Assessment of human exposure to electromagnetic fields from wireless power transfer system in the 1.8 MHz

Abstract

ABSTRACTIn this study, we discuss human exposure to electromagnetic fields from magnetically coupled resonance wireless power transfer system operating at 1.8 MHz. A two‐step method that is composed of the finite element method (FEM) and finite‐difference time domain method are proposed. The applicability of the proposed two‐step method for a localized exposure within this frequency band is discussed by comparing the specific absorption rate (SAR) in a homogenous human‐body model computed using the FEM. From the computational results, the difference between the peaks 10‐g averaged SAR is below 10 %. These suggest results that the proposed method is applicable for evaluating compliance in realistic anatomical human body models from a wireless power transfer system. With proposed two‐step methods, the SAR in the anatomical human body model is computed for the different exposure scenarios under isolated and grounded conditions. The peak 10‐g averaged SAR in grounded human is larger than that in an isolated human. In the worst case, the peak 10‐g averaged SAR for isolated and grounded condition are 50.6 and 60.7 mW/kg, respectively. The peak 10‐g averaged SAR limits are generally reached when the input powers are 33 W for the worst‐exposure condition. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1125–1129, 2015