SAR Comparison of SAM Phantom and Anatomical Head Models for a Typical Bar-Type Phone Model

The current IEEE 1528 and IEC 62209-1 standards specify a simplified physical model of the human head to provide conservative measurement procedures of the peak spatial-average specific absorption rate (SAR) of a mobile phone. This means that the evaluated SAR in a specific anthropomorphic mannequin (SAM) head model should be higher than in the heads of a significant majority of users under normal operational conditions. In this paper, the conservativeness of the SAM is investigated by numerically comparing the SAR in the SAM with those in four anatomical head models at different ages for exposure from a typical bar-type mobile phone. A numerical bar-type phone model with an internal antenna at the bottom of the phone body was implemented at 835 and 1850 MHz. This model provides an SAR pattern and levels similar with the commercial bar phones released in Korea. For two standard test positions, spatial peak 1- and 10-g SARs were calculated for both the SAM phantom and anatomical head models. The SARs were also calculated when the antenna is located on top of the phone. The results show that the SAM phantom provides a conservative evaluation for a phone model with the antenna on the top. However, when the antenna is located at the bottom, the hotspot in the SAM occurred farther from the antenna feed point, and, thus, produced lower 1- and 10-g SAR results compared with the anatomical models.