![Page 1: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/1.jpg)
STANDARDS AND
COMPLIANCE TESTING
P. Bernardi
Department of Electronic Engineering - University of Rome "La Sapienza"
![Page 2: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/2.jpg)
ContentsContents
Exposure assessment
Review and comparison
Radio base stations
Cellular phones
INTRODUCTION
STANDARDS
COMPLIANCE TESTING
THE CEPHOS PROJECT
![Page 3: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/3.jpg)
Exposure assessment - relevant parameters
Electromagnetic field source
EMISSION EXPOSURE ABSORPTION
Environment Human
![Page 4: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/4.jpg)
The Mobile Cellular Phone System
Radio Base Station
Two different exposure conditions
Cellular Phone
![Page 5: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/5.jpg)
Standard for safe human exposure Standard for safe human exposure to RF fieldsto RF fields
In the frequency range from 30 MHz to a few GHz the basic parameter is the Specific Absorption Rate (SAR):
SARWB Tot PowerTot Mass whole body
Restrictions on the effects of exposure are based on established health effects and are termed basic restrictions.
Protection against adverse health effects requires that the basic restrictions are not exceeded (ICNIRP, 1998).
SAR E 2
(W/kg)
On the whole body:
![Page 6: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/6.jpg)
Basic limits
• The SARWB of 4 W/kg has been established as a reasonable value for adverse effect threshold.
• Using a safety factor of 50 for the exposure of general population, the limit of 0.08 W/kg is obtained.
• To avoid excessive hot spots, a limit for the spatial peak SAR is also established.
![Page 7: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/7.jpg)
Established SAR related effects
BRAIN T > 4.5 °C Neuron thermal damage
EYE T > 3 - 5 °C Cataract of the lens
SKIN T > 10 - 20 °C Thermal damage
WHOLE BODY T > 1 °C Various physiological effects
The most widely accepted effect of RF exposure is a heating effect.
Threshold temperature increase for some effects:
![Page 8: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/8.jpg)
Comparison of basic limits
• ANSI 1992 0.08 1.6 (1g)
• CENELEC - 1995 0.08 2.0 (10g)
• FCC - 1997 0.08 1.6 (1g)
• ICNIRP - 1998 0.08 2.0 (10g)
General public
SARwb SARpeak(W/kg) (W/kg)
Using an averaging cube of 10 g instead of 1 g of tissue mass can reduce the spatially averaged SAR value by a factor of about two, at higher frequencies
![Page 9: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/9.jpg)
Derived or secondary limits(Reference levels)
• Represent a practical approximation of the incident plane wave power density flux needed to produce the whole-body-averaged SAR of 0.08 W/kg.
• They are defined in terms of external
electric field, magnetic field, and incident power density
![Page 10: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/10.jpg)
Basic restrictions and reference levels
While
compliance with all reference levels will ensure compliance with basic restriction
it does not necessarily follow that
if measured values are higher than reference levels, the basic restrictions are exceeded.
In this case a more detailed analysis is necessary to assess compliance with basic restrictions (ICNIRP, 1998)
![Page 11: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/11.jpg)
10
110
210
310
410
510
-1
100
101
102
103
Chinese (violet)
NRPB adults (red)
ICNIRP - CENELEC - German (blue)
IEEE (green) FCC - Japan (cyan)
Public limits of exposure
10 100 1 000 10 000 100 000Frequency (MHz)
0.1
1
10
100
1000
Power density (W/m2)
Comparison of reference levelsGeneral public
![Page 12: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/12.jpg)
Safety standards conclusions
While there is almost general consensus on the limit on SAR as averaged over the whole body, differences are present among the limits on spatial SAR and on the derived reference levels.
This renders compliance testing for new devices more complicated
![Page 13: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/13.jpg)
Compliance with standards
Compliance testing consists in checking that
• the field exposure from MTE is below reference
levels
OR
• SAR absorbed in body is below the basic limits
![Page 14: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/14.jpg)
Radio Base station
rmin 1
Emax 30Pi G , rmin
1Emax
30Pi G ,
Exposure in free space
Emax => reference level
![Page 15: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/15.jpg)
Urban scenarioExposure in complex environment
A
C
B
DA
B
C
![Page 16: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/16.jpg)
Radio Base stationExposure levels in urban environment
Erms [V/m]
rooftop (A) balcony (b) street (C)
f = 947.5 MHz Pirr = 30 W G = 14.7 dBif = 947.5 MHz Pirr = 30 W G = 14.7 dBi
Erms [V/m] Erms [V/m]
(cm)
(cm
)
(cm)
(cm
)
(cm)
(cm
)
![Page 17: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/17.jpg)
Cellular phonesWe can differentiate between portable and mobile devices according
to their proximity to the exposed person (FCC, 1996).
