Design of a High-Gain Reflector-Based Slotted Antenna for RF Energy Harvesting Application

This study presents the design, analysis, and implementation of a rectenna system (rectifying antenna) optimized for RF energy harvesting in IoT applications. With the exponential growth of low-power IoT devices, sustainable power solutions are increasingly critical. Our work introduces a novel heptagonal patch antenna with strategically placed slots functioning at 2.45 GHz. The design fabricated on FR4 achieves a substantial gain improvement from 2.63 dBi to 6.1 dBi at 2.45 GHz and 11.5 dBi at 2.42 GHz through the integration of a reflector positioned 20 mm behind the antenna. A voltage doubler rectifier circuit utilizing SMS7630-079LF Schottky diodes successfully converts the harvested RF energy to DC power. The proposed rectenna provides a DC output voltage (VDC) of 180.8 mV placed at 45 cm from the commercial Wi-Fi router, demonstrating the solution's suitability for powering low-energy IoT devices. This cost-effective approach addresses key issues in IoT deployment by eliminating dependencies on conventional batteries and providing a sustainable alternative power for smart city applications, including agriculture, healthcare, smart factories, and transportation.