Study of Body Position Dependence on Human Exposure in the 2.4 GHz Band

Abstract

Personal exposimeters (PEMs) are small battery-powered and portable devices used to measure electric field levels, and suitable for logging data in dynamic conditions. These devices are worn by the user during the measurement campaigns. The disturbance of the logged levels due to the extreme proximity with the body wearer is known as the body shadow effect (BSE). Several factors influence on the attenuation level of logged data due to the BSE. This work evaluates the influence on PEM measurements, of the wave incoming direction on the body, under dynamic conditions and at the frequency band of 2.4 GHz. By comparing experimental measurements and simulated results, the PEM wearer is modeled theoretically as a shadow angle whose value is determined in terms of maximum P-value. The shadow angle is 13° for frontal incidence, and 9°, for back incidence. The BSE corresponds to a lower loss when the waves come directly from the front of the body than when they come from the back. Therefore, the direction of the incoming waves on the human body is a dependence factor for exposure assessment.