A dual polarized CPW-Fed aperture-coupled stacked patch

Abstract

This paper presents concept of a broadband, dual-polarized aperture-coupled stacked patch fed by coplanar waveguide (CPW). The isolated ground planes in a coplanar feed line are known to support various unwanted propagation modes, which lead to severe degradation in antenna performances, especially the isolation between two orthogonally polarized channels. Consequently, it is very difficult to feed a dual polarized CPW-fed patch and achieve good isolation between two polarizations, especially in the case of an aperture-coupled patch where a back-cavity is required. The proposed structure eliminates these couplings between the orthogonal feed-lines by using an H-slot feed and an E-slot feed in a symmetrical collinear geometry. This method enables collocation of two orthogonally polarized radiators within close proximity with a relatively broad frequency bandwidth of over 25% (VSWR 1.5:1) and good isolation of typically 30dB between the two polarizations.