Sep 18, 2006
Characterization of the Electromagnetic Near-field Absorption in Layered Biological Tissue in the Frequency Range from 30 MHz to 6000 MHz
Andreas Christ, Theodoros Samaras, Anja Klingenböck and Niels Kuster in Physics in Medicine and Biology, Volume 51, Number 19, pp. 4951-4966, October 2006
New functionality of mobile phones and new wireless applications result in other exposure scenarios than exposure of the head. As a consequence, various tissue regions of the body are exposed to electromagnetic radiation. This paper identifies two different effects which can lead to increased SAR in layered tissue in comparison to the SAR assessed using homogeneous tissue simulating liquid: (1) for larger distances between the tissue and the antenna, standing wave effects occur depending on the frequency and fat layer thickness. (2) In the very close near-field, reactive E-field components lead to high local absorption in the skin. The latter effect occurs at lower frequencies and depends on the antenna type. A conservative exposure estimate can be obtained by applying a multiplication factor between 1 and 3 to the values assessed using current experimental dosimetric techniques.
