al fees) and expenses arisi ng out of the publ ication, use of, or relian ce upon, this I EC Publicati on or any other I EC Publications 8) Attention is drawn to th e N orm ative references cited in th is publ ication Use of the referenced publ ications is indispensable for the correct applicati on of this publication 9) Attention is drawn to the possibility that som e of the elem ents of this I EC Publication m ay be the su bject of patent rig hts I EC shall not be held responsibl e for identifyi ng any or all such patent ri ghts I nternational Standard I EC 621 53-4-1 has been prepared by I EC technical committee 46: Cables, wires, waveguides, R.F connectors, R F and m icrowave passive components and accessories This second edition cancels and replaces the first edition published in 2009 I t constitutes a technical revision The main technical changes with regard to the previous edition are as follows: – addition of a new clause that describes a procedure for verification of the measurement setup and further information regarding sample preparation ; – addition of a new Annex that describes how to im prove m easurement certainty in the very low frequency area The text of this standard is based on the following docum ents: I EC 621 53-4-1 0: 201  I EC 201 –5– FDI S Report on votin g 46/563/FDI S 46/580/RVD 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 I SO/I EC Directives, Part A list of all parts of the I EC 621 53 series, under the general title: cable test methods, can be found on the I EC website Metallic communication The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the I EC website under "http: //webstore.iec ch" in the data related to the specific publication At this date, the publication will be • • • • reconfirm ed, withdrawn, replaced by a revised edition, or amended A bilingual version of this publication may be issued at a later date I M P O R T AN T – T h e ' c o l o u r i n s i d e ' th at it tai n s u n d e rs t a n d i n g c o l o u r p ri n t e r of c o l o u rs i ts wh i ch c o n te n ts l ogo a re U s e rs on th e co ve r p ag e o f th i s c o n s i d e re d s h ou l d to t h e re fo re be p u b l i c ati o n u s e fu l p ri n t th i s fo r i n d i c a te s th e d o cu m en t c o rre c t u sin g a –6– M E T AL L I C C O M M U N I C AT I O N P a rt -1 : I EC 621 53-4-1 0:201  I EC 201 C AB L E T E S T M E T H O D S – E l e c tro m a g n e t i c c o m p a ti b i l i t y ( E M C ) – T n s fe r i m p e d a n c e a n d s c re e n i n g a t te n u a t i o n o f fe e d -th ro u g h s a n d e l e c tro m a g n e t i c g a s k e ts – D o u b l e c o a x i a l te s t m e th o d S cop e This part of I EC 621 53 details a coaxial m ethod suitable for determ ining the transfer impedance and/or screening attenuation of feed -throughs and electrom agnetic gaskets The shielded screening attenuation test set-up according to I EC 621 53-4-4 (triaxial m ethod) has been m odified to take into account the particularities of feed-throughs and gaskets A wide d ynam ic and frequency ran ge can be applied to test even super screened feed-throughs and gaskets with norm al instrumentation from low frequencies up to the lim it of defined transversal waves in the coaxial circuits at approximatel y GH z N o rm a t i ve re fe re n c e s The following docum ents, in whole or in part, are norm ativel y referenced in this docum ent and are indispensable for its application For dated references, onl y the edition cited applies For undated references, the latest edition of the referenced docum ent (including an y amendments) applies Void T e rm s a n d d e fi n i t i o n s For the purposes of this docum ent, the following terms and definitions apply o p e t i o n a l ( B e t ri e b s ) t n s fe r fu n c t i o n o p e t i o n a l ( B e t ri e b s ) s c a t t e ri n g i n t h e fo rw a rd p a m e t e r S21 d i re c t i o n HB21 quotient of the reflected square root of power wave fed into the reference im pedance of the output of the two-port and the unreflected square root of the power wave consum ed at the input of the two-port