IEC 62153-4-7:2021

IEC 62153-4-7 ®
Edition 3.1 2025-11
INTERNATIONAL
STANDARD
CONSOLIDATED VERSION
Metallic cables and other passive components test methods -
Part 4-7: Electromagnetic compatibility (EMC) -Test method for measuring of
transfer impedance ZT and screening attenuation aS or coupling attenuation aC of
connectors and assemblies - Triaxial tube in tube method
ICS 33.100.10; 33.120.10 ISBN 978-2-8327-0859-0
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CONTENTS
FOREWORD . 5
INTRODUCTION . 7
INTRODUCTION to Amendment . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Physical background. 11
5 Principle of the test methods . 11
5.1 General . 11
5.2 Transfer impedance . 12
5.3 Screening attenuation . 12
5.4 Coupling attenuation . 13
6 Test procedure . 14
6.1 General . 14
6.2 Tube in tube procedure . 14
6.3 Test equipment . 15
6.4 Calibration procedure. 15
6.5 Connection between extension tube and device under test . 16
6.6 Dynamic range respectively noise floor . 16
6.7 Impedance matching . 17
6.8 Influence of adapters . 17
7 Sample preparation . 18
7.1 Coaxial connector or device . 18
7.2 Balanced or multiconductor device . 18
7.3 Cable assembly . 20
8 Measurement of transfer impedance . 20
8.1 General . 20
8.2 Principle block diagram of transfer impedance . 20
8.3 Measuring procedure – Influence of connecting cables . 21
8.4 Measuring . 21
8.5 Evaluation of test results . 21
8.6 Test report . 22
9 Screening attenuation . 22
9.1 General . 22
9.2 Impedance matching . 22
9.2.1 General . 22
9.2.2 Evaluation of test results with matched conditions . 23
9.2.3 Measuring with mismatch . 24
9.2.4 Evaluation of test results . 24
9.3 Test report . 24
10 Coupling attenuation . 25
10.1 General . 25
10.2 Procedure for testing connectors . 25
10.3 Procedure for testing cable assemblies . 26
10.4 Evaluation of test results when using a balun . 27
10.5 Evaluation of test results when using a multiport VNA . 27
10.6 Test report . 28
Annex A (normative) Determination of the impedance of the inner circuit . 29
Annex B (informative) Example of a self-made impedance matching adapter . 30
Annex C (informative) Measurements of the screening effectiveness of connectors
and cable assemblies . 32
C.1 General . 32
C.2 Physical basics . 32
C.2.1 General coupling equation . 32
C.2.2 Coupling transfer function . 34
C.3 Triaxial test set-up . 36
C.3.1 General . 36
C.3.2 Measurement of cable assemblies . 37
C.3.3 Measurement of connectors . 38
C.4 Conclusion . 41
Annex D (informative) Influence of contact resistances . 42
Annex E (informative) Direct measurement of screening effectiveness of connectors. 44
E.1 Scope . 44
E.2 Test set-up . 44
E.3 Construction details of test set-up . 45
Annex F (normative) Mixed mode S-parameters . 47
F.1 General . 47
F.2 Definition of mixed mode S-parameters . 47
F.3 Reference impedance of a VNA . 50
Annex G (normative) Accessories for measuring coupling attenuation . 51
G.1 TP connecting unit . 51
G.2 Termination of the DUT . 51
G.3 Test adapter . 52
G.3.1 General . 52
G.3.2 Direct feeding with coaxial cables . 52
G.3.3 Balanced feeding cable . 53
G.3.4 Movable short circuit. 53
Annex H (informative) Low frequency screening attenuation . 55
Annex I (normative) Coupling attenuation of unscreened single or multiple pairs . 56
I.1 General . 56
I.2 Coupling attenuation of unscreened connector . 56
I.3 Coupling attenuation of unscreened cable assembly . 57
I.4 Coupling attenuation of long unscreened cable assembly . 57
I.5 Alternative coupling attenuation test method for cable assembly . 58
Annex J (normative) Low frequency coupling attenuation (LFCA) . 59
J.1 General . 59
J.2 Test procedure. 59
J.3 Sample preparation . 59
J.4 Set-up verification and measurement uncertainties . 59
J.5 Expression of the test results . 60
Annex K (normative) Coupling attenuation expressed by mixed mode scattering
parameter and an envelope line . 61
K.1 General . 61
K.2 Coupling attenuation expressed by mixed mode scattering parameter. 61
K.3 Envelope line of coupling attenuation . 61
Annex L (normative) Measurement of screening attenuation at higher frequencies. 63
L.1 General . 63
L.2 Cut-off frequencies of higher order modes (HOM) . 63
L.3 The effect of acting higher order modes in the measurements. 65
L.4 Suppression of higher order modes with magnetic absorbers . 65
L.5 Evaluation of results . 66
L.6 Further considerations . 66
Bibliography . 67

