Millimeter-Wave Broadband Dual-Polarized Sub-Wavelength Patch Array Fed by E-shaped Patches

A broadband dual-polarized antenna with a single-layer structure is reported in this conference paper. The proposed antenna comprises of two orthogonal placed E-shape patches and 2×2 small square patches, all of which are printed on the same substrate. Each E-shaped patch is excited through a via from its central line with the other two side lines shoring to the ground, and the 2×2 small square patches are coupled by the two E-shaped patches from two adjacent sides. The resonant modes of the E-shaped patches and small square patches contribute to a broad operating bandwidth. An L-shaped neutralization line is introduced to improve the port isolation. Simulated results show that the proposed antenna achieves a broad overlapped impedance bandwidth of 41.35% (29.58-45 GHz) and an isolation higher than 15 dB between the two ports. The cross-to-co polarization level is less than -18 dB. The proposed dual-polarized antenna has features of low cost and ease of fabrication, which is promising for millimeter wave applications.