MSCR: Multi-Source-Collaborative Reconfigurable RF Energy Harvester With 3-D MPPT Achieving -32 dBm Sensitivity and 8x Boost in Available Output Power

This paper presents a multi-source-collaborative reconfigurable RF energy harvesting (MSCR-RFEH) interface IC that can efficiently harvest and combine the energy from four RF sources. The proposed interface can regulate three loads at different voltages using a single-input multiple-output (SIMO) buck-boost dc-dc converter with low cascading loss. It implements a novel event-triggered 3-D maximum power point tracking (MPPT) achieving self-adaptive regulation and high MPPT accuracy by optimizing the rectifier reference voltage, searching the rectifier effective stage and regulating the converter input. Fabricated in a 65 nm CMOS process, the proposed interface IC achieves 32.2% peak efficiency, -32 dBm sensitivity, 99.2% peak MPPT accuracy, and a 10.5 dB input range with efficiency >20%. Compared to the single-source reconfigurable architecture, it achieves a 6 dB improvement in sensitivity and an 8x boost in available output power.