IEC 63138-2:2023

IEC 63138-2 ®
Edition 2.0 2023-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Multi-channel radio-frequency connectors –
Part 2: Sectional specification for MQ4 series circular connectors

Connecteurs radiofréquences multicanaux –
Partie 2: Spécification intermédiaire pour les connecteurs circulaires de
série MQ4
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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

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and withdrawn publications.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.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC -  IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez
La recherche avancée permet de trouver des publications IEC gratuitement tous les aperçus des publications. Avec un
en utilisant différents critères (numéro de référence, texte, abonnement, vous aurez toujours accès à un contenu à jour
comité d’études, …). Elle donne aussi des informations sur les adapté à vos besoins.
projets et les publications remplacées ou retirées.

Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
Le premier dictionnaire d'électrotechnologie en ligne au monde,
Restez informé sur les nouvelles publications IEC. Just
avec plus de 22 300 articles terminologiques en anglais et en
Published détaille les nouvelles publications parues.
français, ainsi que les termes équivalents dans 19 langues
Disponible en ligne et une fois par mois par email.
additionnelles. Egalement appelé Vocabulaire

Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC 63138-2 ®
Edition 2.0 2023-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Multi-channel radio-frequency connectors –

Part 2: Sectional specification for MQ4 series circular connectors

Connecteurs radiofréquences multicanaux –

Partie 2: Spécification intermédiaire pour les connecteurs circulaires de

série MQ4
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.120.30  ISBN 978-2-8322-7638-9

– 2 – IEC 63138-2:2023 © IEC 2023
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Mating face and gauge information . 7
4.1 Mating face dimensions . 7
4.1.1 MQ4 socket connector . 7
4.1.2 MQ4 plug connector . 8
4.1.3 Mating face of RF channel . 11
4.2 Gauges . 12
4.2.1 Gauge for RF channel. 12
4.2.2 Gauge rings for plug outer contact . 13
4.2.3 Gauge for MQ4 socket connector . 14
4.2.4 Gauge for MQ4 plug connector . 15
5 Quality assessment procedure . 17
5.1 General . 17
5.2 Rating and characteristics . 17
5.3 Quality assessment . 19
5.3.1 General . 19
5.3.2 Inspection procedure . 19
5.3.3 Lot-by-lot inspection . 20
5.3.4 Periodic inspections . 21
6 Instructions for preparation of detail specifications . 23
6.1 General . 23
6.2 Identification of the detail specification . 23
6.3 Identification of the component . 23
6.4 Performance . 23
6.5 Marking, ordering information and related matters . 24
6.6 Selection of tests, test conditions and severities . 24
6.7 Blank detail specification pro forma for MQ4 series circular connectors . 24
7 Marking . 29
7.1 Marking of components . 29
7.2 Marking and contents of package . 29

Figure 1 – MQ4 socket connector . 7
Figure 2 – MQ4 quick-lock plug connector . 9
Figure 3 – MQ4 threaded plug connector . 10
Figure 4 – Mating face of RF channel . 11
Figure 5 – Gauge for socket contact of RF channel . 13
Figure 6 – Gauge for plug outer contact . 14
Figure 7 – Gauge for MQ4 socket connector . 15
Figure 8 – Gauge for MQ4 plug connector . 16

Table 1 – Dimensions of MQ4 socket connector . 8
Table 2 – Dimensions of MQ4 quick-lock plug connector . 9

Table 3 – Dimensions of MQ4 threaded plug connector . 10
Table 4 – Dimensions of RF channel . 12
Table 5 – Dimensions of gauge for socket contact . 13
Table 6 – Dimensions of gauge for outer contact . 14
Table 7 – Dimensions of gauge for MQ4 socket connector . 15
Table 8 – Dimensions of gauge for MQ4 plug connector . 16
Table 9 – Rating and characteristics . 17
Table 10 – Qualification inspection . 19
Table 11 – Lot-by-lot inspection . 21
Table 12 – Sampling plans for mechanical compatibility and return loss inspection . 21
Table 13 – Periodic inspection . 22

