IEC 62037-1:2021
(Main)Passive RF and microwave devices, intermodulation level measurement - Part 1: General requirements and measuring methods
Passive RF and microwave devices, intermodulation level measurement - Part 1: General requirements and measuring methods
IEC 62037-1:2021 is available as IEC 62037-1:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62037-1:2021 deals with the general requirements and measuring methods for intermodulation (IM) level measurement of passive RF and microwave components, which can be caused by the presence of two or more transmitting signals. The test procedures given in this document give the general requirements and measurement methods required to characterize the level of unwanted IM signals using two transmitting signals. The IEC 62037 series addresses the measurement of PIM, but does not cover the long-term reliability of a product with reference to its performance. This second edition cancels and replaces the first edition published in 2012. This edition includes the following significant technical changes with respect to the previous edition:
a. clarification added that test equipment may utilize pulsed generators to reduce power consumption;
b. heating effect differences in the device under test noted in Annex B for tests conducted using pulsed generators;
c. guidance added in Annex B to improve probability of detection of short duration PIM events while dynamic testing.
Dispositifs RF et à micro-ondes passifs, mesure du niveau d'intermodulation - Partie 1: Exigences générales et méthodes de mesure
IEC 62037-1:2021 est disponible sous forme de IEC 62037-1:2021 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.
L'IEC 62037-1:2021 est applicable aux exigences générales et aux méthodes de mesure du niveau d’intermodulation (IM) des composants RF et à micro-ondes passifs, qui peut être provoquée par la présence de deux ou plusieurs signaux d’émission. Les procédures d’essai présentées dans le présent document donnent les exigences générales et les méthodes de mesure exigées pour caractériser le niveau des signaux d’intermodulation indésirables à l’aide de deux signaux d’émission. La série IEC 62037 porte sur la mesure de l’intermodulation passive (PIM), mais ne couvre pas la fiabilité à long terme des produits par rapport à ses performances. Cette seconde édition annule et remplace la première édition parue en 2012. Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente:
a. ajout d’une clarification au fait que le matériel d’essai peut utiliser des générateurs à impulsions pour réduire la consommation de puissance;
b. description des différences d’effet de chauffage sur le dispositif en essai à l’Annexe B dans les essais réalisés avec des générateurs à impulsions;
c. ajout de recommandations à l’Annexe B pour améliorer la probabilité de détection d’événements d’intermodulation passive de courte durée lors des essais dynamiques.
General Information
Standards Content (sample)
IEC 62037-1
Edition 2.0 2021-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Passive RF and microwave devices, intermodulation level measurement –
Part 1: General requirements and measuring methods
Dispositifs RF et à micro-ondes passifs, mesure du niveau d’intermodulation –
Partie 1: Exigences générales et méthodes de mesure
IEC 62037-1:2021-11(en-fr)
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IEC 62037-1
Edition 2.0 2021-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Passive RF and microwave devices, intermodulation level measurement –
Part 1: General requirements and measuring methods
Dispositifs RF et à micro-ondes passifs, mesure du niveau d’intermodulation –
Partie 1: Exigences générales et méthodes de mesure
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.040.20 ISBN 978-2-8322-1050-8
Warning! Make sure that you obtained this publication from an authorized distributor.
