RF Power Transmission for Self-sustaining Miniaturized IoT Devices

TL;DR

This paper presents an RF wireless power transfer system designed for miniaturized IoT devices, achieving over 30% power conversion efficiency and enabling battery-less operation through optimized energy harvesting and management.

Contribution

It introduces a novel RF energy conversion subsystem with impedance matching, rectification, and energy storage, validated experimentally for efficient IoT power harvesting.

Findings

Achieved over 30% power conversion efficiency at -10 dBm input

Peak efficiency of 57% at 3 dBm input power

Demonstrated feasibility for self-sustaining IoT devices

Abstract

Radio Frequency (RF) wireless power transfer is a promising technology that has the potential to constantly power small Internet of Things (IoT) devices, enabling even battery-less systems and reducing their maintenance requirements. However, to achieve this ambitious goal, carefully designed RF energy harvesting (EH) systems are needed to minimize the conversion losses and the conversion efficiency of the limited power. For intelligent internet of things sensors and devices, which often have non-constant power requirements, an additional power management stage with energy storage is needed to temporarily provide a higher power output than the power being harvested. This paper proposes an RF wireless power energy conversion system for miniaturized IoT composed of an impedance matching network, a rectifier, and power management with energy storage. The proposed sub-system has been experimentally validated and achieved an overall power conversion efficiency (PCE) of over 30 % for an input power of -10 dBm and a peak efficiency of 57 % at 3 dBm.