Analytical calculation of the specific absorption rate from cellular phone in some realistic situations

Abstract

In this paper, we treated analytically the cellular phone antenna radiation parameters in the presence of a human body and the electromagnetic absorption concept by a human body in different realistic talking situations (in free space, in conductive environment, indoor, outdoor) is also investigated. Numerical investigations have been carried out to analyse the EM field coupling problem from cellular phone antenna to a spherical modelled head in different realistic scenarios by using the concept of the coupled integral equations; in which the electric field induced inside the model and the current distribution of the linear antenna can be expressed with coupled integral equations using dyadic Green's function. Some radiation parameters (radiation patterns, input impedance,....) has been evaluated, and also some investigations on the electromagnetic absorption, which is defined by the local specific absorption rate (SAR) distribution, has been calculated in each scenario for a spherical homogeneous head modelled irradiated by a dipole antenna. Results from different conductive media using the same antenna are compared showing that the SAR parameter is not related only to the radiating device but it depends mainly on the external environment. The resonance frequency of the input impedance is affected when the operator is placed near perfect conductor and will change considerably when the human head is surrounded by perfect conductors and the SAR distribution gives different absorption patterns therefore hazards health problems will be enhanced in such situations.