Interaction between a six-layered spherical head model and a half-wave dipole antenna

The interaction between a six-layered spherical human head model and a half-wave dipole antenna is analyzed in this paper. The proposed method is based on deriving a simple form of Green´s function for six-layered sphere. First the Sommerfeld integral is used to expand the field of a simple electric dipole as a sum of an infinite number of the TE and TM plane waves. The response of the six-layered sphere is then calculated for each external plane wave. Finally the total filed is obtained as an integral of the responses to each plane wave. The method of auxiliary sources (MAS) is then applied to find the current distribution along a half-wave dipole antenna. In the numerical results, the important design parameters such as antenna radiation patterns, gain and specific absorption rate (SAR) are calculated at 900 MHz.