Compact Quad-Mode Substrate Integrated Waveguide Dual-Band Filter With Controllable Frequency

In this article, a compact dual-band bandpass filter based on quad-mode substrate integrated waveguide (SIW) resonators with controllable frequency is proposed. The bandwidth of the filter can be adjusted by changing the position and angle of the metallized vias in the SIW resonant cavity. The X-shaped slot on the resonant cavity extends the transmission path of the surface current, which can realize the controllability of the filter frequency.