An Ultra-Low-Power RF Energy-Harvesting Transceiver for Multiple-Node Sensor Application

An ultra-low-power wirelessly powered radiofrequency (RF) transceiver for wireless sensor network is implemented using 180-nm CMOS technology. We propose a 98-μW 457.5-MHz transmitter with output radiation power of -22 dBm. This transmitter utilizes 915-MHz wirelessly powering RF signal by frequency division using a true-single-phase-clock divider to generate the carrier frequency with very low power consumption and small die area. The transmitter can support up to 5-Mb/s data rate. The telemetry system uses an eight-stage Cockcroft-Walton rectifier to convert RF to dc voltage for energy harvesting. The bandgap reference and linear regulators provide stable dc voltage throughout the system. The receiver recovers data from the modulated wireless powering RF signal to perform time-division multiple access (TMDA) for the multiple-node system. Power consumption of the TDMA receiver is less than 15 μW. Our proposed transmitter and receiver each occupies 0.0018 and 0.0135 mm² of active die area, respectively.