Single polarization slot antenna array with inter-element capacitive coupling plate and associated methods

The slot-mode antenna includes an array of slot antenna units carried by a substrate, and each slot antenna unit has a pair of patch antenna elements arranged in laterally spaced apart relation about at least one central feed position. Adjacent patch antenna elements of adjacent slot-mode antenna units include respective spaced apart edge portions defining gaps therebetween, and a capacitive coupling layer or plates overlap the respective spaced apart edge portions to provide increased capacitive coupling therebetween. The capacitive coupling layer may include continuous or periodic capacitive coupling plates along each gap defined by the respective spaced apart edge portions.