ETSI TS 103 941 V1.1.1 (2024-01)

TECHNICAL SPECIFICATION
Short Range Devices (SRD) and Ultra Wide Band (UWB);
Measurement setups and specifications
for testing under full environmental profile
(normal and extreme environmental conditions)

2 ETSI TS 103 941 V1.1.1 (2024-01)

Reference
DTS/ERM-TGUWB-620
Keywords
environment, measurement, radio measurement,
SRD, UWB
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ETSI
3 ETSI TS 103 941 V1.1.1 (2024-01)
Contents
Intellectual Property Rights . 6
Foreword . 6
Modal verbs terminology . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definition of terms, symbols and abbreviations . 8
3.1 Terms . 8
3.2 Symbols . 8
3.3 Abbreviations . 9
4 Radiated environmental profile measurements . 10
4.1 Background . 10
4.2 State of the art of radiated measurements over environmental profile . 11
4.3 Possibilities to measure over environmental profile . 11
4.3.1 General . 11
4.3.2 Temperature chamber . 13
4.3.3 Radio transparent dome . 13
4.3.3.1 General . 13
4.3.3.2 Performance . 14
4.4 Procedure for Tests at Extreme Temperatures. 15
4.5 Test Conditions, Power Supply and Ambient Temperatures . 15
4.5.1 General . 15
4.5.2 Power Sources . 16
4.5.2.1 Power Sources for Stand-Alone Equipment . 16
4.5.2.2 Power sources for plug-in radio devices . 16
4.5.3 Normal and Extreme Test Conditions . 16
4.5.3.1 Normal Test Conditions . 16
4.5.3.1.1 Normal Temperature and Humidity. 16
4.5.3.1.2 Normal Power Source . 17
4.5.3.2 Extreme Conditions . 17
4.5.3.2.1 Extreme Temperatures . 17
4.5.3.2.2 Extreme Test Source Voltages . 17
4.5.4 Complete environmental profile test conditions and procedure in general . 18
5 Test solutions for TX-behaviour under environmental profile . 20
5.1 General . 20
5.2 Assessment within temperature chamber . 21
5.2.1 General considerations for radiated test set-up and EUT inside a temperature chamber . 21
5.2.2 In Detail: radiated set-up with radio transparent part of the temperature chamber . 22
5.2.2.1 Set-up Description . 22
5.2.2.2 Justification of the impact on the radio emissions in the set-up . 23
5.2.3 In Detail: radiated with measurement antenna inside the temperature chamber . 23
5.2.3.1 Set-up Description . 23
5.2.3.2 Justification of the impact on the radio emissions in the set-up . 24
5.2.4 In Detail: connected if EUT has permanent antenna connector (inside the temperature chamber) . 24
5.2.4.1 Set-up Description . 24
5.2.4.2 Justification of the impact on the emissions in the set-up . 25
5.2.5 In Detail: with absorbing box inside a temperature chamber . 25
5.2.5.1 Set-up Description . 25
5.2.5.2 Justification of the impact on the emissions in the set-up . 26
5.3 (Semi-) anechoic chamber and transparent dome . 26
5.4 Considering's for settings of the measurement receiver . 27
6 Assessment procedures over environmental profile . 27
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4 ETSI TS 103 941 V1.1.1 (2024-01)
6.1 General on assessment procedures . 27
6.2 Assessment of the radiated power (Mean e.i.r.p. or Peak e.i.r.p.) . 28
6.2.1 Procedural steps . 28
6.2.1.1 Step 1: EUT OFR and regulated TX requirements . 28
6.2.1.2 Step 2: Assessment absolute measurement . 28
6.2.1.3 Step 3: Test set-up TX-behaviour environmental profile . 28
6.2.1.4 Step 4: Relative reference measurement at normal conditions . 29
6.2.1.5 Step 5: Calculate an adjusted limit for the TX-behaviour testing under environmental profile . 29
6.2.1.6 Step 6: Relative measurement over environmental profile . 29
6.2.1.7 Step 7: Assessment procedure . 29
6.2.2 Overview on recorded values (measured/calculated) . 30
6.3 Assessment of the radiated power (Mean e.i.r.p. or Peak e.i.r.p.) and frequencies within the permitted
range . 30
6.3.1 Procedural steps . 30
6.3.1.1 Step 1: EUT OFR and regulated TX requirements . 30
6.3.1.2 Step 2: Assessment absolute measurement . 31
6.3.1.3 Step 3: Test set-up TX-behaviour environmental profile . 31
6.3.1.4 Step 4: Relative reference measurement at normal conditions . 31
6.3.1.5 Step 5: Calculate an adjusted limit for the TX-behaviour testing under environmental profile . 31
6.3.1.6 Step 6: Relative measurement over environmental profile . 32
6.3.1.7 Step 7: Assessment procedure . 32
6.3.2 Overview on recorded values (measured/calculated) . 33
6.4 Full assessment over OFR & Mean e.i.r.p. Spectral Density . 34
6.4.1 Procedural steps . 34
