Numerical modeling of adsorption and scattering of EM energy radiated by cellular phones by human arms

The antenna radiation pattern and other characteristics are significantly altered by the presence of the human body. This interaction as well as the resultant deposition of microwave power in the body (specific absorption rates) are of particular interest for cellular phones and similar devices. For arbitrary shaped obstacles numerical methods prove to be very effective in analyzing such effects. This paper presents the numerical modelling of electromagnetic energy absorption and radiation by cylinders of biological tissues simulating human arms. The numerical analysis is performed with the method of moments applied to a coupled pair of surface integral equations involving unknown surface fields. The influence of various parameters on the SAR and scattered energy has been computed. Our findings are: (i) the internal electric field distribution, hence the SAR shows strong resonance effects and possible 'hot spots'; (ii) an arm holding the handset absorbs a significant amount of power causing the fear of health hazards; and (iii) the scattered energy by the hands is also appreciable and alters the antenna pattern significantly. The frequency chosen is 900 MHz.