Metallic communication cable test methods - Part 4-7: Shielded screening attenuation test method for measuring the transfer impedence ZT and the screening attenuation aS or the coupling attenuation aC of RF-Connectors and asemblies up to and above 3 GHz, Tube in tube method (IEC 62153-4-7:2015)

This triaxial method is suitable to determine the surface transfer impedance and/or screening
attenuation and coupling attenuation of mated screened connectors (including the connection
between cable and connector) and cable assemblies. This method could also be extended to
determine the transfer impedance, coupling or screening attenuation of balanced or multipin
connectors and multicore cable assemblies. For the measurement of transfer impedance and
screening- or coupling attenuation, only one test set-up is needed.

Prüfverfahren für metallische Kommunikationskabel - Teil 4-7: Geschirmtes Prüfverfahren zur Messung von Kopplungswiderstand ZT und von Schirm as- oder Kopplungsdämpfung ac von HF-Steckverbindern und konfektionierten Kabeln bis zu und über 3 GHz - Rohr-im-Rohr-Verfahren

Méthodes d'essai des câbles métalliques de communication - Partie 4-7: Compatibilité électromagnétique (CEM) - Méthode d'essai pour mesurer l'impédance de transfert ZT et l'affaiblissement d'écrantage as ou l'affaiblissement de couplage aC des connecteurs et des cordons jusqu'à 3 GHz et au-dessus - Méthode triaxiale en tubes concentriques

L'IEC 62153-4-7:2015 décrit une méthode triaxiale, qui convient pour déterminer l'impédance surfacique de transfert et/ou l'affaiblissement d'écrantage et l'affaiblissement de couplage de connecteurs équipés d'un écran accouplés (y compris la connexion entre le câble et le connecteur) et de cordons. Cette méthode pourrait également être étendue pour déterminer l'impédance de transfert, l'affaiblissement d'écrantage ou l'affaiblissement de couplage de connecteurs symétriques ou à plusieurs broches et de cordons multiconducteurs. Pour le mesurage de l'impédance de transfert et de l'affaiblissement d'écrantage ou l'affaiblissement de couplage, un seul montage d'essai est nécessaire. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: Le document a été révisé et mis à jour. Les modifications de l'IEC 62153-4-3:2013 et de l'IEC 62153-4-4:2015 sont incluses. Les mesurages peuvent à présent être effectués sans adaptation du côté du générateur, les dispositifs d'adaptation d'impédance ne sont pas nécessaires.

Preskusne metode za kovinske komunikacijske kable - 4-7. del: Metoda za preskušanje slabljenja oklepljenega zaslona za meritve prehodne impedance ZT in zaslonskega slabljenja aS ali sklopnega slabljenja aC rf-konektorjev in sestavov do in nad 3 GHz - Metoda "cev v cevi" (IEC 62153-4-7:2015)

Ta triosna metoda je primerna za določevanje površinske prehodne impedance in/ali zaslonskega slabljenja in sklopnega slabljenja spojnih zaslonskih konektorjev (vključno s povezavo med kablom in konektorjem) ter kabelskih sestavov. S to metodo je mogoče določiti tudi prehodno impedanco ter sklopno oz. zaslonsko slabljenje simetričnih ali večpolnih konektorjev in večjedrnih kabelskih sestavov. Za merjenje prehodne impedance in zaslonskega oz. sklopnega slabljenja je potrebna le ena priprava preskusa.

General Information

Status
Published
Publication Date
04-Apr-2016
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
23-Mar-2016
Due Date
28-May-2016
Completion Date
05-Apr-2016

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SLOVENSKI STANDARD
SIST EN 62153-4-7:2016
01-maj-2016
1DGRPHãþD
SIST EN 62153-4-7:2007
Preskusne metode za kovinske komunikacijske kable - 4-7. del: Metoda za
preskušanje slabljenja oklepljenega zaslona za meritve prehodne impedance ZT in
zaslonskega slabljenja aS ali sklopnega slabljenja aC rf-konektorjev in sestavov
do in nad 3 GHz - Metoda "cev v cevi" (IEC 62153-4-7:2015)

