Comparison of temperature elevation between in physical phantom skin and in human skin during local exposure to a 28 GHz millimeter-wave

A millimeter-wave (MMW) at 28 GHz band, a candidate frequency for 5th generation wireless systems (5G), causes some concern about possible adverse effects on the human body. To investigate biological effects of local exposure to MMW, exposure systems equipped with a newly lens antenna, that can irradiate focused beam, were developed and characteristics of exposure for the skin were evaluated. The basic exposure performance of the systems was evaluated using temperature monitoring in physical phantom simulated human's skin and actual skin of forearm. Local temperature elevations were observed in both exposed skins, meaning achievement of results we expected in dosimetry. However, the time courses of these elevations were significantly different. These results suggest that some elements related to the temperature control such as heat conductivity and cooling by skin blood flow should be considered.