IEC 62037-7:2022
(Main)Passive RF and microwave devices, intermodulation level measurement - Part 7: Field measurements of passive intermodulation
Passive RF and microwave devices, intermodulation level measurement - Part 7: Field measurements of passive intermodulation
IEC 62037-7:2022 defines test methods for reverse measurement of passive intermodulation (PIM) in systems of RF components deployed in the field. Field PIM measurements can be conducted on RF systems terminated into low PIM loads or on antenna feed systems that broadcast the test signals into the environment.
Dispositifs RF et à micro-ondes passifs, mesure du niveau d’intermodulation – Partie 7: Mesures de l’intermodulation passive sur le terrain
IEC 62037-7:2022 définit des méthodes d’essai de mesure inverse de l’intermodulation passive (PIM) dans les systèmes de composants RF déployés sur le terrain. Les mesures de l’intermodulation passive sur le terrain peuvent être effectuées sur des systèmes RF terminés par des charges à faible intermodulation passive ou sur des systèmes d’alimentation d’antenne qui diffusent les signaux d’essai dans l’environnement.
General Information
Standards Content (Sample)
IEC 62037-7
®
Edition 1.0 2022-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Passive rf and microwave devices, intermodulation level measurement –
Part 7: Field measurements of passive intermodulation
Dispositifs rf et à micro-ondes passifs, mesure du niveau d’intermodulation –
Partie 7: Mesures de l’intermodulation passive sur le terrain
IEC 62037-7:2022-10(en-fr)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 62037-7
®
Edition 1.0 2022-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Passive rf and microwave devices, intermodulation level measurement –
Part 7: Field measurements of passive intermodulation
Dispositifs rf et à micro-ondes passifs, mesure du niveau d’intermodulation –
Partie 7: Mesures de l’intermodulation passive sur le terrain
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.120.01 ISBN 978-2-8322-5883-5
Warning! Make sure that you obtained this publication from an authorized distributor.
Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 62037-7:2022 © IEC 2022
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 . 6
4 General considerations . 6
4.1 Test environment . 6
4.2 Test frequencies . 6
4.3 Safety . 6
5 Field PIM test equipment . 7
6 Test procedure . 7
6.1 General . 7
6.2 Equipment verification . 7
6.2.1 General . 7
6.2.2 Clean and inspect RF connections . 7
6.2.3 Residual PIM test . 7
6.2.4 PIM standard test . 7
6.3 VSWR verification . 8
6.4 Interference verification . 8
6.5 Static PIM test . 8
6.6 Dynamic PIM test . 8
6.6.1 General . 8
6.6.2 Coaxial cable assemblies . 9
6.6.3 Coaxial connectors . 9
6.6.4 Splitters, combiners, filters and receive low noise amplifiers . 9
6.6.5 Antennas . 9
7 Test specification . 9
8 Report . 9
Annex A (informative) Distance-to-PIM measurements . 10
Figure A.1 – Internal vs. external PIM sources . 11
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IEC 62037-7:2022 © IEC 2022 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PASSIVE RF AND MICROWAVE DEVICES,
INTERMODULATION LEVEL MEASUREMENT –
Part 7: Field measurements of passive intermodulation
FOREWORD
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 62037-7 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.
The text of this International Standard is based on the following documents:
Draft Report on voting
46/903/FDIS 46/912/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.
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– 4 – IEC 62037-7:2022 © IEC 2022
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 62037 series, 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.
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IEC 62037-7:2022 © IEC 2022 – 5 –
PASSIVE RF AND MICROWAVE DEVICES,
INTERMODULATION LEVEL MEASUREMENT –
Part 7: Field measurements of passive intermodulation
1 Scope
This part of IEC 62037 defines test methods for reverse measurement of passive
intermodulation (PIM) in systems of RF components deployed in the field. Field PIM
measurements can be conducted on RF systems terminated into low PIM loads or on antenna
feed systems that broadcast the test signals into the environment.
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 62037-1:2021, Passive RF and microwave devices, intermodulation level measurement –
Part 1: General requirements and measuring methods
IEC 62037-2:2021, Passive RF and microwave devices, intermodulation level measurement –
Part 2: Measurement of passive intermodulation in coaxial cable assemblies
IEC 62037-3:2021, Passive RF and microwave devices, intermodulation level measurement –
Part 3: Measurement of passive intermodulation in coaxial connectors
IEC 62037-5:2021, Passive RF and microwave devices, intermodulation level measurement –
Part 5: Measurement of passive intermodulation in filters
IEC 62037-6:2021, Passive RF and microwave devices, intermodulation level measurement –
Part 6: Measurement of passive intermodulation in antennas
3 Terms, definitions and abbreviated terms
3.1 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 https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
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– 6 – IEC 62037-7:2022 © IEC 2022
3.2 Abbreviated terms
DTP Distance to PIM
DUT Device under test
IM Intermodulation
PIM Passive intermodulation
TMA Tower mounted amplifier
VSWR Voltage standing wave ratio
4 General considerations
4.1 Test environment
When a field PIM measurement is conducted on an antenna feed system that allows the test
signals to broadcast into the environment, it is important to ensure that government regulations
pertaining to the maximum authorized RF radiation levels are met. This applies to all fixed
frequency PIM tests, swept PIM tests and distance-to-PIM (DTP) tests described in this
document. See Annex A for information on distance-to-PIM measurements.
