Design of High Efficiency Rectifier Circuit for 920 MHz Wireless Power Transmission

In recent years, wearable devices have attracted attention in medical and welfare settings. By attaching a wearable device to patients, it is possible to constantly detect and manage the patient's biological information. However, due to the feature of long-time operation, the weight of the battery and the trouble of replacing it are problems. As a method to solve this problem, it is considered to make battery-less by power supply using wireless power transmission. In this study, we designed a 920 MHz high-efficiency rectifier circuit for wireless power transmission for wearable devices. In the simulation of the rectifier circuit, rf-dc conversion efficiency of 90% was achieved. In the measurement, maximum rf-dc conversion efficiency was 85%.