Bandwidth-controllable millimeter wave filter based on plasmon

The invention belongs to the technical field of microwave communication, and particularly relates to a bandwidth-controllable millimeter wave filter based on plasmon. Thebandwidth-controllable millimeter wave filter based on plasmon comprises a first dielectric substrate and a second dielectric substrate which are stacked from bottom to top, wherein the first dielectric substrate is arranged to be an SIW transmission line, the upper surface of the SIW transmission line is provided with a first rectangular area, and metal etching in the first rectangular area is in a periodic arrangement grid shape; the second dielectric substrate is provided with an SIW cavity, the lower surface of the SIW cavity is provided with a second rectangular area, metal in the second rectangular area is removed, the area of the first rectangular area is the same as that of the second rectangular area, and the SIW cavity and the SIW transmission line are aligned and stacked according to the rectangular areas. The SIW transmission line