Ultra low power 900MHz/225MHz transceiver based on injection locking for a semi-active RFID sensor node

This paper presents an ultra low power transceiver with 900MHz BPSK downlink and 225MHz ASK uplink using injection locking based architecture for a semi-active RFID sensor node. For BPSK demodulation, two second harmonic injection locked oscillators (ILO) are employed to convert BPSK signals to ASK signals, which are then demodulated by an envelope detector to baseband. The oscillating signal at one receiver ILO also injects to another transmitter ILO for accurate carrier generation to avoid local frequency synthesis circuits at both the transmitter and receiver. Designed in a 45nm CMOS technology, post-layout simulation indicates that the transceiver achieves downlink bit rate of 10Mb/s at the sensitivity of -40dBm and uplink bit rate of 10Mb/s at the transmitted power of -24 dBm with total power consumption of 631μW.