IEC TR 61169-1-8:2025

IEC TR 61169-1-8 ®
Edition 1.0 2025-12
TECHNICAL
REPORT
Radio-frequency connectors -
Part 1-8: Electrical test methods - Voltage standing wave ratio for a single
connector by double connector method
ICS 33.120.30  ISBN 978-2-8327-0930-6

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CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Theory of test method . 5
5 Preparation of test sample (DUT) . 6
5.1 RF cable connector . 6
5.2 Microstrip connector. 7
6 Test procedure . 7
Annex A (informative) Test report on correction coefficient . 8
A.1 Verification test method . 8
A.2 Test results . 10
A.2.1 Test verification of 2,92-KFD microstrip connectors from the same batch . 10
A.2.2 Test verification of 2,4-KFD microstrip connectors in the same batch . 11
A.2.3 Test verification of 1,85-KFD microstrip connectors from the same batch . 11
A.3 Conclusion . 12
Annex B (informative) Test report on cable length . 13
B.1 Verification method . 13
B.2 Test verification . 14
B.2.1 Test verification of N-J type cable connectors from the same batch . 14
B.2.2 Test verification of TNC-J type cable connectors from the same batch. 14
B.2.3 Test verification of SMA-J type cable connectors from the same batch . 15
B.2.4 Test verification of 2,92-J type cable connectors from the same batch . 16
B.2.5 Test verification of 2,4J type cable connectors from the same batch . 16
B.3 Conclusion . 17
Bibliography . 18

Figure 1 – Test sample of cable connectors by double connector method . 6
Figure 2 – Test sample of microstrip connectors by double connector method . 7
Figure A.1 – Tested at no. 1 connector end . 9
Figure A.2 – Tested at no. 2 connector end . 10
Figure B.1 – N-J type cable connectors. 13
Figure B.2 – N-J type cable connectors. 14

Table A.1 – Test results of 2,92-KFD microstrip connectors . 11
Table A.2 – Test results of 2,4-KFD microstrip connectors . 11
Table A.3 – Test results of 1,85-KFD microstrip connectors . 12
Table B.1 – Test results of N-J connectors with 300 mm 3 450 cable (cable
length/λ = 13,1) . 14
min
Table B.2 – Test results of TNC-J connector with 300 mm 3449 cable length/λ = 13,1 . 15
min
Table B.3 – Test results of SMA-J connectors with 50 mm 3 507 cable cable
length/λ = 3,6 . 15
min
Table B.4 – Test results of SMA-J connectors with 100 mm 3 507 cable cable
length/λ = 7,1 . 15
min
Table B.5 – Test results of SMA-J connectors with 300 mm 3 450 cable cable
length/λ = 21 . 16
min
Table B.6 – Test results of 2,92-J connectors with 600 mm 3 506 cable cable
length/λ = 95,2 . 16
min
Table B.7 – Test results of 2,4-J type cable connector assemblies cable
length/λ = 198,4 . 17
min
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Radio-frequency connectors -
Part 1-8: Electrical test methods - Voltage standing wave ratio for a single
connector by double connector method

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for
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IEC TR 61169-1-8 has been prepared by subcommittee 46F: RF and microwave passive
components, of IEC technical committee 46: Cables, wires, waveguides, RF connectors, RF
and microwave passive components and accessories. It is a Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
46F/727/DTR 46F/735/RVDTR
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 Technical Report 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/publications.
A list of all parts in the IEC 61169 series, published under the general title Radio-frequency
connectors, 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, or
– revised.
1 Scope
This part of IEC 61169, which is a Technical Report, provides a test method for voltage standing
wave ratio (VSWR, hereinafter) of single RF connector by double-connector method.
This document is applicable to single RF cable connectors and single microstrip RF connectors
as well as single adapters if an estimation of the VSWR of a single completely installed RF-
connector is used and a time domain feature is not available on the vector network analyzer.
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 61169-1, Radio frequency connectors - Part 1: Generic specification - General
requirements and measuring methods
IEC 61169-1-4, Radio-frequency connectors - Part 1-4: Electrical test methods - Voltage
standing wave ratio, return loss and reflection coefficient
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61169-1 and IEC
61169-1-4 apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
4 Theory of test method
When two identical connectors are connected in series into the system under standard
environmental conditions according to IEC 60068-1 [1], at a certain frequency, the reflections
of both connectors can reach the maximum value, resulting in superposition. In this case, the
total reflection of the two connectors in series is twice as much as that of the single connector,
namely:
𝛤𝛤 = 2𝛤𝛤 (1)
double single
Where Γ and Γ are reflection coefficients of double connectors in series and a single
double single
connector, respectively.
From the relationship between reflection coefficient and voltage standing wave ratio, we can
derive Formula (2):
𝑆𝑆 − 1 1 1𝑆𝑆 − 1
single double
Г = = Г = (2)
single double
𝑆𝑆 + 1 2 2𝑆𝑆 + 1
single double
By conversion, we have:
3𝑆𝑆 + 1
double
𝑆𝑆 = (3)
single
𝑆𝑆 + 3
double
When 1 ≤S <2, we can use empirical formula as follows:
double
𝑆𝑆 = 𝑆𝑆 (4)
�
single double
In Formula (2), Formula (3) and Formula (4), S and S are VSWR for a single connector
single double
and double connectors respectively.
Due to the limitation of materials, process, assembly and other factors, two or more completely
identical connectors do not exist in practice. What can be only done is to use relatively
consistent connectors from same lot to do the double-connector test. Therefore, for some
connectors, it is important that Formula (4) is modified with a correction coefficient A, as shown
in Formula (5). The correction coefficient A is closely related to the consistency of products, for
which refer to Annex A.
𝑆𝑆 =𝐴𝐴 × 𝑆𝑆 (5)
�
single double
Because connectors are reciprocal parts, Formula (4) or Formula (5) are still valid when two
identical connectors are mirror symmetrically connected.
Double-connector method is applicable to measure single RF cable connector and single
microstrip connector for VSWR. It is also applicable to measure single RF connector adapter.
5 Preparation of test sample (
...