A 5.2 GHz BFSK Receiver with On-Chip Antenna for Self-Powered RFID Tags and Medical Sensors

A completely integrated receiver design suitable for short range wireless applications is presented. The circuit represents one half of an SoC solution that makes use of an on-chip antenna, and consumes 5.5 mW while receiving. A thin film ultracapacitor and a solar cell can be stacked on top of the chip to supply power to the radio; yielding a completely integrated solution. The receiver makes use of a PLL to initially lock an RF VCO which is then allowed to be injection-locked to an incoming FM signal. An integrated antenna provides adequate gain given the short range radio's intended applications. The solution has a communication range of 1.75 m which can be increased at the expense of the bit-rate, increased power consumption in the receiver, or by using off-chip antennas.