Abstract: Provided herein are various enhancements for planar antennas and corresponding antenna arrays. In one example, an assembly includes a plurality of antenna cells formed in a shared printed circuit board stackup, a rigid superstrate layer mounted onto the printed circuit board stackup, and a substrate layer mounting the printed circuit board stackup to a baseplate. Each of the antenna cells comprise conductive plates at quadrants of the antenna cell and coupled through vias in the layered stackup arrangement from a plate layer to a ground plane layer, flared antenna feeds arranged in an orthogonal pair positioned within central gaps between the conductive plates and below the plate layer, and barrier vias positioned in sets below the conductive plates in each of the quadrants and arrayed about the flared antenna feeds.