Self-Tracking Far-Field Wireless Power Transfer System With Tracking and Charging Scheme Enabled by a Programmable Metasurface

Far-field wireless power transfer (WPT) is a key technology for powering large-scale, widely dispersed Internet of Things (IoT) devices. To enable long-distance power transmission, a high-gain, narrow WPT beam is required. As a result, effective tracking of IoT targets becomes a significant challenge, especially when the target is moving. In this article, we present a self-tracking far-field WPT system, featuring an innovative time-diversity tracking and charging scheme enabled by a programmable metasurface. During each duty cycle, the metasurface antenna array is first configured to tracking mode to detect the direction of the beacon signal emitted by the IoT target. Next, the metasurface is reconfigured to charging mode, and the WPT power is directionally beamed to the target. By continuously repeating this duty cycle, the programmable metasurface enables effective WPT tracking and charging for both stationary and moving IoT targets. We have successfully implemented the system, and its WPT performance has been evaluated and validated through experiments. This novel WPT scheme offers a promising solution for powering the massive devices in future IoT systems.