Toward High Efficiency and Sensitivity: Design and Optimization of RF-DC Rectifier with Reconfigurable Logics

Maintenancing batteries and long distance wireless charging for Internet of Things (IoT) devices are challenging because of the shrinking size and always-on functions required by the devices. Radio frequency (RF) energy harvesting systems can convert RF energy into a stable and usable direct current (DC). However, traditional rectifier designs fail to achieve sufficient efficiency with ultra-low input power, so we need to deploy reconfigurable logic circuits to adaptively adjust the topology of the rectifier to improve the performance. In this paper, we discussed both Dickson-type and cross-coupled differential drive (CCDD)-type rectifiers with diverse reliable reconfigurable designs by embedding with maximum power point tracking (MPPT) control elements, provide flexibility and enhance power conversion efficiency (PCE) and power dynamic range (PDR). Despite these advancements, challenges such as increased chip area, power loss due to additional switches, and design complexity still remain. We also discussed future works which should focus on exploring the design optimization and modeling to achieve more efficient and compact RF energy harvesting solutions.