Substrate Integrated Waveguide Filtering Horn Antenna Facilitated by Embedded Via-Hole Arrays

A substrate integrated waveguide (SIW) H-plane filtering horn antenna with embedded metallized via-hole arrays is proposed in this letter. The SIW H-plane filtering horn originates from a simple SIW H-plane horn with very narrow bandwidth and no frequency selectivity performance. To significantly increase bandwidth, two metal strips are printed on both sides of the substrate near the radiating aperture of the horn antenna. Critically, four rows of inductive metallized via holes are embedded into the flare region of the horn antenna, forming three coupled resonant cavities to achieve filtering function without any increase of the antenna dimension. The proposed SIW H-plane filtering horn antenna achieves good frequency selectivity, which satisfies the increasing demand of the miniaturization and integration of multifunctional devices. An optimized prototype is manufactured and measured to verify the design feasibility. The results show that the filtering performance is successfully realized with high level of integration.