A 4 nW, -77 dBm Sensitivity Wake-up Receiver with Differential Gate-biased Envelope Detector

This paper proposes an ultra-low-power wake-up receiver (WuRX) based on SMIC 55-nm ULP CMOS technology. The receiver front-end utilizes a 25 -stage differential passive envelope detector with gate biasing, eliminating the off-chip balun and enhancing sensitivity. The baseband circuit is improved and designed with a combination of high and low threshold transistors, allowing it to operate at a supply voltage of 0.4 V VDD. The proposed WuRX achieves a sensitivity of -77 dBm and a power consumption of 4 nW at an operating frequency of 915 MHz.