ISO 11452-3:2024

Road vehicles - Component test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 3: Transverse electromagnetic (TEM) cell

This document specifies transverse electromagnetic (TEM) cell tests for determining the immunity of electronic components of passenger cars and commercial vehicles to electrical disturbances from narrowband radiated electromagnetic energy, regardless of the vehicle propulsion system (e.g. spark-ignition engine, diesel engine, electric motor). The electromagnetic disturbances considered are limited to continuous narrowband electromagnetic fields.

Véhicules routiers — Méthodes d'essai d'un équipement soumis à des perturbations électriques par rayonnement d'énergie électromagnétique en bande étroite — Partie 3: Cellule électromagnétique transverse (TEM)

General Information

• Status: Published
• Publication Date: 27-May-2024
• 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 - Electrical and electronic components and general system aspects
• Current Stage: 6060 - International Standard published
• Start Date: 28-May-2024
• Due Date: 25-Jul-2025
• Completion Date: 28-May-2024

Relations

• Revises: ISO 11452-3:2016 - Road vehicles - Component test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 3: Transverse electromagnetic (TEM) cell
• Effective Date: 29-Jul-2023

Overview

ISO 11452-3:2024 - "Road vehicles - Component test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 3: Transverse electromagnetic (TEM) cell" - specifies laboratory test methods using a TEM cell to determine the electromagnetic immunity of automotive electronic components to continuous, narrowband radiated fields. Applicable to passenger cars and commercial vehicles regardless of propulsion (ICE, diesel, hybrid, electric), this fourth edition updates the established ISO 11452 series and is intended for R&D, quality control, and pre‑compliance/component qualification.

Key topics and technical requirements

• Test method: Use of a rectangular TEM cell (50 Ω characteristic impedance) to expose a device under test (DUT) to a uniform TEM field without radiating into the surrounding environment.
• Frequency range: Recommended TEM cell for automotive components: 0.01 MHz to 200 MHz (cell upper limit depends on dimensions - see Annex A and B).
• DUT constraints and placement:
  • DUT shall not exceed one‑sixth of the TEM cell internal height to maintain field homogeneity.
  • DUT positioned centrally on a dielectric support (relative permittivity εr ≤ 1.4).
• Test set‑ups:
  • Exposure with wiring harness (major coupling to harness) or
  • Exposure of DUT alone (major coupling to DUT).
• Instrumentation and equipment: signal generator, broadband amplifier, dual‑directional coupler, RF power meter, controller, and optional low‑pass filters or connector panels (see Annex C).
• Low‑pass filter guidance: If used, filters should provide ≥ 60 dB attenuation above 1.5 × TEM‑cell cut‑off frequency to avoid resonances.
• Test planning and procedure: Define frequency range, modulation, severity levels, DUT operating modes, orientation, monitoring and acceptance criteria, and reporting requirements (see Clause 6 and Annex E for severity and function performance status classification).
• Informative annexes: TEM cell dimensions, frequency range calculations, filter installation, alternative setups without filters, and severity level guidance.

Practical applications and users

Who uses ISO 11452-3:2024:

• Automotive OEMs and module suppliers (ECUs, sensors, infotainment, power electronics)
• EMC test laboratories and third‑party compliance labs
• R&D and quality engineers performing component-level immunity testing and pre‑compliance validation Practical uses:
• Component immunity characterization to narrowband radiated fields
• Design validation of wiring harnesses, PCB layouts and shielding strategies
• Pre‑qualification of ECUs and subsystems before full vehicle testing

Related standards

• ISO 11452-1: General principles and terminology for component tests against narrowband radiated electromagnetic energy
• Other parts of the ISO 11452 series for complementary component‑level EMC methods

Keywords: ISO 11452-3:2024, TEM cell, transverse electromagnetic cell, automotive EMC testing, component immunity, narrowband radiated electromagnetic energy, vehicle electronic components, test severity levels, low pass filter.

