Download presentation
1
EN50360/1 Measurement of SAR related to human
exposure to EM fields from mobile phones (300 MHz - 3 GHz) Group 4A member: Eric( ) Sam( ) Wilbur ( )
2
Celluar phone Health concern
Brain cancer? Affect memory? Affect human analysis ability?
3
Motorola SAM Scan Profiler in Hong Kong
4
What is SAR?? SAR - Specific Absorption Rate
It is an indication of the amount of radiation that is absorbed into a head whilst using a cellular phone A SAR value is a measure of the maximum energy absorbed by a unit of mass of exposed tissue. Units = watts per kilogram (W/kg)
5
Definition of SAR Definition of SAR:
Ei : rms value of the electric field strength in the tissue in V/m σ : Conductivity of body tissue in Kg/m3 Ci : heat capacity of body tissue in J/Kg K : derivative of temperature in body tissue in K/s
6
Preparation - Laboratory
15˚c - 30˚c ±2˚c No interact with local network Be aware of ambient EM sources Be aware of reflection from environment Validation At least once a year
7
Preparation - Mobile battery must be Fully charged
So that, the worst case (maximum power) obtained At least 50cm between emulator antenna and the mobile 1‰ or less power from the antenna with respect to the mobile
8
Hardware System Overview
Change 2x9V batteries every 16 hours x z y Indication Board Amplifier 3 channels DVM with DAQ card Serial Ports: COM1, COM2, COM3 Position Controller GPIB to grab the data from the DVM Flat phantom Left head Right head
9
Tests to be performed Cheek and tilted
Left and right sides of the head Center frequency of each band Retractable antenna Extended Retracted Multi-mode/multi-band Performed in each mode with max power
10
Test Setup Mobile phone operating at the maximum power level
Phone holder described positions at a shell phantom of a human being
11
Test Setup Probes with high sensitivity and low field disturbance are used Move along X-axis, Y-axis, Z-axis
12
Test setup Electric field strength E is measured in the tissue simulating liquid Tissue simulation liquid: Dielectric properties 900MHz: 64.81% 1,2-propanediol; 34.4% de-ionized water; 0.79 NaCl salt
13
Phantom Requirements The phantom is a simplified representation of the human anatomy and comprised of material with electrical properties similar to the corresponding tissues. The physical characteristics of the phantom model shall resemble the head and the neck of a user since the shape is a dominant parameter for exposure.
14
Phantom Requirements Shape is a dominant parameter for exposure.
90% large adult male study by anthropomorphic study in 1989 Fill with tissue simulating liquid through head to neck
15
Test Setup
16
Handset vertical and horizontal reference lines.
17
Phantom reference points.
18
Cheek Position
19
Tilted position
20
Validation Simplified performance checking System validation
Phantom setup Dipole source Dipole input power measurement System check procedure System validation known SAR values of selected mobile
21
Test Setup
22
Validation Test installation (Use flat phantom)
For SAM Profiler, 250mW output will give 2.5mW/g. 11mm 250mW =24dBm Directional Coupler Amplifier Signal Generator Checked the reflected power
23
SAM Profiler is used to control the Scan Profiler
SAM Profiler is used to control the Scan Profiler. The interface is shown below:
24
Result
29
Definition of SAR Definition of SAR:
Ei : rms value of the electric field strength in the tissue in V/m σ : Conductivity of body tissue in Kg/m3 Ci : heat capacity of body tissue in J/Kg K : derivative of temperature in body tissue in K/s
30
Quantization Having in mind a worst case consideration, the SAR limit is valid for uncontrolled environment mobile respectively portable transmitters. Standard Max allowable limit ICNIRP 2 watt/kg ANSI / IEEE 1.6 watt/kg
31
The SAR values of your mobile phone may be found from the following website
32
SAR values of some models
Manufacturer Model SAR values Motorola V80 0.54 V600 0.82 E398 1.01 Sony Ericsson K500i 0.53 K700 0.48 P900 0.91 T630 0.88 Nokia N-Gauge 0.57 7200 0.36 7600 0.71 Samsung SGH-E800 0.32 .
33
Future Development Whole body measurement
34
Thanks for attention
35
Q & A
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.