3-D Wireless Power Transfer With Noise Cancellation Technique for −62-dB Noise Suppression and 90.1% Efficiency

This letter proposes a wireless power transfer (WPT) that includes three single-coil transmitters (TX) and one central controller to arrange the power transfer of each TX according to the 3-D position of the receiver (RX). The proposed noise cancellation technique uses the auxiliary coil to enhance the received signal by 52% and the noise can be reduced to −62.6 dB. The demodulator and the vector detector at the central controller can obtain and use the $k$ factor of each TX to decide the power transfer of each TX. The peak efficiency of the main TX can reach 90.1% and the maximum power is 69 W with 3TXs.