Tubular endfire slot-mode antenna array with inter-element coupling and associated methods

A cylindrical slot-mode antenna comprising:

• a cylindrical substrate comprising a ground plane and a dielectric layer adjacent thereto, said cylindrical substrate defines an interior;
• an array of slot-mode antenna units carried by said substrate;
• each slot-mode antenna unit comprising a pair of patch antenna elements arranged in laterally spaced apart relation about a central feed position and on said dielectric layer opposite said ground plane;
• adjacent patch antenna elements of adjacent slot-mode antenna units comprising respective spaced apart interdigitated edge portions to provide increased capacitive coupling therebetween;
• and
• a feed arrangement coupled to said array of slot-mode antenna units from within the interior of said cylindrical substrate to operate said array of slot-mode antenna units in an endfire mode.