IEC TR 63170:2018

IEC TR 63170 ®
Edition 1.0 2018-08
TECHNICAL
REPORT
colour
inside
Measurement procedure for the evaluation of power density related to human
exposure to radio frequency fields from wireless communication devices
operating between 6 GHz and 100 GHz

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC TR 63170 ®
Edition 1.0 2018-08
TECHNICAL
REPORT
colour
inside
Measurement procedure for the evaluation of power density related to human

exposure to radio frequency fields from wireless communication devices

operating between 6 GHz and 100 GHz

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.220.20 ISBN 978-2-8322-5878-1

– 2 – IEC TR 63170:2018 © IEC 2018
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 11
2 Normative references . 11
3 Terms and definitions . 11
4 Symbols and abbreviated terms . 15
4.1 Symbols . 15
4.1.1 Physical quantities . 15
4.1.2 Constants . 15
4.2 Abbreviated terms . 16
5 Description of the measurement system . 16
5.1 General . 16
5.2 Scanning system . 16
5.3 Device holder . 17
5.4 Reconstruction algorithms . 17
6 Power density assessment . 17
6.1 General . 17
6.2 Measurement preparation . 19
6.2.1 System check . 19
6.2.2 Preparation of the device under test . 20
6.2.3 Operating modes . 20
6.2.4 Test frequencies for DUT . 20
6.2.5 Evaluation surface and DUT test position . 21
6.3 Tests to be performed . 23
6.4 General measurement procedure . 23
6.4.1 General . 23
6.4.2 Power density assessment based on E- and H-field . 24
6.4.3 Power density measurement based on the evaluation of E-field or H-
field amplitude only . 25
6.5 Measurements of devices with multiple antennas or multiple transmitters . 26
6.5.1 General . 26
6.5.2 Examples. 28
7 Uncertainty estimation . 30
7.1 General considerations . 30
7.2 Uncertainty model . 30
7.3 Uncertainty components dependent on the measurement system . 30
7.3.1 Calibration of the measurement equipment . 30
7.3.2 Probe correction . 30
7.3.3 Isotropy . 31
7.3.4 Multiple reflections. 31
7.3.5 System linearity . 31
7.3.6 Probe positioning . 31
7.3.7 Sensor location . 31
7.3.8 Amplitude and phase drift . 31
7.3.9 Amplitude and phase noise . 31
7.3.10 Data point spacing . 32

7.3.11 Measurement area truncation . 32
7.3.12 Reconstruction algorithms . 32
7.4 Uncertainty terms dependent on the DUT and environmental factors . 32
7.4.1 Probe coupling with DUT . 32
7.4.2 Modulation response . 32
7.4.3 Integration time . 32
7.4.4 DUT alignment . 32
7.4.5 RF ambient conditions . 33
7.4.6 Measurement system immunity/secondary reception. 33
7.4.7 Drift of DUT . 33
7.5 Combined and expanded uncertainty . 33
8 Measurement report . 35
8.1 General . 35
8.1.1 General . 35
8.1.2 Items to be recorded in the measurement report . 35
9 Recommendation for future work . 36
9.1 Measurement standard for EMF compliance assessment of devices
operating at frequencies above 6 GHz . 36
9.1.1 General . 36
9.1.2 Test frequencies . 37
9.1.3 Evaluation surfaces . 37
9.1.4 Evaluation of exposure from multiple transmitters . 38
9.1.5 Other future work items . 38
9.2 Numerical standard for EMF compliance assessment of devices operating at
frequencies above 6 GHz . 39
9.3 Updates to IEC 62232 . 39
Annex A (informative) Measurement system check and validation . 40
A.1 Background. 40
A.1.1 General . 40
A.1.2 Objectives of system check . 40
A.1.3 Objectives of system validation . 40
A.2 Measurement setup and procedure for system check and system validation . 41
A.2.1 General . 41
A.2.2 Power measurement setups . 41
A.2.3 Procedure to normalize the measured power density . 42
A.3 System check . 42
A.3.1 System check sources and test conditions . 42
A.3.2 Test procedure . 42
A.4 System validation . 42
A.4.1 Reference sources and test conditions . 42
A.4.2 System validation procedure . 43
Annex B (informative) Examples of reference sources . 44
B.1 Background. 44
B.2 Cavity-fed dipole arrays . 44
B.2.1 Description . 44
B.2.2 Target values . 47
B.3 Pyramidal horns loaded with a slot array . 52
B.3.1 Description . 52
B.3.2 Target values . 53

