Auto-Induced, Radiofrequency, Downlink Exposure Focused at the Human Ear

A numerical study is performed to determine the auto-induced downlink exposure due to 5G New Radio (NR) networks at 3.5 GHz. The exposure scenario consists of a subject situated in the far-field of the base station (BS) equipped with Multiple-Input-Multiple-Output (MIMO) technology and the user equipment (UE) located next to the ear with the BS using two different precoding schemes, i.e., maximum ratio transmission and equal gain transmission, emulating a call over 5G NR. The localized absorption in the head is quantified as a function of the distance between the UE and the ear using two different exposure quantities, i.e., SAR
ear
and psSAR
10g
. Two normalization strategies of the exposure were applied, i.e., normalizing to the average incident power density in free space and normalizing to the incident power density found at the UE. Additionally, two different phantoms were used to assess the exposure and no significant differences were found.