ISO 11451-3:2015

Road vehicles - Vehicle test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 3: On-board transmitter simulation

ISO 11451-3:2015 specifies methods for testing the immunity of passenger cars and commercial vehicles to electromagnetic disturbances from on-board transmitters connected to an external antenna and portable transmitters with integral antennas, regardless of the vehicle propulsion system (e.g. spark ignition engine, diesel engine, electric motor).

Véhicules routiers — Méthodes d'essai d'un véhicule soumis à des perturbations électriques par rayonnement d'énergie électromagnétique en bande étroite — Partie 3: Simulation des émetteurs embarqués

General Information

• Status: Withdrawn
• Publication Date: 01-Jun-2015
• ICS: 33.100.20 - Immunity
• ICS: 43.040.10 - Electrical and electronic equipment
• Technical Committee: ISO/TC 22/SC 32 - Electrical and electronic components and general system aspects
• Drafting Committee: ISO/TC 22/SC 32/WG 3 - Electromagnetic compatibility
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 11-Jun-2024
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO 11451-3:2024 - Road vehicles - Vehicle test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 3: On-board transmitter simulation
• Effective Date: 06-Jun-2022
• Revises: ISO 11451-3:2007 - Road vehicles - Vehicle test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 3: On-board transmitter simulation
• Effective Date: 09-Apr-2011

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 11451-3
Third edition
2015-06-01
Road vehicles — Vehicle test
methods for electrical disturbances
from narrowband radiated
electromagnetic energy —
Part 3:
On-board transmitter simulation
Véhicules routiers — Méthodes d’essai d’un véhicule soumis
à des perturbations électriques par rayonnement d’énergie
électromagnétique en bande étroite —
Partie 3: Simulation des émetteurs embarqués
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test conditions . 1
5 Test location . 2
5.1 General . 2
5.2 Absorber lined shielded enclosure (ALSE) . 2
5.3 Outdoor test site . 2
6 Test instrumentation . 2
6.1 General . 2
6.2 Signal sources . 2
6.2.1 Transmitters with antenna outside the vehicle . 2
6.2.2 Transmitters with antenna inside the vehicle . 3
6.3 RF power and field monitoring equipment . 3
6.4 Antennas . 3
6.4.1 Transmitters with antenna outside the vehicle . 3
6.4.2 Transmitters with antenna inside the vehicle . 3
6.5 Stimulation and monitoring of the device under test. 4
7 Test set-up . 4
7.1 Transmitters with antenna outside the vehicle . 4
7.1.1 Simulated on-board transmitters . 4
7.1.2 Commercial on-board transmitters . 6
7.2 Transmitters with antenna inside the vehicle . 7
7.2.1 General. 7
7.2.2 Simulated portable transmitters . 7
7.2.3 Commercial portable transmitters . 8
8 Test procedure .10
8.1 General .10
8.2 Test plan .10
8.3 Test method .11
8.3.1 Transmitters with antenna outside the vehicle .11
8.3.2 Transmitters with antenna inside the vehicle .12
8.4 Test report .13
Annex A (informative) Typical characteristics of on-board transmitters .14
Annex B (informative) Guidance on tuning antennas on the vehicle for minimum voltage
standing wave ratio (VSWR) .17
Annex C (informative) Examples of simulated portable transmitter antennas .20
Bibliography .54
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 22, Road vehicles, Subcommittee SC 32, Electrical
and electronic components and general system aspects.
This third edition cancels and replaces the second edition (ISO 11451-3:2007), which has been
technically revised.
ISO 11451 consists of the following parts, under the general title Road vehicles — Vehicle test methods for
electrical disturbances from narrowband radiated electromagnetic energy:
— Part 1: General principles and terminology
— Part 2: Off-vehicle radiation source
— Part 3: On-board transmitter simulation
— Part 4: Bulk current injection (BCI)
Annexes A, B and C of of this part of ISO 11451 are for information only.
iv © ISO 2015 – All rights reserved

