Far-Field Beam Wireless Power Transfer with Combination of Beam Forming and Optical Target Detection

Far-field wireless power transfer (WPT) is an efficient unconscious wireless power system with high efficiency. The present study used optical target-detecting and beam-forming technology to build an unconscious WPT tracking system. The coordinate position of the target is obtained from the image recognition module and transformed into the phase information of the phased array, which transmits microwave waves beyond the target position by controlling the microwave beam. The camera and microcomputer unit are adopted to control the beam in the proposed system. Here, the transmitting array receives the voltage data from the rectenna array via Bluetooth low energy. Then, the transmitting array readjusts the amplitude and the phase. The transmitting system can also adjust the phase with a resolution of 0.09°. We showed that a smartphone can be charged at a transmission distance of 40 cm.