– 4 – IEC TR 63170:2018 © IEC 2018
Annex C (informative) Examples of system check sources . 59
C.1 Background. 59
C.2 Source description . 59
C.3 Target values . 59
Annex D (informative) Information on the applicability of far-field methods . 60
D.1 Background. 60
D.2 Evaluation method using EIRP . 60
D.2.1 General . 60
D.2.2 Numerical simulated results . 60
D.3 Plane wave equivalent approximation . 63
D.3.1 General . 63
D.3.2 Numerical simulated results . 63
Annex E (informative) Rationale for the use of square or circular shapes for the

averaging area applied to the power density for compliance evaluation . 66
E.1 General . 66
E.2 Method using computational analysis . 66
E.3 Areas averaged with square and circular shapes . 66
Annex F (informative) Near field reconstruction algorithms . 68
F.1 General . 68
F.2 Field expansion methods . 69
F.2.1 General . 69
F.2.2 The plane wave spectrum expansion . 69
F.3 Inverse source methods . 71
F.4 Implementation scenarios . 72
F.4.1 General . 72
F.4.2 Alternative field measurements . 72
F.4.3 Phase-less approaches . 72
F.4.4 Direct or quasi-direct near field measurements . 72
Annex G (informative) Example of a mixed (numerical and experimental) approach to
assess EMF compliance for a WiGig device . 73
G.1 General . 73
G.2 Approach used to assess conformance . 73
G.3 Conclusion . 76
Annex H (informative) Use cases . 77
H.1 General . 77
H.2 Configurations . 78
H.3 Results obtained at Laboratory 1 . 79
H.3.1 General . 79
H.3.2 Miniaturized probe . 79
H.3.3 Scans . 79
H.3.4 Total field and power density reconstruction . 81
H.3.5 Power density averaging . 81
H.3.6 Measuring setup . 82
H.3.7 Simulated results . 83
H.3.8 Measured results . 83
H.4 Results obtained at Laboratory 2 . 89
H.4.1 General . 89
H.4.2 Measurement setup . 89
H.4.3 Data processing . 90

H.4.4 Numerical simulations and comparison with measurements . 90
H.5 Measurements at Laboratory 3 . 96
H.5.1 General . 96
H.5.2 Measurement setup . 96
H.5.3 Scans . 97
Bibliography . 98

Figure 1 – Simplified view of a generic measurement setup involving the use of
reconstruction algorithms . 17
Figure 2 – Evaluation process overview . 18
Figure 3 – Overview of power density measurement methods . 19
Figure 4 – Illustration of evaluation surface (in black) . 22
Figure 5 – Illustration of evaluation surface corresponding to the flat phantom surface
shape . 22
Figure 6 – Illustration of evaluation surface corresponding to the maximum available

