SAR Associated with the Use of Hands-Free Mobile Telephones

The material presented here outlines a study to determine the level of Specific Absorption Rate (SAR) associated with the use of Hands Free Kit's (HFK's) with GSM mobile telephones and to identify the factors that influence these levels. A novel current probe was designed to measure the current profile along the HFK cables. Measurements of the HFK current were made on human subjects in an anechoic chamber and in the presence of a phantom head used for SAR measurements – good agreement was found. The SAR level was measured for both the phones and phones with HFK's and the comparative data is presented. The factors that influence the observed level of SAR when using a HFK have been identified and their relative importance determined.