Figure 1 – Definition of Z . 9
T
Figure 2 – Principle of the test set-up to measure transfer impedance and screening or
coupling attenuation of connectors with tube in tube . 12
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 . 17
Figure 5 – Preparation of balanced or multiconductor connectors . 20
Figure 6 – Test set-up (principle) for transfer impedance measurement according to
test of IEC 62153-4-3 with load resistor in inner circuit and without damping resistor in
outer circuit . 21
Figure 7 – Measuring the screening attenuation with tube in tube with impedance
matching device . 23
Figure 8 – Coupling attenuation, principle test set-up with 2-port VNA and balun . 25
Figure 9 – Coupling attenuation, principle set-up with multiport VNA and
TP‑connecting unit . 26
Figure 10 – Coupling attenuation, principle test set-up with multiport VNA and
TP‑connecting unit for measuring complete cable assemblies . 26
Figure 11 – Coupling attenuation, principle test set-up with multiport VNA and
TP‑connecting unit for measuring halved cable assemblies . 27
Figure 12 – Typical measurement of a connector of 0,04 m length with 1 m
extension tube . 28
Figure B.1 – Attenuation and return loss of a 50 Ω to 5 Ω impedance matching adapter,

log scale . 30
Figure B.2 – Attenuation and return loss of a 50 Ω to 5 Ω impedance matching adapter,
lin scale . 31
Figure C.1 – Equivalent circuit of coupled transmission lines . 33
Figure C.2 – Summing function S . 34
Figure C.3 – Calculated coupling transfer function (l = 1 m; e = 2,3; e = 1; Z = 0) . 35
r1 r2 F
Figure C.4 – Triaxial set-up for the measurement of the screening attenuation a and
S
the transfer impedance Z . 36
T
Figure C.5 – Simulation of a cable assembly (logarithmic scale) . 38
Figure C.6 – Simulation of a cable assembly (linear scale) . 38
Figure C.7 – Triaxial set-up with extension tube for short cable assemblies . 39
Figure C.8 – Triaxial set-up with extension tube for connectors. 39
Figure C.9 – Simulation, logarithmic frequency scale . 40
Figure C.10 – Measurement, logarithmic frequency scale . 40
Figure C.11 – Simulation, linear frequency scale. 40
Figure C.12 – Measurement, linear frequency scale . 40
Figure C.13 – Simulation, logarithmic frequency scale . 41
Figure C.14 – simulation, linear frequency scale . 41
Figure D.1 – Contact resistances of the test set-up . 42
Figure D.2 – Equivalent circuit of the test set-up . 42
Figure E.1 – Principle of the test set-up to measure transfer impedance and screening
attenuation of a connector . 44
Figure E.2 – Principle of the test set-up to measure transfer impedance and screening
attenuation of a cable assembly . 45
Figure E.3 – Example of sample preparing . 45
Figure E.4 – Screening tube with separate nut . 46
Figure E.5 – Screening fixed with associated nut . 46
Figure F.1 – Common two-port network . 47
Figure F.2 – Common four port network . 47
Figure F.3 – Physical and logical ports of a VNA . 48
Figure F.4 – Nomenclature of mixed mode S-parameters . 48
Figure F.5 – Measurement configuration, single ended response . 49
Figure F.6 – Measurement configuration, differential mode response . 50
Figure G.1 – Termination of the device under test, principle . 52
Figure G.2 – Balunless measurement of coupling attenuation of a balanced connector,
direct feeding, principle . 53
Figure G.3 – Balunless measurement of coupling attenuation of a cable assembly
using balanced feeding cable, principle . 53
Figure G.4 – Balunless measurement of coupling attenuation of a cable assembly
using adapters with implemented short circuit, principle . 54
Figure H.1 – Example for a screening attenuation test result of a cable assembly with a
test length of 2 meters . 55
Figure I.1 – Coupling attenuation of unscreened balanced pairs/cables . 56
Figure I.2 – Coupling attenuation of an unscreened connector . 57
Figure I.3 – Coupling attenuation of unscreened cable assembly . 57
Figure I.4 – Coupling attenuation of long unscreened cable assembly . 58
Figure I.5 – Coupling attenuation of connected ends . 58
Figure J.1 – Example of reflected mode conversion S . 60
cd11
Figure K.1 – Example of coupling attenuation with envelope line . 62
Figure L.1 – Basic triaxial test procedure . 63
Figure L.2 – Screening attenuation of an RG 214 up to 9 GHz . 64
Figure L.3 – Shielding attenuation measurements including higher order modes when
the CUT is mounted in 4 different radial positions . 65
Figure L.4 – Comparison of shielding attenuation results obtained when narrow stripe
of sheet absorbers are applied . 66
Figure L.5 – Shielding attenuation results when two stripes of sheet absorbers are
applied and 4 CUT positions were measured . 66

Table 1 – IEC 62153, Metallic communication cable test methods – Test procedures
with triaxial test set-up . 11
Table G.1 – TP-connecting unit performance characteristics (100 kHz to 2 GHz) . 51
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Metallic cables and other passive components test methods -
Part 4-7: Electromagnetic compatibility (EMC) -
Test method for measuring of transfer impedance Z and screening
T
attenuation a or coupling attenuation a of connectors and assemblies -
S C
Triaxial tube in tube method
FOREWORD
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This consolidated version of the official IEC Standard and its amendment has been prepared
for user convenience.
IEC 62153-4-7 edition 3.1 contains the third edition (2021-07) [documents 46/812/FDIS and
46/820/RVD] and its amendment 1 (2025-11) [documents 46/1061/FDIS and 46/1070/RVD].
In this Redline version, a vertical line in the margin shows where the technical content is
modified by amendment 1. Additions are in green text, deletions are in strikethrough red text.
A separate Final version with all changes accepted is available in this publication.

