A cross-coupled double folded substrate integrated waveguide filter with novel coupling structures

This paper proposes two novel coupling structures for double folded substrate integrated waveguide (DFSIW) cavity filters. Both coupling structures realize electric coupling between DFSIW cavities, and the coupling mechanism is investigated. With electric coupling realized by the proposed structures in the main path and magnetic coupling by a conventional coupling structure in the cross coupling path, an X-band cross-coupled filter is designed and fabricated. The simulated and measured results show good performance of the presented filter.