Triple-Band Modified Square Slotted Antenna with Enhanced Gain for RF Energy Harvesting

Abstract

A tri-band symmetrically truncated modified square slot antenna with enhanced gain integrated with a triple-band rectifier for low-power RF energy harvesting applications is presented in this paper. The antenna triple bands of 1.9 GHz, 3.1 GHz, and 6.4 GHz are obtained by coupling the slot with an optimized microstrip feed line length of 37 mm. To enhance the realized gain, a full copper patch reflector size greater than the antenna size is positioned in the bottom of the antenna at a distance of λ/4. where ‘λ’ is free space wavelength at the lowest frequency of 1.9 GHz. A single diode series-configuration-based triple-band rectifier along with an impedance matching network is designed at the aforementioned similar frequencies of the antenna. The designed prototypes are fabricated, measured the essential parameters, and compared with the simulation results. The measurement results show that the enhanced gains of the antenna are 4.8 dB, 6.7 dB, and 8.9 dB obtained at the corresponding frequencies, and the rectenna peak conversion efficiency reached 27% at an optimized values of 1 KΩ load resistance and –5 dBm input power. The proposed triple-band rectenna is found to be suitable for low-power RF energy harvesting and wireless power transfer applications. © 2021 IEEE.