Metallic communication cable test methods - Part 4-7: Shielded screening attenuation

test method for measuring the transfer impedence ZT and the screening attenuation aS

or the coupling attenuation aC of RF-Connectors and asemblies up to and above 3 GHz,

Tube in tube method (IEC 62153-4-7:2015)
Ta slovenski standard je istoveten z: EN 62153-4-7:2016
ICS:
33.100.01 Elektromagnetna združljivost Electromagnetic compatibility
na splošno in general
33.120.10 Koaksialni kabli. Valovodi Coaxial cables. Waveguides
SIST EN 62153-4-7:2016 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 62153-4-7:2016
---------------------- Page: 2 ----------------------
SIST EN 62153-4-7:2016
EUROPEAN STANDARD EN 62153-4-7
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2016
ICS 33.100; 33.120.10 Supersedes EN 62153-4-7:2006
English Version
Metallic communication cable test methods -
Part 4-7: Electromagnetic compatibility (EMC) - Test method for
measuring of transfer impedance Z and screening attenuation
a or coupling attenuation a of connectors and assemblies up to
s c
and above 3 GHz - Triaxial tube in tube method
(IEC 62153-4-7:2015)

Méthodes d'essai des câbles métalliques de communication Prüfverfahren für metallische Kommunikationskabel -

- Partie 4-7: Compatibilité électromagnétique (CEM) - Teil 4-7: Geschirmtes Prüfverfahren zur Messung von

Méthode d'essai pour mesurer l'impédance de transfert Z Kopplungswiderstand Z und von Schirm a - oder

T T s

et l'affaiblissement d'écrantage a ou l'affaiblissement de Kopplungsdämpfung a von HF-Steckverbindern und

s c

couplage a des connecteurs et des cordons jusqu'à 3 GHz konfektionierten Kabeln bis zu und über 3 GHz - Rohr-im-

et au-dessus - Méthode triaxiale en tubes concentriques Rohr-Verfahren
(IEC 62153-4-7:2015) (IEC 62153-4-7:2015)

This European Standard was approved by CENELEC on 2016-01-13. 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.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC

Management Centre or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation

under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the

same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,

Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN 62153-4-7:2016 E
---------------------- Page: 3 ----------------------
SIST EN 62153-4-7:2016
EN 62153-4-7:2016
European foreword

The text of document 46/572/FDIS, future edition 2 of IEC 62153-4-7, prepared by IEC/TC 46 "Cables,

wires, waveguides, R.F. connectors, R.F. and microwave passive components and accessories" was

submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 62153-4-7:2016.

The following dates are fixed:
(dop) 2016-10-13
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2019-01-13
standards conflicting with the
document have to be withdrawn
This document supersedes EN 62153-4-7:2006.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such

patent rights.
Endorsement notice

The text of the International Standard IEC 62153-4-7:2015 was approved by CENELEC as a

European Standard without any modification.
---------------------- Page: 4 ----------------------
SIST EN 62153-4-7:2016
EN 62153-4-7:2016
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:

www.cenelec.eu
Publication Year Title EN/HD Year
IEC/TS 62153-4-1 - Metallic communication cable test methods - -
- Part 4-1: Electromagnetic compatibility
(EMC) - Introduction to electromagnetic
screening measurements
IEC 62153-4-3 - Metallic communication cable test methods - -
- Part 4-3: Electromagnetic Compatibility
(EMC) - Surface transfer impedance -
Triaxial method
IEC 62153-4-4 - Metallic communication cable test methods - -
- Part 4-4: Electromagnetic compatibility
(EMC) - Shielded screening attenuation,
test method for measuring of the screening
attenuation as up to and above 3 GHz
IEC 62153-4-15 - Metallic communication cable test methods - -
- Part 4-15: Electromagnetic compatibility
(EMC) - Test method for measuring
transfer impedance and screening
attenuation - or coupling attenuation with
triaxial cell
---------------------- Page: 5 ----------------------
SIST EN 62153-4-7:2016
---------------------- Page: 6 ----------------------
SIST EN 62153-4-7:2016
IEC 62153-4-7
Edition 2.0 2015-12
INTERNATIONAL
STANDARD
colour
inside
Metallic communication cable test methods –
Part 4-7: Electromagnetic compatibility (EMC) – Test method for measuring of
transfer impedance Z and screening attenuation a or coupling attenuation a
T s C
of connectors and assemblies up to and above 3 GHz – Triaxial tube in tube
method
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.100; 33.120.10 ISBN 978-2-8322-3054-1

Warning! Make sure that you obtained this publication from an authorized distributor.

® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 7 ----------------------
SIST EN 62153-4-7:2016
– 2 – IEC 62153-4-7:2015 © IEC 2015
CONTENTS

FOREWORD ........................................................................................................................... 5

INTRODUCTION ..................................................................................................................... 7

1 Scope .............................................................................................................................. 8

2 Normative references ...................................................................................................... 8

3 Terms and definitions ...................................................................................................... 8

4 Physical background ...................................................................................................... 10

5 Principle of the test methods ......................................................................................... 10

5.1 General ................................................................................................................. 10

5.2 Transfer impedance .............................................................................................. 12

5.3 Screening attenuation ........................................................................................... 12

5.4 Coupling attenuation ............................................................................................. 12

6 Test procedure .............................................................................................................. 13

6.1 General ................................................................................................................. 13

6.2 Tube in tube procedure ......................................................................................... 13

6.3 Test equipment ..................................................................................................... 14

6.4 Calibration procedure ............................................................................................ 15

6.5 Connection between extension tube and device under test ................................... 15

6.6 Dynamic range respectively noise floor ................................................................. 15

6.7 Impedance matching ............................................................................................. 16

6.8 Influence of Adapters ............................................................................................ 16

7 Sample preparation ....................................................................................................... 17

7.1 Coaxial connector or device .................................................................................. 17

7.2 Balanced or multiconductor device ........................................................................ 17

7.3 Cable assembly .................................................................................................... 19

8 Measurement of transfer impedance .............................................................................. 19

8.1 General ................................................................................................................. 19

8.2 Principle block diagram of transfer impedance ...................................................... 19

8.3 Measuring procedure – Influence of connecting cables ......................................... 19

8.4 Measuring ............................................................................................................. 20

8.5 Evaluation of test results ....................................................................................... 20

8.6 Test report ............................................................................................................ 20

9 Screening attenuation .................................................................................................... 21

9.1 General ................................................................................................................. 21

9.2 Impedance matching ............................................................................................. 21

9.2.1 General ......................................................................................................... 21

9.2.2 Evaluation of test results with matched conditions ......................................... 22

9.2.3 Measuring with mismatch............................................................................... 22

9.2.4 Evaluation of test results ............................................................................... 22

9.3 Test report ............................................................................................................ 23

10 Coupling attenuation ...................................................................................................... 23

10.1 Procedure ............................................................................................................. 23

10.2 Expression of results ............................................................................................ 24

10.3 Test report ............................................................................................................ 24

10.4 Balunless procedure ............................................................................................. 25

Annex A (normative) Determination of the impedance of the inner circuit ............................. 26

---------------------- Page: 8 ----------------------
SIST EN 62153-4-7:2016
IEC 62153-4-7:2015 © IEC 2015 – 3 –

Annex B (informative) Example of a self-made impedance matching adapter ....................... 27

Annex C (informative) Measurements of the screening effectiveness of connectors

and cable assemblies ........................................................................................................... 29

C.1 General ................................................................................................................. 29

C.2 Physical basics ..................................................................................................... 29

C.2.1 General coupling equation ............................................................................. 29

C.2.2 Coupling transfer function .............................................................................. 31

C.3 Triaxial test set-up ................................................................................................ 33

C.3.1 General ......................................................................................................... 33

C.3.2 Measurement of cable assemblies ................................................................. 34

C.3.3 Measurement of connectors ........................................................................... 35

C.4 Conclusion ............................................................................................................ 38

Annex D (informative) Influence of contact resistances ........................................................ 39

Bibliography .......................................................................................................................... 41

Figure 1 – Definition of Z ...................................................................................................... 9

Figure 2 – Principle of the test set-up to measure transfer impedance and screening or

coupling attenuation of connectors with tube in tube ............................................................. 11