local or spatial-average power density . 23
Figure 7 – SAR and power density evaluation at a point r . 27
Figure A.1 – A recommended power measurement setup for system check and system
validation . 41
Figure B.1 – Main dimensions for the cavity-backed array of dipoles . 45
Figure B.2 – 10 GHz patterns for the |E | and Re{S} for the cavity-backed array
total total
of dipoles at various distances, d, from the upper surface of the dielectric substrate . 48
Figure B.3 – 30 GHz patterns for the |E | and Re{S} for the cavity-backed array
total total
of dipoles at various distances, d, from the upper surface of the dielectric substrate . 49
Figure B.4 – 60 GHz patterns for the |E | and Re{S} for the cavity-backed array
total total
of dipoles at various distances, d, from the upper surface of the dielectric substrate . 50
Figure B.5 – 90 GHz patterns for the |E | and Re{S} for the cavity-backed array
total total
of dipoles at various distances, d, from the upper surface of the dielectric substrate . 51
Figure B.6 – Main dimensions for the 0,15 mm stainless steel stencil with slot array . 52
Figure B.7 – Main dimensions for the pyramidal horn antennas . 52
Figure B.8 – 10 GHz patterns for the |E | and Re{S} for the pyramidal horn
total total
loaded with an array of slots at various distances, d, from the array surface and

P = 0 dBm . 55
in
Figure B.9 – 30 GHz patterns for the |E | and Re{S} for the pyramidal horn
total total
loaded with an array of slots at various distances, d, from the array surface and
P = 0 dBm . 56
in
Figure B.10 – 60 GHz patterns for the |E | and Re{S} for the pyramidal horn
total total
loaded with an array of slots at various distances, d, from the upper surface of the slot
array . 57
Figure B.11 – 90 GHz patterns for the |E | and Re{S} for the pyramidal horn
total total
loaded with an array of slots at various distances, d, from the upper surface of the slot
array . 58
Figure D.1 – Antenna models at 28,5 GHz . 61
Figure D.2 – S compared to S (normalized to maximum of S ) . 62
eirp av eirp
Figure D.3 – Plane wave equivalent approximation (S ) and simulation (S ) results . 64
e av
Figure D.4 – Difference of S to S for all antennas (%) . 65
e av
Figure E.1 – Schematic view of the assessment of the variation of S using square
av
shape by rotating AUT . 66

– 6 – IEC TR 63170:2018 © IEC 2018
Figure E.2 – Comparison of maximum values of S averaged toward square and
av
circular shapes . 67
Figure F.1 – Comparison of maximum values of S between the computational
av
simulation and back projection at 30 GHz . 70
Figure F.2 – Comparison of maximum values of S between the computational
av
simulation and back projection at 60 GHz . 71
Figure G.1 – Evaluation plane and antenna position . 74
Figure G.2 – Local and spatial-average power densities in mW/cm . 75
Figure G.3 – Spatial-average power densities variation with the distance from
evaluation plane . 76
Figure G.4 – Correlation (simulation vs. measurement) . 76
Figure H.1 – Picture of the mock-up used for power density measurements . 77
Figure H.2 – Antenna geometry . 78
Figure H.3 – Picture of the mock-up numerical model . 78
Figure H.4 – Illustration of the angles used for the numerical description of the sensor
and the orientation of an ellipse in 3-D space . 80
Figure H.5 – Numerical algorithm for reconstructing the ellipse parameters . 81
Figure H.6 – Measuring setup used at Laboratory 1 . 82
(b) TOP orientation . 83
Figure H.7 – DUT while measuring showing the numbering for the ports . 83
Figure H.8 – Simulated (left) and measured (right) power density distribution for the
TOP configuration . 85
Figure H.9 – Simulated (left) and measured (right) power density distribution for the
FRONT configuration . 86
Figure H.10 – Averaged power density as a function of distance for port 1, at
27,925 GHz, for TOP and FRONT configurations averaged over an area of 4 cm . 87
Figure H.11 – Averaged power density as a function of averaging area for port 1 at
different frequencies . 88
Figure H.12 – Distribution of the power density corresponding to the array with zero
phase-shift between elements (configuration w of Table H.1) . 89
Figure H.13 –Mock-up with antenna port number 2 connected to the VNA (left) and the
open waveguide probe and alignment system (right) . 90
Figure H.14 – Simulated (left) and measured (right) power density distribution for the
TOP configuration over a 15 cm × 15 cm plane . 92
Figure H.15 – Simulated (left) and measured (right) power density distribution for the
FRONT configuration over a 15 cm × 15 cm plane . 93
Figure H.16 – Averaged power density as a function of distance for port 1, at
27,925 GHz, for TOP and FRONT configurations averaged over an area of 4 cm . 94
Figure H.17 – Averaged power density as a function of averaging area for port 1 at
different frequencies . 95
Figure H.18 – Distribution of the power density corresponding to the array with zero
phase-shift between elements (configuration w of Table H.1) . 96
Figure H.19 – Measurement setup . 97