6.4.1.1 Step 1: EUT OFR and regulated TX requirements . 34
6.4.1.2 Step 2: Assessment absolute measurement . 34
6.4.1.3 Step 3: Test set-up TX-behaviour environmental profile . 35
6.4.1.4 Step 4: Relative reference measurement at normal conditions . 35
6.4.1.5 Step 5: Calculate an adjusted limit for the TX-behaviour testing under environmental profile . 36
6.4.1.6 Step 6: Measurement on one environmental profile point . 37
6.4.1.7 Step 7: Assessment procedure . 37
6.4.2 Overview on recorded values (measured/calculated) . 39
6.5 Assessment over OFR and based on Mean e.i.r.p. Spectral Density . 39
6.5.1 Procedural steps . 39
6.5.1.1 Step 1: Assessment mean e.i.r.p. power spectral density measurement . 39
6.5.1.2 Step 2: Test set-up TX-behaviour environmental profile . 40
6.5.1.3 Step 3: Relative reference measurement . 41
6.5.1.4 Step 4: Measurement on one environmental profile point . 41
6.5.1.5 Step 5: next environmental profile point . 42
6.5.1.6 Step 6: Calculate changes of the emission over the environmental profile . 42
6.5.1.7 Step 7: Assess the changes over specified profile . 43
6.5.1.8 Step 8: Adjust emission levels for the TX-behaviour testing under environmental profile . 43
6.5.1.9 Step 9: Assess absolute emission measurement in in relation to the adjusted UWB emission mask . 45
6.5.2 Overview on recorded values (measured/calculated) . 46
7 Assessment of power (Mean e.i.r.p. or Peak e.i.r.p.) requirement and frequencies within the
permitted range based on a conducted set-up . 47
7.1 General . 47
7.2 Detailed description of the procedure . 47
7.2.1 Step 1: EUT OFR and regulated TX requirements . 47
7.2.2  Step 2: Assessment the reference measurement. 47
7.2.3 Step 3: Test set-up TX-behaviour environmental profile . 48
7.2.4 Step 4: Absolute measurement over environmental profile . 48
7.2.5 Step 5: Assessment procedure . 48
Annex A (informative): Additional information for materials used in environmental test set-
ups . 50
A.1 General . 50
A.2 Radio Transparent Material . 50
A.3 Absorbing Material. 50
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5 ETSI TS 103 941 V1.1.1 (2024-01)
A.4 Radio Transparent Material . 51
A.4.1 Procedure to measure the attenuation . 51
Annex B (informative): Measurements on TX-behaviour testing under the environmental
profile as specified in the present document . 53
B.1 General . 53
B.2 Measurement based on LPR and TLPR devices . 53
B.2.1 Introduction . 53
B.2.2 Used EUT and measurement antennas . 53
B.2.2.1 EUT antenna: ¾" horn antenna with screw-in thread . 53
B.2.2.2 EUT antenna: 3" plastic horn antenna . 54
B.2.2.3 Measurement antenna: Standard Gain Horn (SGH) . 54
B.2.2.4 Nearfield - Far field consideration . 54
B.2.3 Test set-up and Measurements . 55
B.2.3.1 General . 55
B.2.3.2 EUT with antenna connector . 55
B.2.3.3 EUT with (integral) antenna . 56
B.2.4 Measurement Results . 58
B.2.4.1 EUT with antenna connector: conducted measurement . 58
B.2.4.2 EUT with ¾" horn antenna with screw-in thread . 63
B.2.4.3 EUT with 3" plastic horn antenna . 67
B.2.5 Summary and Conclusion . 70
B.2.5.1 Summary . 70
B.2.5.2 Conclusions. 71
B.3 Measurement based on a UWB wall scanning device . 71
B.3.1 Introduction . 71
B.3.2 Used EUT and measurement antennas . 71
B.3.3 Test set-up and Measurements . 71
B.3.4 Measurement Results and Assessment . 74
B.3.4.1 Assess f of the indirect emissions mean power e.i.r.p. spectral density . 74
max
B.3.4.2 Measurement results and assessment . 74
B.3.4.3 Final assessment for TX-behaviour based on procedure in clause 6.3 . 77
B.3.5 Summary and Conclusion . 77
B.4 Assessment and Justification Absorbing Box . 77
B.4.1 Guidance to create an absorbing box . 77
B.4.2 Guidance to justify the performance of the absorbing box . 80
B.4.2.1 General . 80
B.4.2.2 Absorbing Box and used measurement antenna . 80
B.4.2.3 Impact absorbing box on EUT emission . 82
B.4.2.4 Scalar link budget measurement within box over temperature profile . 83
B.5 Measurement based on a UWB tracking tag . 86
Annex C (informative): Change history . 93
History . 94

ETSI
6 ETSI TS 103 941 V1.1.1 (2024-01)
Intellectual Property Rights
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ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the
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Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Electromagnetic compatibility and
Radio spectrum Matters (ERM).