Figure 3 – Principle of the test set-up to measure transfer impedance and screening

attenuation of a cable assembly ............................................................................................ 14

Figure 4 – Principle set-up for verification test ...................................................................... 16

Figure 5 – Preparation of balanced or multiconductor connectors ......................................... 18

Figure 6 – Test set-up (principle) for transfer impedance measurement according to

test method B of IEC 62153-4-3 ............................................................................................ 19

Figure 7 – Measuring the screening attenuation with tube in tube with impedance

matching device .................................................................................................................... 21

Figure 8 – Measuring the coupling attenuation with tube in tube and balun ........................... 24

Figure 9 – Typical measurement of a connector of 0,04 m length with 1 m extension

tube ...................................................................................................................................... 25

Figure 10 – Measuring the coupling attenuation with multiport VNA (balunless

procedure is under consideration) ......................................................................................... 25

Figure B.1 – Attenuation and return loss of a 50 Ω to 5 Ω impedance matching

adapter, log scale ................................................................................................................. 27

Figure B.2 – Attenuation and return loss of a 50 Ω to 5 Ω impedance matching

adapter, lin scale .................................................................................................................. 28

Figure C.1 – Equivalent circuit of coupled transmission lines ................................................ 30

Figure C.2 – Summing function S .......................................................................................... 31

Figure C.3 – Calculated coupling transfer function (l = 1 m; e = 2,3; e = 1; Z = 0) .......... 32

r1 r2 F

Figure C.4 – Triaxial set-up for the measurement of the screening attenuation a and

the transfer impedance Z .................................................................................................... 33

Figure C.5 – Simulation of a cable assembly (logarithmic scale) ........................................... 35

Figure C.6 – Simulation of a cable assembly (linear scale) ................................................... 35

Figure C.7 – Triaxial set-up with extension tube for short cable assemblies .......................... 36

Figure C.8 – Triaxial set-up with extension tube for connectors ............................................. 36

Figure C.9 – Simulation, logarithmic frequency scale .......................................................... 37

Figure C.10 – Measurement, logarithmic frequency scale ................................................... 37

Figure C.11 – Simulation, linear frequency scale................................................................. 37

---------------------- Page: 9 ----------------------
SIST EN 62153-4-7:2016
– 4 – IEC 62153-4-7:2015 © IEC 2015

Figure C.12 – Measurement, linear frequency scale ............................................................ 37

Figure C.13 – Simulation, logarithmic frequency scale ........................................................ 38

Figure C.14 – simulation, linear frequency scale ................................................................. 38

Figure D.1 – Contact resistances of the test set-up ............................................................... 39

Figure D.2 – Equivalent circuit of the test set-up ................................................................... 39

Table 1 – IEC 62153, Metallic communication cable test methods – Test procedures

with triaxial test set-up .......................................................................................................... 11

---------------------- Page: 10 ----------------------
SIST EN 62153-4-7:2016
IEC 62153-4-7:2015 © IEC 2015 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
METALLIC COMMUNICATION CABLE TEST METHODS –
Part 4-7: Electromagnetic compatibility (EMC) – Test method for
measuring of transfer impedance Z and screening attenuation a
T s
or coupling attenuation a of connectors and assemblies
up to and above 3 GHz – Triaxial tube in tube method
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence

between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

the latter.

5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable 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 62153-4-7 has been prepared by IEC technical committee 46:

Cables, wires, waveguides, R.F. connectors, R.F. and microwave passive components and

accessories.

This second edition cancels and replaces the first edition published in 2006. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

The document is revised and updated. The changes of the revised IEC 62153-4-3:2013, and

IEC 62153-4-4:2015, are included.
---------------------- Page: 11 ----------------------
SIST EN 62153-4-7:2016
– 6 – IEC 62153-4-7:2015 © IEC 2015
Measurements can be achieved now with mismatch at the generator site, impedance
matching devices are not necessary.
The text of this standard is based on the following documents:
FDIS Report on voting
46/572/FDIS 46/585/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 ISO/IEC Directives, Part 2.

A list of all parts of the IEC 62153 series, under the general title: Metallic communication

cable test methods, can be found on the IEC website.

