![]() These restriction values are based on evidence of microwave-induced thermal effects and dosimetric findings of thermal changes ( 2– 5) and also include the safety factor considered with the individual differences and age. ![]() For example, the restriction values in occupational and general public exposures for the local exposure (6–300 GHz) including the MMW band are 100–20 W/m 2, respectively. To provide protection against known adverse health effects, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) established guidelines ( 1), which specify the basic restriction values in terms of specific absorption rates (SAR, W/kg) or absorbed power density (W/m 2) for occupational or general public. But this causes some new concerns about possible adverse health effects on the human body. The use of millimeter waves (MMW) such as 5th generation (5G) wireless systems and WiGig (IEEE 802.11ad) is now widely expanding. Under these exposure conditions, the local temperature changes, which could evoke warmth sensations, were obtained at the target area of the human forearm skin, which means the achievement of exposure performance we intended. The interference fringes generated in the exposed area due to the combined two-directional beam radiations were observed both in the simulation and in the phantom experiment but eliminated by applying an orthogonalizing polarized feeding structure. The exposure performance we estimated was verified by temperature elevations of surface in a physical arm-shaped silicone phantom during the MMW exposure. Variety distributions and intensities of electromagnetic fields at the exposed area, which is modified by incident angles of the combined beams, were simulated using finite-difference time-domain methods. A spatial synthetic beam-type exposure setup using two dielectric lens antennas was proposed to achieve high intensity 60 GHz irradiation to the target area of human skin. To investigate biological effects of local exposure to 5G-MMW on human body, a novel 60 GHz band exposure setup was developed, and its performance was validated. The global spread of 5th generation (5G) wireless systems causes some concern about health effects of millimeter waves (MMW).
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