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI
7 ETSI TS 103 941 V1.1.1 (2024-01)
1 Scope
The purpose of the present document is to explain and to provide a justification for an additional (radiated or conducted)
test (procedure and test sept up arrangement) for devices and applications under the complete (normal and extreme)
conditions of the environmental profile. This requirement is proposed to name as "TX behaviour under extreme
environmental profile conditions".
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or non-
specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
Not applicable.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or non-
specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long-term validity.
The following referenced documents are not necessary for the application of the present document, but they assist the
user with regard to a particular subject area.
[i.1] ETSI TS 103 789 (V1.1.1): "Short Range Devices (SRD) and Ultra Wide Band (UWB); Radar
related parameters and physical test setup for object detection, identification and RCS
measurement".
[i.2] IEC 60068-3-5:2018: "Environmental testing - Part 3-5: Supporting documentation and guidance -
Confirmation of the performance of temperature chambers".
[i.3] ETSI TS 102 321 (V1.1.1): "Electromagnetic compatibility and Radio spectrum Matters (ERM);
Normalized Site Attenuation (NSA) and validation of a fully lined anechoic chamber up to
40 GHz".
[i.4] R&S ATS-TEMO: "Temperature Option for R&S ATS 1000", order no. 1533.8147.02.
[i.5] EDN: "Near field or far field" C. Capps, August 16, 2001, pp. 95-102.
[i.6] Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014 on the
harmonisation of the laws of the Member States relating to the making available on the market of
radio equipment and repealing Directive 1999/5/EC (RED).
[i.7] Günter Pfeifer and Benoit Derat: "Optimized Air Flow and Thermally Efficient Test System
Enables 3D OTA Measurements Over Temperature", Microwave Journal, January 2023. ®
[i.8] R&S ATS1800C compact 3GPP compliant ota chamber for 5g nr mmwave signals.
ETSI
8 ETSI TS 103 941 V1.1.1 (2024-01)
[i.9] ETSI EN 302 065-4-1 (V2.1.0): "Short Range Devices (SRD) using Ultra Wide Band technology
(UWB); Harmonised Standard for access to radio spectrum; Part 4: Material Sensing devices;
Sub-part 1: Building material analysis below 10,6 GHz".
[i.10] ETSI EN 302 065-2 (V2.1.1): "Short Range Devices (SRD) using Ultra Wide Band technology
(UWB); Harmonised Standard covering the essential requirements of article 3.2 of the Directive
2014/53/EU; Part 2: Requirements for UWB location tracking".
[i.11] IEC 60068-2-1:2007: "Environmental testing - Part 2-1: Tests - Test A: Cold".
[i.12] IEC 60068-2-2:2007: "Environmental testing - Part 2-2: Tests - Test B: Dry heat".
[i.13] ETSI EN 302 729 (V2.1.1): "Short Range Devices (SRD); Level Probing Radar (LPR) equipment
operating in the frequency ranges 6 GHz to 8,5 GHz, 24,05 GHz to 26,5 GHz, 57 GHz to 64 GHz,
75 GHz to 85 GHz; Harmonised Standard covering the essential requirements of article 3.2 of the
Directive 2014/53/EU".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
absolute measurement: values of a requirement as measured with an instrument within a calibrated test set-up
NOTE: The measurement can be reproduced irrespective of the laboratory or instrument manufacturer.
environmental profile point (Tstep): measurement requirement (e.g. temperature, voltage) under the specified
environmental profile to assess the TX behaviour at this point
relative measurement: measurement of changes/behaviour of values compared to a reference value
NOTE: The measurement of the behaviour can be reproduced irrespective of the laboratory or instrument
manufacturer but there is no possibility to provide information of the absolute measurement result over
laboratories or instruments.
temporary antenna connector: EUT hardware design provide connector mounting option (e.g. landing pads on PCB)
NOTE: The connector is either a standardized coaxial or a hollow waveguide connector and the necessary
information how to install the connector should be in the technical documentation of the EUT.