IEC 62153-4-7 has been prepared by IEC technical committee 46: Cables, wires, waveguides,
RF connectors, RF and microwave passive components and accessories. It is an International
Standard.
This third edition cancels and replaces the second edition published in 2015 and its
Amendment 1:2018. 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. It now includes IEC 62153-4-7:2015/COR1:2016 and
IEC 62153-4-7:2015/AMD1:2018. Furthermore, the changes of the revised
IEC 62153-4-9:2018 are included.
Measurements of the coupling attenuation can be achieved now by using a mixed mode
network analyser (virtual balun). The following new annexes have been added:
– Annex E contains informative information about the direct measurement of screening
effectiveness of connectors;
– Annex F gives normative information about mixed mode parameters;
– Annex G contains normative information about accessories for measuring coupling
attenuation;
– Annex H discusses the low frequency screening attenuation.
The text of this International Standard is based on the following documents:
FDIS Report on voting
46/812/FDIS 46/820/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement,
available at www.iec.ch/members_experts/refdocs. The main document types developed by
IEC are described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts of the IEC 62153 series, under the general title Metallic cables and other
passive components test methods can be found on the IEC website.
The committee has decided that the contents of this document and its amendment will remain
unchanged until the stability date indicated on the IEC website under webstore.iec.ch in the
data related to the specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
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 electrically short (transfer impedance Z ) and electrically long (screening attenuation
T
a ) can be achieved.
S
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.
INTRODUCTION to Amendment
The goal of this amendment is:
– to extend coupling attenuation measurements to unscreened connectors and cable
assemblies
– to extend coupling attenuation measurements of connectors and cable assemblies to low
frequencies by introducing the LFCA
– to extend 10.5, expression of results by a conversion formula between scattering
parameter and coupling attenuation
– to introduce the application of a 20 dB/dec envelope curve for coupling attenuation
– to introduce the effect and the mitigation techniques of higher order modes when doing
high frequency measurements beyond the higher order mode cutoff-frequency of the
triaxial outer system
1 Scope
This part of IEC 62153 deals with the triaxial tube in tube method. 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 are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC TS 62153-4-1:2014, 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) –Test method for measuring of the screening attenuation as up to and
above 3 GHz, triaxial method
IEC 62153-4-8, Metallic cables and other passive components – Test methods – Part 4-8:
Electromagnetic compatibility (EMC) – Capacitive coupling admittance
IEC 62153-4-9:2018, Metallic communication cable test methods - Part 4 - 9: Electromagnetic
compatibility (EMC) - Coupling attenuation of screened balanced cables, triaxial method
IEC 62153-4-9:2018/AMD1:2020
IEC 62153-4-9:2018/AMD2:2024
IEC 62153-4-10, Metallic communication cable test methods – Part 4-10: Electromagnetic
compatibility (EMC) – Transfer impedance and screening attenuation of feed-throughs and
electromagnetic gaskets - Double coaxial test method
IEC 62153-4-15:20152021, Metallic communication cables and other passive components test
methods - Part 4-15: Electromagnetic compatibility (EMC) – related test method for
measuring transfer impedance and screening attenuation – or coupling attenuation with
triaxial cell
IEC 62153-4-15:2021/AMD1:2024
IEC 62153-4-16, Metallic communication cable test methods – Part 4-16: Electromagnetic
compatibility (EMC) – Extension of the frequency range to higher frequencies for transfer
impedance and to lower frequencies for screening attenuation measurements using the
triaxial set-up
EN 50117-9-2:2019, Coaxial cables – Part 9-2: Sectional specification for coaxial cables for
analogue and digital transmission – Indoor droop cables for systems operating at 5 MHz –
3 000 MHz
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
surface transfer impedance
Z
T
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
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
T
1 Ω.
Note 3 to entry: See Figure 1.

Figure 1 – Definition of Z
T
U
Z =
(1)
T
I
Z
T
Z dB(Ω)=+×20 log (2)

T 10
1Ω

3.2
effective transfer impedance
Z
TE
maximum absolute value of the sum or difference of the capacitive coupling impedance Z
F
and the transfer impedance Z at every frequency:
T
Z max ZZ± (3)
TE F T
3.3
screening attenuation
a
S
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
=
 P 
r,max
a =−×10 log Env
(4)
 
