Cavity matching of high dielectric constant SIW H-Plane horn antenna

A simple SIW H-plane horn antenna with a loaded open cavity is introduced. The new combination of the SIW H-plane horn and the open cavity results in a wide and constant impedance bandwidth, which has been hard to achieve by a single SIW horn antenna. Besides matching improvement, the new configuration results in higher gain with radiation pattern focused in antenna aperture. The longitudinal size of the structure is kept as the simple SIW horn; however, it is three times thicker than the simple horn.