Single-Paint-Fed Broadband CP Antenna With Enhanced Axial Ratio

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 $25\times 25\ \text{mm}^{2}$. With the proposed technique, an impedance bandwidth $\vert \mathrm{S}_{11}\vert \leq-10$ dB of ~70-percent (4.2 GHz- 9.05 GHz), and AR bandwidth $\leq 3\text{dB}$ 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 $\pm z-$ direction is observed.