Reduction of Beam Squinting and Cross-Polarized Fields in a Wideband CP Element

Achieving wide circularly polarized (CP) bandwidth in a simple probe-fed microstrip antenna is essential for many practical applications. Existing knowledge guides exploring a thick substrate-based patch design. However, it suffers from two major inherent issues: squinting of beam and high cross-polarized (XP) radiation. No solution is available so far. This letter successfully addresses both issues by imposing restriction on the fringing characteristics as well as modal fields of a suspended substrate circular patch. Engineered ground plane bearing different strategic defects has been explored leading to about 50% correction in beam squinting with reference to antenna boresight and 2–8 dB reduction in a peak XP level. Realistic design, physical insight, and the experimental validation ensure its huge potential for practical applications.