A Self-Powered and Self-Tracking Charging Multifunctional Wireless Power Transfer System

This article introduces a multifunctional wireless power transfer (WPT) system, uniquely capable of self-sustaining power generation and automatic directional charging. This system integrates a retrodirective array (RDA), loaded with active radio frequency (RF) circuits, with solar cells (SCs), thus enabling the RDA to function as a transmitter in the WPT system independently, without reliance on external power sources. This integration facilitates direct solar-to-RF energy conversion while simultaneously achieving self-tracking and targeted RF energy transmission to the device requiring recharging. The proposed system comprises three primary components: the transmitter represented by solar antenna with retrodirective capability, the receiver at the terminal comprising a rectenna, and the power management circuit (PMC) designed for harvesting solar energy and energizing the RF active circuits. The feasibility of the proposed WPT system is substantiated through simulations, assemblies, and measurement processes. Both monostatic and bistatic radar cross section (RCS) measurements were conducted. The outcomes of these measurements demonstrate the WPT system’s proficiency in far-field tracking, facilitating both signal reception and transmission across a significant angular range of
$-$
40
$^{\circ}$
to 40
$^{\circ}$
. Furthermore, the rectifier antenna consistently maintains an optimal output voltage within this angular range. The system’s SC exhibits remarkable efficiency, fully charging a 70-mF supercapacitor within 30 s via the PMC. The proposed work holds the effective merge for multienergy synergy and interaction systems, opening up an ingenious pathway to the utilization of solar and RF energy in WPT systems.