Introduction
In recent years, an increasing number of electronic devices for controlling, monitoring, and displaying a
variety of functions have been introduced into vehicle designs. It is necessary to consider the electrical
and electromagnetic environment in which these devices operate.
Electrical and radio frequency disturbances occur during the normal operation of many items of
motor vehicle equipment. They are generated over a wide frequency range with various electrical
characteristics and can be distributed to on-board electronic devices and systems by conduction,
radiation, or both. Narrowband signals generated from sources on or off the vehicle can also be coupled
into the electrical and electronic system, affecting the normal performance of electronic devices. Such
sources of narrowband electromagnetic disturbances include mobile radios and broadcast transmitters.
The characteristics of the immunity of a vehicle to radiated disturbances have to be established.
ISO 11451 provides various test methods for the evaluation of vehicle immunity characteristics (not all
methods need be used to test a vehicle).
ISO 11451 is not intended as a product specification and cannot function as one. Therefore, no specific
values for the test severity level are given.
Protection from potential disturbances needs to be considered in a total system validation, and this can
be achieved using the various parts of ISO 11451.
NOTE Immunity measurements of complete vehicles are generally able to be carried out only by the vehicle
manufacturer, owing to, for example, high costs of absorber-lined shielded enclosures, the desire to preserve the
secrecy of prototypes, or a large number of different vehicle models. ISO 11452 specifies test methods for the
analysis of component immunity, which are better suited for supplier use.
INTERNATIONAL STANDARD ISO 11451-3:2015(E)
Road vehicles — Vehicle test methods for electrical
disturbances from narrowband radiated electromagnetic
energy —
Part 3:
On-board transmitter simulation
1 Scope
This part of ISO 11451 specifies methods for testing the immunity of passenger cars and commercial
vehicles to electromagnetic disturbances from on-board transmitters connected to an external antenna
and portable transmitters with integral antennas, regardless of the vehicle propulsion system (e.g.
spark ignition engine, diesel engine, electric motor).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 11451-1, Road vehicles — Vehicle test methods for electrical disturbances from narrowband radiated
electromagnetic energy — Part 1: General principles and terminology
ISO 11451-2, Road vehicles — Vehicle test methods for electrical disturbances from narrowband radiated
electromagnetic energy — Part 2: Off-vehicle radiation sources
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11451-1 and the following apply.
3.1
integral antenna
permanent fixed antenna which may be built-in, designed as an indispensable part of the portable
transmitting device
4 Test conditions
The applicable frequency range of the test method is 1,8 MHz to 5,85 GHz.
The user of this part of ISO 11451 shall specify the test severity level or levels over the frequency
bands. Typical on-board transmitter characteristics (frequency bands, power level and modulation)
are given in Annex A.
NOTE Users of this part of ISO 11451 should be aware that Annex A is for information only and cannot be
considered as an exhaustive description of various on-board transmitters available in all countries.
Standard test conditions are given in ISO 11451-1 for the following:
— test temperature;
— supply voltage;
— dwell time;
— test signal quality.
5 Test location
5.1 General
This test would typically be performed in an absorber lined shielded enclosure (ALSE). Where national
regulations permit, the test can also be performed at an outdoor test site.
5.2 Absorber lined shielded enclosure (ALSE)
An absorber lined shielded enclosure with the characteristics specified in ISO 11451-2 is adequate
for this test.
NOTE At frequencies where absorbers are not effective, the reflections in the chamber can affect the exposure
of the vehicle.
5.3 Outdoor test site
Where national regulations permit the use of an outdoor test site, the outdoor test site should have an
area with a radius of 10 m free from large metal structures or objects. When performing outdoor test-
site tests, care shall be taken to ensure that harmonic suppression regulations are met.
6 Test instrumentation
6.1 General
The following test instrumentation is used:
— signal sources with internal or external modulation capability;
— power amplifier(s);
— power meter (or equivalent measuring instrument) to measure the forward and reverse power;
— field generating devices: antennas;
— field probes (for environmental monitoring).
6.2 Signal sources
6.2.1 Transmitters with antenna outside the vehicle
Signal sources for transmitters with antenna outside the vehicle can be
— simulated on-board transmitters: use of a signal generator and broadband power amplifier, and
— commercial on-board transmitters installed in vehicle capable of generating radio frequency (RF)
power in their operational frequency ranges with specific output power.
NOTE When using simulated on-board transmitters, it is advisable to place an RF choke (ferrite or powdered
iron toroid, depending on frequency) around the coaxial cable to the antenna, in order to reduce skin currents and
more closely simulate a transmitter installed in the vehicle.
2 © ISO 2015 – All rights reserved

