Circular Polarized Antenna for Radio Frequency Energy Harvesting Applications in the Smart Cities

Abstract

Objectives: In this work, the Circularly Polarized (CP) broadband antenna with a simple monopole structure is proposed.
Method: The antenna includes the rectangular patch antenna slotted with the four arcs in a circular shape and Top-right, and down-left vertices are removed to obtain the CP and to harvest power from the frequency 1.95-3.05 GHz, it covers the LTE 2100 GHz and Wi-Fi 2.45 GHz, bands. The defected ground structure is considered to design the broadband frequency. The antenna is excited using microstrip feeding. The proposed antenna is simulated, fabricated, and measured. The Dimensions of the antenna are 45 mm x 50 mm x 1.6 mm.
Findings: The maximum gain obtained was 4.71dB at a frequency of 2.45 GHz with a Return loss of -43.21 dB, the axial ratio (AR) obtained 1.98dB (less than 3dB) in the same frequency. The impedance bandwidth of 59.8% and 44.89% simulated and measured, respectively, at 2.45 GHz, and VSWR is 0.128 and 1.142 at 2.45 GHz for the simulated and measured, respectively.
Novelty: The designed antenna radiation Phenomenon resembles omnidirectional characteristics. Rectenna is designed at 2.45GHz and is connected to the antenna with the help of an impedance matching network. It is used to achieve the RF- DC power conversion efficiency of 84.52%.