The Study of Electromagnetic Field Distribution inside Biological Objects

Determining the degree of electromagnetic radiation's influence of mobile communication devices on their users is a relevant problem nowadays. This is especially due to the fact that enhanced functionality of such devices led to their almost continuous use by their owners. Solving the problem of the electromagnetic wave's excitation in the media with sharply changing parameters (skin, muscle, bone, fat) is necessary for building an adequate electrodynamic model of a biological tissue. This model must allow to perform investigation of the electromagnetic waves’ influence on people. This research is based on simplified electrodynamic models of biological objects, in particular, for models in the form of a multilayer medium with flat layers, as well as a multilayer sphere or ellipsoid. In this work we used an ellipsoid of revolution as a model of the human head. Inside it was placed another ellipsoid which described the human brain. The simulation was performed for two models of a cell phone antenna – a microstrip one and a spiral one. FEKO software was used to calculate distribution of electromagnetic fields and SAR in the considered models. According to the obtained results spatial peak SAR, averaged over 10 g/ of the human body, is below the threshold value recommended by international standards. Moreover, the level of SAR can be significantly reduced by increasing the distance between the head and the cell phone. However, the position of the area where peak SAR values are reached doesn't change.