Millimeter-Wave Substrate Integrated Dual Level Gap Waveguide Horn Antenna

Substrate integrated H-plane horn antenna design is introduced based on elevated substrate integrated gap waveguide (E-SIGW) configuration. The E-SIGW topology allows designing the horn from two substrates of different thicknesses. A thin substrate for the feed line to eliminate the radiation losses and a thicker one for the radiating aperture. The proposed configuration allows the H-plane horn aperture to be three times thicker than the feed line substrate, which is not possible with the conventional substrate integrated waveguide technology. The transition between the horn layers enhances the matching bandwidth without any aperture modification. The outer surface of the horn around its aperture is loaded with soft surfaces realized by transverse strips. As a result, more symmetric fan beam radiation patterns with suppressed back lobes are achieved.