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® Registered trademark of the International Electrotechnical CommissionMarque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 62037-1:2021 © IEC 2021
CONTENTS
FOREWORD ........................................................................................................................... 3
1 Scope .............................................................................................................................. 5
2 Normative references ...................................................................................................... 5
3 Terms, definitions and abbreviated terms ........................................................................ 5
3.1 Terms and definitions .............................................................................................. 5
3.2 Abbreviated terms ................................................................................................... 5
4 Characteristics of intermodulation products ..................................................................... 6
5 Principle of test procedure .............................................................................................. 6
6 Test set-up ...................................................................................................................... 6
6.1 General ................................................................................................................... 6
6.2 Test equipment ....................................................................................................... 7
6.2.1 General ........................................................................................................... 7
6.2.2 Set-up 1 .......................................................................................................... 7
6.2.3 Set-up 2 .......................................................................................................... 8
7 Preparation of DUT and test equipment ............................................................................ 8
7.1 General ................................................................................................................... 8
7.2 Guidelines for minimizing generation of passive intermodulation ............................. 8
8 Test procedure ................................................................................................................ 9
9 Reporting....................................................................................................................... 10
9.1 Results ................................................................................................................. 10
9.2 Example of results ................................................................................................ 10
10 Measurement error ........................................................................................................ 10
Annex A (informative) Configuration of low-PIM termination ................................................ 13
A.1 General ................................................................................................................. 13
A.2 Configuration of low-PIM terminations ................................................................... 13
A.2.1 Long cable termination .................................................................................. 13
A.2.2 Lumped termination with a linear attenuator .................................................. 13
Annex B (informative) Test procedure considerations .......................................................... 15
B.1 PIM variation versus frequency ............................................................................. 15
B.2 Stepped frequency sweep method ........................................................................ 15
B.3 Fixed frequency method ........................................................................................ 15
B.4 Dynamic PIM testing ............................................................................................. 15
B.5 Heating effects ...................................................................................................... 15
Figure 1 – Set-up 1: reverse IM-test set-up .......................................................................... 11
Figure 2 – Set-up 2: forward IM-test set-up .......................................................................... 11
Figure 3 – Passive intermodulation (PIM) measurement error caused by residualsystem error ......................................................................................................................... 12
Figure A.1 – Long cable termination ...................................................................................... 13
Figure A.2 – Lumped termination with a linear attenuator ...................................................... 14
Table 1 – Guide for the design, selection of materials and handling of components that
can be susceptible to PIM generation ....................................................................................... 9
Table 2 – Test set-up conditions ........................................................................................... 10
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PASSIVE RF AND MICROWAVE DEVICES,
INTERMODULATION LEVEL MEASUREMENT –
Part 1: General requirements and measuring methods
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
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 62037-1 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 second edition cancels and replaces the first edition published in 2012. This edition
constitutes a technical revision.This edition includes the following significant technical changes with respect to the previous
edition:a) clarification added that test equipment may utilize pulsed generators to reduce power
consumption;b) heating effect differences in the device under test noted in Annex B for tests conducted
using pulsed generators;c) guidance added in Annex B to improve probability of detection of short duration PIM events
while dynamic testing.---------------------- Page: 5 ----------------------
– 4 – IEC 62037-1:2021 © IEC 2021
The text of this International Standard is based on the following documents:
Draft Report on voting
46/834/FDIS 46/855/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.This International Standard is to be used in conjunction with IEC 62037 (all parts).
A list of all the parts in the IEC 62037 series, published under the general title Passive RF and
microwave devices, intermodulation level measurement, 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 document 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.
---------------------- Page: 6 ----------------------IEC 62037-1:2021 © IEC 2021 – 5 –
PASSIVE RF AND MICROWAVE DEVICES,
INTERMODULATION LEVEL MEASUREMENT –
Part 1: General requirements and measuring methods
1 Scope
This part of IEC 62037 deals with the general requirements and measuring methods for
intermodulation (IM) level measurement of passive RF and microwave components, which can
be caused by the presence of two or more transmitting signals.The test procedures given in this document give the general requirements and measurement
methods required to characterize the level of unwanted IM signals using two transmitting signals.
The IEC 62037 series addresses the measurement of PIM, but does not cover the long-term
reliability of a product with reference to its performance.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 62037 (all parts), Passive RF and microwave devices, intermodulation level measurement
3 Terms, definitions and abbreviated terms3.1 Terms and definitions
No terms and definitions are listed in this document.
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
3.2 Abbreviated terms
CATV Community antenna television
CFEC Carbon fibre epoxy composite
CW Continuous wave
DUT Device under test
IM Intermodulation
PCB Printed circuit board
PIM Passive intermodulation
RBW Resolution bandwidth
VDA Vacuum deposited aluminium
---------------------- Page: 7 ----------------------
– 6 – IEC 62037-1:2021 © IEC 2021
4 Characteristics of intermodulation products
PIM interference is caused by sources of non-linearity 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.) and climatic
changes.The generation of intermodulation products originates from point sources inside a DUT and
propagates equally in all available directions.The generation of passive intermodulation (PIM) 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 and PIM comparisons should be made
at the same power level.Furthermore, PIM generation can be frequency dependent. When PIM generation is frequency
dependent, the PIM performance shall be investigated over the specified frequency band.