– 4 – IEC 63138-2:2023 © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MULTI-CHANNEL RADIO-FREQUENCY CONNECTORS –

Part 2: Sectional specification for MQ4 series circular connectors

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, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely 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
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
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
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch shall
not be held responsible for identifying any or all such patent rights.
IEC 63138-2 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 an International Standard.
This second edition cancels and replaces the first edition published in 2020. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) change the supplementary key and groove position degree from 0,1 to 0,05 in Figure 1,
Figure 2, Figure 3, Figure 7 and Figure 8;
b) change dimension q from min.1,60 to min.1,65 in Table 1;
c) add an electrical reference plane in Figure 4;

d) add dimensions in Table 1;
e) change dimension n from max.1,55 to max.1,50 in Table 2, Table 3 and Table 7;
f) update some dimensions in Figure 4 and Table 4;
g) change dimension a from min.7,50 to min.7,52, and max.7,60 to max. 7,58 in Table 7;
h) update some dimensions in Figure 8 and Table 8;
i) change mechanical compatibility from 50 N to 60 N in 4.2.3 and 4.2.4.
The text of this International Standard is based on the following documents:
Draft Report on voting
46F/644/FDIS 46F/651/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/publications.
This document is to be read with IEC 63138-1:2019.
A list of all parts in the IEC 63138 series, published under the general title Multichannel
radio­frequency 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,
• replaced by a revised edition, or
• amended.
– 6 – IEC 63138-2:2023 © IEC 2023
MULTI-CHANNEL RADIO-FREQUENCY CONNECTORS –

Part 2: Sectional specification for MQ4 series circular connectors

1 Scope
This part of IEC 63138, which is a sectional specification (SS), provides information and rules
for the preparation of detail specifications (DS) for MQ4 series circular connectors with four RF
channels, as well as a detailed specification of the blank format.
An MQ4 series circular connector with 50 Ω nominal impedance has four RF channels which
can be engaged and disengaged at the same time. There are two versions of plug connectors,
one is a quick-lock version, and the other is a threaded version. The socket connector provides
two coupling mechanisms, a quick-lock and a threaded coupling.
MQ4 series circular connectors can be used in mobile communication systems and in other
communication equipment.
This document also specifies the mating face dimensions and gauging information of MQ4
series circular connectors, and tests selected from IEC 63138-1, applicable to all detail
specifications relating to MQ4 series circular connectors.
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 63138-1:2019, Multi­channel radio frequency connectors – Part 1: Generic specification –
General requirements and test methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63138-1 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 Mating face and gauge information
4.1 Mating face dimensions
4.1.1 MQ4 socket connector
The mating face of MQ4 socket connectors is shown in Figure 1 and its dimensions are shown
in Table 1.
NOTE Metric dimension are original dimensions. All undimensioned pictorial configurations are for reference
purpose only.
NOTE 1 Mechanical reference plane.
NOTE 2 Chamfer of the four supplementary grooves is optional.
NOTE 3 Chamfer of the main groove is optional.
NOTE 4 The mating face of the RF channel with pin contact is shown in Figure 4a) and its dimensions are shown
in Table 4.
NOTE 5 The shape of seal ring is optional.
NOTE 6 The initial position number of the RF channel with pin contact and the other positions numbered clockwise.
Figure 1 – MQ4 socket connector

– 8 – IEC 63138-2:2023 © IEC 2023
Table 1 – Dimensions of MQ4 socket connector
Ref. Dimensions
mm
Min. Max.
a 31,75 31,80
b 30,35 30,40
c M30 × 1 tolerance 6 g
d 6,80 7,00
e 26,42 26,48
f 6,00 --
g R3,0 nom.
h 7,95 8,05
i 10,95 11,00
j 1,50 1,80
k 19,30 19,45
m 13,90 14,00
p 3,20 3,35
q 1,65 1,75
r 0,50 0,60
s 7,28 7,32
t 15,48 15,52
u 10,30 10,90
4.1.2 MQ4 plug connector
4.1.2.1 MQ4 quick-lock plug connector
The mating face of the MQ4 connector with quick-lock type is shown in Figure 2 and its
dimensions are shown in Table 2.