The committee has decided that the contents of this publication will remain unchanged until

the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data

related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
---------------------- Page: 12 ----------------------
SIST EN 62153-4-7:2016
IEC 62153-4-7:2015 © IEC 2015 – 7 –
INTRODUCTION
The shielded screening attenuation test set-up according to IEC 62153-4-3 and

IEC 62153-4-4 have been extended to take into account the particularities of electrically short

elements like connectors and cable assemblies. Due to the concentric outer tube of the

triaxial set-up, measurements are independent of irregularities on the circumference and outer

electromagnetic fields.

With the use of an additional resonator tube (inner tube respectively tube in tube), a system is

created where the screening effectiveness of an electrically short device is measured in

realistic and controlled conditions. Also a lower cut off frequency for the transition between

) and electrically long (screening attenuation a ) can
electrically short (transfer impedance Z
T S
be achieved.

A wide dynamic and frequency range can be applied to test even super screened connectors

and assemblies with normal instrumentation from low frequencies up to the limit of defined

transversal waves in the outer circuit at approximately 4 GHz.
---------------------- Page: 13 ----------------------
SIST EN 62153-4-7:2016
– 8 – IEC 62153-4-7:2015 © IEC 2015
METALLIC COMMUNICATION CABLE TEST METHODS –
Part 4-7: Electromagnetic compatibility (EMC) – Test method for
measuring of transfer impedance Z and screening attenuation a
T s
or coupling attenuation a of connectors and assemblies
up to and above 3 GHz – Triaxial tube in tube method
1 Scope

This triaxial method is suitable to determine the surface transfer impedance and/or screening

attenuation and coupling attenuation of mated screened connectors (including the connection

between cable and connector) and cable assemblies. This method could also be extended to

determine the transfer impedance, coupling or screening attenuation of balanced or multipin

connectors and multicore cable assemblies. For the measurement of transfer impedance and

screening- or coupling attenuation, only one test set-up is needed.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and

are indispensable for its application. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any
amendments) applies.

IEC TS 62153-4-1, Metallic communication cable test methods – Part 4-1: Electromagnetic

compatibility (EMC) – Introduction to electromagnetic screening measurements

IEC 62153-4-3, Metallic communication cable test methods – Part 4-3: Electromagnetic

Compatibility (EMC) − Surface transfer impedance − Triaxial method

IEC 62153-4-4, Metallic communication cable test methods – Part 4-4: Electromagnetic

compatibility (EMC) – Shielded screening attenuation, test method for measuring of the

screening attenuation as up to and above 3 GHz

IEC 62153-4-15, Metallic communication cable test methods – Part 4-15: Electromagnetic

compatibility (EMC) – Test method for measuring transfer impedance and screening
attenuation – or coupling attenuation with Triaxial Cell
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
surface transfer impedance

for an electrically short screen, quotient of the longitudinal voltage U induced to the inner

circuit by the current I fed into the outer circuit or vice versa, see figure 1
Note 1 to entry: The surface transfer impedance is expressed in ohms.

Note 2 to entry: The value Z of an electrically short screen is expressed in ohms [Ω] or decibels in relation to

1 Ω.
Note 3 to entry: See Figure 1.
---------------------- Page: 14 ----------------------
SIST EN 62153-4-7:2016
IEC 62153-4-7:2015 © IEC 2015 – 9 –
I I
2 2
l < λ/10
IEC
Figure 1 – Definition of Z
Z = (1)
 Z 
 
Z dB(Ω)=+20×log (2)
T 10
 
 
3.2
effective transfer impedance
effective transfer impedance, defined as:
Z = max Z ± Z (3)
TE F T
where
Z is the capacitive coupling impedance.
3.3
screening attenuation

for electrically long devices, i.e. above the cut-off frequency, logarithmic ratio of the feeding

power P and the periodic maximum values of the coupled power P in the outer circuit

1 r,max
 
r,max
 
a=−10log Env (4)
s 10
 
 
where
Env is the minimum envelope curve of the measured values in dB

Note 1 to entry: The screening attenuation of an electrically short device is defined as:

150Ω
(5)
a=− 20log
s 10
where
150 Ω is the standardized impedance of the outer circuit.
---------------------- Page: 15 -------
...

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