Field PIM measurements conducted on antenna feed systems measure the linearity of the entire
RF path including the site RF infrastructure (coaxial cables, filters, antennas, etc.) and the
environment where the antenna is installed (mounting hardware, cable support brackets, metal
objects in front of or in the vicinity of the antenna). Technicians performing field PIM tests
through an antenna shall avoid placing objects with non-linear PIM behaviour such as keys, cell
phones, ladders and tools in locations in front of or in the vicinity of the antenna that might
impact results.
4.2 Test frequencies
The f , f and IM product frequency selected for the test shall fall within the operating bandwidth
1 2
of the system under test. The f and f test frequencies shall be able to pass through the entire
1 2
system and the IM product frequency being measured shall be able to return to the PIM analyzer
for measurement. If devices are present in the RF path that block the f and/or f test frequency
1 2
or prevent the desired IM product frequency from returning to the PIM analyzer, bypass these
devices with short, low PIM jumper cables while testing.
The f and f test signals shall be spaced far enough apart in frequency to place the IM product
1 2
being measured in the receive band of the PIM analyzer. To meet this requirement, one or both
test signals will likely be outside of the spectrum owned by the operator commissioning the test.
While it is unlikely that PIM test signals will cause harmful interference to other operators, it is
good practice to select f and f test frequencies that fall in the guard bands between operators.
1 2
When PIM testing through an antenna, interfering signals can be received from user equipment
operating at the IM product frequency. A survey of frequencies locally in use should be
conducted prior to testing. If interfering signals are detected, change the f and/or f test
1 2
frequency to move the IM product frequency to unused spectrum, such as a guard band
frequency between active channels.
4.3 Safety
Performing field PIM tests through antennas can be dangerous. Potentially high voltages and
high levels of RF energy can be present near the antenna. Technicians performing field PIM
tests shall remain at a safe distance from the antenna and minimize exposure to
electromagnetic fields in order to not exceed the acceptable levels specified by government
agencies.
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IEC 62037-7:2022 © IEC 2022 – 7 –
PIM tests require technicians to disconnect the coaxial cables at the radio output ports. Make
sure that all radios feeding the line under test are locked-off and non-transmitting to prevent RF
burns.
5 Field PIM test equipment
PIM test equipment used for field measurements shall be capable of performing a reverse
(reflected) PIM test in accordance with IEC 62037-1:2021, 6.2.2. Field PIM test equipment will
experience shock and vibration during transportation to a site and during use. In addition, field
test equipment will often be used in outdoor, uncontrolled thermal environments. For these
reasons, field PIM test equipment shall be ruggedized to perform reliably under typical test
conditions.
6 Test procedure
6.1 General
Unless otherwise specified, test tones from the PIM analyzer will be injected into the system
under test through the same connector that transmit signals enter the system from the radio.
6.2 Equipment verification
6.2.1 General
Because field PIM test equipment can be exposed to mechanical and thermal stress between
tests, it is important to verify before testing that the equipment is in good operating condition.
In addition to good operating condition verification, the following verification steps can be
performed as needed while testing to rule out equipment issues when unexpected results are
encountered.
6.2.2 Clean and inspect RF connections
Clean and inspect all RF connectors in the test set-up using isopropyl alcohol and a lent-free
wipe prior to beginning verification tests. Mating surfaces inside the RF connectors should be
clean and free of oils, dirt or objects that will increase contact resistance. In addition, all metal
flakes shall be removed from inside the RF connector. Replace any worn or damaged
components found during visual inspection.
6.2.3 Residual PIM test
Measure the residual PIM of the test set-up including the PIM analyzer and any coaxial cables
and RF adapters used to connect the PIM analyzer to the system under test. Connect one end
of the coaxial cable test lead to the PIM analyzer and the other end to a low PIM termination.
Flex the test cable while measuring the test set-up. The test set-up peak self-intermodulation
(including contribution of the load) should be at least 10 dB below the level to be measured on
the system under test as specified in IEC 62037-1.
6.2.4 PIM standard test
rd
A PIM standard is a device that consistently produces a known 3 order IM product level when
tested at a specified power level using specified f and f test signals. Some PIM standards
1 2
include an integrated RF termination while others are "in-line" standards that require a low PIM
termination to be connected to the output port of the standard. Connect the PIM standard plus
rd
termination directly to the output port of the PIM analyzer and measure the 3 order IM level.
The value measured should be within 3 dB of the expected value for that standard.
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– 8 – IEC 62037-7:2022 © IEC 2022
6.3 VSWR verification
Measure the VSWR of the system including the test lead and any RF adapters used to connect
the PIM analyzer to the system at the f , f and IM product frequencies. Unless otherwise
1 2
specified, the VSWR should be <1,92:1 (10 dB return loss). If higher reflected energy is detected,
investigate and repair the fault prior to performing a field PIM test.
