Design and Characterization of an Active Low-Pass Envelope Detector for Wake-Up Radio Receivers

This paper presents a design flow for an active low-pass (LP) Envelope Detector (ED) for Wake-Up Radio (WUR) receivers and provides insight on the well-known bitrate-sensitivity-current trade-off and on additional aspects which may be critical in Internet of Things (IoT) applications, such as maximum receivable input power and robustness against Continuous Wave (CW) interferers. The implemented LP ED, designed using the STMicroelectronics 90-nm BCD technology, receives 400-bit OOK-modulated packets with an 868-MHz carrier frequency and achieves -35.5-dBm sensitivity with a 2.7-nW power consumption. Finally, it receives input power levels up to 15 dBm and achieves 22-dB Signal-to-Interference Ratio (SIR) with a CW interferer with a 100-kHz frequency offset.