Standards Content (Sample)

International
Standard
ISO 11452-3
Fourth edition
Road vehicles — Component test
2024-05
methods for electrical disturbances
from narrowband radiated
electromagnetic energy —
Part 3:
Transverse electromagnetic
(TEM) cell
Véhicules routiers — Méthodes d'essai d'un équipement soumis
à des perturbations électriques par rayonnement d'énergie
électromagnétique en bande étroite —
Partie 3: Cellule électromagnétique transverse (TEM)
Reference number
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test conditions . 1
5 Test apparatus . 2
5.1 TEM cell.2
5.2 Instrumentation .3
5.3 Test set-up .4
5.3.1 General .4
5.3.2 Exposure of device under test and wiring harness (for major field coupling to
the harness) .4
5.3.3 Exposure of device under test alone (for major field coupling to that device) .5
6 Test procedure . 6
6.1 Test plan .6
6.2 Test method .7
6.2.1 General .7
6.2.2 Test level setting .7
6.2.3 DUT test .8
6.3 Test report .8
Annex A (informative) TEM cell dimensions . 9
Annex B (informative) Calculations and measurements of TEM-cell frequency range .11
Annex C (informative) Installation of external components and low pass filter design .13
Annex D (informative) Test setup without low pass filters .16
Annex E (informative) Function performance status classification (FPSC) and test severity
levels .20
Bibliography .21

iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 32,
Electrical and electronic components and general system aspects.
This fourth edition cancels and replaces the third edition (ISO 11452-3:2016), of which it constitutes a minor
revision. The changes are as follows:
— Formula (1) in 6.2.2 was modified.
A list of all parts in the ISO 11452 series can be found on the ISO website.
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
Introduction
Immunity measurements of complete road 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.
For research, development and quality control, a laboratory measuring method can be used by both vehicle
manufacturers and equipment suppliers to test electronic components.
The TEM cell method has the major advantage of not radiating energy into the surrounding environment.
The method can be used for testing either the immunity of a component with the field coupling to the wiring
harness or the immunity of the component alone with minimum exposure to the wiring harness.

v
International Standard ISO 11452-3:2024(en)
Road vehicles — Component test methods for electrical
disturbances from narrowband radiated electromagnetic
energy —
Part 3:
Transverse electromagnetic (TEM) cell
1 Scope
This document specifies transverse electromagnetic (TEM) cell tests for determining the immunity
of electronic components of passenger cars and commercial vehicles to electrical disturbances from
narrowband radiated electromagnetic energy, regardless of the vehicle propulsion system (e.g. spark-
ignition engine, diesel engine, electric motor).
The electromagnetic disturbances considered are limited to continuous narrowband electromagnetic fields.
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, 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 terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Test conditions
The upper frequency range limit of the TEM cell is a direct function of the TEM cell dimensions.
For testing automotive electronic systems, a 0,01 MHz to 200 MHz TEM cell should be used. See Annex A for
suggested cell dimensions. See Annex B for methods to determine TEM-cell frequency range.
The user shall specify the test severity level or levels over the frequency range. See Annex E for suggested
test severity levels.
Standard test conditions shall be those given in ISO 11452-1 for:
— test temperature;
— supply voltage;
— modulation;
— dwell time;
— frequency step sizes;
— definition of test severity levels;
— test-signal quality.
5 Test apparatus
5.1 TEM cell
The TEM cell used for this test is a rectangular coaxial line with a 50 Ω characteristic impedance (see
Figure 1). The device under test is exposed to a uniform TEM field.
The TEM cell is a laboratory measurement system which can be used to generate test fields within 2 dB of the
theoretical value if the device under test does not occupy an excessive portion of the test volume (see 5.3).
Key
1 outer conductor (shield)
2 septum (inner conductor)
3 access door
4 connector panel (optional)
5 coaxial connectors
6 dielectric support (relative permittivity ε ≤ 1,4)
r
7 device under test
8 input/output leads
Figure 1 — TEM cell
5.2 Instrumentation
Figure 2 shows an example of a TEM cell test set-up. The TEM cell has high resonances in the region greater
than the recommended upper frequency limit.
A low pass filter with an attenuation of at least 60 dB at frequencies above 1,5 times the cut-off frequency
of the TEM cell may be installed (e.g. 200 MHz TEM cell: 60 dB for frequencies above 300 MHz) to avoid
resonances.
Example of installation of low pass filter is given in Annex C.
Key
1 signal generator 9 low pass filters/connector panel
2 broadband amplifier 10 coupler
3 low pass filter (optional) 11 high power load (50 Ω)
4 dual-directional coupler (30 dB decoupling ratio 12 controller
minimum) 13 TEM cell
a
5 RF-power meter P (forward power).
forward
b
6 peripheral P (reflected power).
reflected
c
7 device under test P (output power).
output
8 dielectric support
Figure 2 — Example TEM cell configuration

