Compact slotted semi-circular antenna for implantable medical devices

A novel, compact, semi-circular, implantable, planar-inverted-F antenna (PIFA) is presented for the medical implant communications services (MICSs) band (402-405 MHz). By cutting three arc-shaped slots in a semi-circular patch, the proposed antenna can obtain effective size reduction. The total volume of the proposed antenna, including substrate and superstrate, is about 151 mm³. A bandwidth of 25 MHz is obtained at return loss of 10 dB. In addition, the radiation and specific absorption rate (SAR) performance of the antenna are examined and characterised.