INTERNATIONAL ISO

STANDARD 11452-3
Third edition
2016-09-01

Road vehicles — Component test

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 11452-3:2016(E)

© ISO 2016
ISO 11452-3:2016(E)

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ii © ISO 2016 – All rights reserved

 ISO 11452-3:2016(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 apparatus ......................................................................................................................................................................................................... 2
5.1 TEM cell ......................................................................................................................................................................................................... 2
5.2 Instrumentation ..................................................................................................................................................................................... 3
5.3 Test set-up ................................................................................................................................................................................................... 3
5.3.1 General...................................................................................................................................................................................... 3
5 .3 .2 E xp o s ure o f device under tes t and wiring harnes s ( o r maj o r field f
coupling to the harness) ............................................................................................................................................ 4
5 .3 .3 E xp o s ure o f f
device under tes t alo ne ( o r maj o r field co up ling to that device) .......... 6
6 Test procedure ........................................................................................................................................................................................................ 7
6.1
Test plan ........................................................................................................................................................................................................ 7
Test method ............................................................................................................................................................................................... 7
6.2
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 ............................................................................................................................................. 10
Annex B (informative) Calculations and measurements of TEM-cell frequency range ................................ 12
Annex C (informative) Installation o f external components and low pass filter design .............................. 14
Annex D (informative) Test setup without low pass filters ........................................................................................................ 17
Annex E (informative) Function performance status classification (FPSC) and test
severity levels ....................................................................................................................................................................................................... 20
Bibliography ............................................................................................................................................................................................................................. 21

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ISO 11452-3:2016(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work o f 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 o f
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
di fferent types o f ISO documents should be noted. This document was dra fted 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 o f the elements o f this document may be the subject o f
patent rights. ISO shall not be held responsible for identi fying any or all such patent rights. Details o f
any patent rights identified during the development o f 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 in formation given for the convenience o f users and does not
constitute an endorsement.
For an explanation on the meaning o f ISO specific terms and expressions related to con formity 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.
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 11452-3:2001), which has been
technically revised with the following changes:
— the use of forward power as the levelling parameter to make it consistent with the other ISO 11452
standards has been implemented;
— Annex D for testing of devices without using low pass filters has been included.
A list of all parts in the ISO 11452 series can be found on the ISO website.

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 ISO 11452-3:2016(E)

Introduction
I m mu n ity me as u rements o f comple te ro ad veh icle s are genera l ly ab le to b e c arrie d out on ly b y the

vehicle manufacturer, owing to, for example, high costs of absorber-lined shielded enclosures, the desire
to pre s er ve the s e cre c y o f pro to typ e s or a large nu mb er o f d i fferent veh icle mo del s .

For re s e arch , development and qua l ity control, a lab orator y me as u ri ng me tho d c a n b e u s e d b y b o th

vehicle manufacturers and equipment suppliers to test electronic components.

T he T E M cel l me tho d h as the maj or advantage o f no t rad iati ng energ y i nto the s u rrou nd i ng envi ron ment.

T he me tho d c a n b e u s e d for te s ti ng either the i m mun ity o f a comp onent with the field coupl i ng to the

wi ri ng harne s s or the i m mu n ity o f the comp onent a lone with m i n i mum exp o s u re to the wi ri ng harne s s .

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INTERNATIONAL STANDARD ISO 11452-3:2016(E)

Road vehicles — Component test methods for electrical

disturbances from narrowband radiated electromagnetic
energy —
Part 3:
Transverse electromagnetic (TEM) cell
1 Scope
T h i s do c u ment s p e c i fie s tran s vers e ele c tromagne tic ( T E M ) cel l te s ts for de term i n i ng the i m mun ity

of electronic components of passenger cars and commercial vehicles to electrical disturbances from
f
na rrowb a nd rad iate d ele c tromagne tic energ y, regard le s s o the veh icle propu l s ion s ys tem (e . g. s p a rk-

ignition engine, diesel engine, electric motor).

The electromagnetic disturbances considered are limited to continuous narrowband
e le c tro m a g ne tic fie ld s .

2 Normative references
T he fol lowi ng do c u ments are re ferre d to i n the tex t i n s uch a way th at s ome or a l l o f thei r content

con s titute s re qu i rements o f th i s do c u ment. For date d re ference s , on ly the e d ition cite d appl ie s . For

u ndate d re ference s , the late s t e d ition o f the re ference d do c ument (i nclud i ng a ny amend ments) appl ie s .

