Low Power On/Off Control Method for Active-Diode Applied in Wireless Power Transmission

In this paper, multiple-pulse (MP) problem of comparator based active rectifier is theoretically analyzed by establishing control loop model. Two methods to eliminate the MP problem are demonstrated. Then a delay time based high precision on/off control method is proposed. The new controller senses the current passing through MOSFET and generates the gate driving signals to control the next operating cycle of the active rectifier. Under a 13.65 MHz wireless power transmission test platform, with the same rectification parameters, the experimental results show that the quiescent power consumption of the proposed controller is reduced by 2/3 compared with that of the comparator-based structure. The reverse current is almost eliminated because the on/off control precision reachesps level. Thus, the conversion efficiency of the rectifier is improved significantly. The good performance of the proposed design shows its well practicality for energy harvesting systems.