Human RF-EMF Exposure Assessment due to Access Point in Incoming 5G Indoor Scenario

The study aimed at expanding the knowledge about the assessment of radio-frequency electromagnetic fields (RF-EMF) exposure, considering the novelties introduced by the incoming 5G networks. Specifically, a possible future case of indoor exposure scenario is investigated, where the presence of a 5G access point (AP) in a room is simulated. The AP was modelled by two different indoor uniform planar array (UPA) antennas at 3.7 GHz and at 14 GHz, to evaluate how the beamforming and the higher frequency use could impact the exposure levels. Different scenarios were evaluated, considering the maximum antenna gain, two different human computational models, an adult model and a child one, and by varying the distance and the orientation between the UPA antenna and the two models head. All the simulations were conducted using the Sim4Life platform and in particular the exposure levels were expressed by the specific absorption rate averaged on 10 g of tissue ( $SAR {_\text{10}{g}}$ ), which was analyzed for the skin and for some specific tissues. The work underlined that the highest $SAR {_\text{10}{g}}$ values were obtained in the head area for all scenarios, with the skin $SAR {_\text{10}{g}}$ highest peaks when the UPA is placed laterally to the human model (195.73 mW/kg and 223.29 mW/kg for the adult and child model, respectively, for 100 mW input power). Furthermore, the work permitted to highlight that the $SAR {_\text{10}{g}}$ exposure levels are slightly higher for the child model, compared to the adult one and that the distance between the UPA antenna and the human models could greatly lower the $SAR {_\text{10}{g}}$ levels. At last, it was found that the $SAR {_\text{10}{g}}$ exposure levels obtained with the UPA antenna at 14 GHz were lower than the ones at 3.7 GHz, although further investigations will be necessary.