Patent ID: 7142074

Claim:
A waveguide filter comprising: a lower conductive layer; a plurality of dielectric layers stacked on the lower conductive layer; an upper conductive layer formed on a top surface of the plurality of dielectric layers; a waveguide formed on the upper conductive layer; and two sets of first via metals arranged at longitudinal sides of the waveguide filter, wherein each of the sets form a two-fold line shape, wherein the waveguide includes: filtering units formed in middle of the waveguide and including groups of a plurality of second via metals; a pair of transitions coupled to both sides of the filtering units; and a pair of input/output ports each of which coupled to each of the transitions, respectively, wherein the plurality of second via metals in each group are arranged in an overlapped manner in order to form a cavity and the overlapped second via metals are filled with a metallic material.