5 Principle of test procedureTest signals of frequencies f and f with equal specified test port power levels are combined
1 2and fed to the DUT. The test signals should contain a harmonic or self-intermodulation signal
level at least 10 dB lower than the expected level generated in the DUT.The PIM is measured over the specified frequency range. The intermodulation products of order
(2f ± f ), (2f ± f ), etc., are measured.1 2 2 1
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 Clause 6 are suitable for measuring
other intermodulation products.In other systems (such as CATV), the third order may not be as applicable in characterizing the
DUT.Intermodulation can be measured in the reverse and forward direction. Reverse and forward
refer to the direction of propagation of the most powerful carrier.6 Test set-up
6.1 General
Experience shows that the generation of intermodulation products originates from point sources
inside a device under test (DUT) and propagates equally in all available directions. Therefore,
either the reverse (reflected) or the forward (transmitted) intermodulation signal can be
measured.Two different test set-ups are described in Figure 1 and Figure 2 and are for reference only.
Other topologies are possible.Set-up 1 is for measuring the reverse (reflected) intermodulation signal only, and set-up 2 is for
measuring the forward (transmitted) intermodulation signal. The measurement method (reverse
or forward) is dependent upon the DUT. The set-ups may be assembled from standard
microwave or radio link hardware selected for this particular application. All components shall
be checked for lowest self-intermodulation generation.---------------------- Page: 8 ----------------------
IEC 62037-1:2021 © IEC 2021 – 7 –
Experience shows that devices containing magnetic materials (circulators, isolators, etc.) can
be prominent sources of intermodulation signal generation.See Annex B for additional set-up considerations.
6.2 Test equipment
6.2.1 General
Two signal sources or signal generators with power amplifiers are required to reach the
specified test port power. The combining and diplexing device can comprise a circulator, hybrid
junction, coupler or filter network.The test set-up self-intermodulation generated (including contribution of the load) should be at
least 10 dB below the level to be measured on the DUT. The associated error may be obtained
from the graph in Figure 3.The DUT shall be terminated by a load for the specified power if necessary. The receiving
bandpass filter, tuned for the desired intermodulation signal, is followed by a low noise amplifier
(if required) and a receiver.See Annex B for additional set-up considerations.
6.2.2 Set-up 1
This set-up is for measuring the reverse (reflected) IM-product and is therefore suitable for one-
port and multi-port DUTs. On multi-port DUTs, the unused ports shall be connected to a linear
termination. See Annex A for information on low PIM terminations.a) Generators
The generators shall provide continuous wave (CW) signals of the specified test port power.
They shall have sufficient frequency stability to ensure that the IM-product can be detected
properly by the receiver. The generators may be pulsed on and off while testing to reduce
power consumption.Some limitations apply when using pulsed generators. See Annex B for test procedure
considerations when using equipment with pulsed generators.b) Transmit-filters
The filters are bandpass filters tuned to the particular frequencies. They isolate the
generators from each other and filter out the harmonics of f and f .1 2
c) Combining and diplexing device
This device is used for combining the signals f and f , delivering them to the test port and
1 2provides a port for the extraction of the reverse (reflected) signal f .
d) Receive-filter
This filter is used for isolating the input of the receiver from the signals f and f to the extent
1 2that IM-products are not generated within the receiver.
e) Test port
The DUT is connected to P4. The specified input power shall be at the DUT, with any set-
up loss between the receiver and the DUT compensated for.f) Termination
When a multi-port DUT is measured, the DUT shall be connected to a sufficiently linear
termination (low intermodulation) of suitable power handling capability.---------------------- Page: 9 ----------------------
– 8 – IEC 62037-1:2021 © IEC 2021
g) Receiver
The receiver shall be sensitive enough to detect a signal of the expected power level.
