Design of A Ka-Band Bandpass Filter Based on High Order Mode SIW Resonator

This paper presents a scheme for designing band pass filters based on the high-mode of SIW cavity. Compared with the dominant mode SIW cavity filters, the SIW cavity filters resonated on the high-mode can work on the higher frequency with the same size. This property can be used to implement a higher frequency device with normal PCB process. The response of dominant mode is suppressed by the cutoff frequency of SIW, the desired higher order modes are excited with special design, and the nearby spurious band is suppressed by adding a metal post in the center of the cavity.