IEC 62153-4-9:2018/AMD1:2020

IEC 62153-4-9 ®
Edition 2.0 2020-07
INTERNATIONAL
STANDARD
colour
inside
AMENDMENT 1
Metallic communication cable test methods –
Part 4-9: Electromagnetic compatibility (EMC) – Coupling attenuation of
screened balanced cables, triaxial method

IEC 62153-4-9:2018-05/AMD1:2020-07(en)

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 IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and definitions clause of
IEC publications issued between 2002 and 2015. Some
IEC Customer Service Centre - webstore.iec.ch/csc entries have been collected from earlier publications of IEC
If you wish to give us your feedback on this publication or TC 37, 77, 86 and CISPR.

need further assistance, please contact the Customer Service

Centre: sales@iec.ch.
IEC 62153-4-9 ®
Edition 2.0 2020-07
INTERNATIONAL
STANDARD
colour
inside
AMENDMENT 1
Metallic communication cable test methods –

Part 4-9: Electromagnetic compatibility (EMC) – Coupling attenuation of

screened balanced cables, triaxial method

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.100.10; 33.120.10 ISBN 978-2-8322-8519-0

– 2 – IEC 62153-4-9:2018/AMD1:2020
© IEC 2020
FOREWORD
This amendment has been prepared by IEC technical committee 46: Cables, wires,
waveguides, RF connectors, RF and microwave passive components and accessories.
The text of this amendment is based on the following documents:
FDIS Report on voting
46/773/FDIS 46/776/RVD
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base 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.
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.
_____________
INTRODUCTION to Amendment 1
The goal of this amendment is to extent IEC 62153-4-9 such that also the coupling attenuation
of unscreened single or multiple balanced pairs or unscreened quads can be measured with
the triaxial test procedure.
Further complement is the extension of the usable frequency range down to frequencies
below 9 kHz to measure the low frequency coupling attenuation of screened and unscreened
balanced pairs or quads.
© IEC 2020
Add, after Annex C, the following new Annex D:
Annex D
(normative)
Measuring the screening effectiveness
of unscreened single or multiple balanced pairs
D.1 General
IEC 62153-4-9 describes the measurement of coupling attenuation of balanced pairs with the
triaxial test set-up. Due to the short circuit between the screen of the cable under test (CUT)
and the triaxial tube at the near end, the method described in IEC 62153-4-9 applies only to
screened balanced cables.
This annex describes the procedures for measuring coupling attenuation of unscreened single
or multiple balanced pairs. Furthermore, the screening effectiveness of screened and
unscreened balanced pairs at frequencies down to 9 kHz is described.
D.2 Background
Figure D.1 shows the basic triaxial test set-up with a short circuit between the screen of the
cable under test (CUT) and the tube at the near end.
Due to the energy which couples through the screen from the inner system (the CUT) into the
outer system (the tube), a wave is travelling in both directions in the outer system. The short
circuit at the near end causes a total reflection so that the complete energy that couples from
the CUT into the outer system is travelling to the receiver and is measured as superimposed
curve. The measured maximum values, respectively the envelope curve, is the screening
attenuation according to IEC 62153-4-4, see also IEC TS 62153-4-1.

Figure D.1 – Basic triaxial tube procedure according to IEC 62153-4-3 / IEC 62153-4-4
The same principle applies to screened balanced cables, where also the interaction between
differential mode and common mode shall be considered (see Figures 1 and 3).
D.3 Triaxial set-up for unscreened balanced pairs
D.3.1 Principle
Basically, it should be distinguished between single unscreened pairs and multiple
unscreened pairs. In case of multiple unscreened pairs, the EMC behavior, respectively test
results, depends on the treatment of the remaining pairs, e.g. grounded or not.

– 4 – IEC 62153-4-9:2018/AMD1:2020
© IEC 2020
Figure D.2 – Screening effectiveness of unscreened balanced pairs, principle set-up
Figure D.2 shows the principle triaxial set-up for balanced unscreened single or multiple
balanced pairs. The signal is fed into the tube in the differential mode via two parallel semi
rigid coaxial cables of equal length with the screens connected to the tube. Due to the
conversion from the differential mode into the common
...