On the General Energy-Absorption Mechanism in the Human Tissue

In this paper, the general energy-absorption mechanism in human tissue is investigated. The purpose is to increase the under- standing of this process, which is important, for example, when design- ing mobile handset antennas with minimized user interaction. The be- havior of the electric fields of small antennas located near a lossy dielectric half-space, which consists of several material layers, is stud- ied by numerical simulations. Two different RF sources operating at 900 MHz are used: a half-wave dipole and a patch antenna on a mobile handset chassis. The results show that the peak specific absorption rate (SAR) is not actually related to the antenna current, as has been com- monly believed. Instead, the location of the SAR maximums can be ex- plained by inspecting the boundary conditions of the quasi-static electric near-fields of the antenna at the air-tissue interface. © 2004 Wiley Peri- odicals, Inc. Microwave Opt Technol Lett 43: 195-201, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20418