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 pu r p o s e s o f th i s do c u ment, the term s and defi nition s given i n I S O 1 145 2 -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 http://www.iso.org/obp
4 Test conditions
T he upp er fre quenc y range l i m it o f the T E M cel l i s a d i re c t fu nc tion o f the T E M cel l d i men s ion s .

For te s ti ng automo tive ele c tronic s ys tem s , a 0 , 01 M H z to 2 0 0 M H z T E M cel l s hou ld b e u s e d . S e e Annex A

for suggested cell dimensions.
T he u s er sh a l l s p e ci fy the te s t s everity level or level s over the fre quenc y range . See Annex E for
s ugge s te d te s t s everity level s .

Standard test conditions shall be those given in ISO 11452-1 for the following:
— test temperature;
— s upply voltage;

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ISO 11452-3:2016(E)

— modulation;
— dwell time;
— fre quenc y s tep s i ze s;

— defi n ition o f te s t s everity level s;

— te s t- s igna l qua l ity.

5 Test apparatus

5.1 TEM cell

T he T E M cel l u s e d for th i s te s t i s a re c tangu lar co a xia l l i ne with a 5 0 Ω charac teri s tic i mp e da nce (s e e

Figure 1 ) . T he device u nder te s t i s e xp o s e d to a un i form T E M field .

T he T E M cel l i s a l ab orator y me a s u rement s ys tem wh ich c a n b e u s e d to generate te s t field s with i n 2 d B

o f the the ore tic a l va lue i f the device u nder te s t do e s no t o cc upy an exce s s ive p or tion o f the te s t volu me

(see 5.3).

Key
1 outer conductor (shield)
2 septum (inner conductor)
3 access door
4 connector panel (optional)
5 coaxial connectors
6 dielectric s up p o rt (relative p ermittivity εr ≤ 1 , 4)

7 device under test

8 input/output leads
Figure 1 — TEM cell

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 ISO 11452-3:2016(E)

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 o f at least 60 dB at frequencies above 1,5 times the cut-o ff frequency
o f the TEM cell may be installed (e.g. 200 MHz TEM cell: 60 dB for frequencies above 300 MHz) to avoid
resonances.

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
5 RF-power meter a Pforward (forward power)
6 peripheral b Preflected (reflected power)
7 device under test c Poutput (output power)
8 dielectric support
F i g u r e 2 — E x a m p l e T E M c e l l c o n fi g u r a t i o n

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
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ISO 11452-3:2016(E)

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 o f 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 o f 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 o f an unshielded harness or printed circuit
board will result in a common mode electrical field coupling and a di fferential 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 εr ≤ 1,4)
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
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 ISO 11452-3:2016(E)

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 te s t wi l l yield repro duc ib le me a s urement re s u lts i f the p o s ition o f the le ad s and the device u nder

te s t i n the T E M cel l a re fi xe d .

Key
1 device under test
2 dielectric s up p o rt (relative p ermittivity εr ≤ 1 , 4)

3 printed circuit board or wiring harness

4 connector
5 coaxial connectors
6 connector panel
7 TEM cell wall
8 cables
NO TE RF fi lters can be con ne c te d to the co a xi a l con ne c tors in the co n ne c tor p a nel o r d i re c tl y to the

connector in the TEM cell wall.

F i g u r e 4 — E x a m p l e t e s t s e t- u p — M a j o r fi e l d c o u p l i n g t o w i r i n g h a r n e s s (t o p v i e w)

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ISO 11452-3:2016(E)

5.3.3 Exposure o f 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 s up p o rt (relative p ermittivity εr ≤ 1 , 4)

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)

T he con ne c tor p anel s hou ld b e attache d to the T E M cel l . T he arra ngement and natu re o f s upply and

signal leads shall be chosen in order to minimize the coupling on these leads, which shall be secured on
the flo or o f the T E M cel l and sh ielde d b e twe en the con ne c tor i n the cel l wa l l and the device u nder te s t.

T h i s ca n b e done by u s i ng me ta l tap e with conduc ti ve ad he s ive to cover the le ad s on the flo or o f the

TEM cell.
T he sh ield s ha l l b e i n ele c tric a l contac t with the cel l flo or, but s ha l l no t b e i n contac t with the ca s e o f the

device under test.

