A structure and method for adjusting the bandwidth of a ceramic waveguide filter comprising, in one embodiment, a monoblock of dielectric ceramic material defining respective steps and respective input/output through-holes extending through the monoblock and the respective steps. In one embodiment, the steps are defined by notches in the monoblock and the input/output through-holes define openings terminating in the notch. The bandwidth of the ceramic waveguide filter may be adjusted by adjusting the height/thickness and direction of the steps relative to an exterior surface of the monoblock and/or the diameter of the input/output through-holes.