NOTE 1 Mechanical reference plane.
NOTE 2 The mating face of the RF channel with socket contact is shown in Figure 4b) and its dimensions are shown
in Table 4.
NOTE 3 The shape of the four supplementary keys is optional.
NOTE 4 The shape of the main key is optional.
NOTE 5 The shape of the spring finger is optional.
NOTE 6 The initial position number of the RF channel with socket contact and the other positions numbered
anticlockwise.
Figure 2 – MQ4 quick-lock plug connector
Table 2 – Dimensions of MQ4 quick-lock plug connector
Dimensions
Ref. mm
Min. Max.
a -- 42,00
b 31,80 31,90
c 30,05 30,15
d 26,30 26,40
e 8,40 8,60
f 1,20 1,50
g 11,00 11,10
h 6,60 6,80
i 15,48 15,52
j 13,70 13,80
k 7,52 7,58
m 3,00 3,15
n 1,40 1,50
– 10 – IEC 63138-2:2023 © IEC 2023
4.1.2.2 MQ4 threaded plug connector
The mating face of the MQ4 threaded plug connector is shown in Figure 3 and its dimensions
are shown in Table 3.
NOTE 1 Mechanical reference plane.
NOTE 2 The mating face of the RF channel with socket contact is shown in Figure 4b) and its dimensions are shown
in Table 4.
NOTE 3 The shape of the four supplementary keys is optional.
NOTE 4 The shape of the main key is optional.
NOTE 5 The initial position number of the RF channel with socket contact and the other positions numbered anti-
clockwise.
Figure 3 – MQ4 threaded plug connector
Table 3 – Dimensions of MQ4 threaded plug connector
Dimensions
Ref. mm
Min. Max.
a 7,52 7,58
b 26,35 26,40
c M30 × 1 tolerance 6 H
d 1,20 1,50
e 5,20 5,60
f 11,20 --
i 7,00 --
j 13,70 13,80
k 15,48 15,52
m 3,00 3,15
n 1,40 1,50
p 32,0 nom.
4.1.3 Mating face of RF channel
The mating face of the RF channel with pin contact is shown in Figure 4a), the mating face of
the RF channel with socket contact is shown in Figure 4b), and their dimensions are shown in
Table 4.
a) RF channel with pin contact

b) RF channel with socket contact
NOTE 1 Mechanical reference plane.
NOTE 2 Electrical reference plane.
Figure 4 – Mating face of RF channel

– 12 – IEC 63138-2:2023 © IEC 2023
Table 4 – Dimensions of RF channel
Dimensions
Ref. mm
Min. Max.
a 1,17 1,23
b 5,90 5,93
c R1,00 nom
d 0,35 0,65
e 2,60 2,90
f 3,30 3,70
g 0 0,25
h 0,75 1,00
i 1,70 --
j 0 0,25
k 0 0,25
m 3,00 --
a
-- --
n
p 1,8 nom
b
q -- 6,40
r 3,80 --
u 6,60 6,70
v 2,00 2,20
a
s -- --
a
Slot design optional when mating with a pin with Φ1,17 mm to Φ1,23 mm. It
should meet the requirements of mechanical and electrical performance.
b
Expand to meet the requirements with gauge rings for socket outer contact.

4.2 Gauges
4.2.1 Gauge for RF channel
4.2.1.1 Socket centre contact
4.2.1.2 Dimensions of gauge
The gauge for the socket contact of the RF channel is shown in Figure 5 and its dimensions are
shown in Table 5.
Figure 5 – Gauge for socket contact of RF channel
Table 5 – Dimensions of gauge for socket contact
Gauge C
(For retention purpose)
Gauge A Gauge B
(For sizing purpose) (For insertion purpose) +2
Mass of gauge：40 g
Ref.
mm mm mm
Min. Max. Min. Max. Min. Max.
a 1,235 1,240 1,230 1,235 1,165 1,170
b 0,700 1,000 0,900 1,200 0,900 1,200
Material: Polished steel, cylindrical surface roughness of diameter a: Ra ≤ 0,4 μm.

4.2.1.3 Test procedure
Test procedure as follows:
a) Sizing test
Insert gauge A into centre contact three times, the depth of insertion is not less than 0,7 mm;
this is a sizing operation.
b) Insertion test
After sizing operation, insert gauge B into centre contact, the insertion force shall not exceed
6 N.
c) Retention test
After the sizing or insertion operation, the gauge C shall be inserted into the socket centre
contact. The contact shall retain the mass of the gauge C in a vertical downward position.
4.2.2 Gauge rings for plug outer contact
4.2.2.1 Dimensions of gauge
The gauge for the outer contact of the RF channel is shown in Figure 6 and its dimensions are
shown in Table 6.
– 14 – IEC 63138-2:2023 © IEC 2023

