A Fully Integrable 915MHz Implantable Antenna System for Long-range Telemetry in Rodents

In this paper, an implantable planar inverted-F antenna (PIFA) operating in the industrial, scientific, and medical (ISM) band (915 MHz) is proposed. It was designed and fabricated on a flex printed circuit board (PCB) platform and is capable of full integration with driving circuitry for biopotential measurements. The antenna's dimensions (26mm x 54mm x 0.2mm) were optimized for implantation and use in Norway rats to facilitate wireless biomedical testing. In a live rodent model, the antenna showed a peak S11 of -17.94 dB at its resonance frequency with a peak gain of -3.94 dBi, an efficiency of 14.86%, and a -10 dB bandwidth of 42.21 MHz. To the best of our knowledge, this paper marks the first time a 915 MHz antenna was specifically built for implantation using a flex PCB substrate and a parylene-C insulating coating.