Enhanced Axial-Ratio Bandwidth Single-Point-Fed CP Antenna Using Slot Structure Modification

Abstract

In this paper, a compact single-point-fed circularly polarized antenna with enhanced axial ratio (AR) bandwidth is investigated. A combination of parasitic strips and modified geometry of the wide-slot is used to improve circular polarization (CP) performance of the antenna. The total footprint of the antenna is only 25×25 mm2. With the proposed technique, an impedance bandwidth |S 11 | ≤ −10 dB of ~70-percent (4.2 GHz- 9.05 GHz), and AR bandwidth ≤ 3 dB of 48-percent (5.4 GHz to 8.65 GHz) has been achieved with the average realized gain of 3.1 dBi through the CP operating band. A stable bidirectional radiation pattern with left- hand CP and right-hand CP in the ±z-direction is observed.