Fully Passive RF Wake-Up Receiver Including a Small Loop Antenna With −30.7-dBm Sensitivity at 26-kbps Bitrate

This brief presents a fully passive RF wake-up receiver (WuRX) fabricated in a 130nm CMOS process with a matched small loop antenna. The WuRX consists of a high-sensitivity RF energy harvester that supplies the circuitry necessary for passive WuRX functionality. The circuit consists of an on-chip voltage reference, current reference, power-on reset, low-dropout regulator, relaxation oscillator, envelope detector, comparator, and a digital processor. The WuRX supports an input bitrate of 26 kbps and has a user-defined 12-bit wake-up pattern. Measurements at 830 MHz reveal a wake-up sensitivity of −30.7 dBm and a 1V harvested output sensitivity of −31 dBm. The RF-powered fully-passive WuRX paves the way for autonomous batteryless sensor nodes.