A Fraunhofer-Based Approach for the Assessment of the Field Radiated in the Fresnel Region of an Antenna

The letter focuses on a simplified and conservative method for the assessment of the electromagnetic exposure in proximity of a radiator. The method allows the use of the Fraunhofer antenna pattern to estimate the electromagnetic field radiated in the Fresnel region of base transceiver station (BTS) antennas. The proposed approach is introduced from a theoretical point of view and validated with simulations and measurements on linear and planar array systems. For its application, a specific description of the boundaries of the Fresnel region for a generic antenna of parallelepipedal shape, which takes into account the dependency from the direction of observation, is introduced. The method provides a rapid and simple solution of assessment issues in relation to the electromagnetic fields exposure limits.