EM absorption reduction of helix with shielding material for mobile phone applications

This paper proposes the reduction of specific absorption rate (SAR) with shielding sheet is performed by the finite-difference time-domain method (FDTD) with Lossy-Drude model by CST Microwave Studio. We propose SAR evaluation and reduction methods based on power conservation. It has been shown that even though the use of shielding (ferrite) material not only reduces the SAR in the human head but also the radiated power, it reduces the SAR in head more considerably than the radiated power. Shielding materials have achieved a 58.68% reduction of the initial SAR value for the case of 1 gm SAR. These results suggest a guideline to choose various types of materials with the maximum SAR reducing effect for a phone model.