Assessment of Polarization Dependence of Body Shadow Effect on Dosimetry Measurementsin 2.4 GHz Band

Abstract

Personal exposure meters (PEMs) are portable measuring devices of electromagnetic field (EMF) levels. The extreme proximity of the wearer causes an underestimation in logged data, known as body shadow effect (BSE) that undermines the reliability of exposure measurements. This paper analyzes the influence of the horizontal polarization of the radiation source on the PEM measurements in four multipath environments and under dynamic conditions, at the frequency band of 2.4 GHz. By comparing experimental measurements and simulated results, the PEM wearer is modeled theoretically as a shadow angle whose value is determined in terms of maximum P-value and minimum root mean square error. This angle is 9º for horizontal polarization, and tripled, 26º, for vertical polarization. Therefore, the polarization of the radiation source is a dependence factor for exposure assessment, since in horizontal polarization the BSE corresponds to a lower loss than in vertical polarization. In addition, the validity of using correction factors in order to mitigate the errors induced by the BSE is questioned, since the correction factors do not reflect all the properties of the fading components of unperturbed exposure.