Impact of textile on electromagnetic power and heating in near-surface tissues at 26 GHz and 60 GHz

With the development of 5th generation (5G) networks the operating frequencies have been progressively expanding towards millimeter waves (MMW). In some exposure scenarii, presence of textiles impacts the interaction of the electromagnetic field radiated by wireless devices with human tissues. We investigate the impact of a textile layer in contact or in proximity of skin on the power transmission coefficient, absorbed power density and temperature rise using a near-surface tissue model at 26GHz and 60 GHz. Cotton and wool are considered as representative textiles. Our results demonstrate that the textile in contact with skin increases the absorbed power density up to 41.5% at 26 GHz and 34.4% at 60 GHz. The presence of an air gap between a textile and skin modifies the electromagnetic power deposition in the tissues depending on the thicknesses and permittivity. The temperature rise increases compared to the bare skin by up to 52% at 26GHz and 46% at 60 GHz with the textile in direct contact with skin. With an air gap, for typical textile thicknesses, the temperature variations range from −3.5% to 20.6% and from −11.1% to 20.9% at 26GHz and 60 GHz, respectively.