ISO 11452-2:2019

Road vehicles — Component test methods for electrical disturbances from narrowband radiated electromagnetic energy — Part 2: Absorber-lined shielded enclosure

This document specifies an absorber-lined shielded enclosure method for testing the immunity (off-vehicle radiation source) of electronic components for passenger cars and commercial vehicles regardless of the propulsion system (e.g. spark-ignition engine, diesel engine, electric motor). The device under test (DUT), together with the wiring harness (prototype or standard test harness), is subjected to an electromagnetic disturbance generated inside an absorber-lined shielded enclosure, with peripheral devices either inside or outside the enclosure. It is applicable only to disturbances from continuous narrowband electromagnetic fields. See ISO 11452-1 for general test conditions.

Véhicules routiers — Méthodes d'essai d'un équipement soumis à des perturbations électriques par rayonnement d'énergie électromagnétique en bande étroite — Partie 2: Chambre anéchoïque

General Information

• Status: Published
• Publication Date: 09-Jan-2019
• 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: 6060 - International Standard published
• Start Date: 10-Jan-2019
• Completion Date: 10-Jan-2019

RELATIONS

• Replaces: ISO 11452-2:2004 - Road vehicles — Component test methods for electrical disturbances from narrowband radiated electromagnetic energy — Part 2: Absorber-lined shielded enclosure
• Effective Date: 04-Nov-2015

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 11452-2
Third edition
2019-01
Road vehicles — Component test
methods for electrical disturbances
from narrowband radiated
electromagnetic energy —
Part 2:
Absorber-lined shielded enclosure
Véhicules routiers — Méthodes d'essai d'un équipement soumis
à des perturbations électriques par rayonnement d'énergie
électromagnétique en bande étroite —
Partie 2: Chambre anéchoïque
Reference number
ISO 11452-2:2019(E)
ISO 2019
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ISO 11452-2:2019(E)
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© ISO 2019

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

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Published in Switzerland
ii © ISO 2019 – All rights reserved
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ISO 11452-2:2019(E)
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

6 Test apparatus and instrumentation............................................................................................................................................... 2

6.1 General ........................................................................................................................................................................................................... 2

6.2 Measuring equipment ....................................................................................................................................................................... 2

6.3 Stimulation and monitoring of DUT ..................................................................................................................................... 3

7 Test set-up for DUT powered by an unshielded power system ............................................................................ 3

7.1 Ground plane ............................................................................................................................................................................................ 3

7.2 Power supply and AN ........................................................................................................................................................................ 3

7.3 Location of DUT ...................................................................................................................................................................................... 4

7.4 Location of test harness .................................................................................................................................................................. 4

7.5 Location of load simulator ............................................................................................................................................................ 4

7.6 Location of field generating device (antenna) ............................................................................................................. 4

8 Test setup for DUT powered by a shielded power system ......................................................................................11

8.1 Ground plane .........................................................................................................................................................................................11

8.2 Power supply and AN .....................................................................................................................................................................11

8.3 Location of DUT ...................................................................................................................................................................................11

8.4 Location of test harness ...............................................................................................................................................................12

8.5 Location of load simulator .........................................................................................................................................................12

8.6 Location of field generating device (antenna) ..........................................................................................................13

9 Test method ............................................................................................................................................................................................................31

9.1 General ........................................................................................................................................................................................................31

9.2 Test plan .....................................................................................................................................................................................................31

9.3 Test procedure ......................................................................................................................................................................................32

9.3.1 General...................................................................................................................................................................................32

9.3.2 Substitution method ..................................................................................................................................................32

9.3.3 Field calibration .............................................................................................................................................................32

9.3.4 DUT test ................................................................................................................................................................................33

9.4 Test report ................................................................................................................................................................................................33

Annex A (informative) Remote/local grounding ...................................................................................................................................34

Annex B (informative) Function performance status classification (FPSC) .............................................................36

Bibliography .............................................................................................................................................................................................................................37

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ISO 11452-2:2019(E)
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 voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 32,

Electric and electronic equipment.

