A Topology-based Array Compensation Empowered by Equivalent Current Modeling of TM10 Patch Antennas for Cross-Polarization Reduction

This paper introduces a comprehensive analysis of cross-polarization effects originating from current imbalances in patch antennas and array configurations. A simplified yet broadly applicable mitigation strategy is proposed, offering a generalized approach to improve cross-polarization performance for antenna arrays operating in the TM10 mode. In contrast to earlier works that predominantly employed heuristic array rotation techniques, the present work adopts a systematic modeling approach to elucidate and regulate cross-polarization across a wide range of array scales and topologies. By utilizing electric current modeling at both the single-element and array levels, and analyzing radiation behavior in multiple planes, the beam pattern characteristics are thoroughly examined. Several optimized array configurations, specifically targeting cross-polarization suppression, are proposed. The proposed array system incorporates a series-type power divider, validated through both simulation and measurement, demonstrating significant suppression of cross-polarization over all scan angles. Notably, the fabricated series power divider achieves amplitude and phase mismatches of less than 3 dB and 10 degrees, respectively, across 16 output branches. The analytical and empirical results outlined in this work establish a conceptual design methodology that achieves substantial cross-polarization reduction without altering individual element geometries. Most significantly, a cross-polarization discrimination (XPD) level of -40 dB is attained in beamforming scenarios. These findings confirm that enhanced cross-polarization performance can be systematically realized by refining array sequencing and periodicity.