SAR Reduction for an Implantable Antenna Using Ferrite Superstrate

Specific Absorption rate (SAR) is one of the most important aspects of biomedical implantable antenna system. It provides the measure of the rate at which energy is absorbed by the human body when exposed to a radio frequency (RF) electromagnetic field. Despite of having the hazards of damaging human tissues due to power absorption and heating, the implantable antennas are of utmost necessity for recent bio-telemetry applications. Hence, the challenge is to reduce the SAR without affecting the normal antenna parameters and effectively keep it inside an IEEEC9S.1-1999 specified value (1.6 W/Kg for 1 g tissue model). In this paper by using a ferrite sheet we have significantly reduced SAR value of an implantable monopole antenna. By this technique about 42% reduction of SAR value has been achieved without compromising the other antenna parameters.