Computation of Whole-Body Average SAR in Realistic Human Models From 1 to 100 GHz

The reliability of numerical human modeling, especially for the skin, is one of the challenging topics in the frequency region above 6 GHz. This study provides a first computation of the frequency dependence of whole-body average specific absorption rate (WBASAR) from 1 to 100 GHz to provide the limit of external power density of the international guidelines using high-resolution anatomical human models. A high-resolution anatomical model with fine-tuned skin thickness was developed to compute the WBASAR. The effects of skin thickness on the WBASAR were evaluated at frequencies >6 GHz where power deposition in the skin predominates. The absorption cross Section (ACS) was derived according to the results acquired using a high-resolution model for semianalytically estimating the WBASAR. The WBASAR is affected by skin thicknesses at frequencies ≤20 GHz. Above 20 GHz, the WBASARs in the models without surface smoothness were 10%–17% higher compared with those in a model with surface smoothing. A simple estimation of WBASAR is also presented in terms of the ACS, in which the ACS becomes close to the projection area above 10 GHz. The WBASAR can be estimated according to a projection area with an accuracy of 5% above 10 GHz.