A UTD/FDTD model to evaluate human exposure to base-station antennas in realistic urban environments

A technique combining uniform asymptotic theory of diffraction and finite-difference time-domain (UTD/FDTD), suitable to characterize human exposure in realistic urban environments at a reasonable computational cost, is presented. The technique allows an accurate evaluation of field interaction with penetrable objects (walls, windows, furniture, etc.) and of power absorption in a high-resolution model of the exposed subject. The method has been applied to analyze the exposure of a subject standing behind a window in a building situated in front of a rooftop-mounted base-station antenna. A comparison of the obtained results with those computed neglecting the presence of the building (free-space condition) evidences that a realistic modeling of field propagation in the actual scenario is essential for an accurate evaluation of absorbed power distribution inside the human body.