Patent ID: 9325046
Filing Date: 2016-04-26
CPC Classification: H01P

Claim Text:
1. A multi-mode cavity filter, comprising: a dielectric resonator body incorporating a piece of dielectric material, the piece of dielectric material having a shape such that it can support at least a first resonant mode and a second substantially degenerate resonant mode; and a coupling structure comprising a first coupling portion and a second coupling portion, the first coupling portion being arranged to generate a first magnetic field for coupling to at least one of the first resonant mode and the second resonant mode within the dielectric resonator body, the second coupling portion being arranged to generate a second magnetic field for coupling to at least one of the first resonant mode and the second resonant mode within the dielectric resonator body, the second magnetic field having a magnitude and a direction so as to partially cancel the coupling due to the first magnetic field, wherein the first coupling portion comprises a first conductive track arranged adjacent to a surface of the dielectric resonator body, and wherein the second coupling portion comprises a second conductive track arranged adjacent to the surface of the dielectric resonator body, and wherein the first and second conductive tracks have different lengths.