High-frequency selectivity balance band-pass filter based on substrate integrated waveguide

The invention discloses a high-frequency selectivity balance band-pass filter based on a substrate integrated waveguide. The high-frequency selectivity balance band-pass filter comprises an upper-layer dielectric substrate and a lower-layer dielectric substrate, wherein the upper-layer dielectric substrate is provided with three upper metal layers; the lower-layer dielectric substrate is provided with three lower metal layers; an intermediate metal layer is arranged between the upper-layer dielectric substrate and the lower-layer dielectric substrate; two rows of metallized through holes are formed in the upper-layer dielectric substrate; two rows of metallized through holes are formed in corresponding positions of the lower-layer dielectric substrate; the upper metal layers are all of isosceles right-angled triangles; two differential feed microstrip lines are arranged on the upper-layer dielectric substrate and are connected with a bevel edge of the middle upper metal layer; two differential feed microstrip