EMF Exposure Analysis of Combining Specific Absorption Rate and Incident Power Density Using Canonical Dipoles

The millimeter-wave (mmWave) band has been allocated to the next generation (5G) mobile communication. For 5G devices, the dosimetric quantity of the electromagnetic field (EMF) exposure is the incident power density (IPD) above 6 GHz in lieu of the specific absorption rate (SAR) below 6 GHz. When exposed to sub-6-GHz antennas and above-6-GHz antennas simultaneously, total exposure ratio (TER) could be applied to evaluate EMF exposure. However, TER is not easy to measure because of the alignment difficulty between the SAR and IPD measurement set-ups. To avoid the alignment problem, based on the Gaussian distribution approximation of the SAR or IPD on the skin surface from canonical dipoles, an approximate expression of TER is given in this work. Because of the transition from SAR to IPD, the TER expression lacks a good linear correlation with temperature increase in human tissue. In this paper, we propose the temperature-based TER (TBTER) expression to represent the EMF exposure to human tissue to protect from excessive heating.