An RFID front end for smart biological sensing

Wirelessly powered implantable smart RFID sensors must be capable of performing intended functions reliably for decades without replacement. As a result the focus for implantable RFIDs is on efficient energy harvesting, low power VLSI and biocompatibility. In this paper we present a far field RFID front end consisting of RF to DC converter, Low Drop Out regulators (LDO) which provides supply for control and signal conditioning, the Phase Lock Loop (PLL), demodulator and modulator for effective communication. The RF front harvests up to 42μW at -3dBm, the clock data recovery PLL consumes 2.86μW providing a systems clock of 5.12MHz.