EMF exposure study of multilayer human head model at close distance of 28 GHz patch arrays

In the millimeter-wave frequencies, the dosimetric quantity for human exposure to electromagnetic fields changes from the specific absorption rate to incident power density. In this study, we used 28 GHz various fixed-beam patch arrays and plane waves to investigate the temperature elevation in a multilayer model of human heads and its correlation with incident power density in free space. The results show that the averaging area of a few square-centimeters may be a good candidate for the spatial-average power density. The findings provide valuable input to the ongoing revision and updating of relevant safety standards and guidelines.