S 10
 
P
 
Note 1 to entry: The screening attenuation of an electrically short device is defined as:
150Ω
a 20× log
(5)
S 10
Z
TE
where
150 Ω is the standardized impedance of the outer circuit.
3.4
coupling attenuation
a
C
for a screened balanced device, the sum of the unbalance attenuation a of the symmetric
U
pair and the screening attenuation a of the screen of the device under test
S
Note 1 to entry: For electrically long devices, i.e. above the cut-off frequency, the coupling attenuation a is
C
defined as the logarithmic ratio of the feeding power P and the periodic maximum values of the coupled power
P in the outer circuit.
r,max
3.5
coupling length
length of device under test
Note 1 to entry: The coupling length is electrically short, if
c
λ
o
o
f<
or  (6)
>×10 ε
r1
l 10××l ε
r1
or electrically long, if
c
λ
o
o
or f≥ (7)
≤×π ε ± ε
r1 r2
l
π××l εε±
r1 r2
where
is the effective coupling length, in m;
l
λ is the free space wavelength, in m;
ε is the resulting relative permittivity of the dielectric of the cable;
r1
ε
is the resulting relative permittivity of the dielectric of the secondary circuit;
r2
f is the frequency, in Hz;
c is the velocity of light in free space.
o
3.6
device under test
DUT
device consisting of the mated connectors with their attached cables
=
4 Physical background
See respective clauses of IEC TS 62153-4-1, IEC 62153-4-3, IEC 62153-4-4, IEC 62153-4-9
and Annex C and Annex D.
5 Principle of the test methods
5.1 General
IEC 62153-4 (all parts) describes different test procedures to measure screening
effectiveness on communication cables, connectors and components with triaxial test set-up.
Table 1 gives an overview about IEC 62153-4 (all parts) test procedures with triaxial test
set-up.
Table 1 – IEC 62153, Metallic communication cable test methods –
Test procedures with triaxial test set-up
Metallic communication cable test methods – Electromagnetic compatibility (EMC)
IEC TS 62153-4-1 Introduction to electromagnetic (EMC) screening measurements
IEC 62153-4-3 Surface transfer impedance − Triaxial method
IEC 62153-4-4 Test method for measuring of the screening attenuation as up to and above 3 GHz,
triaxial method
IEC 62153-4-7 Test method for measuring the transfer impedance Z and the screening attenuation a or
T s
coupling attenuation a of RF-connectors and assemblies up to and above 3 GHz –
C
Triaxial tube in tube method
IEC 62153-4-9 Coupling attenuation of screened balanced cables, triaxial method
IEC 62153-4-10 Transfer impedance and screening attenuation of feed-throughs and electromagnetic
gaskets – Double coaxial test method
IEC 62153-4-15 Test method for measuring transfer impedance and screening attenuation − or coupling
attenuation with triaxial cell
IEC 62153-4-16 Extension of the frequency range to higher frequencies for transfer impedance and to
lower frequencies for screening attenuation measurements using the triaxial set-up

Usually, RF connectors have mechanical dimensions in the longitudinal axis in the range of
20 mm to maximum 50 mm. With the definition of electrical short elements, we get cut off or
corner frequencies for the transition between electrically short and long elements of about
1 GHz or higher for usual RF-connectors.
To measure the screening attenuation instead of transfer impedance also in the lower
frequency range, the tube in tube procedure was designed. The electrically length of the
RF-connector is extended by a RF-tightly closed metallic extension tube (tube in tube).
See Figure 2.
Figure 2 – Principle of the test set-up to measure transfer impedance
and screening or coupling attenuation of connectors with tube in tube
The tube in tube test set up is based on the triaxial system according to IEC 62153-4-3 and
IEC 62153-4-4 consisting of the DUT, a solid metallic tube and (optional) a RF-tight extension
tube. The matched device under test, DUT, which is fed by a generator, forms the disturbing
circuit which may also be designated as the inner or the primary circuit. The connecting
cables to the DUT are additionally screened by the tube in tube.
The disturbed circuit, which may also be designated as the outer or the second circuit, is
formed by the outer conductor of the device under test (and the extension tube), connected to
the connecting cable and a solid metallic tube, having the DUT under test in its axis.
5.2 Transfer impedance
The test determines the screening effectiveness of a shielded cable by applying a well-
defined current and voltage to the screen of the cable, the assembly or the device under test
and measuring the induced voltage in secondary circuit in order to determine the surface
transfer impedance. This test measures only the magnetic component of the transfer
impedance. To measure the electrostatic component (the capacitance coupling impedance),
the method described in IEC 62153-4-8 should be used.
The triaxial method of the measurement is in general suitable in the frequency range up to
30 MHz for a 1 m sample length and 100 MHz for a 0,3 m sample length, which corresponds
to an electrical length less than 1/6 of the wavelength in the sample. A detailed description is
found in Clause 9 of IEC TS 62153-4-1:2014 as well as in IEC 62153-4-3.
5.3 Screening attenuation
The disturbing or primary circuit is the matched cable, assembly or device under test. The
disturbed or secondary circuit consists of the outer conductor (or the outermost layer in the
case of multiscreen cables or devices) of the cable or the assembly or the device under test
and a solid metallic housing, having the device under test in its axis (see Figure 3).
The voltage peaks at the far end of the secondary circuit shall be measured. The near end of
the secondary circuit is short-circuited. For this measurement, a matched receiver is not
necessary. The expected voltage peaks at the far end are not dependent on the input
impedance of the receiver, provided that it is lower than the characteristic impedance of the
secondary circuit. However, it is an advantage to have a low mismatch, for example, by
selecting of housings of sufficient size. A detailed description can be found in
...