This third edition cancels and replaces the second edition (ISO 11452-2:2004), which has been

technically revised.
The main changes compared to the previous edition are as follows:

a) introduction of reference to additional artificial networks (HV-AN, AMN, AAN) for DUT powered by

a shielded power system;
b) precisions for ground plane dimensions;

c) suppression of the minimum distance requirement between rear of horn antenna and absorbers;

d) addition of test set-up descriptions and Figures for DUT powered by a shielded power system;

e) suppression of Annex A relative to artificial networks which are now defined in ISO 11452-1; and

f) update of previous Annex C to be in line with new functional performance status classification

(FPSC) format.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved
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ISO 11452-2:2019(E)
Introduction

Immunity measurements of complete vehicles are generally able to be carried out only by the vehicle

manufacturer, owing to, for example, high costs of an absorber-lined shielded enclosure (ALSE), the

desire to preserve the secrecy of prototypes or a large number of different vehicles models.

For research, development and quality control, a laboratory measuring method can be used by both

vehicle manufacturers and equipment suppliers to test electronic components.
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INTERNATIONAL STANDARD ISO 11452-2:2019(E)
Road vehicles — Component test methods for electrical
disturbances from narrowband radiated electromagnetic
energy —
Part 2:
Absorber-lined shielded enclosure
1 Scope

This document specifies an absorber-lined shielded enclosure method for testing the immunity (off-

vehicle radiation source) of electronic components for passenger cars and commercial vehicles

regardless of the propulsion system (e.g. spark-ignition engine, diesel engine, electric motor). The

device under test (DUT), together with the wiring harness (prototype or standard test harness), is

subjected to an electromagnetic disturbance generated inside an absorber-lined shielded enclosure,

with peripheral devices either inside or outside the enclosure. It is applicable only to disturbances from

continuous narrowband electromagnetic fields. See ISO 11452-1 for general test conditions.

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.

ISO 11452-1:2015, Road vehicles — Component test methods for electrical disturbances from narrowband

radiated electromagnetic energy — Part 1: General principles and terminology
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 11452-1 apply.

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 https: //www .iso .org/obp
4 Test conditions

The applicable frequency range of the absorber-lined shielded enclosure test method is 80 MHz to 18 GHz.

The user shall specify the test severity level(s) over the frequency range. Suggested test levels are

included in Annex B.
Standard test conditions shall be according to ISO 11452-1 for the following:
— test temperature;
— supply voltage;
— modulation;
— dwell time;
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ISO 11452-2:2019(E)
— frequency step sizes;
— definition of test severity levels; and
— test signal quality.
5 Test location
The tests shall be performed in an ALSE.

The purpose of such an enclosure is to create an isolated electromagnetic compatibility test facility

which simulates open field testing. Basically, an ALSE consists of a shielded room with absorbing

material on its internal reflective surfaces except the floor. However, flat ferrite tiles with a maximum

thickness of 25 mm may be optionally applied on the floor.
The same ALSE configuration shall be used for calibration and the DUT test.

The design objective is to attenuate the reflected energy in the test area by at least 10 dB compared to

the direct energy.

NOTE In order to achieve this objective, the performance of the absorbing material for the walls and ceiling

can be greater than or equal to 6 dB in the frequency range of use. A test method for evaluating absorbing

[1]
material is described in IEEE STD 1128-1998 .
6 Test apparatus and instrumentation
6.1 General

Radiated electromagnetic fields are generated using antennas with a radio frequency (RF) energy

source capable of producing the desired field strengths. A set of antennas and multiple RF amplifiers

could be required to cover the range of test frequencies.
6.2 Measuring equipment

6.2.1 Field-generating device, any available antenna (including high-power baluns, if appropriate)

capable of radiating the specified field strength at the DUT with the available power may be used. The

construction and orientation of any field-generating device shall be such that the generated field can be

polarized in the mode specified in the test plan.

