UHF energy harvesting system using reconfigurable rectifier for wireless sensor network

In RF energy harvesting, due to the variation of the available RF power, the conventional Dickson rectifier could not achieve the optimal harvesting efficiency in a wide available power range. To tackle this issue, in this work, a reconfigurable rectifier with adjustable conversion ratio is proposed without affecting the matching with the antenna under different configurations. Based on this, a UHF (900 MHz) energy harvesting system with maximum power point tracking (MPPT) is proposed. The system is implemented using TSMC 65 nm CMOS process. Post-layout HSPICE simulation is performed for verification. With the MPPT, the reconfigurable rectifier is always configured to achieve the maximum efficiency.