IEC 62153-4-7 ®
Edition 3.0 2021-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Metallic cables and other passive components test methods –
Part 4-7: Electromagnetic compatibility (EMC) – Test method for measuring
of transfer impedance Z and screening attenuation a or coupling attenuation
T S
a of connectors and assemblies – Triaxial tube in tube method
C
Méthodes d’essai des câbles métalliques et autres composants passifs –
Partie 4-7: Compatibilité électromagnétique (CEM) – Méthode d’essai pour
mesurer l’impédance de transfert, Z ,et l’affaiblissement d’écrantage, a , ou
T S
l’affaiblissement de couplage, a , des connecteurs et des cordons – Méthode
C
triaxiale en tubes concentriques

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IEC 62153-4-7 ®
Edition 3.0 2021-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Metallic cables and other passive components test methods –

Part 4-7: Electromagnetic compatibility (EMC) – Test method for measuring

of transfer impedance Z and screening attenuation a or coupling attenuation
T S
a of connectors and assemblies – Triaxial tube in tube method
C
Méthodes d’essai des câbles métalliques et autres composants passifs –

Partie 4-7: Compatibilité électromagnétique (CEM) – Méthode d’essai pour

mesurer l’impédance de transfert, Z ,et l’affaiblissement d’écrantage, a , ou
T S
l’affaiblissement de couplage, a , des connecteurs et des cordons – Méthode
C
triaxiale en tubes concentriques

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.100.10; 33.120.10 ISBN 978-2-8322-9988-3

– 2 – IEC 62153-4-7:2021 © IEC 2021
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references. 9
3 Terms and definitions . 10
4 Physical background . 12
5 Principle of the test methods . 12
5.1 General . 12
5.2 Transfer impedance . 13
5.3 Screening attenuation . 13
5.4 Coupling attenuation . 14
6 Test procedure . 15
6.1 General . 15
6.2 Tube in tube procedure . 15
6.3 Test equipment . 16
6.4 Calibration procedure . 16
6.5 Connection between extension tube and device under test . 17
6.6 Dynamic range respectively noise floor . 17
6.7 Impedance matching . 18
6.8 Influence of adapters . 18
7 Sample preparation . 19
7.1 Coaxial connector or device . 19
7.2 Balanced or multiconductor device . 19
7.3 Cable assembly . 21
8 Measurement of transfer impedance . 21
8.1 General . 21
8.2 Principle block diagram of transfer impedance . 21
8.3 Measuring procedure – Influence of connecting cables . 22
8.4 Measuring . 22
8.5 Evaluation of test results . 22
8.6 Test report . 23
9 Screening attenuation . 23
9.1 General . 23
9.2 Impedance matching . 23
9.2.1 General . 23
9.2.2 Evaluation of test results with matched conditions . 24
9.2.3 Measuring with mismatch . 25
9.2.4 Evaluation of test results . 25
9.3 Test report . 25
10 Coupling attenuation . 26
10.1 General . 26
10.2 Procedure for testing connectors . 26
10.3 Procedure for testing cable assemblies . 27
10.4 Evaluation of test results when using a balun . 28
10.5 Evaluation of test results when using a multiport VNA . 28

10.6 Test report . 29
Annex A (normative) Determination of the impedance of the inner circuit . 30
Annex B (informative) Example of a self-made impedance matching adapter . 31
Annex C (informative) Measurements of the screening effectiveness of connectors
and cable assemblies . 33
C.1 General . 33
C.2 Physical basics . 33
C.2.1 General coupling equation . 33
C.2.2 Coupling transfer function . 35
C.3 Triaxial test set-up . 37
C.3.1 General . 37
C.3.2 Measurement of cable assemblies . 38
C.3.3 Measurement of connectors . 39
C.4 Conclusion . 42
Annex D (informative) Influence of contact resistances . 43
Annex E (informative) Direct measurement of screening effectiveness of connectors . 45
E.1 Scope . 45
E.2 Test set-up. 45
E.3 Construction details of test set-up . 46
Annex F (normative) Mixed mode S-parameters . 48
F.1 General . 48
F.2 Definition of mixed mode S-parameters . 48
F.3 Reference impedance of a VNA . 51
Annex G (normative) Accessories for measuring coupling attenuation . 52
G.1 TP connecting unit . 52
G.2 Termination of the DUT . 52
G.3 Test adapter . 53
G.3.1 General . 53
G.3.2 Direct feeding with coaxial cables . 53
G.3.3 Balanced feeding cable . 54
G.3.4 Movable short circuit . 54
Annex H (informative) Low frequency screening attenuation . 56
Bibliography . 57

Figure 1 – Definition of Z . 10
T
Figure 2 – Principle of the test set-up to measure transfer impedance and screening or
coupling attenuation of connectors with tube in tube . 13
Figure 3 – Principle of the test set-up to measure transfer impedance and screening
attenuation of a cable assembly . 15
Figure 4 – Principle set-up for verification test . 18
Figure 5 – Preparation of balanced or multiconductor connectors . 21
Figure 6 – Test set-up (principle) for transfer impedance measurement according to
test of IEC 62153-4-3 with load resistor in inner circuit and without damping resistor in
outer circuit . 22
Figure 7 – Measuring the screening attenuation with tube in tube with impedance
matching device . 24
Figure 8 – Coupling attenuation, principle test set-up with 2-port VNA and balun . 26

