laterally shielded exposure cabin with the inner surface covered by pyramidal RF absorbing material
Test subjects wore a special head set consisting of a modified stereo head phone (all metallic parts removed) with small matched helical antennas mounted in a way to achieve an exposure distribution in the head similar to the case of mobile phone usage. Subjects were exposed only at the left side of the head, but they were not informed about this fact.
A detailed dosimetric analysis of the exposure system was based on the power recordings (forward as well as reverse power measurements) obtained during the experiments and extensive numerical simulations using the SEMCAD simulation platform and the anatomical European male head model at a spatial resolution of 1.5-3 mm. The validity of the numerical model of the small helical antennas used was verified prior to the dosimetric analysis by comparisons of experimental and numerical results, showing deviations of less than ±5%. Furthermore, the SAR inside the homogeneous specific anthropomorphic mannequin (SAM) phantom measured using an automated SAR test facility (DASY 3) agreed within ±10% with corresponding SEMCAD calculations. The minimum and maximum values of SAR to be expected in the test subjects' temporalcortex were obtained by an uncertainty analysis, the main contribution (~85%) being due to the variations of the antenna's position with respect to the head, caused by different head sizes and shapes.