Cross-Polarization Suppression in Probe-Fed Circular Patch Antenna Using Two Circular Clusters of Shorting Pins

Abstract

A novel aspect in cross-polarization (XP) reduction in probe-fed circular microstrip patch antenna has been proposed employing a pair of symmetric circular clusters of shorting pins (CCSP) peripherally located along the radius of the patch. The proof of the concept is first established using a pair of shorting pins located symmetrically on the circular patch. Once the optimum position of the shorting pins for maximized XP reduction was identified, the design was modified by replacing an individual shorting pin using multiple numbers of shorting pins arranged in a circular geometry that is defined as CCSP. Effect of the incorporation of the CCSP structures on the antenna characteristics like resonance frequency, co-polarized radiation, and cross-polarized radiation has been studied extensively. The design concept has been discussed and experimentally established using simulated and measured results of the CCSP integrated circular patch over conventional circular patch for S-band. The integration of CCSP resulted in a relative suppression in XP levels of around 51 dB at the boresight and an average of 30 dB around ±60° on either side of the boresight in both the principal radiation planes.