IEC TS 61156-1-2:2023
(Main)Multicore and symmetrical pair/ quad cables for digital communications - Part 1-2: Electrical transmission characteristics and test methods of symmetrical pair/ quad cables
Multicore and symmetrical pair/ quad cables for digital communications - Part 1-2: Electrical transmission characteristics and test methods of symmetrical pair/ quad cables
IEC TS 61156-1-2:2023 specifies symmetrical pair/quad electrical transmission characteristics and test methods present in IEC 61156-1:2002 (Edition 2) and not carried into IEC 61156-1:2007 (Edition 3). It details characteristic impedance test methods and function fitting procedures, the open/short-circuit method and the background of unbalance attenuation measurement.
It is extended by a description of the balunless measurements technique, which is an amendment to the former technical report and is improved and incorporated into this new edition. The complete document is transferred into a technical specification.
General Information
Relations
Buy Standard
Standards Content (Sample)
IEC TS 61156-1-2 ®
Edition 1.0 2023-11
TECHNICAL
SPECIFICATION
colour
inside
Multicore and symmetrical pair/quad cables for digital communications –
Part 1-2: Electrical transmission characteristics and test methods of symmetrical
pair/quad cables
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 Secretariat 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 IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC TS 61156-1-2 ®
Edition 1.0 2023-11
TECHNICAL
SPECIFICATION
colour
inside
Multicore and symmetrical pair/quad cables for digital communications –
Part 1-2: Electrical transmission characteristics and test methods of
symmetrical pair/quad cables
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 21.220 ISBN 978-2-8322-7881-9
– 2 – IEC TS 61156-1-2:2023 © IEC 2023
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, symbols, units and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Symbols, units and abbreviated terms . 8
4 Basic transmission line formulae. 8
4.1 Overview. 10
4.2 Complex characteristic impedance and propagation coefficient formulae . 11
4.2.1 General . 11
4.2.2 Propagation coefficient . 11
4.2.3 Complex characteristic impedance. 12
4.2.4 Phase and group velocity . 14
4.3 High frequency representation of secondary parameters . 15
4.4 Frequency dependence of the primary and secondary parameters . 17
4.4.1 Resistance . 17
4.4.2 Inductance . 17
4.4.3 Complex characteristic impedance. 17
4.4.4 Attenuation coefficient . 18
4.4.5 Phase delay and group delay . 18
5 Measurement of the complex characteristic impedance . 19
5.1 General . 19
5.2 Open/short circuit single-ended impedance measurement made with a balun
(reference method) . 20
5.2.1 Principle . 20
5.2.2 Test equipment . 21
5.2.3 Procedure . 21
5.2.4 Expression of results . 22
5.3 Function fitting the impedance magnitude and angle . 22
5.3.1 General . 22
5.3.2 Impedance magnitude . 22
5.3.3 Function fitting the angle of the complex characteristic impedance . 24
5.4 Complex characteristic impedance determined from measured phase
coefficient and capacitance . 25
5.4.1 General . 25
5.4.2 Formulae for all frequencies case and for high frequencies. 25
5.4.3 Procedure for the measurement of the phase coefficient . 26
5.4.4 Phase delay . 27
5.4.5 Phase velocity . 28
5.4.6 Procedure for the measurement of the capacitance . 28
5.5 Determination of the complex characteristic impedance using the terminated
measurement method . 28
5.6 Extended open/short circuit method using a balun but excluding the balun
performance . 29
5.6.1 Test equipment and cable-end preparation . 29
5.6.2 Basic formulae . 29
5.6.3 Measurement principle. 29
5.7 Extended open/short circuit method without using a balun . 32
5.7.1 Basic formulae and circuit diagrams . 32
5.7.2 Measurement principle. 34
5.8 Open/short impedance measurements at low frequencies with a balun . 35
5.9 Complex characteristic impedance and propagation coefficient obtained from
modal decomposition technique . 37
5.9.1 General . 37
5.9.2 Procedure . 37
5.9.3 Measurement principle. 38
5.9.4 Scattering matrix to impedance matrix . 40
5.9.5 Expression of results . 42
6 Measurement of return loss and structural return loss . 42
6.1 General . 42
6.2 Principle . 42
7 Propagation coefficient effects due to periodic structural variation related to the
effects appearing in the structural return loss . 43
7.1 General . 43
7.2 Formula for the forward echoes caused by periodic structural
inhomogeneities . 43
8 Unbalance attenuation . 45
8.1 General . 45
8.2 Unbalance attenuation near end and far end . 46
8.3 Theoretical background . 48
9 Balunless test method . 51
9.1 Overall test arrangement . 51
9.1.1 Test instrumentation . 51
9.1.2 Measurement precautions . 52
9.1.3 Mixed mode S-parameter nomenclature . 52
9.1.4 Coaxial cables and interconnect for network analysers . 54
9.1.5 Reference loads for calibration . 54
9.1.6 Calibration . 55
9.1.7 Termination loads for termination of conductor pairs . 56
9.1.8 Termination of screens . 57
9.1.9 Calibration . 57
9.1.10 Establishment of noise floor . 57
9.2 Cabling and cable measurements . 57
9.2.1 Insertion loss and EL TCTL . 57
9.2.2 NEXT . 59
9.2.3 ACR-F . 61
9.2.4 Return loss and TCL . 63
9.2.5 PS alien near-end crosstalk (PS ANEXT-Exogenous crosstalk) . 64
9.2.6 PS attenuation to alien crosstalk ratio, far-end crosstalk (PS AACR-F-
Exogenous crosstalk . 67
Annex A (informative) Example derivation of mixed mode parameters using the modal
decomposition technique . 70
Bibliography . 74
Figure 1 – Secondary parameters extending from 1 kHz to 1 GHz . 19
Figure 2 – Diagram of cable pair measurement circuit . 21
– 4 – IEC TS 61156-1-2:2023 © IEC 2023
Figure 3 – Determining the multiplier of 2π radians to add to the phase measurement . 27
Figure 4 – Measurement configurations . 30
Figure 5 – Measurement principle with four terminal network theory . 30
Figure 6 – Admittance measurement configurations . 34
Figure 7 – Admittance measurement principle . 34
Figure
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.