6.2.2 Field probes, shall be electrically small in relation to the wavelength, isotropic and with three

orthogonal axes. The communication lines from the probe shall be fibre optic links.

6.2.3 Artificial networks (AN), high voltage artificial networks (HV-AN), artificial mains

networks (AMN), and asymmetric artificial networks (AAN), see 7.2 and ISO 11452-1: 2015, Annex B.

6.2.4 RF generator, with internal (or external) modulation capabilities.
6.2.5 High-power amplifier.

6.2.6 Power meter and/or power sensors (or equivalent measuring instrument) and dual directional

coupler, for measuring forward power and reflected power.
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ISO 11452-2:2019(E)
6.3 Stimulation and monitoring of DUT

The device under test (DUT) shall be operated as required in the test plan by actuators that have a

minimum effect on the electromagnetic characteristics, e.g. plastic blocks on the push-buttons,

pneumatic actuators with plastic tubes.

Connections to equipment monitoring electromagnetic interference reactions of the DUT may be

accomplished by using fibre-optics, or high-resistance leads. Other types of lead may be used but

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 DUT may cause malfunctions of the DUT.

Extreme care shall be taken to avoid such an effect.
7 Test set-up for DUT powered by an unshielded power system
7.1 Ground plane

The ground plane shall be made of 0,5 mm thick (minimum) copper, brass or galvanized steel.

The minimum width of the ground plane shall be 1 000 mm, or the width of the entire underneath

of the test setup (DUT and associated equipment (e.g. harness including supply lines, load simulator

located on the test bench and AN(s)), excluding battery and/or power supply) plus 200 mm, whichever

is the larger.

The minimum length of the ground plane shall be 2 000 mm, or the length of the entire underneath

of the test setup (DUT and associated equipment (e.g. harness including supply lines, load simulator

located on the test bench and AN(s)), excluding battery and/or power supply) plus 200 mm, whichever

is the larger.

The height of the ground plane (test bench) shall be (900 ± 100) mm above the floor.

The ground plane shall be bonded to the shielded enclosure such that the DC resistance shall not exceed

2,5 mΩ. The distance from the edge of the ground strap to the edge of the next strap shall not be greater

than 300 mm. The maximum length to width ratio for the ground straps shall be 7:1.

7.2 Power supply and AN
Each DUT power supply lead shall be connected to the power supply through an AN.

Power supply is assumed to be negative ground. If the DUT utilizes a positive ground, then the test

set-ups shown in the figures shall be adapted accordingly. Power shall be applied to the DUT via a

5 µH/50 Ω AN (see ISO 11452-1:2015, Annex B for the schematic). The number of ANs required depends

on the intended DUT installation in the vehicle.

— For a remotely grounded DUT (vehicle power return line longer than 200 mm), two ANs are required:

one for the positive supply line and another for the power return line (see Annex A).

— For a locally grounded DUT (vehicle power return line 200 mm or shorter), only one AN is required,

for the positive supply (see Annex A).

The AN(s) shall be mounted directly on the ground plane. The case or cases of the AN(s) shall be bonded

to the ground plane.

The power supply return shall be connected to the ground plane between the power supply and the AN(s).

The measuring port of each AN shall be terminated with a 50 Ω load.
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ISO 11452-2:2019(E)

The length of the power supply lines between the power supply and the load simulator shall be as short

as possible and defined in the test plan. Unless otherwise specified, the power supply lines between the

power supply and the load simulator shall be placed directly on the ground plane.

7.3 Location of DUT

The DUT shall be placed on a non-conductive, low relative permittivity (dielectric-constant) material

(ε ≤ 1,4), at (50 ± 5) mm above the ground plane unless otherwise specified in the test plan.

The case of the DUT shall not be grounded to the ground plane unless it is intended to simulate the

actual vehicle configuration.

