Additively Manufactured and Liquid Metal-Sprayed Rectenna for Energy-Harvesting Application

Abstract

This research demonstrates the additively manufactured dual-band radio-frequency (RF) energy harvester for green Internet of Things (IoT) applications. The proposed energy-harvesting system consists of a dual-band circular monopole antenna (CMA) array, an impedance transformer, and a RF rectifier. The CMA array is printed on the circular substrate having a radius of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.007\lambda _{g}^{2}$ </tex-math></inline-formula> to achieve a compact size. The single-stage Villard rectifier converts the RF signal to dc voltage and the impedance transformer matches the impedance between the antenna and the rectifier. The proposed rectenna is 3-D printed on a biodegradable polylactic acid (PLA) substrate using fused deposition modeling (FDM) of 3-D printing. The experimental verification is carried out in RF ambient environment using a horn antenna and RF signal generator. The fabricated configuration offers conversion efficiencies of 72.2% and 51.21% at 2.4 and 5.2 GHz, respectively. The simulation and test results of the proposed configurations are in good agreement. The designed energy harvester would be a suitable source for low-power wireless sensor network-based green IoT applications.