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 ISO 11452-3:2016(E)

6 Test procedure
6.1 Test plan
Prior to performing the test, a test plan shall be generated and which shall cover the following:
— frequency range;
— modulation;
— test set-up to be used (5.3.2 or 5.3.3 or Annex D);
— device under test mode of operation;
— device under test acceptance criteria;
— definition o f test severity levels;
— test signal quality;
— use of net or output power measurements;
— device under test monitoring conditions;
— device under test orientation;
— test report content (see 6.3);
— any special instructions and changes from the standard test.
Each device under test shall be tested under the most significant situations, i.e. at least in stand-by
mode and in a mode where all the actuators can be excited.
6.2 Test method
6.2.1 General
IMPORTANT — The appropriate guidelines (national regulation, ICNIRP, [2][3] etc.) shall be
followed for the protection of the test personnel.
6.2.2 Test level setting
Prior to applying the test field intensity to the DUT and harness, a test field intensity calibration shall be
per formed at all test frequencies with an empty TEM cell. This will determine the test forward power
levels Pforward (test) to be used during the DUT test.
The doors of the TEM cell shall be closed at all times during the measurement.
Unused connectors shall be shielded, so that they do not emit radiation.
At each test frequency with a CW RF signal:
— calculate the net power required to achieve the test electric field intensity using Formula (1);
— apply a given forward power (see Figure 2);
— record the reflected power and calculate the corresponding net power;
— adjust the forward power level until the net power to obtain the required test field intensity is
achieved and record this test forward power level as Pforward (test).

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ISO 11452-3:2016(E)

Z * Pnet
E=
d
(1)
where
E is the value o f the electric field in volts per metre;
Z is the characteristic impedance o f the TEM cell in ohms (typically 50 Ω);
Pnet is the net input power (Pnet = Pforward − Preflected), in watts;
d is the distance, in metres, between the floor and the TEM cell septum (b/2 in Figure A.1).
NOTE The theoretical or supplier data characteristic impedance of the TEM cell can be used in Formula (1).
The test forward power level established during the empty TEM cell field calibration (at the required
test field intensity) will be the levelling parameter used during the DUT test. The test power required to
achieve the test field intensity level shall be maintained at 0/+1 dB o f Pforward (test) during the DUT test.
An electrically small field-measuring device may be used to veri fy the calculated calibration curve for
the field in the uni form field region.

6.2.3 DUT test

Place the DUT and harness inside the TEM cell as shown in Figure 3, Figure 5 or Figure D.1 and
Figure D.2 , depending upon what type of major field coupling (harness or DUT) is desired.
The conductor on the printed circuit board shall be designed to handle the load current. See Annex D
or a test setup without low pass filters.
f

The doors of the TEM cell shall be closed at all times during the measurement.
Unused connectors shall be shielded, so that they do not emit radiation.
Wherever possible, use the actual vehicle loads, sensors and actuators.
Do not ground the device under test to the TEM cell floor unless it is intended that the actual vehicle
configuration be simulated.
Care should be taken not to create ground loops.
The test on the DUT and wiring harness shall be performed using the test level forward power, Ptest,
established during the test field calibration o f 6.2.2.
For AM signals, the peak power conservation principal as defined in ISO 11542-1 shall be used.
Apply the predetermined test field intensity to the DUT at each frequency while monitoring the DUT
for any deviations in operation. I f any responses occur, document the frequency where the deviation
occurs. A response threshold amplitude measurement should be made at each responding frequency to
assist with the evaluation of the test results and DUT performance.
6.3 Test report
As required by the test plan, a test report shall be submitted detailing the following in formation:
— the test equipment;
— the systems tested;
— the frequencies;

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 ISO 11452 -3 :2 016(E)

— the power levels;

— the test modulation;
— the maj or field coupl i ng me tho d u s e d (D U T and/or h arne s s) ;

— the s ys tem i nterac tion s;

— other relevant information regarding the test.

