RF Energy Harvesting System: Design of Antenna, Rectenna, and Improving Rectenna Conversion Efficiency

The paper presents the discussion and design of a rectenna at 2.45GHz wireless frequency. Rectenna consists of an integration of an antenna and a rectifier circuit. A patch rectenna with FR-4 substrate is designed to map a dip at 2.45GHz to capture Wi-Fi signals and consume power -11.92db. The rectifier circuit includes a bridge rectifier, and instead of a simple diode, Schottky diodes HSMS8101 are used, having a threshold voltage between 0.15-0.45 Volts. The antenna is designed in CST. However, the rectifier circuit and matching circuitry are designed in ADS Keysight. An impedance matching circuitry is used to integrate both designs, which is designed using RL circuit to avoid an imaginary impedance of 3j, and it integrates the designs at 50 Ohm. The proposed rectenna’s RF to DC conversion efficiency is 67.9%, which is much improved for low input power density over a bandwidth of 150 MHz and attained an output voltage of 306mv and output power of 30mW. This research has produced some critical designs and results for wireless energy harvesting, and it is a vital step to the possible widespread application of rectennas soon.