Figure 6 – Gauge for plug outer contact
Table 6 – Dimensions of gauge for outer contact
Gauge C
(For retention purpose)
Gauge A Gauge B
(For sizing purpose) (For insertion purpose) +2
Mass of gauge：400 g
Ref.
mm mm mm
Min. Max. Min. Max. Min. Max.
a 5,880 5,885 5,895 5,900 5,930 5,935
b 7,250 7,350 7,250 7,350 7,250 7,350
c 6,700 6,800 6,700 6,800 6,700 6,800
d 2,700 3,000 2,700 3,000 2,700 3,000
v 1,55 1,65 1,55 1,65 1,55 1,65
Material: Polished steel, cylindrical surface roughness of diameter a: Ra ≤ 0,4 μm.

4.2.2.2 Test procedure
a) Sizing test
The gauge A should be inserted into the outer contact of RF channel three times, the depth of
insertion is not less than 2,7 mm; this is a sizing operation.
b) Insertion test
After the sizing operation, if specified in the detail specification, the force necessary to insert
gauge B fully into the outer contact shall be measured and it shall not exceed 15 N.
c) Retention test
After the sizing or insertion operation, the gauge C shall be inserted into the outer contact. The
contact shall retain the mass of the gauge C in a vertical downward position.
4.2.3 Gauge for MQ4 socket connector
4.2.3.1 Dimensions of gauge
The gauge for the MQ4 socket connector is shown in Figure 7 and its dimensions are shown in
Table 7.
NOTE 1 Mechanical reference plane.
NOTE 2 The shape of the four supplementary keys is optional.
NOTE 3 The shape of the main key is optional.
Figure 7 – Gauge for MQ4 socket connector
Table 7 – Dimensions of gauge for MQ4 socket connector
Dimensions
Ref. mm
Min. Max.
a 7,52 7,58
b 5,00 --
c 1,20 1,50
d 15,48 15,52
e 26,35 26,40
f 13,70 13,80
m 3,00 3,15
n 1,40 1,50
4.2.3.2 Test procedure
The gauge should be inserted into the MQ4 socket connector three times, and then the insertion
force is measured; the insertion force should not be more than 60 N.
4.2.4 Gauge for MQ4 plug connector
4.2.4.1 Dimensions of gauge
The gauge for the MQ4 plug connector is shown in Figure 8 and its dimensions are shown in
Table 8.
– 16 – IEC 63138-2:2023 © IEC 2023

