Radiation-Pattern Reconfigurable Antenna for Medical Implants in MedRadio Band

The objective of this letter is to design a radiation-pattern reconfigurable antenna that operates at the Medical Device Radio communications Service band (MedRadio band: 401-406 MHz) for medical implants. By spiraling a monopole, an antenna miniaturization is accomplished. Two artificial switches are employed to perform a radiation-pattern reconfigurable property. The proposed antenna has dimensions of 28 mm x 11.5 mm x 0.6 mm (193.2 mm(3)) and utilizes sub-strate (FRA epsilon(r) = 4.4). A one-layer skin model (epsilon(r) = 46.74, sigma = 0.69 S/m) is adopted for the antenna simulation and in vitro test.