A Self-Powered WuRX With RF Energy Harvesting: Time Division Multiplexing for Dual Band

This paper presents a dual-band architecture, which combines radio-frequency energy harvesting (RFEH) and a wake-up receiver (WuRX) for wireless sensor networks (WSNs). By separating the wake-up and energy-harvesting frequency bands, the design eliminates co-channel interference (CCI), improving wake-up sensitivity. To achieve high integration, a frequency-blocking single-balun time-division multiplexing (FB-TDM) is proposed, enabling RFEH and WuRX to share antenna (ANT), matching network (MN), and balun across different frequency bands, without high-loss MOS switches or bulky off-chip filters. Moreover, to address missed detection caused by time division multiplexing (TDM), discontinuity-tolerant coding and correlator are proposed. The self-powered WuRX is implemented in a 65nm CMOS process, occupying an active area of 0.33 mm2. The measurement results show that the chip can harvest RF energy at -35 dBm with a DC output exceeding 0.45 V, and supports wake-up reception at -55 dBm with 50 bps data rate, 158 ms latency, and an energy cost of 3.712 nJ per activation.