6.2.2 Transmitters with antenna inside the vehicle
Signal sources for transmitters with antenna inside the vehicle can be
— simulated portable transmitters: use of a metallic box with similar dimension to the portable
transmitter and amplifier (if needed), and
— commercial portable transmitters with integral antennas.
6.3 RF power and field monitoring equipment
A power meter is required when using simulated on-board transmitters for measuring power to the
antenna. Both forward power and reverse power shall be measured and recorded.
6.4 Antennas
6.4.1 Transmitters with antenna outside the vehicle
6.4.1.1 Simulated on-board transmitters
When an original equipment manufacturer (OEM) antenna is not installed on the vehicle, the antenna(s)
described below shall be used.
— For frequency ranges lower than 30 MHz, loaded antennas shall be used. Loaded antennas employ
lumped or distributed reactive components with a radiating element physically shorter than quarter
wave at resonance.
— For frequency ranges higher than 30 MHz, e.g. for the very high frequency (VHF) and ultra-high
frequency (UHF) bands, quarter wave antennas should be given preference over 5/8 wave antennas,
since there are higher skin currents created by quarter wave antennas.
All antennas shall be tuned on the vehicle for minimum voltage standing wave ratio (VSWR, typically
less than 2:1), unless otherwise specified in the test plan. As a minimum, the VSWR value shall be
recorded with the antenna on the vehicle at the lower and upper band edge and at a middle frequency
(see Annex B for guidance on influence of cable loss and VSWR).
When an OEM antenna is actually installed on the vehicle, this antenna shall be used for the test in the
appropriate frequency range. In this case, the VSWR shall not be adjusted, but shall be recorded.
6.4.1.2 Commercial on-board transmitters
The vehicle OEM antenna shall be used for the test in the appropriate frequency range. In this case, the
VSWR shall not be adjusted.
6.4.2 Transmitters with antenna inside the vehicle
6.4.2.1 Simulated portable transmitter
Unless otherwise specified the simulated portable transmitter antenna characteristics shall be a passive
antenna as detailed in C.2. Examples of other antennas which can be used are defined in Annex C.
All antennas should have a minimum VSWR (typically less than 4:1), unless otherwise specified in the
test plan. As a minimum, the VSWR value shall be recorded at the lower and upper band edge and at a
middle frequency.
6.4.2.2 Commercial portable transmitters
When a commercial portable transmitter with integral antenna is used, its antenna shall be used for the
test in the appropriate frequency range. In this case, the VSWR shall not be adjusted.
6.5 Stimulation and monitoring of the device under test
If remote stimulation and monitoring are required in the test plan, the vehicle shall be operated by
actuators which have a minimum effect on the electromagnetic characteristics, e.g. plastic blocks on the
push-buttons, pneumatic actuators with plastic tubes.
Connections to monitoring equipment can be accomplished by using fibre-optics or high resistance
leads. Other types of leads can be used, but they require extreme care to minimize interactions. The
orientation, length and location of such leads shall be carefully documented to ensure repeatability of
test results.
Any electrical connection of monitoring equipment to the vehicle can cause malfunctions of the vehicle.
Extreme care shall be taken to avoid such an effect.
7 Test set-up
7.1 Transmitters with antenna outside the vehicle
7.1.1 Simulated on-board transmitters
The test can be performed with test antenna(s) or with the vehicle’s OEM antenna, as defined in
6.4.1.1.
When a test antenna is used, the location(s) of the transmitting antenna on the vehicle shall be defined
in the test plan. If no specific location(s) are agreed between the users of this part of ISO 11451, the
following location (s) are recommended, as illustrated in Figure 1:
— locations 1 (vehicle roof, front) and 2 (vehicle roof, rear) are the default locations for
frequencies ≥30 MHz;
— location 9 (bumper) is the default location for frequencies <30 MHz.
Key
1 vehicle roof (front) 6 fender (rear, right)
2 vehicle roof (rear) 7 fender (rear, left)
3 vehicle roof (middle) 8 trunk lid (middle)
4 fender (front, right) 9 bumper (middle)
5 fender (front, left)
Figure 1 — Recommended locations for antennas outside the vehicle
4 © ISO 2015 – All rights reserved

