A wideband stacked patch-ring antenna with corner perturbations for circular polarization

This paper presents a method of wideband circular polarization (CP) generation using a stacked patch-ring microstrip antenna with a single probe feed. An enhanced axial ratio (AR) bandwidth is obtained when a combination of a square ring and a square patch with negative perturbations is used as parasitic and driven elements, respectively. The axial ratio bandwidth obtained is significantly larger compared to the case when square rings are used as parasitic and driven rings with a single feed. A simulated impedance bandwidth (S₁₁<; -10dB) of 16%, 3dB AR bandwidth of 8%and a peak gain of 8.65 dBic are obtained from this antenna.