A Metamaterial-inspired Approach to RF Energy Harvesting

TL;DR

This paper presents a novel RF energy harvesting rectenna design inspired by metamaterials, utilizing a Fabry-Perot cavity resonance to significantly enhance energy capture and conversion efficiency at low power levels.

Contribution

The work introduces a metamaterial-based rectenna with a Fabry-Perot cavity resonance that greatly improves RF energy harvesting efficiency, especially at ambient RF levels.

Findings

16-fold improvement in RF-DC conversion efficiency

Enhanced voltage across Schottky diodes due to high Q-factor resonance

Effective energy harvesting at low ambient RF power levels

Abstract

We demonstrate an RF energy harvesting rectenna design based on a metamaterial perfect absorber (MPA). With the embedded Schottky diodes, the rectenna converts captured RF waves to DC power. The Fabry-Perot (FP) cavity resonance of the MPA greatly improves the amount of energy captured. Furthermore, the FP resonance exhibits a high Q-factor and significantly increases the voltage across the Schottky diodes, which improves the rectification efficiency, particularly at low power. This leads to factor of 16 improvement of RF-DC conversion efficiency at ambient intensity level.