EXAMPLE (see Fi gu re ) I EC 621 53-4-1 0: 201  I EC 201 ZA Key E1 , E2 ZA, ZB I1 , I2 U1 , U2 I1 U1 E1 –7– ZB I2 Two-port Z1 Z2 U2 Vi1 Vi2 Vr1 Vr2 network anal yzer at i n put, output respecti vel y reference im pedance at in put and output respecti vel y Vi , Vi current at in put and output, respectively voltage at input an d output, respectivel y Z1 , Z2 Vr1 , Vr2 E2 IEC incident square root of com plex power waves (see n ote) at input an d output, respecti vel y reflected squ are root of com plex power waves (see note) at in put and output, respecti vel y im pedance at i nput and output, respecti vel y Figu re – A two-port Note to entry: Com plex power is the product U ⋅ I Apparent power is the prod uct U ⋅ I ∗ , wh ich is used in electrical power techni qu e, where th e ang le between th e voltag e and current is of interest I ∗ I s the com plex conjug ate of th e current I S21 or HB21 is the operation al (Betri ebs) transfer function in the forward direction d efin ed as follows: S 21 = Vr2 Vi1 Vi2 =0 = 2U2 Z A = HB21 E1 ZB See Ann ex C of I EC TR 621 52: 2009 3.2 transfer impedance equivalent circuit of the measurem ent of a feed-through or gasket, shunt impedance ZT between the prim ary and secondary circuit EXAMPLE Th e transfer im pedance of an el ectricall y sh ort screen is defin ed as the qu oti ent of the open circuit voltage U2 ind uced to the secondary ci rcuit by th e current I1 fed into the prim ary circuit or vice versa See Figu re ZT of an el ectricall y short screen is expressed i n Ω or decibels i n rel ation to Ω I1 Zo, l ZT U2 Zo, l IEC Figure – Equivalent circuit of the test set-up and definition of ZT ZT = U2 I1 (1 ) –8– ZT I EC 621 53-4-1 0:201  I EC 201 Z  = +20 × log1  T   1Ω  (2) 3 operati on al (Betri ebs) atten u ation the quotient of the unreflected square root of power wave fed into the reference im pedance of the input of the two-port and the square root of the power wave consumed by the load of the two-port expressed in dB and radians Note to entry: See I EC TR 621 52 screen in g atten u ati on as logarithmic ratio of the incident (unreflected) square root of power wave fed into the nom inal im pedance of the primary circuit of the test set-up and the periodic m axim um values of the square root of power wave Vr2 , m ax coupled into the secondary circuit of the test set-up when its characteristic impedance Zo is normalized to 50 Ω EXAMPLE as  V = −20 × log1  Env r2, max Vi1  = 20 × log1 Env S21 , max (  50 Ω  + 20 × log1 Zo = ) + 20 × log 10 50 Ω Zo = (3) = Min Env ( AB21 ) + 20 × log1 50 Ω Zo where as Env is the screeni ng atten uation expressed in dB; ( AB21 ) Min En v ( is the operati on al attenuati on record ed as the en velope curve of the m easured valu es in dB (See ); AB21 ) is the operati onal atten uati on recorded as the m inim um envelope curve of th e m easured val ues in dB (See ); 50 Ω is the standardi zed im pedance of the secon dary (“outer” or d isturbed ) circuit The screenin g attenuati on, expressed i n dB of an electrically short d evice is: as ≈ 20 × log1 50 Ω (4) ZT where as is the screeni ng atten uation expressed in Z is the transfer im pedance of th e device u nder test T Ω; Note to entry: Form ula (4) m ay be d educed from Form ul as (3) and (5) as follows, assum ing an el ectricall y short device: Zo × 50 Ω × ZT as = 20 × log1 as = 20 × log1 50 Ω × ZT I f we assum e that 50 Ω ≈ × Zo , then and approxim ate ≈ then as ≈ 20 × log1 50 Ω ZT and Form ula (4) is valid I n the m easurem ent, both prim ary and secondary circuits are low im ped ance This leads to a dB lower in e g the tube m easu rem ent of connectors; see I EC 621 53-4-7 AB21 than – 16 – I EC 621 53-4-1 0:201  I EC 201 For the case of an ideal open circuit and a short circuit as an equivalent circuit for the feedthrough, the following S-m atrices are calculated:  −   −  z → : S =  for (A 3) 0    z → ∞ : S =  or Formula (A ) indicates that the shunt impedance equal to ZT of the feed-through m ay be estimated from the measured S-param eter S21 by: ZT A = z ⋅ Zo = S21 ⋅Z 2(1 − S21 ) o ≈ S21 ⋅ Zo for S21