3.2 Symbols
For the purposes of the present document, the following symbols apply:
°C Celsius
λ wavelength
Adjusted_RL adjusted regulated limit to assess TX-behaviour on each environmental profile point
Adjusted_RL adjusted regulated limit to assess TX-behaviour on each environmental profile point and for each
SX
range of the UWB emission which is overlapping with the OFR
c the velocity of light [m/s]
CON max emission assessed in the "connected" measurement
abs
d Measurement distance (distance between EUT and measurement antenna)
d thickness material
m
D aperture size (the maximum dimension of the antenna orthogonal to the direction of propagation)
ap
deg degree [°C]
dB decibel
dBi gain in decibels relative to an isotropic antenna
dBm gain in decibels relative to one milliwatt
DELTA difference between RL and NORM
power abs
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9 ETSI TS 103 941 V1.1.1 (2024-01)
DELTA difference between the high frequency of the OFR to the upper edge of the permitted frequency
fH
range
difference between the low frequency of the OFR to the lower edge of the permitted frequency
DELTAfL
range
DELTASX difference between RLSX and NORMSX
di measurement direction in polar coordinates in relation to the EUT
φ,θ
f lowest frequency of the EUT OFR
L
f higher edge of the OFR within the absolute measurement under normal conditions
H_abs
f higher edge of the OFR within the relative measurement under normal conditions
H_REF
f higher edge of the OFR within the relative measurement at one environmental profile point
H_step
f lower edge of the OFR within the absolute measurement under normal conditions
L,abs
f lower edge of the OFR within the relative measurement under normal conditions
L_REF
f lower edge of the OFR within the relative measurement at one environmental profile point
L_step
f higher edge of the regulated permitted frequency range
PER_H
lower edge of the regulated permitted frequency range
fPER_L
g gain of the antenna under test in main beam direction in the respective plane [dBi]
AEUT
K kelvin
NOTE: The numerical value of a temperature difference is the same for kelvin and Celsius (°C).
NORM max emission assessed in the "absolute" measurement
abs
NORM max emission assessed in the "absolute" measurement for each range of the UWB emission which
SX
is overlapping with the OFR
P measured emission level (at each environmental profile point)
step
REF measured relative reference
power
REF measured relative reference for each range of the UWB emission which is overlapping with the
SX
OFR
REF measured relative reference for f
fL L
REF measured relative reference for f
fH H
RL regulated limit
RL regulated limit for each range of the UWB emission which is overlapping with the OFR
SX
t lowest value of the environmental profile
low
t highest value of the environmental profile
high
t steps in deg [°C or kelvin] from one to the next environmental profile point
steps
environmental profile point
Tstep
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
CATR Compact Antenna Test Ranges
d measurement distance
DFF Direct Far Field
DoC Declaration of Conformity
DRH Double Ridged Horn
e.i.r.p. equivalent isotopically radiated power
NOTE: Based on kind of power, e.g. mean power, peak power or mean power spectral density.
EUT Equipment Under Test
FMCW Frequency Modulated Continuous Wave
HF high frequency
HS Harmonised Standard
LNA low noise amplifier
LPR Level Probing Radar
MU measurement uncertainty
OFR Operating Frequency Range
OTA far-field Over-The-Air
PCB Printed Circuit Board
PSD power spectral density
QZ Quiet Zone
RBW Resolution bandwidth
ETSI
10 ETSI TS 103 941 V1.1.1 (2024-01)
RCS Radar Cross Section
RL Regulated Limit
RMS Root Mean Square
RX Receiver
SGH Standard Gain Horn
SX Index for a frequency segment for the assessment
TC Technical Committee
TG Task Group
TLPR Tank Level Probing Radar
TR Technical Report
TX Transmitter
UWB Ultra Wide Band
VBW Video Bandwidth
VSWR Voltage standing Wave Ratio
4 Radiated environmental profile measurements
4.1 Background
Requirements of radio equipment according to article 3.2 of the RED [i.6] are clearly to be compliant under all
circumstances, including the environmental conditions.
However, radiated conformance tests to demonstrate compliance against a requirement are mostly not possible to
execute under all circumstances/environmental conditions:
• Not possible to adjust temperature and humidity in a common standard test site (fully anechoic chamber, semi
anechoic chamber, open area test site) as such chambers are not available in the market. This would lead to
immense/unrealistic costs and used for extreme environmental tests, this would lead to damages at the site
itself.