The front of the DUT shall be located at a distance of (200 ± 10) mm from the edge of the ground plane.

7.4 Location of test harness

The part of the test harness parallel to the front edge of the ground plane shall be (1 500 ± 75) mm.

The total length of the test harness between the DUT and the load simulator (or the RF boundary) shall

+300

be (1700 ) mm. The wiring type is defined by the actual system application and requirement.

The detailed layout of the harness on DUT side between the ground plane front edge and the DUT

connector(s) shall be described in the test plan.

The test harness shall be placed on a non-conductive, low relative permittivity (dielectric-constant)

material (ε ≤ 1,4), at (50 ± 5) mm above the ground plane.

The part of the test harness parallel to the front edge of the ground plane shall be at a distance of

(100 ± 10) mm from the edge of the ground plane.
7.5 Location of load simulator

Unless otherwise specified in the test plan, the load simulator shall be placed directly on the ground

plane. If the load simulator has a metallic case, this case shall be bonded to the ground plane.

Alternatively, the load simulator may be located adjacent to the ground plane (with the case of the load

simulator bonded to the ground plane) or outside of the test chamber, provided the test harness from

the DUT passes through an RF boundary bonded to the ground plane. The layout of the test harness

that is connected to the load simulator shall be defined in the test plan and recorded in the test report.

When the load simulator is located on the ground plane, the DC power supply lines of the load simulator

shall be connected through the AN(s).
7.6 Location of field generating device (antenna)

The height of the phase centre of the antenna shall be (100 ± 10) mm above the ground plane.

No part of any antenna radiating element shall be closer than 250 mm to the floor. The radiating

elements of the antenna, excluding the rear part of the horn antenna, shall not be closer than 500 mm to

any absorber material.

The distance between the wiring harness and the antenna shall be (1 000 ± 10) mm. This distance is

measured from:
— the phase centre (mid-point) of the biconical antenna; or
— the nearest part of the log-periodic antenna; or
— the nearest part of the horn antenna.
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ISO 11452-2:2019(E)

The phase centre of the antenna for frequencies from 80 MHz to 1 000 MHz shall be in line with the

centre of the longitudinal part (1 500 mm length) of the wiring harness.

The phase centre of the antenna for frequencies above 1 000 MHz shall be in line with the DUT.

Examples of test set-ups are shown in Figures 1 to 3.
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ISO 11452-2:2019(E)
Dimensions in millimetres
Key

1 DUT (grounded locally if required in test plan) 7 low relative permittivity support (ε ≤ 1,4)

2 test harness 8 biconical antenna
3 load simulator (placement and 9 stimulation and monitoring system

ground: connection according to 7.5) 10 high quality double-shielded coaxial cable (50 Ω)

4 power supply (location optional) 11 bulkhead connector
5 artificial network (AN) 12 RF signal generator and amplifier
6 ground plane (bonded to shielded enclosure) 13 RF absorber material
Upper view (horizontal polarisation). 14 ground straps
Front view.
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ISO 11452-2:2019(E)
Side view.
See 7.1
Vertical polarisation.
Figure 1 — Example test set-up — Biconical antenna
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ISO 11452-2:2019(E)
Dimensions in millimetres
Key

1 DUT (grounded locally if required in test plan) 7 low relative permittivity support (ε ≤ 1,4)

2 test harness 8 log-periodic antenna
3 load simulator (placement 9 stimulation and monitoring system

and ground: connection according to 7.5) 10 high quality double-shielded coaxial cable (50 Ω)

4 power supply (location optional) 11 bulkhead connector
5 artificial network (AN) 12 RF signal generator and amplifier
6 ground plane (bonded to shielded enclosure) 13 RF absorber material
Upper view (horizontal polarisation). 14 ground straps
Front view.
Side view.
See 7.1
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ISO 11452-2:2019(E)
Vertical polarisation.
Figure 2 — Example test set-up — Log-periodic-antenna
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ISO 11452-2:2019(E)
Dimensions in millimetres
Key