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ISO 11452-3:2016(E)

Annex A
(informative)
TEM cell dimensions

T he d i men s ion s o f a typic a l T E M cel l a re s hown i n Figure A.1 and given in Table A.1.
Dimensions in millimetres

a) Horizontal section view through septum

Figure A.1 (continued)

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 ISO 11452-3:2016(E)

b) Vertical section view

Key
1 allowed working region: 0,33 ; 0,60 w l

2 access door
3 dielectric supports
Figure A.1 — TEM cell

Table A.1 — Typical TEM cell dimensions

Upper frequency Cell form factor TEM cell height Septum width
MHz /
w b /
l w
b
m
s
m
100 1,00 1,00 1,20 1,00
Typic a l for automo tive co mp onent te s ti ng:

200 1,69 0,66 0,56 0,70

1,00 1,00 0,60 0,50
300 1,67 1,00 0,30 0,36
500 1,50 1,00 0,20 0,23

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ISO 11452-3:2016(E)

Annex B
(informative)
Calculations and measurements of TEM-cell frequency range

B.1 General
T he u s e fu l fre quenc y range for e ach T E M cel l and its te s t s e t-up c an b e de term i ne d b y one o f two

me tho d s , u s i ng , for example, a ne twork ana lys er.

B.2 Method 1
Veri fy that, for the whole u s e fu l fre quenc y range at b o th i nputs (o f the emp ty T E M cel l) , the fol lowi ng
requirements are met:
r=
Preflected
Pforward
≤ 0 , 15 or voltage standing wave ratio, VSWR = 11 +− rr ≤ 1 , 35 (B.1)
where
r i s the ab s olute va lue o f the refle c tion co e fficient;

Pre fle c te d i s the refle c te d p ower;

Pforward is the forward power.

B.3 Method 2
Before testing the operative device under test, determine the TEM cell’s resonances with the installed
test set-up and device under test (without electrical connection). In this case, the TEM cell transmission
lo s s i n the u s e fu l fre quenc y ra nge s ha l l b e:

 Preflected Poutput 
a t loss = 10 log  +  ≤ 1 dB (B.2)
 Preflected Pforward 
 Poutput 
a t loss = 10 log   ≤ 1 dB
 Pforward − Preflected 
where
a t loss is the TEM cell transmission loss;
Pre fle c te d i s the refle c te d p ower;

Pforward is the forward power;

Poutput is the power at the TEM cell output.

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 ISO 11452 -3 :2 016(E)

Measurements and results at frequencies at which the requirements [Formula (B.1) or Formula (B.2)]
are not met shall be disregarded, but shall be noted in the test report.
NOTE 1 A TEM cell impedance that does not equal 50 Ω, resulting in an r not equal to zero, leads to a variation
o f the field strength along the TEM cell longitudinal direction. Such variations can be measured over the whole
use ful frequency range in the empty TEM cell. The relative field strength non-uni formity ( D E ) in the
longitudinal direction of the TEM cell can be calculated with Formula (B.3):
E max − E min
∆E = ≈ 2r (B.3)
E0
� �

(typical: ∆ E = 0 , 3 for r = 0 , 15 )

where
E0 is the uni form field strength (without any reflection);
Emax is the maximum value o f a non-uni form field strength;
Emin is the minimum value o f a non-uni form field strength.
NOTE 2 Measurements at the TEM cell resonance frequencies are not allowed, because there is no field
uni formity and no TEM mode (e.g. transmission line coupling instead o f radiated coupling).

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ISO 11452-3:2016(E)

Annex C
(informative)
I n s ta l l a ti o n o f e x te r n a l c o m p o n e n ts a n d l o w p a s s fi l te r d e s i g n

C.1 Connector panel

The wiring in the connector panel between connector (4) and the coaxial connectors (5) shown in
Figure 3 should be done with 50 Ω coaxial cable to trans fer the 50 Ω RF-impedance from the low pass
filters attached to the coaxial connectors in the connector panel to the connector in the TEM cell wall.

C . 2 E x te r n a l c o m p o n e n ts a n d l o w p a s s fi l te r

External components such as sensors, power supply and actuators should be connected to the filter at
the connector panel.
All power and signal leads should be connected via a low pass filter (see Figure C.1) at the connector
panel to the peripheral, to the directly connected parts at the panel or to the vehicle. This minimizes
influences from the external connection, such as type and length o f leads and lead impedances
(peripheral, i f possible with original sensors and loads), and unwanted radio frequency (RF) emissions
into, or out of, the TEM cell.