• Small climate chambers are available in the market, but calibrated, radiated measurements are not possible
applying such.
• Measurements over the complete environmental profile is possible for equipment with permanent antenna
connector (tests within a temperature chamber) but challenging for equipment with integral antennas without
antenna connector (and where no provision is made in the EUT design for a temporary antenna connector, e.g.
connector landing pads).
There is discussion ongoing in ETSI on how much effort in harmonised standards is needed to demonstrate, that the
requirements are fulfilled over the entire environmental profile.
The current common understanding in ETSI is the following:
• A HS should define the environmental profile, if possible.
• If a HS cannot define the environmental profile (e.g. scope too broad, too many different profiles, only
manufacturer knows the profile, too many different markets), then the declaration for the tests is possible, but
the data needs to be objectively verifiable (e.g. within the EUT manual or DoC).
• Tests for specified requirements in the related standards shall be made under normal environmental conditions
(e.g. within 20 °C to 25 °C).
• For equipment with integral antenna a HS should specify one or two requirements (e.g. radiated power or
frequency stability) relative to measurements in a climate chamber over the complete profile (e.g. using test
fixture, temperature chamber with radio transparent window) to give some confidence. The
connection/calibration of relative measurement with absolute measurement should be made at normal
temperature.
ETSI
11 ETSI TS 103 941 V1.1.1 (2024-01)
NOTE: The risk assessment of the manufacturer may be able to fill the gap which the limited radiated
conformance measurements have left, e.g. by providing simulation results and calculations, and/or by
making relative conducted measurements (using a temporary connection if necessary for internal antenna
equipment), over the complete profile.
4.2 State of the art of radiated measurements over
environmental profile
Today widespread available are (semi-) anechoic-chambers which do not provide a temperature-chamber function and
o
are typically used at ambient environmental conditions of +5/+10 °C to +35/+40 C and 30 % to 60 %/70 % humidity.
Such solutions are state of the art for radiated emission tests.
The following technical reasons, why it is difficult for a typical a (semi-) anechoic chamber, to execute radiated tests
over a complete environmental profile (extreme conditions):
• Huge energy consumption, costs and time to heat up and cool down the chamber space (considering thermal
balance).
• Large temperature changes could lead to condensation of water and water (behind absorbers) could lead to
gridiron (steel parts) and could form verdigris (at copper) which would lead to deterioration of the shielding
parts and the bonding of the absorbers will be reduced.
• In addition, temperature changes would also lead to expansion of the shielding structure causing changes that
would create leakage problems and could create gaps between ferrite tiles.
• The temperature changes could also "destroy the fitting of the absorbers and this could lead to absorber
damages (falling down).
• Absorbing material (attenuation) is only specified for a limited range of temperature and humidity, e.g. +5 °C
to +90 °C and 30 % to 60 %/70 % for humidity, more information are provided in clause Annex A.
• All this possible changes in shielding and absorption parameter could lead to a higher maintenance effort and
additional certification measures of the (semi-) anechoic chambers (worst case: re-certification).
• In addition, the specified environmental behaviour of "supporting structure", measurement equipment and
"turntable/positioner" inside the (semi-) anechoic chambers could limit the possible operational temperature
range for the testing as well.
4.3 Possibilities to measure over environmental profile
4.3.1 General
Tx parameters of EUTs shall be tested with regard to the ambient condition's temperature and supply voltage. For this
purpose, the ambient temperature of the EUTs shall be changed via temperature chambers, for example.
The chamber size for temperature tests shall be selected depending on the size of the EUT, its frequency range and
whether the EUT has an antenna connector or not.
A further distinction is made here as to whether the EUT's antenna is connected via a standardized antenna connector or
whether the antenna is an integral part of the EUT.
If EUTs have a detachable antenna, the signal from the EUT can be fed out of the temperature chamber and to the
measurement receiver via its permanent antenna connector using a cable. This is also possible if the antenna is not
detachable, but a temporary antenna connector is provided in the EUT design (landing pads).
For EUTs with integral antennas three possibilities to measure the Tx parameters are available.
Test equipment manufacturers are working on solutions of radiated temperature tests, such as a radio transparent dome
which covers a temperature-controlled volume (clause 4.3.3). Such test sides are under development and a few solutions
are already available on the market. With these systems, depending on availability, the entire measurements can be
carried out in an anechoic chamber. Here, even absolute measurements can be carried out after calibrating the entire
system.
ETSI
...