When the vehicle OEM antenna is used, it should be used as it is installed in the vehicle without any
change of antenna characteristics (location, VSWR, etc.).
Examples of test set-up for simulated on-board transmitters are shown in Figure 2 (use of test antenna)
and Figure 3 (use of vehicle OEM antenna).
NOTE When the vehicle OEM antenna is used for multiple transmitters/receivers frequency, it is advisable not
to use a simulated on-board transmitter (with “broadband” amplifier). The amplifier noise level can be sufficient
to degrade some vehicle functions, like GPS satellite reception. The validation of such functions (relative to vehicle
on-board-transmitter immunity) can only be performed with the vehicle OEM on-board transmitter. In this case,
it might be necessary to operate the on-board vehicle transmitter in real conditions. This can be performed by
using specific equipment, like a GSM base station simulator (see 7.1.2 and Figure 4).
Key
1 ALSE
2 RF signal generator (can be outside test facility)
3 power amplifier (can be outside test facility)
4 dual directional coupler (can be outside test facility)
5 power meter (can be outside test facility)
6 test antenna (positions defined in test plan)
Figure 2 — Example of test set-up for simulated on-board transmitter and test antenna
Key
1 ALSE
2 RF signal generator (can be outside test facility)
3 power amplifier (can be outside test facility)
4 dual directional coupler (can be outside test facility)
5 power meter (can be outside test facility)
6 vehicle OEM antenna
7 on-board transmitter (disconnected from vehicle antenna)
8 vehicle antenna cable connector
Figure 3 — Example of test set-up for simulated on-board transmitter and vehicle OEM antenna
7.1.2 Commercial on-board transmitters
The vehicle commercial on-board transmitter and OEM antenna should be used as it is installed in the
vehicle, without any change of transmitter and antenna characteristics (location, VSWR, etc.).
An example of test set-up for commercial on-board transmitters is shown in Figure 4.
6 © ISO 2015 – All rights reserved

Key
1 ALSE
2 on-board transmitter (connected to vehicle antenna)
3 vehicle OEM antenna
4 antenna (when necessary)
5 base station simulator inside or outside test facility (when necessary)
6 vehicle antenna cable connector
Figure 4 — Example of test set-up for commercial on-board transmitter
7.2 Transmitters with antenna inside the vehicle
7.2.1 General
The location(s) of a simulated or commercial portable transmitter in the vehicle shall be defined in the
test plan. If no specific location(s) are agreed between the users of this part of ISO 11451, the following
location(s) are recommended:
— at the driver’s head position (centred on the back of the seat at a height of 0,8 m from the seat
cushion, with the seat in medium position), antenna in vertical polarization;
— at the passenger’s head position (centred the back of the seat at a height of 0,8 m from the seat
cushion, with the seat in medium position), antenna in vertical polarization;
— in specified places where a portable transmitter can be placed, i.e. between front seats, on the
vehicle’s centre console, storage compartments;
— at the rear passenger’s head position (centred on the back of the seat at a height of 0,8 m from the
seat cushion, with the seat in medium position), antenna in vertical polarization.
7.2.2 Simulated portable transmitters
An example of test set-up for simulated portable transmitters is shown in Figure 5.
Key
1 ALSE
2 RF signal generator (can be outside test facility)
3 power amplifier (can be outside test facility)
4 dual directional coupler (can be outside test facility)
5 power meter (can be outside test facility)
6 simulated portable transmitter (positions defined in test plan)
Figure 5 — Example of test set-up for simulated portable transmitters
7.2.3 Commercial portable transmitters
Examples of test set-up for commercial portable transmitters are shown in Figures 6 and 7 (use of base
station simulator).
NOTE Certain RF systems (e.g. GSM phones) transmit with different RF power levels and frequencies. In such
cases, the test might not necessarily be performed at the maximum RF power level. To control output power and
frequency, either devices with modified software or base station simulators can be used.
8 © ISO 2015 – All rights reserved

