Abstract

This paper proposes a dosimetric analysis in realistic human head model for a helical antenna with phone model. The finite-difference time-domain (FDTD) method with lossy-Drude model is adopted in this study. The technique of SAR measurement is addressed and then the effects of head model size on SAR characteristics for a cellular phone exposure at 835 MHz respectively. The head model, was developed from magnetic resonance imaging (MRI) data of an adult head, consists of 630 thousand voxels, of 2 mm dimensions, segmented into 15 tissue types. The helical antenna was modeled as a heap of dipoles and loops with a sufficient relative weight, whose legality was established by comparing the calculated near magnetic fields with published measured data. SAR is given for both the spatial peak value in the whole head and the averages in various major organs.

Key words: Specific absorption rate (SAR), head size, helical antenna, finite difference time domain method (FDTD), electromagnetic dosimetry.