A Hybrid Solar-RF Energy Harvesting System Based on an EM4325-Embedded RFID Tag

Abstract

This paper presents the deployment of a hybrid energy harvesting system that combines a wireless energy harvesting (EH) system and a 6 V, 170 mA monocrystalline solar energy derived from the Sun’s rays. The hybrid energy harvesting (HEH) system comprises the rectifier, the solar cell panel, the charging circuit, and the EM4325 embedded RFID tag. This study aims to design an efficient EH system capable of increasing the read range of an active RFID tag. The proposed approach integrates a meandered line radio frequency identification (RFID) tag with an EM4325 IC chip as the receiver antenna. A halfwave doubler RF rectifier circuit is connected to the antenna using a 50 Ω SMA connector to convert the captured RF waves into usable electrical power. A solar energy charging module equipped with a Maximum Power Point Tracking (MPPT) system, a rechargeable lithium-ion battery, and a DC-DC converter is configured to manage and store the harvested energy efficiently. The UHF tag antenna operates at 919 MHz, achieving a peak gain of 3.54 dB. The proposed rectenna achieves a maximum measured harvested power conversion efficiency (PCE) of 55.14% for an input power (Pin) of 15 dBm at a distance of 5.10 cm, while the solar cell panel realizes 3.92 W of power. Experimental results demonstrate the hybrid harvester system’s effectiveness, achieving a PCE of 86.49% at an output voltage (VDC) of 5.35 V. The main advantage of this approach is the creation of a compact hybrid RF and solar EH system by combining the solar cell panel with the antenna, thus enabling multi-functionality.

An Efficient Electrothermal Model of a Thermoelectric Converter for a Thermal Energy Harvesting Process Simulation and Electronic Circuits Powering

“…That is why energy harvesting from freely available environmental sources of energy has attracted great research attention [5][6][7][8]. Apart from very wellrecognized free energy sources being subjects of energy harvesting applications, like heat, light [9][10][11], mechanical vibrations [12][13][14], and electromagnetic background [15][16][17], hybrid harvesting systems are also being developed [18,19] and new solutions investigated as pyroelectric or triboelectric [20][21][22]. From the above-mentioned ambient energy sources, heat energy and thermoelectric conversion play increasingly important roles in the fields of energy harvesting and energy scavenging, although the heat-to-energy conversion efficiency still leaves much to be desired.…”