NOTE 1 Mechanical reference plane.
NOTE 2 Chamfer of the four supplementary grooves is optional.
NOTE 3 Chamfer of the main groove is optional.
Figure 8 – Gauge for MQ4 plug connector
Table 8 – Dimensions of gauge for MQ4 plug connector
Dimensions
Ref. mm
Min. Max.
a -- 7,30
b 5,88 5,90
c 3,70 --
d
10,90 11,00
e 26,42 26,48
f 29,80 30,00
g
10,50 10,60
h 3,30 3,70
j R1,00 nom
p 13,90 14,00
t 15,48 15,52
m 3,20 3,35
n 1,65 1,75
u 6,50 6,70
v 1,55 1,65
4.2.4.2 Test procedure
The gauge should be inserted into the MQ4 plug connector three times, and then the insertion
force is measured; the insertion force should not be more than 60 N.
5 Quality assessment procedure
5.1 General
Subclauses 5.2 to 5.3.4 provide the recommended rating, performance and test conditions to
be considered when preparing a detail specification. They also specify the test schedules and
procedure that suit the corresponding quality inspection level.
5.2 Rating and characteristics
The values indicated in Table 9 are recommended for MQ4 series circular connectors, and are
given for the writer of the detail specification. They are applicable for the condition when the
connectors are fully mated. The preferable characteristics can be seen in Table 9.
Certain tests are listed without any recommended values being given when they are not required.
When such tests are required, appropriate values shall be entered in the detail specification at
the discretion of the specification writer.
Table 9 – Rating and characteristics
Test method Remarks, deviation
Rating and characteristics IEC 63138-1:2019 Value from standard test
Subclause method
Electrical
Nominal impedance 50 Ω
a
Frequency range DC～6 GHz
Return loss 8.4.1 ≥26 dB (DC to 3 GHz) Each RF channel
≥19 dB (3 GHz to 6 GHz) tested separately
b
8.4.3 Each RF channel
Centre contact resistance
tested separately
– initial ≤3,0 mΩ
– after conditioning ≤5,0 mΩ
Outer conductor resistance 8.4.3 Each RF channel
tested separately
– initial ≤2,0 mΩ
– after conditioning ≤ 3,0 mΩ
b
8.4.4 Each RF channel
Insulation resistance
tested separately
– initial ≥ 5 000 MΩ
– after conditioning ≥ 200 MΩ
c d
8.4.5 1 000 V (86～106) kPa, Test
Proof voltage at sea level
each RF channel
separately
e
8.4.6 ≥ 90 dB, up to 3 GHz Z ≤ 10 mΩ, Each RF
Screening effectiveness
t
≥ 70 dB, 3 GHz to 6 GHz
channel tested
separately
RF power rating 8.4.10 150 W at 2 GHz, CW
Discharge test 8.4.7 See DS Each RF channel
tested separately
– 18 – IEC 63138-2:2023 © IEC 2023
Test method Remarks, deviation
Rating and characteristics IEC 63138-1:2019 Value from standard test
Subclause method
Isolation 8.4.9 ≥ 90 dB, 0,05 GHz～6 GHz Test between two
adjacent channels
Intermodulation level (PIM3) 8.4.8 ≥ 160 dBc Each RF channel
Frequency: 0 GHz to 2,7 GHz tested separately
Power: 2 × 20 W
Mechanical
Each RF channel
Centre contact captivation 8.5.2
tested separately
– axial force See DS After the test, the
centre contact shall
– axial torque
meet the requirement
for the dimension of
mating face.
RF channel captivation 8.5.3 Test each RF channel
with socket centre
contact separately
– axial force  ≥ 240 N After the test, RF
channels of the
connector shall meet
the requirement for the
dimension of mating
face.
Engagement and 8.5.4
disengagement forces
– axial force (engagement)  ≤ 100 N (quick lock type)
– axial force ≤ 100 N (quick lock type)
(disengagement)
– torque  ≥ 25 N·m (threaded type)
Gauge retention (resilient 8.5.5
contacts)
– centre contact ≥ 0,4 N See 4.2.1
– outer contact ≥ 4 N See 4.2.2
Mechanical compatibility 8.3.4 Insertion force ≤ 60 N See 4.2.3 to 4.2.4
Mechanical test for cable
clamping device
– cable rotation (nutation of 8.5.6 See DS
cable end)
– cable pulling 8.5.7 See DS
– cable bending 8.5.8 See DS
– cable torsion 8.5.9 See DS
Strength of coupling 8.5.10 Axial force: ≥ 450 N
mechanism
Coupling torque
resistance: ≥ 30 N·m (threaded
type)
High frequency vibration 8.5.12
100 m/s (10 to 2 000) Hz
Shock 8.5.13
500 m/s , 1/2 sine wave, 11 ms
Environmental
f
A:40/85/21
Climatic category
Hermetic seal 8.6.6 NA
Leakage 8.6.5
Salt mist 8.6.7 48 h Duration of spraying,
test after mating
Test method Remarks, deviation
Rating and characteristics IEC 63138-1:2019 Value from standard test
Subclause method
Endurance
Mechanical endurance 8.5.14 100 operations
a
These values apply to the basic connector. In practice, these can be influenced by the cable used and
reference should always be made to the actual values given in the DS.
b
Values for a single pair of RF channels.
c
Voltages are RMS values of AC at 40 Hz to 65 Hz, unless otherwise specified.
d
Some cables usable with these connectors have ratings lower than the values given here.
e
When interfaces are fully mated.
f
For certain connectors, the upper temperature limit is restricted by the cable characteristics. Reference should
be made to the relevant cable specification.