6.4 Interference verification
Perform an external noise level measurement at the desired IM product frequency prior to
performing a field PIM test. The magnitude of external received signals at the IM product
frequency should be 10 dB lower than the IM level to be measured on the system under test.
This test can be performed using a spectrum analyzer attached to the system under test or by
using the PIM test equipment itself with the receiver active and the test signs turned off.
6.5 Static PIM test
"Static" means "without movement or stress". Perform an initial static PIM test to determine the
lM product level generated by the system. If the static IM product level is below the specified
pass/fail threshold, proceed to “dynamic” PIM testing. If the IM product level is above the
specified pass/fail threshold, find and repair the PIM faults before proceeding.
Static PIM tests on antenna feed systems are typically conducted using fixed f , f and IM
1 2
product frequencies to avoid external interference at the IM product frequency and to minimize
the probability of harmful interference by the test signals on other operators. Fixed frequency
testing can occasionally report a passing PIM test result at the specified IM product frequency
when there are multiple PIM sources present in the system under test. If multiple PIM sources
are physically separated in such a way that the signals arrive at the PIM test equipment receiver
180º out of phase, the PIM signals will cancel, indicating low PIM in the system under test.
Static PIM tests can also be conducted using swept PIM measurements where one test
frequency is fixed while sweeping the second test frequency across a range of spectrum.
Changing the test frequencies changes the phase relationship between multiple IM product
signals on the line. Sweeping across multiple test frequency combinations provides a range of
IM product data points to help ensure that poor system PIM performance is not reported as
good performance due to an unfortunate selection of test frequencies.
Swept PIM measurements on antenna feed systems can broadcast one or both test signals
outside the licensed spectrum owned by the operator commissioning the test. The test signals
are short duration and are typically transmitted in the downlink range of licensed spectrum
holders. As a result, this test is unlikely to cause harmful interference to other users.
6.6 Dynamic PIM test
6.6.1 General
"Dynamic" means "with movement and/or with stress". Unless otherwise specified, perform a
PIM test on the system while applying the specified dynamic stimulus to all components and
connections in the system. The peak IM product level measured during the dynamic PIM test
shall not exceed the specified pass/fail level for the system.
The purpose for applying a dynamic stimulus while PIM testing is to verify that all connections
are tight and to identify any components with unstable PIM performance. The stimulus does not
have to simulate environmental conditions to identify loose connections and unstable
components. In addition, the stimulus does not have to exactly replicate the stimulus specified
for factory PIM testing. The field dynamic stimulus shall not, however, be more severe than the
stimulus defined in the relevant IEC 62037 specification for the component under test.
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IEC 62037-7:2022 © IEC 2022 – 9 –
Fixed frequency PIM tests shall be used for maximum responsiveness while performing dynamic
PIM tests. Multiple dynamic stimuli are required at each component and connection as
described below to increase the probability of detection of PIM events.
6.6.2 Coaxial cable assemblies
Hold the cable at a distance of 4× the specified repeated bending radius of the cable and rotate
the cable in either a clockwise or counterclockwise direction for 3 cycles. The radius of rotation
should be equal to the cable diameter plus approximately 10 mm as specified in
IEC 62037-2:2021, 4.2.
6.6.3 Coaxial connectors
Strike the connector with an instrument that will not damage the surface of the connector such
as the plastic end of a screwdriver or the rubberized end of an adjustable wrench. Be careful
not to strike the coaxial cable. Apply 5 impacts per connector with an impact energy less than
or equal to the level specified in IEC 62037-3:2021, Table 1 for the connector type under test.
6.6.4 Splitters, combiners, filters and receive low noise amplifiers
Strike the device body with an instrument that will not damage the surface of the device such
as the plastic end of a screwdriver or the rubberized end of an adjustable wrench. Two impacts
shall be applied as close as possible to each connector on the device while still impacting the
device body. For any side of the device that has no connectors, apply 3 impacts along each
side. Impact energy shall be less than or equal 0,14 J per impact as specified in
IEC 62037-5:2021, 4.2.
6.6.5 Antennas
Strike the rear surface of the antenna with an instrument that will not damage the surface of the
antenna such as the plastic end of a screwdriver or the rubberized end of an adjustable wrench.
Strikes should not be applied to AUT accessories or other fragile parts of the antenna. Two
impacts shall be applied as close as possible to each connector on the device while still
impacting the antenna rear surface. Additional impacts will be applied every 30 cm along the
height of the antenna. Impact energy shall be less than or equal 1 J per impact as specified in
IEC 62037-6:2021, 7.3.
7 Test specification
Test specifications shall specify:
a) test power level;
b) IM product order to be measured;
c) frequency band(s) or specific test frequencies within the band(s) to be measured.
8 Report
The report shall document the following:
a) residual PIM of the measurement system;
b) peak PIM of each antenna feed line while applying dynamic loading.
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– 10 – IEC 62037-7:2022 © IEC 2022
Annex A
(informative)
Distance-to-PIM measurements
PIM
...
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