Comparative Study of Numerically Computed Spatial Peak SAR Values in Uniformly Scaled SAM Head Models Exposed to Mobile Phone Radiation

Numerical simulations were conducted to investigate dependence of spatial peak SAR values on head size, and thus reach a conclusion whether child heads absorb more radiation than that of adult ones. A dipole and a generic phone model were used to simulate real mobile phone at 900/835 MHz. The standard SAM phantom represents adult head model. Three child head models were derived after uniformly scaling SAM head in all directions by 90%, 80% and 70%. The experiment results showed that smaller head models produce statistically higher spatial peak SAR values than larger ones. The conclusion is contrary to the results of recent international research study which suggested larger head models tend to show statistically higher spatial peak SAR values than smaller ones. The maximum increase in peak SAR of up to 16% was observed in smallest head compared to that in SAM original head. We noticed relative positions have significant influence on such trend. Post-processing normalization is another important factor to be considered while making comparison. SAR results normalized to antenna current showed small dependence on head size compared to those normalized to antenna power.