A fully integrable RF energy harvester with dynamic efficiency tuning

In the literature, the cold start-up speed and dynamic charging behavior of ultra-low-power threshold-compensated rectifiers is not often addressed and is, in fact, largely ignored. In this paper, we propose a fully-integrated UHF energy harvester realized in a 130 nm CMOS process to shorten start-up time and enhance charging speed. The proposed design relies on active sensing of the output voltage of the rectifier and dynamic reconfiguration of the rectifier. Using these two approaches, the simulation results show that the harvester is capable of charging a 1 nF capacitor to 1 V from −28 dBm input power, within 0.7 ms.