5.3 Test set-up
5.3.1 General
In order to maintain the homogeneous field in the TEM cell and obtain reproducible measurement results, the
device under test shall be no larger than one-sixth of the cell (inside) height b (see Figure 3 and Figure A.1).
The device under test should be placed in the centre of the cell on a dielectric equipment support.
The device under test and the wiring harness may be positioned in either of two arrangements, depending
on whether the exposure of the device under test and the wiring harness (see 5.3.2) or that of the device
alone (see 5.3.3) is being tested.
An alternative test set-up without low pass filter is presented in Annex D.
5.3.2 Exposure of device under test and wiring harness (for major field coupling to the harness)
The height of the dielectric support is one-sixth of cell height b (see Figure 3). In order to obtain reproducible
measurement results, the device under test, together with its wiring harness or printed circuit board, shall
be placed in the same position in the TEM cell for each measurement. In addition to the direct RF-field
coupling to the device under test, the use of an unshielded harness or printed circuit board will result in a
common mode electrical field coupling and a differential mode magnetic field coupling, depending on the
inclination and the width of the harness or circuit board.
Key
1 device under test
2 dielectric support (relative permittivity ε ≤ 1,4)
r
3 printed circuit board (no ground plane) or wiring harness, unshielded
4 connector
5 coaxial connectors
6 connector panel
7 TEM cell wall
8 cables
9 septum
b TEM cell height (see Annex A)
Figure 3 — Example test set-up — Major field coupling to wiring harness (side view)

The connector panel should be attached to the TEM cell as close as possible to the printed lead system. The
supply and signal leads from the connector in the cell wall are directly connected to the device under test,
using either a printed circuit board of length suitable for positioning the device under test in the allowed
working region of the TEM cell, or a set of leads secured to a rigid support (see Figure 3 and Figure 4). The
printed circuit board or supported wiring harness between the connector and the device under test will
yield reproducible measurement results if the position of the leads and the device under test in the TEM cell
are fixed.
Key
1 device under test
2 dielectric support (relative permittivity ε ≤ 1,4)
r
3 printed circuit board or wiring harness
4 connector
5 coaxial connectors
6 connector panel
7 TEM cell wall
8 cables
NOTE RF filters can be connected to the coaxial connectors in the connector panel or directly to the connector in
the TEM cell wall.
Figure 4 — Example test set-up — Major field coupling to wiring harness (top view)
5.3.3 Exposure of device under test alone (for major field coupling to that device)
The height of the dielectric support is b/6 mm (see Figure 5). In order to obtain reproducible measurement
results, the device under test shall be placed in the same position in the TEM cell for each measurement.

Dimensions in millimetres
Key
1 device under test
2 dielectric support (relative permittivity ε ≤ 1,4)
r
3 shielded wiring harness
4 connector
5 coaxial connectors
6 connector panel
7 TEM cell wall
8 cables
9 septum
b TEM cell height (see Annex A)
Figure 5 — Example test set-up — Major field coupling to device under test (side view)
The connector panel should be attached to the TEM cell. The arrangement and nature of supply and signal
leads shall be chosen in order to minimize the coupling on these leads, which shall be secured
...