Design of a Radio Frequency Energy Harvester Impedance Matching Circuit for 2.4 GHz Microstrip Patch Antenna

Abstract

Energy Harvesting (EH) is the process of capturing energy from external sources and storing it for small wireless autonomous devices. Radio Frequency (RF) EH aims at capturing ambient energy with an antenna and transforms this energy into exploitable power. Different energy fields are available in nature from which energy can be harvested. An impedance matching circuit for an RF energy harvester was designed in this paper. The design is made up of the antenna circuit which captures the RF signals from the mobile and Wi-Fi bands in the atmosphere, and the impedance network that matches between the RF source and the load to capture the power. A Villard voltage multiplier was employed to rectify and step up the captured RF signal into a useable direct current output voltage. Due to the low output voltage obtained after rectification, the voltage was boosted to the power needed for the load. The output of the boost converter was then used to charge a lithium-ion battery. In this paper, Intelligent Schematic Input System proteus professional suite software was used in simulating the designed system. This was used to analyze the performance of each system’s component and to evaluate the quality of the designed circuitry. RF energy harvesters convert electromagnetic waves into usable DC voltage. However, the harvested energy is relatively low to the required voltage. Different techniques have been proposed, but the complexity of energy harvesting persists. This discourages the use of low-power devices. Bridging this gap will improve energy harvesters’ efficiency.