Suppression of Cross-Polarized Fields of Microstrip Patch Across All Skewed and Orthogonal Radiation Planes

This letter explores a novel technique to minimize cross-polarized (XP) fields of a microstrip patch across all radiation planes. This inherent issue is more challenging to mitigate over the skewed, i.e., around the diagonal plane of radiation. A possible way to address this specific challenge by controlling the ground plane (GP) current has been discussed. Strategic but simple engineering has been demonstrated with a representative S-band rectangular patch. It shows the possibility of removing as much as 45% metal from the GP cladding, maintaining its impedance and the primary radiations unaltered. The targeted reduction in XP fields has been experimentally demonstrated by a maximum of 10 dB over the diagonal planes and 13 dB in H-plane. This approach should find potential applications in adaptive arrays and space antennas where three-dimensional (3-D) coverage with reduced XP values is an important requirement.