• Portable devices are defined as devices designed to be used with any part of their radiating structure in direct contact with, or within 20 cm from, the body of the user.
• Mobile devices are defined as transmitting devices designed to be used in definite locations with radiating structures maintained 20 cm or more from the body of the user or nearby persons.
For handheld cellular phones, (portable devices) compliance testing must be done only
with reference to the basic limits on SAR
![Page 18: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/18.jpg)
Procedures to demonstrate compliance of CPs with basic restrictions
General requirements:
• the method should ensure that the assessed SAR do not underestimate the exposure of possible users;
• the CP should be tested at the highest power at the central transmitting band frequency;
• test procedures should give reproducible results
![Page 19: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/19.jpg)
Compliance methods
Compliance with the basic restrictions can be done:
• theoretically: computational simulation procedures;
• experimentally: measurement simulation procedures.
In case of numerical compliance testing,
at least one position of the CP (the intended use position)
should be verified by measurements
(CENELEC, ES 1998)
![Page 20: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/20.jpg)
Intended use position (CENELEC, ES 1998)The intended use position:
• is established by fully extending the CP antenna;
• provides good acoustic coupling
Tests shall be done at least in the intended use position
REFERENCE LINE
LINE CONNECTING AUDITORY CANAL OPENINGS
REFERENCE PLANE
![Page 21: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/21.jpg)
Computational simulation procedures
Numerical method (e.g. FDTD)
Dielectric characteristics
,
Source
Maxwell’s equations SARpeak
basic limits
![Page 22: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/22.jpg)
Open problemsOpen problems
• Phantom model
– head shape, tissue distribution, tissue parameters
– effect of the hand
– metallic accessories and environmental effects
• a worst case can be defined?
• Uncertainty of the evaluation techniques
![Page 23: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/23.jpg)
Measurement simulation procedures
Requirements: • to know with great precision the measurement points (rapid spatial variations);• accurately evaluate the SAR close to the surface;• software for data processing & measurement control.
Phantom
Automatic scanning system
E-field probePower delivering system
Data processing
SARpeak basic limits
Total power
![Page 24: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/24.jpg)
Open problemsOpen problems• Phantom model
– shape and size; heterogeneous or not– dielectric properties– ear simulation– modeling the hand
• worst case scenario?• calibration procedure• Uncertainty of the measurement set-up
– probe isotropy, linearity, sensibility– spatial resolution– phone and probe positioning
![Page 25: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/25.jpg)
The CEPHOS project1997 - 1999
Purpose:
development of a data-base on relevant literature design and study of canonical situations of exposure development of numerical and experimental phantoms assessment of the human exposure in actual situations
Activities:
• to assess a rational basis for a compliance procedure of cellular phones with standards
![Page 26: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/26.jpg)
CEPHOS working groups
Work undertaken:• exposure assessment & uncertainty of numerical simulations:
CNET, National Technical Univ. of Athens, Univ. of Ancona,
Univ. of Bradford, Univ. of Rome La Sapienza
• exposure assessment & uncertainty of experimental set-ups:Alcatel, CSELT, ENEA, NPL, Univ. of Bordeaux, Univ. of Bristol
• definition of a testing procedure: Univ. of Rome La Sapienza, Alcatel, CNET , CSELT,
National Technical Univ. of Athens, Univ. of Bradford
CEPHOS consortium is made up of 6 universities,4 research laboratories and 4 industries.
![Page 27: STANDARDS AND COMPLIANCE TESTING P. Bernardi Department of Electronic Engineering - University of Rome "La Sapienza"](https://reader036.vdocuments.us/reader036/viewer/2022062516/56649db65503460f94aa8854/html5/thumbnails/27.jpg)
Conclusions• In the recent years significant progress in the area of exposure
assessment of cellular phone systems has been done;
• the precision of experimental and numerical techniques has been greatly improved.
However:
• a universally accepted compliance procedure (numerical and experimental) is still lacking;
• improvements are still necessary to assess the exposure in complex environments (both for radio base stations and hand-held phones).