A 152μW −99dBm BPSK/16-QAM OFDM Receiver for LPWAN Applications

This paper presents a 152μW BPSK/16-QAM OFDM receiver operating in the 151MHz Multi-Use Radio Service (MURS) frequency band for low power and long-range IoT applications. Sub-harmonic passive mixers and an injection locked ring oscillator are used, together with a dual-IF architecture for power efficiency and blocker rejection. As a solution for LPWAN applications, the receiver is designed to operate in two modes of single-carrier and multi-carrier transmission schemes, and is implemented in a 40nm CMOS process consuming 152μW of power while achieving a sensitivity of −99dBm for BPSK modulation at 5kb/s and −77dBm for 16-QAM OFDM modulation at 384kb/s. Under only 0.9V of supply, it achieves a phase noise of −128dBc/Hz at 1MHz offset, a blocker rejection of 63dB, and is fully integrated except for the reference crystal and the balun.