Reduction of Specific Absorption Rate using carbon foam inside enclosures

Abstract

The interaction of a mobile antenna and a passenger is analyzed inside a metallic enclosure. The specific absorption rate (SAR) of the passenger in the elevator using a mobile phone is calculated. A standardized model of human head is filled with liquid that simulates the RF absorption characteristics. The non-uniform mesh technique in frequency domain is employed to obtain 1g SAR [Specific Absorption Rate] and other important parameters. The mobile phone is modeled as a quarter wavelength Planar Inverted F Antenna (PIFA), and it is of .01m from the head. PIFA is operated at frequencies of 900 and 1800MHz with transmitting power .3 W . It is observed that the values of SAR inside the metallic enclosure exceeds the RF safety limits. Therefore, this project proposes a novel method to reduce the SAR by using carbon foam which absorbs microwave radiation. Simulated results have evidenced the efficiency of the proposed technique of SAR reduction inside the enclosures.