Design of implantable rectangular spiral antenna with U-shaped loop for biomedical applications

In this study, an implantable rectangular spiral antenna with U-shaped loop is designed for medical biotelemetry in the medical implant communication service (MICS) frequency band (402-405 MHz). To verify the potentials of the antenna for the desired applications, a prototype is fabricated and measurement of its performance is carried out in terms of the resonant characteristics and gain radiation patterns. The measured resonant characteristics show good agreement with the predictions, and the -10 dB frequency band is within the range of 398 to 420 MHz. The antenna exhibits a maximum gain of -22.26 dBi and efficiency of 0.215 % in measurement.