A Method for Improving the Cross-Polarization Ratio of Low Profile $*45^{\circ}$ Dual-Polarized Transmit Array Antennas

This article proposes a method for improving the cross-polarization ratio of low-profile transmit arrays (TAs). Due to the inconsistent response of elements with rotational symmetry structure to TE polarization and TM polarization during oblique incidence, electromagnetic waves with
$\pm 45^{\circ}$
polarization undergo polarization torsion. By modifying a T A unit with a rotational symmetric structure, the response of the unit to TE polarization and TM polarization is made consistent under oblique incidence. The improved TA unit design leads to an array with a cross-polarization ratio improved by over 10dB.