An implantable Hilbert PIFA antenna for RFID based telemetry

In this paper, a Hilbert planar inverted F-antenna (H-PIFA) is presented that has been designed to be functional in the Australian 900MHz ISM band (915-928 MHz). The antenna is intended to be attached to an RFID PCB board which is further implanted under the skin of laboratory rats. The overall dimensions of the antenna including the ground plane are 25×25×7.6 mm³. Although the bandwidth of the antenna is only ~3%, the total efficiency is around 60% which is significant for implantable antennas. Return loss, impedance bandwidth and radiation patterns have been investigated and found being useful for a short range (2~3m) RFID telemetry link.