Investigation of SAR (Specific Absorbtion Rate) in Different Head Models Placed in Shielded Space

This article deals with effects of electromagnetic (EM) fields to different types of numerical models of human head. There are differences between specific absorption rate (SAR) near human head model inside shielded space like in elevator or non-shielded space (open area). In the presented approach, the investigation is focused on modelling of EM field proceeded on the finite integration method. The simulations were carried out for specific scenario where a person/passenger was placed in the shielded space using a cellular phone. The results were evaluated in terms of the SAR values - the determination of EM energy absorption inside the human head. The dipole antenna with a frequency of 900 MHz was designed and working as radio frequency source. In the proposed matching method, two models of human head - SAM homogenous human head model and AustinMan model - were chosen to model three different distances of the cellular phone from the human head surface. Both have the dielectric properties determined to the evaluated frequency of source. The numerical results have shown that the obtained maximal SAR values in shielded/enclosure (such as the elevator) is higher than are maximum values determined according to maximum SAR in European standards limit. Additionally, the obtained SAR values are higher than the results achieved by the open space simulations.