Key
1 ALSE
2 commercial portable transmitter (positions defined in test plan)
Figure 6 — Example of test set-up for commercial portable transmitters
Key
1 ALSE
2 commercial portable transmitter (positions defined in test plan)
3 base station simulator inside or outside test facility
4 antenna (when necessary)
Figure 7 — Example of test set-up for commercial portable transmitters and base station simulator
8 Test procedure
8.1 General
The general arrangement of vehicle, transmitter(s) and associated equipment represents a standardized
test condition. Any deviations from the standard test configuration shall be agreed upon prior to testing
and recorded in the test report.
The vehicle shall be made to operate under typical loading and operating conditions. These operating
conditions shall be clearly defined in the test plan.
8.2 Test plan
Prior to performing the tests, a test plan shall be generated which shall include:
— test set-up;
— frequency range(s) and associated modulation(s);
— duration of transmission;
— antenna location and polarization;
— routing of the coaxial cable to the antenna in the vehicle (for simulated on-board transmitters);
— vehicle mode of operation;
10 © ISO 2015 – All rights reserved

— vehicle monitoring conditions;
— vehicle acceptance criteria;
— vehicle exposure methodology (simulated or commercial transmitter);
— simulated portable transmitter antenna or commercial transmitter antenna location;
— definition of test severity levels;
— maximum antenna VSWR value if necessary;
— test report content;
— any special instructions and changes from the standard test.
8.3 Test method
IMPORTANT — The appropriate guidelines (national regulation, ICNIRP [1][2] etc.) shall be
followed for the protection of the test personnel.
8.3.1 Transmitters with antenna outside the vehicle
8.3.1.1 Simulated on-board transmitters
8.3.1.1.1 General
The vehicle, antenna(s) and associated equipment are installed as described in 7.1.1.
The test severity levels are defined in terms of root-mean-square (RMS) power measured for a continuous
wave (CW) signal.
8.3.1.1.2 OEM antenna configuration
The reference parameter for the test is the forward power at the vehicle’s antenna cable terminal.
For vehicles with an OEM antenna, the test shall at least be performed with this configuration even if
tests are also performed with test antenna(s).
With the power amplifier output connected at the OEM antenna cable terminal, increase the forward
power level until the predetermined level is achieved. For modulated signals, the peak conservation
principle shall be applied as defined in ISO 11451-1. Perform the test at frequencies within the designed
bandwidth of the OEM antenna (at least at the lower and upper band edge and at a middle frequency and
at frequency steps not greater than those defined in ISO 11451-1).
Continue testing until all frequency bands, modulations, polarizations and antenna locations specified
in the test plan are completed.
NOTE At test locations on the vehicle where system interactions are observed (changes/degradations in
performance), the test can be repeated in a second step with commercial on-board transmitters transmitting
with the maximum allowed power level, as defined in 8.3.1.2.
When required in the test plan, the immunity threshold shall be determined.
8.3.1.1.3 Test antenna configuration
The reference parameter for the test is the net power at the test antenna feed-point.
With the power amplifier output connected at the test antenna feed-point, increase the net power level
until the predetermined level is achieved. For modulated signals, the peak conservation principle shall
be applied as defined in ISO 11451-1. Perform the test at frequencies within the designed bandwidth of
the test antenna (at least at the lower and upper band edge and at a middle frequency and at frequency
steps not greater than those defined in ISO 11451-1). The use of more than one test antenna might be
necessary to cover an entire frequency band.
Continue testing until all frequency bands, modulations, polarizations and antenna locations specified
in the test plan are completed.
NOTE At test locations on the vehicle where system interactions are observed (changes/degradations in
performance), the test can be repeated in a second step with commercial on-board transmitters transmitting
with the maximum allowed power level, as defined in 8.3.1.2.
When required in the test plan, the immunity threshold shall be determined.
8.3.1.2 Commercial on-board transmitters
The vehicle is installed in the test facility as described in 7.1.2.
The test shall be performed with unmodified commercial on-board transmitter characteristics (power,
modulation, etc.) and the unmodified vehicle OEM antenna. Any exception to this practice shall be
specified in the test plan.
NOTE In general, the commercial on-board transmitter power considered for this test is the commercially
available/declared value of rated power.
Operate the commercial on-board transmitter connected to the OEM antenna in the configuration(s)
indicated in the test plan, noting any anomalies.
Continue testing until all on-board transmitter(s) specified in the test plan are completed.
8.3.2 T
...