A $110\mu \mathrm{W}$ 2.5kb/s −103dBm-Sensitivity Dual-Chirp Modulated ULP Receiver Achieving −41dB SIR

As the number of devices connected to the loT has increased rapidly in recent years, stricter requirements have been placed on loT radio receivers (RX) that can operate in an increasingly crowded spectrum while maintaining ultra-low-power (ULP) consumption, high sensitivity, and low cost. Prior ULP radios utilizing on-off keying (OOK) modulation with $< 1\mu \mathsf{W}$ power consumption offer good sensitivity, but are susceptible to in-band (IB) and out-of-band (OOB) interference and have high latency overhead [1]. As shown in Fig. 24.6.1, high-Q off-chip MEMS resonators and envelope-tracking loops can mitigate OOB blockers and continuous-wave (CW) IB blockers [2], [3], but fail to reject IB pulsed blockers common in the populated ISM bands. Two-tone OOK modulation can alleviate OOB blockers [4], but struggles to address close IB blockers and transient pulsed interferences. The works in [2], [5] achieve strong blocker rejection, but come at the cost of lower sensitivity and higher power consumption compared to other ULP RXs. To address these challenges, we present a dual-chirp OOK (DC-OOK) modulated ULP RX architecture that achieves strong IB and OOB blocker rejection without sacrificing other important RX metrics of sensitivity, power, data-rate, and cost.