Evaluation of antenna configurations for reduced power absorption in the head

This paper describes the use of two-dimensional (2-D) pattern measurements as a tool for evaluating new antenna configurations for reducing power absorbed in the head. The estimation is from comparisons of the total power in measured cuts of the power pattern in a plane containing the head (the principal cut) for various handheld antenna configurations. For the estimate to be reliable, the power in the cuts should be proportional to the total radiated power. In practice this may not always be the case, but useful results for guidance of antenna design can still be obtained. Configurations with parasitic reflecting elements for directing the power away from the head are demonstrated to be effective in reducing the absorbed power in the head. The results are consistent with those from existing forward differences in the time domain (FDTD) analysis for directive antennas. The resulting directive patterns are more efficient and so the in situ terminal can be expected to have an improved performance in a homogeneous multipath environment.