Satellite and terrestrial mobile handheld antenna interactions with the human head

Abstract

Interactions between terrestrial and satellite mobile handheld antennas and the human head are compared, using the transmission line modelling technique (TLM). The approach to modelling the terrestrial antenna (monopole), satellite antenna (quadrifilar helix), a simple spherical head model and a detailed head model using the TLM method is described. The modelling approach is compared with previous work for purely terrestrial cases and good agreement is obtained. The radiation pattern in both polarisation planes, specific absorption rate and near-field magnitude have been calculated and compared for both antennas. When both antenna types are fed with the same input power, the terrestrial mobile handheld antenna gives a higher peak SAR than the satellite antenna. The input power for the satellite antenna can be increased by up to 27% for the same peak SAR level in the skin. The peak SAR in the satellite case can be reduced by 29 dB by shifting its position vertically by 9 cm or by 12 dB by shifting the feed point to the top end of the antenna.