Conformity Assessment of Human Exposed to Radiation From Millimeter-Wave Vehicles Radars

The widespread adoption of advanced driver assistance systems (ADAS) has increased the use of millimeter-wave (mmWave) radars in vehicles, raising concerns about potential electromagnetic field (EMF) exposure for pedestrians. International guidelines for human exposure have introduced absorbed power density (APD) and incident power density (IPD) as physical quantities for evaluating local exposure above 6 GHz. However, pedestrian exposure to automotive radars has been insufficiently investigated, particularly in vehicle–pedestrian interactions with radar operating while stationary. This study employed computational simulations and experimental measurements to evaluate the exposure from a 12 × 1 patch antenna array operating at 79 GHz. Exposure scenarios were analyzed using simplified geometric models and anatomically realistic human models at varying distances and equivalent isotropically radiated power (EIRP) levels. The results demonstrate a good agreement between the simulated and measured electric field distributions in both the near- and far-field regions. For continuous exposure, APD values obtained from anatomical models were consistently lower than those obtained from simplified geometries. At EIRPs of 26.7 dBm and 35.4 dBm, both APD and IPD remain within permissible limits across all distances. In contrast, the exposure at higher power levels (e.g., 55 dBm EIRP) exceeded the APD threshold. Nevertheless, evaluation using absorbed energy density, a metric for brief exposures, indicated compliance even when the human model was positioned directly adjacent to the vehicle surface. These findings provide critical insights into ensuring the conformity and design of next-generation automotive radar development.