A 62nW, 920MHz Wake-up Receiver with Automatic Offset Calibration Technique

The paper introduces a 920 MHz ISM band envelope detector-first (ED-first) wake-up receiver with a sensitivity of 61.2 dBm sensitivity. The system is built using $180-\mathrm{nm}$ CMOS technology and consumes 62 nW from a 1 V supply at room temperature. The receiving path includes an off-chip matching network, a pseudo-differential envelope detector, a fully differential amplifier, a tunable dynamic comparator, and a correlator. In addition, it incorporates an automatic offset calibration loop (AOCL) to automatically adjust the decision threshold of the comparator and balance the offset voltage caused by circuit mismatches or interference from other transmitters. The wake-up receiver utilizes an 8-bit specific OOK-modulated signal with a data rate of 120 bps as the wake-up event.