Table 1 – Minimum separation distance between the DUT’s antenna and the evaluation
surface for which Formula (3) applies . 26
Table 2 – Example of measurement uncertainty evaluation template for power density
measurements . 34

Table B.1 – Main dimensions for the cavity-backed dipole array at each frequency of
interest . 46
Table B.2 – Target values for the cavity-backed dipole arrays at different frequencies

(u (k = 1) = 0,5 dB) . 47
s
Table B.3 – Main dimensions for the stencil with slot array for each frequency . 53
Table B.4 – Main dimensions for the corresponding pyramidal horn at each frequency . 53
Table B.5 – Target values for the pyramidal horns loaded with slot arrays at different
frequencies (u (k = 1) = 0,5 dB) . 54
s
Table C.1 – Target values for pyramidal horn antennas at different frequencies . 59
Table G.1 – Phase shifts between antenna elements leading to the maximum power
density for each channel . 75
Table H.1 – Phase shift values for the mockup antenna ports. . 79
Table H.2 – Measured power at the end of the adapter 2,4 mm to 3,5 mm and input
power at the antenna port after considering extra losses introduced by the semi-rigid
200 mm coaxial cable and connectors. 82
Table H.3 – Edge length of the scanned planes for the different configurations . 84

– 8 – IEC TR 63170:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MEASUREMENT PROCEDURE FOR THE EVALUATION
OF POWER DENSITY RELATED TO HUMAN EXPOSURE TO RADIO
FREQUENCY FIELDS FROM WIRELESS COMMUNICATION DEVICES
OPERATING BETWEEN 6 GHz AND 100 GHz

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a Technical Report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC TR 63170, which is a Technical Report, has been prepared by IEC technical committee
106: Methods for the assessment of electric, magnetic and electromagnetic fields associated
with human exposure.
The text of this Technical Report is based on the following documents:
Enquiry draft Report on voting
106/426/DTR 106/437/RVDTR
Full information on the voting for the approval of this Technical Report can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 10 – IEC TR 63170:2018 © IEC 2018
INTRODUCTION
This Technical Report describes methods and measurement techniques for the evaluation of
power density related to human exposures due to electromagnetic field (EMF) transmitting
devices operating in close proximity to the user at frequencies between 6 GHz and 100 GHz
where basic restrictions can be expressed in terms of power density. The types of devices
include but are not limited to mobile telephones, tablets, and laptops.
With the rapid development of new wireless technologies in the frequency range 6 GHz to
100 GHz for the fifth generation mobile technology (5G), there is a need to establish
assessment procedures to ensure compliance of wireless devices with electromagnetic
exposure limits.
For portable devices, the IEC 62209 series of SAR assessment standards for wireless devices
used in close proximity to the users are valid up to 6 GHz. For base stations, IEC 62232
defines the methods to assess the compliance boundaries based on reference levels and
basic restrictions. SAR tests are applicable when the compliance distance is in close
proximity to the radiating sources in the frequency range 300 MHz to 6 GHz. Power density
measurements above 6 GHz are also applicable in close proximity to the equipment, but no
detailed protocol is available at this stage.
SAR is not considered as the relevant exposure metric above 10 GHz in the International
Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines which specify basic
restrictions in terms of free-space incident power density. Similarly, IEEE C95.1-2005 [1]
requires the assessment of incident power density above 6 GHz.
IEC TC 106 has previously noted the necessity to extend compliance assessment standards
for portable devices beyond 6 GHz. However, with the 5G trials scheduled to commence in
2018, IEC TC 106 has decided on a two-step strategy to ensure that the fundamental
assessment approaches are available by 2018.
1) IEC TC 106 (AHG10) focused in 2017 on the development of a Technical Report,
specifying the state of the art of measurement techniques and test approaches for
evaluating portable devices based on power density measurements from 6 GHz to
100 GHz.
2) IEC TC 106 submitted a new work item proposal in early 2018 to develop a new
International Standard (IS) on the detailed measurement procedures to continue the work
established in the Technical Report.
This informative document serves as the starting point for an International Standard. The
methodologies and approaches described in this document can be useful for the assessment
of early 5G products introduced for consumer trials. It also contains recommendations for
future standardization work and highlights areas that may require additional investigation or
consideration.
A few examples for measurements of a mock-up device characterized by an antenna array
operating at about 28 GHz are given in Annex H.

