Fast assessment of SAR in SAM phantom exposed to a handset antenna
Since the diversification of the electromagnetic (EM) environment is spreading, it is essential to estimate the EM energy absorption rate (SAR) of human's body especially human's head under various exposure situations. A novel method is presented that accurately and quickly estimates the SAR in a specific anthropomorphic mannequin (SAM) phantom by using SAR in a double layered prolate head model with a compensating function. Comparison of SAR induced in a double layered prolate head model and a specific SAM head model was investigated firstly, and the systematic biases resulting from shape effect of the SAM and prolate head model is obtained in different position cases. Then a hybrid Null Field Method / Method of Moments (NFM/MoM) approach is used to analysis EM problem for a double layered prolate head model exposed to a handset antenna. By means of the hybrid approach, the MoM is applied to a handset antenna, and the NFM is used to model the scattering problem from the head model. The electromagnetic coupling between the head model and an antenna is taken into account by a fast convergent iteration process. The numerical results show that the proposed method is able to estimate SAR in SAM head model within an error ±6% for dual band PIFA antenna, which indicate the possibility to quickly assess electromagnetic radiation to human head using double layered prolate model.