Hexagonal ring electromagnetic band gap‐based slot antenna for circular polarization and performance enhancement.

In this article, a hexagonal ring electromagnetic band gap (HREBG) structure‐based circularly polarized (CP) slot antenna for improving performance is proposed. The proposed antenna has a compact structure with a low profile of 0.517λo × 0.517λo × 0.055λo (λo stands for the free space wavelength at 5.10 GHz), is coplanar waveguide fed, and comprises of a circular microstrip patch with a T‐shaped slot. An inclined coupling slot loaded feed line is used on the ground for the generation of CP. Furthermore, eight HREBG's are implemented on the substrate to enhance the performance of the antenna, thereby achieving a measured impedance bandwidth of 18%, 3‐dB axial ratio bandwidth of 6.4%, and a peak gain of 5.93 dBi in the operating bandwidth. A close agreement is reached between the experimental results and the simulated results to verify the proposed antenna's performance. [ABSTRACT FROM AUTHOR]