Research

Project Title:
SAR Testing of Hands-Free Mobile Telephones

Start Date:
July 2002

Status:
Completed

Cost:
£123,000

Principal Investigator:
Dr Stuart Porter

Contact Details:
Applied Electromagnetics Group
Department of Electronics
University of York
Heslington, York,
UK.
YO10 5DD

Expertise:

Computer modelling of electromagnetic fields; design of systems to measure electromagnetic fields reliably; studies of interference between electronic systems; design of antennas for communication systems.

Approach:

The main aim of the project is to estimate the likely differences in exposure between using a mobile telephone in normal mode and when used in conjunction with a hands-free kit (HFK). This includes the likely differences in the measured exposure under standard test conditions (using the standard head phantom) when a mobile telephone is used with and without a HFK; the likely effects upon these measured results of incorporating a representative body phantom in the exposure measurements; estimates of the induced currents on the cabling of HFK’s with and without the presence of a phantom torso to aid in deducing the effects of omitting the torso from SAR tests.

The aim will be achieved through measurements and numerical modelling. Numerical phantoms and models will be developed for a range of exposure scenarios. A compliant SAR test system will be used for exposure measurements. The techniques employed will include Finite- Difference Time Domain and Moment Method modelling, sensitivity analysis, error analysis and exposure measurements.

The main outputs will include: exposure assessments for a range of scenarios both with/without HFK’s and with/without torso phantoms; an enhanced understanding of the factors which effect the measured SAR when using HFK’s and recommendations for appropriate test-scenarios for best assessment of SAR related to HFK use.

Potential Difficulties:

Ensuring that a sufficient range of HFK's/geometry's are used to be representative.

Importance:

A successful outcome to the work will enable us to draw firm conclusions as to the likely variation in exposure to be expected when using a hand's free kit and mobile telephone compared with a mobile telephone alone.