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

Amendment 1 - Metallic communication cable test methods - Part 4 - 9: Electromagnetic compatibility (EMC) - Coupling attenuation of screened balanced cables, triaxial method

General Information

• Status: Published
• Publication Date: 05-Jul-2020
• ICS: 33.100.10 - Emission
• ICS: 33.120.10 - Coaxial cables. Waveguides
• Technical Committee: TC 46 - Cables, wires, waveguides, RF connectors, RF and microwave passive components and accessories
• Drafting Committee: WG 5 - TC 46/WG 5
• Current Stage: PPUB - Publication issued
• Start Date: 06-Jul-2020
• Completion Date: 12-Jun-2020

Relations

• Amends: IEC 62153-4-9:2018 - Metallic communication cable test methods - Part 4 - 9: Electromagnetic compatibility (EMC) - Coupling attenuation of screened balanced cables, triaxial method
• Effective Date: 05-Sep-2023

Overview

IEC 62153-4-9:2018/AMD1:2020 is an amendment to the IEC test method for electromagnetic compatibility (EMC) of metallic communication cables using the triaxial method. The amendment extends the original procedural scope so that coupling attenuation and screening effectiveness can also be measured for unscreened single or multiple balanced pairs, and it expands the usable frequency range down to below 9 kHz to support low-frequency applications.

Key topics and technical requirements

• Triaxial test set‑up: Uses a triaxial tube arrangement where energy coupling from the inner system ( CUT ) into the outer system (tube) is measured. For screened cables the screen is short‑circuited to the tube at the near end; for unscreened pairs a modified set‑up is defined.
• Annex D (normative): Introduces procedures for measuring the screening effectiveness of unscreened balanced pairs and defines configurations for:
  • Near‑end coupling attenuation (equivalent to unbalance attenuation, S_cd11).
  • Far‑end screening and coupling attenuation (S_sc21 and S_sd21).
  • Multiple‑pair measurements with far‑end matching and a TP‑connecting unit grounded at the near end.
• Impedance matching: Differential and common‑mode matching is required; for 100 Ω differential characteristic cables use two 50 Ω resistors. Common‑mode loading for some measurements is specified as 25 Ω with 100/25 matching noted for differential/common mode.
• Low frequency coupling attenuation (a_C,lf): A new measure that starts in principle from DC and captures unbalance attenuation, transfer impedance (if present), and screening attenuation across low-to-high frequencies. A test length of 3 m is specified to provide comparable results.
• Measurement verification & uncertainty: Clause D.9 requires verification of the system mode conversion (typical system artefacts between –80 dB and –40 dB) and inclusion of these values in the uncertainty analysis. Example method: record reflected mode conversion S_cd11 with a TP‑unit open loop. Use of calibrated, phase‑stable VNAs and leads is emphasized.

Applications and who uses it

• Cable and connector manufacturers validating EMC performance of screened and unscreened twisted pairs.
• EMC test laboratories performing standardized coupling attenuation and screening effectiveness measurements.
• Automotive and industrial designers working with single‑pair Ethernet PHYs (e.g., IEEE 802.3cg / 802.3bw) where low‑frequency EMC behavior matters.
• System integrators and compliance engineers assessing cable susceptibility and emissions in communication installations.

Related standards (references)

• IEC 62153-4-3 / IEC 62153-4-4 and IEC TS 62153-4-1 (related triaxial/test method background)
• IEEE 802.3cg-2019 and IEEE 802.3bw-2015 (single-pair Ethernet PHYs)

Keywords: IEC 62153-4-9:2018/AMD1:2020, EMC testing, coupling attenuation, triaxial method, screened balanced cables, unscreened balanced pairs, low frequency coupling attenuation, transfer impedance, VNA, screening effectiveness.

Standards Content (Sample)

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)

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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
...