___________
Numbers in square brackets refer to the Bibliography.

MEASUREMENT PROCEDURE FOR THE EVALUATION
OF POWER DENSITY RELATED TO HUMAN EXPOSURE TO RADIO
FREQUENCY FIELDS FROM WIRELESS COMMUNICATION DEVICES
OPERATING BETWEEN 6 GHz AND 100 GHz

1 Scope
This document describes the state of the art measurement techniques and test approaches
for evaluating the local and spatial-average incident power density of wireless devices
operating in close proximity to the users between 6 GHz and 100 GHz.
In particular, this document provides guidance for testing portable devices in applicable
operating position(s) near the human body, such as mobile phones, tablets, wearable devices,
etc. The methods described in this document may also apply to exposures in close proximity
to base stations.
This document also gives guidance on how to assess exposure from multiple simultaneous
transmitters operating below and above 6 GHz (including combined exposure of SAR and
power density).
NOTE Compliance of devices with sufficiently low radiated power that is incapable of exceeding basic restrictions
is addressed by IEC 62479 [2] and therefore not described in this document.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
3.1
averaging area
rectangular or circular area on the evaluation surface (3.9) over which the assessed power
density is averaged
Note 1 to entry: Because of rotational symmetry a circular area might be preferable since the result of averaging
will not depend on the rotation.
3.2
basic restriction
restriction on exposure to time-varying electric, magnetic and electromagnetic fields that is
based on established biological effects
3.3
RF channel
specific sub-division of the available frequency range according to the operating parameters
of a wireless technology
– 12 – IEC TR 63170:2018 © IEC 2018
3.4
conducted power
power delivered by the power amplifier to a matched load
3.5
correlated signals
electromagnetic fields, associated to distinct signal waveforms, yielding non-zero
time-domain correlation integral at some time instant
F (r,t) F (r,t)
Note 1 to entry: For two power-limited field distributions and , the time-domain correlation integral is
1 2
defined as
T
1 *
(1)
(F⊗F )(r,t) lim Fr( ,τ )⋅F (r,t+ τ )dτ
12 1 2
∫
T →∞ 2T
−T
where r is the location vector, the superscript * represents the complex conjugate operation and the symbol ⋅
represents the inner product operation
Note 2 to entry: Observe that two fields are uncorrelated at locations where they are geometrically orthogonal.
This property does not generally hold at nearby points unless the respective waveforms are uncorrelated.
In case of scalar signals, correlated signal waveforms yield a non-zero time-domain correlation integral at some
s (t) s (t)
time instant. For two power-limited signals , , said integral is defined as:
1 2
T
1 *
(2)
s⊗ s t lim s τ⋅+st τ dτ
( )( ) ( ) ( )
12 1 2
∫
T →∞ 2T
−T
where the superscript * represents the complex conjugate operation.
Note 3 to entry: Two uncorrelated signals would feature a vanishing correlation integral, i.e. the above integral is
equal to zero.
Note 4 to entry: Formulas (1) and (2) are originally specified in IEC TR 62630.
3.6
dev
...