A Dynamic Impedance Matcher to Broaden Input Power and Load Ranges for High-Power Rectifier in Microwave Wireless Power Transmission

This brief presents a dynamic impedance matcher (DIM) for high-power rectifier in microwave wireless power transmission (MWPT) to enhance microwave rectifier efficiency over wide ranges of input power and load. The DIM based on an isolated Sepic converter performs dynamic impedance matching with the maximum power point tracking (MPPT). One digital processor is used to control multiple DIMs simultaneously to reduce power consumption. The DIM is implemented by a microcontroller and analog circuits and applied to 2.45 GHz system-level verification. The experimental results show that the overall power conversion efficiency (PCE) of the rectifier with DIM can reach more than 60% for the input power of 30 - 37 dBm and the load of 10 - $4000~\Omega $ , where the efficiency of the isolated DIM reaches 91.7%. The input power range above 60% PCE of the rectifier is at least 3 times of that under the situation without DIM and 10 times for the load range as well.