– 4 – IEC 62153-4-7:2021 © IEC 2021
Figure 9 – Coupling attenuation, principle set-up with multiport VNA and
TP‑connecting unit . 27
Figure 10 – Coupling attenuation, principle test set-up with multiport VNA and
TP‑connecting unit for measuring complete cable assemblies . 27
Figure 11 – Coupling attenuation, principle test set-up with multiport VNA and
TP‑connecting unit for measuring halved cable assemblies . 28
Figure 12 – Typical measurement of a connector of 0,04 m length with 1 m extension tube . 29
Figure B.1 – Attenuation and return loss of a 50 Ω to 5 Ω impedance matching adapter,
log scale . 31
Figure B.2 – Attenuation and return loss of a 50 Ω to 5 Ω impedance matching adapter,
lin scale . 32
Figure C.1 – Equivalent circuit of coupled transmission lines . 34
Figure C.2 – Summing function S . 35
Figure C.3 – Calculated coupling transfer function (l = 1 m; e = 2,3; e = 1; Z = 0) . 36
r1 r2 F
Figure C.4 – Triaxial set-up for the measurement of the screening attenuation a and
S
the transfer impedance Z . 37
T
Figure C.5 – Simulation of a cable assembly (logarithmic scale) . 39
Figure C.6 – Simulation of a cable assembly (linear scale) . 39
Figure C.7 – Triaxial set-up with extension tube for short cable assemblies . 40
Figure C.8 – Triaxial set-up with extension tube for connectors . 40
Figure C.9 – Simulation, logarithmic frequency scale . 41
Figure C.10 – Measurement, logarithmic frequency scale . 41
Figure C.11 – Simulation, linear frequency scale . 41
Figure C.12 – Measurement, linear frequency scale . 41
Figure C.13 – Simulation, logarithmic frequency scale . 42
Figure C.14 – simulation, linear frequency scale . 42
Figure D.1 – Contact resistances of the test set-up . 43
Figure D.2 – Equivalent circuit of the test set-up . 43
Figure E.1 – Principle of the test set-up to measure transfer impedance and screening
attenuation of a connector . 45
Figure E.2 – Principle of the test set-up to measure transfer impedance and screening
attenuation of a cable assembly . 46
Figure E.3 – Example of sample preparing . 46
Figure E.4 – Screening tube with separate nut . 47
Figure E.5 – Screening fixed with associated nut . 47
Figure F.1 – Common two-port network . 48
Figure F.2 – Common four port network . 48
Figure F.3 – Physical and logical ports of a VNA . 49
Figure F.4 – Nomenclature of mixed mode S-parameters . 49
Figure F.5 – Measurement configuration, single ended response . 50
Figure F.6 – Measurement configuration, differential mode response . 51
Figure G.1 – Termination of the device under test, principle . 53
Figure G.2 – Balunless measurement of coupling attenuation of a balanced connector,
direct feeding, principle . 54
Figure G.3 – Balunless measurement of coupling attenuation of a cable assembly
using balanced feeding cable, principle . 54

Figure G.4 – Balunless measurement of coupling attenuation of a cable assembly
using adapters with implemented short circuit, principle . 55
Figure H.1 – Example for a screening attenuation test result of a cable assembly with a
test length of 2 meters . 56

Table 1 – IEC 62153, Metallic communication cable test methods – Test procedures
with triaxial test set-up . 12
Table G.1 – TP-connecting unit performance characteristics (100 kHz to 2 GHz) . 52

– 6 – IEC 62153-4-7:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
METALLIC CABLES AND OTHER PASSIVE
COMPONENTS TEST METHODS –
Part 4-7: Electromagnetic compatibility (EMC) –
Test method for measuring of transfer impedance Z and screening
T
attenuation a or coupling attenuation a of connectors and assemblies –
S C
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,
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
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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
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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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
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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.
IEC 62153-4-7 has been prepared by IEC technical committee 46: Cables, wires, waveguides,
RF connectors, RF and microwave passive components and accessories. It is an International
Standard.
This third edition cancels and replaces the second edition published in 2015 and its
Amendment 1:2018. 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. It now includes IEC 62153-4-7:2015/COR1:2016 and
IEC 62153-4-7:2015/AMD1:2018. Furthermore, the changes of the revised
IEC 62153-4-9:2018 are included.
Measurements of the coupling attenuation can be achieved now by using a mixed mode
network analyser (virtual balun). The following new annexes have been added:
– Annex E contains informative information about the direct measurement of screening
effectiveness of connectors;
– Annex F gives normative information about mixed mode parameters;
– Annex G contains normative information about accessories for measuring coupling
attenuation;
– Annex H discusses the low frequency screening attenuation.
The text of this International Standard is based on the following documents:
FDIS Report on voting
46/812/FDIS 46/820/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement,
available at www.iec.ch/members_experts/refdocs. The main document types developed by
IEC are described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts of the IEC 62153 series, under the general title Metallic cables and other
passive components test methods can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document 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.
– 8 – IEC 62153-4-7:2021 © IEC 2021
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
electrically short (transfer impedance Z ) and electrically long (screening attenuation a ) can
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.