5.3 Quality assessment
5.3.1 General
Quality assessment shall be performed according to IEC 63138-1, except for the provisions in
5.3.2 to 5.3.4.
5.3.2 Inspection procedure
Table 10 describes the qualification inspection tests to be performed.
Table 10 – Qualification inspection
Test IEC 63138-1:2019 Number of
Subclause specimens
Group 1
Visual inspection 8.2
Marking 8.2
Workmanship 8.2
Dimensions and interchangeability 8.3
RF channel interface dimensions 8.3.1
Connector interface dimensions 8.3.2
Outline dimensions 8.3.3
Mechanical compatibility 8.3.4
Engagement and disengagement forces 8.5.4
a
Gauge retention force 8.5.5
Hermetic seal 8.6.6
Leakage 8.6.5
Insulation resistance 8.4.4
Group 2
Centre contact captivation 8.5.2
RF channel captivation 8.5.3 2
Salt mist 8.6.7
– 20 – IEC 63138-2:2023 © IEC 2023
Test IEC 63138-1:2019 Number of
Subclause specimens
Group 3
Return loss 8.4.1
Insertion loss 8.4.2
Isolation 8.4.9
Screening effectiveness 8.4.6
Passive intermodulation level (PIM) 8.4.8
b
8.4.10
RF power rating
High temperature endurance 8.6.3
Low temperature endurance 8.6.4
Mechanical endurance 8.5.14
Safety wire hole pull-out 8.5.15
Group 4
Contact resistance 8.4.3
Voltage proof 8.4.5
Discharge test 8.4.7
Low frequency vibration 8.5.11
High frequency vibration 8.5.12
Shock 8.5.13
Thermal shock 8.6.2 2
Damp heat, steady state 8.6.1
Effectiveness against cable rotation 8.5.6
Effectiveness against cable pulling 8.5.7
Effectiveness against cable bending 8.5.8
Effectiveness against cable torsion 8.5.9
Strength of coupling mechanism 8.5.10
Group 5
c
8.5.1
Solderability
a
The sample size of RF channels for test for gauge retention force is 3 sets of RF channels.
b
The tests are performed only for initial qualification approval if the qualified connectors have no change in
design and manufacturing processes.
c
The test shall be performed using 3 sets of piece-parts individually taken from the lot before being assembled
into connectors.
5.3.3 Lot-by-lot inspection
The group A and B test shall be subject to the inspections specified in Table 11 and in the order
given in the said table.
Table 11 – Lot-by-lot inspection
IEC 63138-1: Number of
Test
2019 Subclause specimens
Group A
Visual inspection 8.2
Marking 8.2
Workmanship 8.2
Dimensions and interchangeability 8.3
Interface dimensions for RF channels 8.3.1
Interface dimensions for connectors 8.3.2
Outline dimensions 8.3.3
100 %
Mechanical compatibility 8.3.4
Engagement and disengagement forces 8.5.4
a
Gauge retention force 8.5.5
Hermetic seal 8.6.6
Leakage 8.6.5
Insulation resistance 8.4.4
Group B
Mechanical compatibility 8.3.4
See Table 12
Return loss 8.4.1
a
Sample size of RF channels for test for gauge retention force is 3 sets of RF channels.

Table 12 – Sampling plans for mechanical compatibility and return loss inspection
Lot size Sample size for mechanical Sample size for return loss
compatibility inspection inspection
a
1 to 100 1
101 to 1 200 5 2
1 201 to above 10 3
a
When lot size is 1, the corresponding sample size is also 1.

