Efficient Wide-Power-Range RF Power Harvesting System for Self-Sustainable Wireless Sensor Nodes: IEEE ICMMT 2025

This paper proposes an efficient wide-power range radio frequency (RF) power harvester to address the challenge of reduced power conversion efficiency (PCE) in wireless power harvesting systems (WPHS). To manage the variable load conditions introduced by a DC-DC boost converter, a power partitioning network within the power harvester was designed. This network automatically adjusts the power ratio between two branches of the power harvester at different input power levels. As a result, a wide dynamic power range with high PCEs is realized, while showing a stable output voltage of 2.8 V. The proposed power harvester demonstrates a measured PCE larger than 70% at 2.45 GHz over an input power range of 2.7-13.3 dBm. It successfully charges a super capacitor to 3.3 V, forming a reliable WPHS with wide dynamic power range. Finally, a totally self-sustainable wireless sensor node based on this system has been demonstrated.