A 2.45 GHz high gain radio frequency energy harvesting system in the Internet of Thing applications

Abstract

To power dedicated ultra-low-power Internet of Things (IoT) devices, high-voltage electric power must be converted to low voltage, which causes losses. Radio Frequency (RF) energy harvesting allows for scavenging ultra-low RF power from nearby RF sources. This paper proposes a single-band RF Energy Harvesting System (RFEHS) for the self-sustainable IoT application. The proposed Square Microstrip Patch Antenna (SMPA) is designed, simulated, and verified using Mentor Graphics software simulations and Computer Simulation Technology Microwave Studio (CST MWS) 3D electromagnetic simulator. For the design and simulation of the rectenna (Antenna + Rectifier), Advance Design System (ADS) is used. The SMPA is fabricated on Rogers RT5880 substrate material having a dielectric constant of 2.2 and a substrate thickness of 2.5 mm. The SMPA peak gain and directivity of 6.81 dBi and 7.24 dBi, respectively, are recorded. The proposed SMPA has an approximately omnidirectional radiation pattern at 2.45 GHz. The SMPA is tested on Vector Network Analyzer (VNA) to validate simulated CST MWS Mentor Graphics results. A single-stage voltage multiplier circuit has been analyzed and discussed using vendor-defined (Murata) library components. The rectenna has a maximum RF to DC conversion efficiency of 65.17% and a DC output voltage of 3.4 V at 10 dBm RF input power and load resistance, R= 3 kΩ. A Transmission Line (TL) equivalent model is derived for the proposed SMPA.