SAR analysis in human head model exposed to mobile base-station antenna for GSM-900 band

Friis transmission equation combined with Finite Difference in Time Domain (FDTD) method has been used to carry out investigation on Specific Absorption Rate (SAR) inside the human head model exposed to a 100 Watt GSM Base Station Antenna (BSA) at GSM-900 band. Maximum local SAR (MLSAR) has been calculated at 925 MHz, keeping distance between head and BSA in the range of 0.5 m to 5.0 m. The human head is modelled as an inhomogeneous sphere of diameter 21.0 cm. The objective of this study is to estimate MLSAR induced in the human head model by BSA and compared with recommended values.