主权项 |
1. A multi-mode cavity filter comprising:
a dielectric resonator body incorporating a piece of dielectric material, the piece of dielectric material being free of cutouts and holes for coupling probes and having a shape supporting at least a first resonant mode and a second substantially degenerate resonant mode; a conductive layer substantially covering the dielectric resonator body but having one or more apertures therein allowing access to a surface of the dielectric resonator body; and a coupling structure arranged in an aperture of the one or more apertures, said coupling structure being on or contacting the surface of the dielectric resonator body, said coupling structure comprising at least one coupling path for at least one of coupling an input signal to the first and second resonant modes and coupling an output signal from the first and second resonant modes, the coupling path having an open-circuit end located adjacent to an edge of the aperture for controlling a strength of electric field generated by the coupling structure, wherein the open-circuit end is a first open-circuit end, wherein the edge of the aperture is a first edge of the aperture, and wherein the coupling path comprises a second open-circuit end located adjacent to a second edge of the aperture, and wherein the first open-circuit end is located a first distance from the first edge of the aperture, wherein the second open-circuit end is located a second distance from the second edge of the aperture, and wherein the second distance is greater than the first distance. |