Evaluation of SAR in the human head due to hand ring jewellery at 900 and 1800 MHz
This paper presents the simulated results for the possible effects that hand-ring jewellery may have on the relative levels of the energy absorbed in the human head with cellular phone devices. A homogenous SAM phantom head and hand model was used to understand the related mechanism with the representative sources of PIFA at 900 and 1800 MHz. The jewellery items of same size were modeled as conducting objects and positioned at different fingers of the hand phantom for comparison purposes. The metallic jewellery attached with hand models have achieved 3.8% reduction of the initial SAR value for the case of 1g SAR at 900 MHz while at 1800 MHz it is increased by 2.9%. It was found small but still significant differences in 1g and 10g SAR in the head. The SAR enhancement was clear at 1800 MHz especially when the ring was positioned close to radiating source while at 900 MHz, SAR was reduced. However, rings of small size like hand ring jewellery was not enough to cause resonance effect thus give smaller impact on SAR in the human head.