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 ISO 11452-3:2016(E)

Key
1 device under test (DUT) port
2 s up p ly p o rt

X f requency, M H z

Y minimum attenuation, dB
Figure C.1 — Minimum attenuation and frequency response o f the low pass filter with
schematic circuit diagram (artificial network)

In Figure C.1 , the low p a s s fi lter ’s m i n i mu m attenuation from 1 M H z to 8 0 0 M H z i s s hown . For le ad s

with wante d RF s igna l s i n the T E M cel l u s e fu l fre quenc y ra nge, the low p as s fi lter s ha l l b e de s igne d

i n s uch a way that th i s m i ni mu m attenuation i s on ly e ffe c tive outs ide the RF b a ndwidth o f the device

under test.
T he low p a s s fi lter shou ld b e de s igne d s o th at its i mp e dance (from the s ide o f the device under te s t)

does not change the electric data of the input and output of the device under test. Above the useful
fre quenc y ra nge o f the T E M cel l , the i mp e dance o f the low p as s fi lter sh a l l b e 5 0 Ω .

NOTE The transfer function is measured between the TEM cell input and the connector panel referenced to
a 50 W impedance.

C.3 Design rules for the low pass filter

C.3.1 General
T he m i n i mu m attenuation and fre quenc y re s p on s e o f the low p as s fi lter i s a s shown i n Figure C.1. It
i s ne ce s s a r y to term i nate the device u nder te s t at the T E M cel l wa l l with a wel l- de s igne d low p a s s RF

fi lter i n order to

— l i m it the rad io fre quenc y em i s s ion s i nto the s u rrou nd i ng s p ace,

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ISO 11452-3:2016(E)

— isolate the external peripheral or sensors from the TEM cell RF,
— define the RF load o f the printed circuit board output with the result o f minimized resonances,
— decouple the TEM cell septum and the circuit board from external loads, and
— ensure that the RF filter does not influence the device under test and its external load in the use ful
frequency range.

All of the above can be measured and guaranteed via the transfer function between connector panel
and TEM cell input.
EXAMPLE The trans fer function is the same for connectors terminated by a short circuit and open circuit i f the
RF filter is used. I f the trans fer function is measured without using the RF filter, the results di ffer by up to 30 dB.
It is di fficult to define a schematic circuit diagram for the low pass filter because its design is highly
dependent on the positioning o f the filter elements. It is there fore important to define the three ranges
o f filter responses versus frequency, as follows.
C.3.2 Lower cut-off frequency
It is not necessary to define the attenuation from DC to 0,01 MHz because TEM cell automotive immunity
measurements normally start at 0,01 MHz.
C.3.3 Useful frequency range
The necessary attenuation, aD , o f the RF filter in the use ful frequency range o f the TEM cell can be
calculated with Formula (C.1):
P
a ≥
D
10 × log
PE
RF,max

×a ×n
≈ 3 3 dB (C.1)
,max C ,TE M max

where
PRF,max is the maximum RF power outside the TEM cell, <0,1 W;
PE,max is the TEM cell maximum power input, 200 W;
a C,TEM is the coupling factor of the TEM cell, 0,01;
n max is the number of connected leads, 100.
Since the coupling factor o f the TEM cell decreases strongly for frequencies below 30 MHz, the minimum
attenuation can be lowered, as shown in Figure C.1.
C.3.4 Upper cut-off frequency
Above the TEM cell cut-o ff frequency, only harmonics o f the broadband amplifier with nominal 20 dB
harmonic attenuation occur, so that a reduced filter attenuation o f 20 dB is su fficient.
Since the impedance o f the harness o f the device under test outside the TEM cell lies between 20 Ω and
200 Ω, it is recommended that the high frequency impedance from the DUT side o f the RF filter be 50 Ω.
This compromise will allow the RF filter to be the same as the artificial network defined in CISPR 25 [1]
(100 nF and 50 Ω).