METALLIC CABLES AND OTHER PASSIVE
COMPONENTS TEST METHODS –
Part 4-7: Electromagnetic compatibility (EMC) –
Test method for measuring of transfer impedance Z and screening
T
attenuation a or coupling attenuation a of connectors and assemblies –
S C
Triaxial tube in tube method
1 Scope
This part of IEC 62153 deals with the triaxial tube in tube method. 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 are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC TS 62153-4-1:2014, 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) –Test method for measuring of the screening attenuation as up to and
above 3 GHz, triaxial method
IEC 62153-4-8, Metallic cables and other passive components – Test methods – Part 4-8:
Electromagnetic compatibility (EMC) – Capacitive coupling admittance
IEC 62153-4-9:2018, Metallic communication cable test methods – Part 4-9: Electromagnetic
compatibility (EMC) – Coupling attenuation of screened balanced cables, triaxial method
IEC 62153-4-10, Metallic communication cable test methods – Part 4-10: Electromagnetic
compatibility (EMC) – Transfer impedance and screening attenuation of feed-throughs and
electromagnetic gaskets - Double coaxial test method
IEC 62153-4-15:2015, 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

– 10 – IEC 62153-4-7:2021 © IEC 2021
IEC 62153-4-16, Metallic communication cable test methods – Part 4-16: Electromagnetic
compatibility (EMC) – Extension of the frequency range to higher frequencies for transfer
impedance and to lower frequencies for screening attenuation measurements using the
triaxial set-up
EN 50117-9-2:2019, Coaxial cables – Part 9-2: Sectional specification for coaxial cables for
analogue and digital transmission – Indoor droop cables for systems operating at 5 MHz –
3 000 MHz
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
surface transfer impedance
Z
T
induced to the inner
for an electrically short screen, quotient of the longitudinal voltage U
circuit by the current I fed into the outer circuit or vice versa
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
T
1 Ω.
Note 3 to entry: See Figure 1.

Figure 1 – Definition of Z
T
U
Z =
(1)
T
I
Z
T
Z dB(Ω)=+×20 log (2)

T 10
1Ω

3.2
effective transfer impedance
Z
TE
maximum absolute value of the sum or difference of the capacitive coupling impedance Z
F
and the transfer impedance Z at every frequency:
T
Z max ZZ±
(3)
TE F T
3.3
screening attenuation
a
S
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
 
P
r,max
a =−×10 log Env (4)
 
S 10
 
P
 
Note 1 to entry: The screening attenuation of an electrically short device is defined as:
150Ω
a 20× log
(5)
S 10
Z
TE
where
150 Ω is the standardized impedance of the outer circuit.
3.4
coupling attenuation
a
C
for a screened balanced device, the sum of the unbalance attenuation a of the symmetric
U
pair and the screening attenuation a of the screen of the device under test
S
Note 1 to entry: For electrically long devices, i.e. above the cut-off frequency, the coupling attenuation a is
C
defined as the logarithmic ratio of the feeding power P and the periodic maximum values of the coupled power
P in the outer circuit.
r,max
3.5
coupling length
length of device under test
Note 1 to entry: The coupling length is electrically short, if
c
λ o
o
f<
or  (6)
>×10 ε
r1
l 10××l ε
r1
or electrically long, if
c
λ
o
o
or f≥ (7)
≤×π ε ± ε
r1 r2
l
π××l εε±
r1 r2
where
is the effective coupling length, in m;
l
is the free space wavelength, in m;
λ
ε is the resulting relative permittivity of the dielectric of the cable;
r1
ε
is the resulting relative permittivity of the dielectric of the secondary circuit;
r2
f is the frequency, in Hz;
c is the velocity of light in free space.
o
=
=
– 12 – IEC 62153-4-7:2021 © IEC 2021
3.6
device under test
DUT
device consisting of the mated connectors with their attached cables
4 Physical background
See respective clauses of IEC TS 62153-4-1, IEC 62153-4-3, IEC 62153-4-4, IEC 62153-4-9
and Annex C and Annex D.
5 Principle of the test methods
5.1 General
IEC 62153-4 (all parts) describes different test procedures to measure screening
effectiveness on communication cables, connectors and components with triaxial test set-up.
Table 1 gives an overview about IEC 62153-4 (all parts) test procedures with triaxial test
set-up.
Table 1 – IEC 62153, Metallic communication cable test methods –
Test procedures with triaxial test set-up
Metallic communication cable test methods – Electromagnetic compatibility (EMC)
IEC TS 62153-4-1 Introduction to electromagnetic (EMC) screening measurements
IEC 62153-4-3 Surface transfer impedance − Triaxial method
IEC 62153-4-4 Test method for measuring of the screening attenuation as up to and above 3 GHz,
triaxial method
IEC 62153-4-7 Test method for measuring the transfer impedance Z and the screening attenuation a or
T s
coupling attenuation a of RF-connectors and assemblies up to and above 3 GHz –
C
Triaxial tube in tube method
IEC 62153-4-9 Coupling attenuation of screened balanced cables, triaxial method
IEC 62153-4-10 Transfer impedance and screening attenuation of feed-throughs and electromagnetic
gaskets – Double coaxial test method
IEC 62153-4-15 Test method for measuring transfer impedance and screening attenuation − or coupling
attenuation with triaxial cell
IEC 62153-4-16 Extension of the frequency range to higher frequencies for transfer impedance and to
lower frequencies for screening attenuation measurements using the triaxial set-up

