Electromagnetic fields radiated by a cellular phone in close proximity to metallic walls

In this paper, we use the transmission line matrix (TLM) method to calculate the specific absorption rate (SAR) in an inhomogeneous model of human head exposed to the near fields irradiated by a mobile phone very close to metallic walls. The cellular phone is modeled as a λ/4 monopole antenna above a rectangular metal box. For computations, two operation frequencies with different radiated powers were selected: a phone model at 835 MHz and 0.6 W, and a phone model at 1800 MHz and 0.125 W. We accomplish a systematic investigation of the change in SAR due to the presence of metallic walls at different orientations and at different distances from the head. The TLM simulation showed that, in some cases, the walls cause significant increases of SAR over the values corresponding to the free-space