Filter

摘要

A cavity filter, including a dielectric resonator structure comprising a piece of dielectric material having a shape such that it can support a first resonant mode and a second resonant mode which is substantially degenerate with the first resonant mode; and a coupling structure for exciting a resonant mode within the piece of dielectric material or extracting energy from a resonant mode within the piece of dielectric material; wherein the coupling structure consists of a single patch element in contact with a surface of the piece of dielectric material, the patch element being arranged to couple directly to said first and second resonant modes simultaneously.

主权项

1. A cavity filter comprising:
a dielectric resonator structure including a piece of dielectric material having a shape supporting a first resonant mode and a second resonant mode, said second resonant mode being substantially degenerate with the first resonant mode; and a coupling structure for exciting at least one of the first resonant mode and the second resonant mode within the piece of dielectric material or for extracting energy from at least one of the first resonant mode and the second resonant mode within the piece of dielectric material, wherein the coupling structure includes a single patch element in contact with a surface of the piece of dielectric material, the patch element being a substantially flat conductive element arranged to couple directly to said first and second resonant modes simultaneously, the cavity filter further including first and second feedpoints connected to the patch element for feeding input signals to the patch element or for receiving output signals from the patch element, wherein the first and second feedpoints are connected to the substantially flat conductive element so as to generate a circularly polarized field.