Comparison Measurement for Specific Absorption Rate With Physically Different Procedure

The specific absorption rate (SAR) is an indicator of the thermal effects caused by microwave exposure in biological tissue. Conventionally, an electric field probe scanning method is used for SAR evaluation. Although many countries have confirmed the validity of the electric field probe scanning method used in many SAR evaluation devices, a comparison between physically different measurement techniques is an important goal for validating a standard and for evaluating the uncertainty of a measurement system. Hence, the authors developed a thermal SAR measurement method using an optical fiber thermal sensor. In this paper, the results of comparison measurements between the electric field probe scanning system and the proposed thermal SAR measurement system are presented. The results show that the SAR measurements by each system overlap within the range of the expanded standard uncertainty in the frequency range of 2-6 GHz.