1 DUT (grounded locally if required in test plan) 7 low relative permittivity support (ε ≤ 1,4)

2 test harness 8 horn antenna
3 load simulator (placement and 9 stimulation and monitoring system

ground: connection according to 7.5) 10 high quality double-shielded coaxial cable (50 Ω)

4 power supply (location optional) 11 bulkhead connector
5 artificial network (AN) 12 RF signal generator and amplifier
6 ground plane (bonded to shielded enclosure) 13 RF absorber material
Upper view (horizontal polarisation). 14 ground straps
Front view.
Side view.
See 7.1
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ISO 11452-2:2019(E)
Vertical polarisation.
Figure 3 — Example test set-up for frequencies above 1 GHz — Horn antenna
8 Test setup for DUT powered by a shielded power system
8.1 Ground plane
The ground plane conditions defined in 7.1 apply.
8.2 Power supply and AN

Each DUT power supply lead shall be connected to the power supply through an HV-AN (for DUT with

DC HV supply) and/or AMN (for DUT with AC supply).

— DC HV supply shall be applied to the DUT via a 5 µH/50 Ω HV AN (see ISO 11452-1:2015, Annex B for

the schematic).

— AC supply shall be applied to the DUT via a 50 µH/50 Ω AMN (see ISO 11452-1:2015, Annex B for the

schematic).

The HV-AN(s) shall be mounted directly on the ground plane. The case or cases of the HV-AN(s) shall be

bonded to the ground plane.
The measuring port of each HV-AN(s) shall be terminated with a 50 Ω load.

The vehicle HV battery should be used; otherwise the external HV power supply shall be connected via

feed-through-filtering.

Shielded supply lines for the positive HV DC terminal line (HV+), the negative HV DC terminal line

(HV-) and three phase HV AC lines may be separate coaxial cables or in a common shield depending on

the connector system used.

The shielded harnesses used for this test shall be representative of the vehicle application in terms of

cable construction and connector termination as defined in the test plan.

Care should be taken when using a power line filter (Key 16) on the HV supply line. This filter will

increase the common mode capacitance between HV+ and ground reference or HV- and ground

reference and could lead to the generation of extra resonances.

For the charger, the AMN(s) shall be mounted on the test facility floor ground plane. The case or cases

of the AMN(s) shall be bonded to the test facility floor ground plane. The charger PE (protective earth)

line shall be bounded to the test set-up ground plane and to the AMN(s) PE connection.

The measuring port of each HV-AN(s) / AMN(s) shall be terminated with a 50 Ω load.

8.3 Location of DUT

Unless otherwise specified, the DUT shall be placed directly on the ground plane with the DUT case

bonded to the ground plane either directly or via defined impedance.

The front of the DUT shall be located at a distance of (200 ± 10) mm from the edge of the ground plane.

In case of a charger, the battery charger case shall be bonded to the ground plane.

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ISO 11452-2:2019(E)
8.4 Location of test harness

Unless otherwise specified in the test plan (e.g. use of original vehicle harnesses), the length of

harnesses shall be as follows:
+300
— (1700 ) mm for the LV lines;
+300

— (1700 )mm for the HV lines and the length of the HV test harness parallel to the front of the

ground plane shall be (1 500 ± 75) mm; and

— less than 1 000 mm for the three phase lines between DUT and electric motor(s).

If the HV test harness is over 2 000 mm, the HV test harness length should be defined in the test plan

and described in the test report.

All of the harnesses shall be placed on a non-conductive, low relative permittivity material (ε ≤ 1,4) at

(50 ± 5) mm above the ground plane.

The detailed layout of the harness on DUT side between the ground plane front edge and the DUT

connector(s) shall be described in the test plan.

The shielded harnesses used for this test shall be representative of the vehicle application in terms of

cable construction and connector termination as defined in the test plan.

The long segment of LV lines test harness shall be located parallel to the edge of the reference ground

plane facin
...