Wireless power transfer: Exposure assessment for grounded and ungrounded human body

This study compares the exposure of a grounded and ungrounded human body to a representative resonant wireless power transfer (WPT) system. A Duke human body model is adopted all along the paper. Exposure levels with respect to the ICNIRP basic restrictions are assessed as a function of the distance between the WPT system and the ground, and reported in terms of dosimetric quantities E
99
, J
1cm2
, as well as local and whole body SAR. Maximum allowable input power is computed for the considered scenarios. The results demonstrate that, peak dosimetric values are much higher in grounded than ungrounded scenarios independently of the distance of the WPT system from the ground. For the grounded cases, as the WPT system gets closer to the ground, higher exposure levels are induced inside the body in terms of J
1cm2
and SAR
10g
as a difference to E
99
and SAR
wb
. Moreover, SAR
10g
is found to be the most restrictive dosimetric quantity.