Characterisation of Energy Deposition in the Head from Cellular Phones

This paper is an extension of previous work on the evaluation of power deposition in the head from hand-held transceivers deployed at 900 and 1800 MHz. A realistic model of the head was produced by segmenting a close-grained set of serial MRI slices from one subject. A generic transceiver was considered to be a λ/4 monopole on a metal box. The purpose of that study was to find the maximum SAR values averaged over I g and 10 g for comparison with protection standards based on thermal considerations. The present work investigates the distribution of energy deposition in the head with particular reference to putative sites of cancer induction. Various modifications of the original model had to be made to perform this study including the introduction of the paired parotid, submaxillary and sublingual glands. The SAR distribution in the head at 900 and 1800 MHz has been calculated for various positions of the transceiver. The importance of attenuation through the head and its effect on the bilateral distribution of SAR in paired organs such as the salivary glands, ears and tear ducts is noted.