Usually, RF connectors have mechanical dimensions in the longitudinal axis in the range of
20 mm to maximum 50 mm. With the definition of electrical short elements, we get cut off or
corner frequencies for the transition between electrically short and long elements of about
1 GHz or higher for usual RF-connectors.
To measure the screening attenuation instead of transfer impedance also in the lower
frequency range, the tube in tube procedure was designed. The electrically length of the
RF-connector is extended by a RF-tightly closed metallic extension tube (tube in tube).
See Figure 2.
Figure 2 – Principle of the test set-up to measure transfer impedance
and screening or coupling attenuation of connectors with tube in tube
The tube in tube test set up is based on the triaxial system according to IEC 62153-4-3 and
IEC 62153-4-4 consisting of the DUT, a solid metallic tube and (optional) a RF-tight extension
tube. The matched device under test, DUT, which is fed by a generator, forms the disturbing
circuit which may also be designated as the inner or the primary circuit. The connecting
cables to the DUT are additionally screened by the tube in tube.
The disturbed circuit, which may also be designated as the outer or the second circuit, is
formed by the outer conductor of the device under test (and the extension tube), connected to
the connecting cable and a solid metallic tube, having the DUT under test in its axis.
5.2 Transfer impedance
The test determines the screening effectiveness of a shielded cable by applying a well-
defined current and voltage to the screen of the cable, the assembly or the device under test
and measuring the induced voltage in secondary circuit in order to determine the surface
transfer impedance. This test measures only the magnetic component of the transfer
impedance. To measure the electrostatic component (the capacitance coupling impedance),
the method described in IEC 62153-4-8 should be used.
The triaxial method of the measurement is in general suitable in the frequency range up to
30 MHz for a 1 m sample length and 100 MHz for a 0,3 m sample length, which corresponds
to an electrical length less than 1/6 of the wavelength in the sample. A detailed description is
found in Clause 9 of IEC TS 62153-4-1:2014 as well as in IEC 62153-4-3.
5.3 Screening attenuation
The disturbing or primary circuit is the matched cable, assembly or device under test. The
disturbed or secondary circuit consists of the outer conductor (or the outermost layer in the
case of multiscreen cables or devices) of the cable or the assembly or the device under test
and a solid metallic housing, having the device under test in its axis (see Figure 3).

– 14 – IEC 62153-4-7:2021 © IEC 2021
The voltage peaks at the far end of the secondary circuit shall be measured. The near end of
the secondary circuit is short-circuited. For this measurement, a matched receiver is not
necessary. The expected voltage peaks at the far end are not dependent on the input
impedance of the receiver, provided that it is lower than the characteristic impedance of the
secondary circuit. However, it is an advantage to have a low mismatch, for example, by
selecting of housings of sufficient size. A detailed description can be found in Clause 10 of
IEC TS 62153-4-1:2014 as well as in IEC 62153-4-4. Additional Information on the
interpretation of screening attenuation test results at frequencies below the cut-off frequency
can be found in Annex H.
5.4 Coupling attenuation
Balanced cables, connectors, assemblies or devices which are driven in the differential mode
may radiate a small part of the input power, due to irregularities in the symmetry. For
unscreened balanced cables, connectors, assemblies or devices, this radiation is related to
. For screened balanced cables, connectors or assemblies, the
the unbalance attenuation a
u
unbalance causes a current in the screen which is then coupled by the transfer impedance
and capacitive coupling impedance into the outer circuit. The radiation is attenuated by the
screen of the component and is related to the screening attenuation a .
S
Consequently, the effectiveness against electromagnetic disturbances of shielded balanced
cables, connectors or assemblies is the sum of the unbalance attenuation a of the pair and
U
the screening attenuation a of the screen. Since both quantities usually are given in a
S
logarithmic ratio, they may simply be added to form the coupling attenuation a :
C
a a+ a
(8)
C US
Coupling attenuation a is determined from the logarithmic ratio of the feeding power P and
C 1
the periodic maximum values of the power P (which may be radiated due to the peaks of
r,max
voltage U in the outer circuit):

P
r,max
a =−×10 log Env (9)

C 10

P

The relationship of the radiated power P to the measured power P received on the input
r 2
impedance R is:
P P R
R Rmax
(10)
PP 2× Z
2 2max S
There will be a variation of the voltage U on the far end, caused by the electromagnetic
coupling through the screen and superposition of the partial waves caused by the surface
transfer impedance Z , the capacitive coupling impedance Z (travelling to the far and near
T F
end) and the totally reflected waves from the near end.
To feed the balanced device under test, a differential mode signal is necessary. This can be
achieved with a two-port network analyser (generator and receiver) and a balun or a multiport
network analyser. The procedures to measure coupling attenuation are described in
Clause 10. Annex G gives normative information on accessories for coupling attenuation
measurements.
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