FDTD analysis of the handset antenna and human body interaction

With the expansion of current use and anticipated further increases in the use of cellular telephones and other personal communication services (PCS), there have been an interest and considerable research effort devoted to interactions between antennas on handsets and the human body. These activities are motivated by two factors: (i) a need to evaluate the deterioration of the antenna performance and to develop better antennas, and (ii) a need to evaluate the rates of RF energy deposition, called specific absorption rates (SAR), in order to evaluate potential health effects and compliance with standards. We address the following issues: (i) to what extent the effect of the human head on the antenna radiation pattern can be simulated by a multilayered tissue sphere, (ii) how important are the quality and resolution of the head model in determination of the head effect on the antenna pattern, total power absorbed in the head (or antenna efficiency in the presence of the head), the peak SAR, and the maximum SAR in 1 g and (iii) how does the distance between the antenna and the head affect the values and location of the peak, and 1 g values of SAR. Additionally, we include the effect of the hand on the parameters investigated and propose a new handset box design that mitigates the effect of the hand on the antenna radiation pattern.