High-Power Oscillator and High-Efficiency Rectifier for 900-MHz Wireless Power Transfer System With Minimal Components

Far-field wireless power transfer (WPT) has gained significant attention due to its potential to provide convenient and efficient power transmission overextended distances. In this study, we propose a far-field WPT system that only utilizes a transistor and a diode. A single transistor is used to create a high-power oscillator as the transmitter, while a single diode is used to implement a high-efficiency rectifier as the receiver. The hardware integrates the proposed transmitter, rectifier, and a pair of antennas to build a radio frequency WPT system. The experimental results demonstrate that at a frequency of 900 MHz, the oscillator can deliver an RF power of 32.65 dBm, while the rectifier achieves 90.6% efficiency at a load of
$305 \Omega $
. Furthermore, the distance versus delivered power of the radio frequency WPT system shows that it can provide an output power of 29.22 dBm at a distance of 10 cm and 10.41 dBm at a distance of 80 cm. The results of this study provide valuable insights for the design of a low-cost radio frequency WPT system.