Dual-Band Multi-Receiver Wireless Power Transfer: Architecture, Topology, and Control

Wireless power transfer (WPT) via near-field magnetic coupling is an enabling technology for many applications including consumer electronics and electric vehicles. A few WPT standards have been established with frequencies ranging from kHz to MHz. MHz operation offers smaller size and higher tolerance to coil misalignment, and kHz operation offers higher efficiency and higher power rating. This paper presents a WPT architecture with new transmitter and receiver topologies that are reconfigurable for dual-band operation. On the transmitter side, we developed a novel architecture based on the reactance steering network (RSN) which can seamlessly compensate an arbitrary load impedance for radio-frequency (RF) power amplifiers. It can transmit power at two frequencies (kHz and MHz range) with decoupled power modulation. On the receiver side, we developed a reconfigurable dual-band rectifier that can achieve a power density of 300 W/inch
³
at both 100 kHz and 13.56 MHz with very low component count. A dual-band reconfigurable WPT system comprising a dual-band transmitter and multiple dual-band receivers has been built and tested. The RSN-based dual-band transmitter can efficiently and simultaneously deliver 15 W of power to multiple receivers at both 100 kHz and 13.56 MHz.