Design of a two-cavity dual-mode bandpass SIW Filter

In this paper, a two-cavity dual-mode bandpass substrate integrated waveguide (SIW) filter is proposed. Using a dual-mode isosceles triangle cavity with one port on the waist, the other port on the base of the triangle cavity upper surface as basic element, a compact two-cavity dual-mode SIW filter is realized by cascading two basic elements on a single-layer substrate with the standard printed circuit boards (PCB) process, which achieves a more wider bandpass filter. Moreover, metallic via-holes between coupling windows will make up for imperfection of cavities due to the coupling windows. Finally, a 7.02% fractional bandwidth filter is fabricated and tested, which occupies a good performance.