Wideband mmWave Wireless Power Transfer: Theory, Design and Experiments

A new type of wireless power transfer system is presented with wideband mmWave transmitters and rectennas. The proposed system transmits a beam formable and beam steerable signal by exploiting the inherent frequency-dispersive nature of a passive leaky wave antenna, thereby eliminating the need for active phased array and other costly control methods. Multiple nodes can be wirelessly powered simultaneously by using a wideband mmWave rectenna to harvest the frequency scanning signals. A 24-34 GHz rectenna was designed in a highly integrated fashion and has been tested to show its high conversion efficiency of >50% at the frequency and power levels of interest. We have presented a system demonstration for remotely charging diverse nodes at > 1 m distance by using the proposed system with feedback control for the multi-tone frequency modulation and sweeping of the transmitting signals. Our work has showcased the passive beamforming and multi-node tracking of mmWave WPT system using significantly reduced cost and complexity.