|
INTERNATIONAL IEC
STANDARD
First edition
1999-09
RF connectors, connector cable assemblies
and cables –
Intermodulation level measurement
Connecteurs, cordons, câbles –
Mesures du niveau d'intermodulation
Reference number
Numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series.
Consolidated publications
Consolidated versions of some IEC publications including amendments are
available. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the
base publication, the base publication incorporating amendment 1 and the base
publication incorporating amendments 1 and 2.
Validity of this publication
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology.
Information relating to the date of the reconfirmation of the publication is available
in the IEC catalogue.
Information on the subjects under consideration and work in progress undertaken
by the technical committee which has prepared this publication, as well as the list
of publications issued, is to be found at the following IEC sources:
• IEC web site*
•
Catalogue of IEC publications
Published yearly with regular updates
(On-line catalogue)*
• IEC Bulletin
Available both at the IEC web site* and as a printed periodical
Terminology, graphical and letter symbols
For general terminology, readers are referred to IEC 60050: International
Electrotechnical Vocabulary (IEV).
For graphical symbols, and letter symbols and signs approved by the IEC for
general use, readers are referred to publications IEC 60027: Letter symbols to be
used in electrical technology, IEC 60417: Graphical symbols for use on equipment.
Index, survey and compilation of the single sheets and IEC 60617: Graphical symbols
for diagrams.
* See web site address on title page.
INTERNATIONAL IEC
STANDARD
First edition
1999-09
RF connectors, connector cable assemblies
and cables –
Intermodulation level measurement
Connecteurs, cordons, câbles –
Mesures du niveau d'intermodulation
IEC 1999 Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: [email protected] IEC web site http://
Commission Electrotechnique Internationale
PRICE CODE
K
International Electrotechnical Commission
For price, see current catalogue
– 2 – 62037 © IEC:1999(E)
CONTENTS
Page
FOREWORD . 3
Clause
1 Scope and object . 4
2 Level of intermodulation products . 4
3 Principle of test procedure. 4
4 Test set-up. 5
5 Preparation of test specimen . 6
6 Test procedure.7
7 Expression of results. 7
8 Measurement error. 7
Figure 1 – Set-up 1. 8
Figure 2 – Set-up 2. 9
Figure 3 – Passive intermodulation measurement (PIM) error caused
by residual system PIM . 10
62037 © IEC:1999(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
––––––––––––––
RF CONNECTORS, CONNECTOR CABLE ASSEMBLIES
AND CABLES –
INTERMODULATION LEVEL MEASUREMENT
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this technical specification may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62037 has been prepared by IEC technical committee 46: Cables,
wires, waveguides, r.f. connectors, and accessories for communication and signalling.
The text of this standard is based on the following documents:
FDIS Report on voting
46/94/FDIS 46/97/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
The committee has decided that this publication remains valid until 2009. At this date, in
accordance with the committee’s decision, the publication will be
reconfirmed;
withdrawn;
replaced by a revised edition, or
amended.
A bilingual version of this publication may be issued at a later date.
– 4 – 62037 © IEC:1999(E)
RF CONNECTORS, CONNECTOR CABLE ASSEMBLIES
AND CABLES –
INTERMODULATION LEVEL MEASUREMENT
1 Scope and object
This technical specification is applicable to the intermodulation (IM) level measurement of r.f.
connectors, connector cable assemblies and cables.
The object of the test procedure given in this technical specification is to characterize the level
of unwanted signals caused by the presence of two or more transmitting signals in passive r.f.
components.
2 Level of intermodulation products
The basic theory of the generation of intermodulation products in r.f. circuits is well described
in the literature.
In the case of passive r.f. components, intermodulation distortion is caused by sources of
nonlinearity of mostly unknown nature, location and behaviour. A few examples are inter-
metallic contacts, choice of materials, corrosion products, dirt, etc. Most of these effects are
subject to changes over time due to mechanical stress, temperature changes, variations in
material characteristics (cold flow, etc.), climatic changes and so on.
The generation of intermodulation products does not necessarily follow the law of the usual
non-linear equation of quadratic form. Therefore, accurate calculation to other power levels
causing the intermodulation is not possible.
On the other hand, generation of intermodulation is inherently not frequency selective. This
allows for the testing of r.f. components at appropriate frequencies within the band of
operation.
3 Principle of test procedure
For the test, signals of frequencies f and f with equal specified test port power level are
1 2
combined and fed to the device under test (DUT). The test signals should contain at least
10 dB less harmonic or self-intermodulation signal level than the expected level generated in
the DUT.
The intermodulation products of order (f ± f ) or (2f ± f ) etc. are measured with a calibrated
1 2 2 1
receiver.
In most cases, the third order intermodulation signals represent the worst case condition of
unwanted signals generated; therefore the measurement of these signals characterizes the
DUT in a sufficient way. However, the test set-ups given in this technical specification are
suitable for measuring other intermodulation products.
62037 © IEC:1999(E) – 5 –
4 Test set-up
Experience shows that the generation of intermodulation products originates from point-
sources inside a DUT. Therefore, either the reflected or the transmitted intermodulation signal
can be measured.
Two different test set-ups are described in figures 1 and 2 and are for reference only. Other
topologies are possi
...