Wideband antenna element and array thereof

A wideband antenna element includes first and second spaced-apart, mutually parallel conductive plates. Each plate defines a through aperture and a tapered slot extending from the aperture to an edge of the plate. The apertures and the slots of the two plates are registered. A feed structure including a strip conductor extends in the region between the plates, and crosses the slot at a location remote from both the edges of the plates and the apertures. A stub terminates the strip conductor. Through vias or conductors extend from one plate to the other near the edges of the slots, and near the feed. One embodiment includes dielectric sheets lying between the conductive plates.