US Patent 9991607 Circular array of ridged waveguide horns

An antenna horn includes an upper waveguide ridge and a lower waveguide ridge shaped to provide impedance matching. The antenna horn operates unimodally within a 6:1 instantaneous bandwidth. A circular array of antenna horns produces an enhanced radiation pattern in a horizontal plane with reduced radiating in the direction orthogonal to the horizontal plane. Furthermore, two circular arrays of half-height antenna horns may be arranged on a collinear axis, offset by one half of a sector width as defined by each horn aperture to reduce coupling.