5.3.4 Periodic inspections
Table 13 describes the periodic tests to be performed.

– 22 – IEC 63138-2:2023 © IEC 2023
Table 13 – Periodic inspection
IEC 63138-1:2019
Test Sample size
Subclause
Group D1 1
Centre contact captivation 8.5.2
RF channel captivation 8.5.3
Salt mist 8.6.7
Group D2 1
Return loss 8.4.1
Insertion loss 8.4.2
Isolation 8.4.9
Screening effectiveness 8.4.6
Passive intermodulation level (PIM) 8.4.8
a
RF power rating 8.4.10
High temperature endurance 8.6.3
Low temperature endurance 8.6.4
Mechanical endurance 8.5.14
Safety wire hole pull-out 8.5.15
Group D3 1
Contact resistance 8.4.3
Discharge test 8.4.7
Low frequency vibration 8.5.11
High frequency vibration 8.5.12
Shock 8.5.13
Thermal shock 8.6.2
Damp heat, steady state 8.6.1
Effectiveness against cable rotation 8.5.6
Effectiveness against cable pulling 8.5.7
Effectiveness against cable bending 8.5.8
Effectiveness against cable torsion 8.5.9
Strength of coupling mechanism 8.5.10
Group D4
b
8.5.1
Solderability
a
The tests are performed only for initial qualification approval if the qualified connectors have no change in
design and manufacturing processes.
b
The test shall be performed using 3 sets of piece-parts individually taken from the lot before being assembled
into connectors.
6 Instructions for preparation of detail specifications
6.1 General
Detail specification (DS) writers shall use the appropriate blank detail specification (BDS).
Clause 6 comprises the BDS dedicated for use with MQ4 series circular connectors. As such,
the BDS will already have information entered on it in relation to:
– the basic specification number applicable to all the detail specifications covering connector
styles of the series covered by the sectional specification;
– the connector series designation.
The specification writer should enter the details relating to the connector style to be covered by
the BDS, as indicated. The numbers in brackets in the BDS correspond to the following
indications, which shall be given.
6.2 Identification of the detail specification
1) The name of the National Authorized Institution (NAI) under whose authority the DS is
published and, if applicable, the organization from whom the DS is available.
2) The number allocated to the DS by the relevant National Authorized Institution immediately
preceded by the ISO two letter national identity code or "XX" when the DS is produced by
an IEC technical subcommittee.
3) The number and issue number of the generic specification and, when applicable, the
sectional specification; also the national reference if different.
4) If different from the IEC number, the national number of the DS, the date of issue and any
further information required by the national system, together with any amendment numbers.
6.3 Identification of the component
5) Enter the following details:
• style: the style designation of the connector including type of fixing and sealing, if
applicable;
• attachment: by deletion of the inapplicable options of cable/wire given for centre and
outer conductors;
• special features and markings: as applicable;
• series designation: in bold characters/digits 15 mm high.
6) Enter details of assessment level and the climatic category.
7) A reproduction of the outline drawing and details of the panel piercing (if applicable). It shall
provide the maximum envelope dimensions, the position of the reference plane and, in the
case of a fixed connector, the position of the mounting plane relative to the front face of the
connector.
Any maximum panel thickness limitations for fixed connectors shall be stated.
8) Particulars of all variants covered by the DS. As appropriate, the information shall include:
• cable types (or sizes) applicable to each variant;
• alternative plated or protective finishes;
• details of alternative mounting flanges having either tapped or plain mounting holes;
• details of alternative solder spills or solder buckets including, when applicable, those for
use with microwave integrated circuit (MIC) components.
6.4 Performance
9) Performance data listing the most important characteristics of the connector in accordance
with the requirements of the relevant sectional specification. Deviations from the minimum
requirements shall be clearly indicated. Non-applicable parameters shall be marked "na".

– 24 – IEC 63138-2:2023 © IEC 2023
6.5 Marking, ordering information and related matters
10) Insert marking and ordering information as appropriate, together with details of related
documents and any invoked structural similarity.
6.6 Selection of tests, test conditions and severities
"na" shall be used to indicate non-applicable tests. All tests marked "a" by the detail
specification writer shall be mandatory.
When using the normal procedure with a dedicated BDS, the letter "a" – for applicable – shall
be entered in the "test required" column opposite each of the tests indicated as being mandatory
in the test schedule of the relevant sectional specification. Any additional test required at the
discretion of the specification writer shall also be indicated by an "a".
The specification writer shall also indicate, when necessary, details of deviations from the
standard test methods and conditions including any relevant deviations given in the test
schedule of the sectional specification.
6.7 Blank detail specification pro forma for MQ4 series circular connectors
Subclause 6.7 contains the complete BDS.

(1) (2) Page 1 of
(3) ELECTRONIC COMPONENT OF ASSESSED (4) Issue
QUALITY IN ACCORDANCE WITH:
GENERIC SPECIFICATION: IEC 63138-1
SECTIONAL SPECIFICATION: IEC 63138-2
(5) Detail specification for radio frequency coaxial connector of Type
assessed quality
MQ4
Style Special features and markings
Method of cable/wire+ attachment Centre conductor – solder/crimp+
Outer conductor – solder/clamp/crimp+
+Delete as appropriate
(6) Assessment level Characteristic impedance …Ω Climatic category …/…/…
(7) Outline and maximum dimensions Panel piercing and mounting details

(8) Variants
Description of
Variant No IEC 63138-2
variant
Information about manufacturers who have components qualified under the IECQ Conformity Assessment System
is available through the IECQ on-line certificate system.

– 26 – IEC 63138-2:2023 © IEC 2023
(9) Performance (including limiting conditions of use)
Remarks including any
Ratings and Variant no. IEC 63138-1:2019
Value deviations fr
...