Assessment of Electromagnetic Field Exposure from Multiple Sources Simultaneously in the High-Frequency Range Based on Safety Standards

This study presents a method for evaluating electromagnetic field (EMF) exposure from multiple sources operating simultaneously across a wide range of frequencies, based on the guidelines defined by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) in its 2020 publication. The proposed approach adopts the normalized exposure ratio, which combines the exposure values from all relevant sources and frequency bands. A key issue addressed in this study is the lack of standardized measurement methods for absorbed power density (Sab) in high-frequency bands above 10 GHz, despite the existence of defined exposure limits. A comparison reveals that the difference between the limits for Sab and incident power density (Sinc) for the general public is relatively small when compared to the gap between the general public and occupational exposure limits. Therefore, the use of Sinc is proposed as a temporary surrogate for Sab in frequency ranges where direct measurement is not yet feasible. This approach enables comprehensive exposure assessment from multiple sources under both near-field and far-field conditions. It also serves as a practical alternative while Sab measurement techniques for high-frequency applications such as 5G, WiGig, and next-generation wireless technologies are still under development.