Design of Circularly Polarized Koch Snowflake Fractal Antenna With Schottky Band Diode Rectifiers for RF Energy Harvesting Applications

Radio frequency (RF) energy harvesting has recently become an effective way of powering wireless devices, reducing the requirement of batteries along with their related storage as well as lifespan restrictions. One of the main obstacles to RF energy harvesting is the limited quantity of energy that can be obtained from wireless sources due to weak signal strength, low efficiency, and poor gain. To address these shortcomings, the proposed method is designed based on the circularly polarized Koch snowflake fractal antenna with the Jerusalem cross (JC)-based frequency-selective surface (FSS) and Schottky diode-based rectifiers for RF energy harvesting applications at the resonance frequency of 5.8 GHz. The electromagnetic energy from the environment can effectively captured using a proposed wide band and high gain antenna designed using a Koch snowflake array based on FSSs. Flame Retardant-4 (FR-4) material has good dielectric qualities for electronics, and it is employed as the dielectric substrate in this model; copper serves as the ground plane. The squid game optimizer (SGO) determines the ideal outer snowflake dimensions by maximizing the resonance frequency in order to achieve high gain. The optimally selected outer snowflake length and width are 40 and 23.09 mm. The designed antenna model uses a rectifier based on Schottky diodes for RF energy harvesting applications, which involves converting electromagnetic waves into direct current. The fractal antenna model and RF energy harvesting are designed and simulated using the ANSYS HFSS and Matlab RF toolbox. The model is used to evaluate the antenna's performance by concentrating on gain radiation patterns, S11, and voltage standing wave ratio (VSWR). The Koch snowflake fractal antenna, which uses a JC-based FSS, has been measured for performance at 5.8-GHz frequency; the values obtained for impedance bandwidth, gain, S11, and VSWR are 7.61%, 9.962 dB, -33 dB, and 1.01, respectively. The analysis of the experimental data demonstrates that the Koch snowflake fractal antenna, which is being proposed for energy harvesting applications, outperforms several other existing designs in terms of effectiveness.