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 ISO 11452-3:2016(E)

Annex D
(informative)
Te s t s e tu p wi th o u t l o w p a s s fi l te r s

D.1 General
In some cases, the number o f wiring harness o f DUT is huge. So, it becomes very hard to use low pass
filters.
This annex presents a test set-up without low pass filters. TEM cell shall be located inside a shielded
enclosure.
D.2 Test set-up
The wiring harnesses from DUT are passed through either the wall or the floor (ceiling) o f the TEM
cell depending on the TEM cell structure. Figure D.1 and Figure D.2 show the example setup of each
test method.
The position of the DUT connector is centre of TEM cell (see Figure D.1 with horizontal harness and
Figure D.2 with vertical harness). In order to obtain reproducible measurement results, the DUT shall
be placed in the same position in the TEM cell for each measurement.
The clearance between the wire harness and the through-hole shall be between 5 mm and b/6. The
ferrite installed to the wiring harness outside o f the TEM cell may reduce the RF radiation from wiring
harness. The networks (AN, AMN and AAN) shall be used at the correct position and mounted directly
on the shielded enclosure (wall or floor). The detailed setup shall be described in the test plan.

Key
1 DUT
2 dielectric support (relative permittivity εr ≤ 1,4)
3 wiring harness (unshielded)
4 connector
5 TEM cell wall
6 septum
7 ferrite (optional)
b TEM cell height
W TEM cell width
a The height of insulating support should be adapted to ensure that the harness is horizontal.
Figure D.1 — Example test set-up — Wire harness location: horizontal (side view)

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ISO 11452-3:2016(E)

Key
1 DUT
2 dielectric s up p o rt (relative p ermittivity εr ≤ 1 , 4)

3 wiring harness (unshielded)

4 Connector
5 TEM cell wall
6 Septum
7 ferrite (optional)
b TEM cell height
W TEM cell width
Figure D.2 — Example test set-up — Wire harness location: vertical (side view)

Figure D.3 — Example of through-hole panel

18 © ISO 2016 – All rights reserved

 ISO 11452-3:2016(E)

Figure D.4 — Example of TEM cell before attaching a through-hole panel

Figure D.5 — Example of test setup with a through-hole panel

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ISO 11452-3:2016(E)

Annex E
(informative)
F u n c ti o n p e r f
o r m a n c e s ta tu s c l a s s i fi c a ti o n ( F P S C ) a n d te s t

severity levels

E.1 General
This annex gives examples o f test severity levels which should be used in line with the principle o f
functional per formance status classification (FPSC) described in ISO 11452-1.

E . 2 C l a s s i fi c a ti o n o f te s t s e ve r i ty l e ve l s

The suggested minimum and maximum severity levels are given in Table E.1.
T a b l e E . 1 — E x a m p l e s o f t e s t s e ve r i t y l e ve l s ( i n t e r n a l fi e l d )

Frequency band Test level I Test level II Test level III Test level IV Test level V
MHz V/m V/m V/m V/m V/m
0,01 to 10 50 80 150 200
10 to 30 50 80 150 180 Specific value agreed
between the users of
30 to 80 60 100 120 180 this document
80 to 200 60 100 120 200

E.3 Example of FPSC application using test severity levels

Each DUT and its function(s) need to be evaluated prior to test. The category o f the DUT function(s), test
severity level(s) and response criteria should then be agreed upon between the supplier and the vehicle
manufacturer. This information should be documented in the test plan and used for the determination
of DUT acceptance upon completion of the testing and evaluation of the test results.
An example o f severity levels is given in Table E.2.

Table E.2 — Examples of test severity levels

Test severity DUT function DUT function DUT function DUT function
level Category 1 Category 2 Category 3 Category 4
L 4i Level IV — — —
L3i Level III Level IV — —
L2i Level II Level III Level IV —
L1i Level I Level II Level III Level IV

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 ISO 11452-3:2016(E)

Bibliography

[1] CISPR 25, Limits and methods of measurement of radio disturbance characteristics for the
protection of receivers used on board vehicle

[2 ] Guidel i ne s for L i m iti ng E xp o s u re to Ti me -Va r yi ng E le c tric, M agne tic, and E le c tromagne tic

Fields (up to 300 GHz). Health Phys. 1998, 74 (4) pp. 494–522
[3 ] Guidel i ne s for l i m iti ng e xp o s ure to ti me -var yi ng ele c tric and magne tic field s (1 H z to 10 0 kH z) .

Health Physics . 2010, 99 (6) pp. 818-836

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ISO 11452 -3 :2 016(E)

ICS 33.100.20; 43.040.10

Price based on 21 pages
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