Hybrid dielectric resonator/high temperature superconductor filter

Abstract

A waveguide cavity filter having a conductive housing, a plurality of high dielectric constant ceramic resonators disposed within the conductive housing and at least a portion of a sheet of superconductive material which is constrained to be at an ambient temperature below the critical temperature of the superconductor and disposed in contact with at least one of the side walls of the conductive housing and with an opposing surface of each of the resonators, such that the resonators are in close superconductive contact with the side walls of the conductive housing. In particularly, the superconductive sheet is a layer of high temperature superconductor. In a first embodiment of the invention, the resonators in the shape of cylindrical plugs are disposed with a flat surface juxtaposed to the side wall. In a second embodiment, the resonators are in the form of half cylindrical plugs with the axis of the half cylinder transverse to the axis of the resonator, in contact with the superconductor sheet and in juxtaposition to the side wall. In a further embodiment of the invention, the resonators are quarter circular cylindrical plugs and each of the flat side surfaces is in contact with a juxtaposed side wall of the conductive housing through a sheet of superconductive material.