Wireless Energy Transfer from Space to Ground via Satellite Constellation Grids

TL;DR

This paper proposes a satellite grid system for space-to-ground wireless energy transfer, deriving formulas for energy harvesting and analyzing how satellite parameters affect charging efficiency.

Contribution

It introduces a novel framework for satellite-based wireless energy transfer with closed-form energy expressions and simulation insights.

Findings

Milli-joule-level energy can be harvested during satellite visibility.

Charging efficiency depends on satellite number, altitude, frequency, and grid inclination.

Closed-form expressions for harvested energy are derived.

Abstract

This letter presents a framework for space-to-ground wireless energy transfer (WET) for wirelessly chargeable devices (WCD) located in remote areas or disaster situations. We consider a grid of multi-antenna satellites that charge a WCD within line-of-sight. Closed-form expressions for harvested energy are derived considering maximum ratio transmission (MRT) ensuring that the WCD meets its circuit charging threshold $P_{th}$. Simulations elucidate that milli-joule-level energy can be harvested during satellite grid visibility, with charging efficiency influenced by the number of satellites, their altitude, charging frequency, and grid inclination.