The receiver response time shall be sufficiently short to allow acquisition of rapid changes
in amplitude. Sensitivity can be increased by a low noise preamplifier. Frequency stability
shall be sufficient for the proper detection of the IM-signal.When the PIM measurement result is close to the thermal noise floor of the receiver, the
receiver sensitivity can be improved by reducing the resolution bandwidth (RBW).Furthermore, by using the averaging mode rather than the max-hold mode, a further
improvement can be achieved, since the max-hold mode essentially measures the maximum
thermal noise peak, while the averaging mode results in a measurement that is closer to the
RMS value.6.2.3 Set-up 2
This set-up is for measuring the forward (transmitted) IM-product and is therefore suitable only
for two- or multi-port DUTs.All components are the same as those of set-up 1, except for those as noted below:
a) Combining and diplexing deviceThe extraction-port P3 on this device shall be terminated to prevent reflection of the IM-
signals.b) Diplexing device
The signals f , f and f are split to P6 and P7. This device, together with an additional
1 2 IMreceive-filter, is used for the extraction of the intermodulation signals.
7 Preparation of DUT and test equipment
7.1 General
The DUT and test equipment shall be carefully checked for proper power handling range,
frequency range, cleanliness and correct interconnection dimensions. All connector interfaces
shall be tightened to the applicable IEC specification or, if none exists, to the manufacturer’s
recommended specification.See Annex B for additional set-up considerations.
7.2 Guidelines for minimizing generation of passive intermodulation
The following guidelines and Table 1 should be considered and adhered to wherever possible.
a) Non-linear materials should not be used in or near the current paths.b) Current densities should be minimized in the conduction paths (e.g. Tx channel), by using
larger conductors.c) Minimize metallic junctions, avoid loose contacts and rotating joints.
d) Minimize the exposure of loose contacts, rough surfaces and sharp edges to RF power.
e) Keep thermal variations to a minimum, as the expansion and contraction of metals can create
non-linear contacts.f) Use brazed, soldered or welded joints if possible, but ensure these joints are good and have
no non-linear materials, cracks, contamination or corrosion.g) Avoid having tuning screws or moving parts in the high current paths; if necessary, ensure
all joints are tight and clean, and preferably, free from vibration.h) Cable lengths in general should be minimized and the use of high quality, low-IM cable is
essential.---------------------- Page: 10 ----------------------
IEC 62037-1:2021 © IEC 2021 – 9 –
i) Minimize the use of non-linear components such as high-PIM loads, circulators, isolators and
semiconductor devices.j) Achieve good isolation between the high-power transmit signals and the low power receive
signals by filtering and physical separation.Table 1 – Guide for the design, selection of materials and handling
of components that can be susceptible to PIM generation
Part, material or procedure Recommendations
Interfaces Minimize the total number.
Connectors Minimize the number of connectors used. Use high quality, low-PIM
connectors mated with proper torque.
Inter-metallic connections Each inter-metallic connection should be evaluated in terms of
criticality for the total PIM level. Methods of controlling theperformance are high contact pressure, insulation, soldering,
brazing, etc.
Ferromagnetic materials Not recommended (non-linear).
Non-magnetic stainless steel Not recommended (contains iron).
Circulators, isolators and other ferrite
Not recommended.
devices
Sharp edges Avoid if it results in high current density.
Terminations or attenuators Should be evaluated before use.
Hermetic seals / gaskets Evaluate before use and avoid ferromagnetic materials.
Materials, processes and design should all be considered and
Printed circuit boards (PCBs)
evaluated. Use low-PIM materials; be careful with material
impurities, contamination and etching residuals. The copper trace
should be finished to prevent corrosion.
Dissimilar metals Not recommended (risk of galvanic corrosion).
Dielectric material Use clean, high quality material. Ensure it does not contain
electrically conductive particles.
Machined dielectric materials Use clean non-contaminated tools for machining.
Welded, soldered or brazed joints Well executed and thoroughly cleaned, they provide satisfactory
results. Shall be carefully inspected.Carbon fibre epoxy composite (CFEC) Generally acceptable for use in reflector and support structures,
provided the fibres are not damaged. Should be evaluated if highflux density (e.g. > 10 mW /cm ) is expected.
Standard multilayer
...
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