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.

Hybrid dielectric resonator/high temperature superconductor filter

A transmission line including a dielectric or semi-insulating substrate; a groove in the substrate; a metallization film disposed on the bottom surface of the groove; a dielectric filling the groove and making contact with the metallization film; a wiring conductor film disposed on the dielectric; and a grounding metallization film disposed on the rear surface of the substrate. Excellent confinement of electromagnetic waves is achieved and electromagnetic wave interference between two neighboring lines is extremely small, realizing a high density arrangement of transmission lines and a compact and lightweight microwave/millimeter wave integrated circuit. Higher modes of electromagnetic wave propagation are avoided by controlling the thickness of the dielectric filling the groove while the thickness of the substrate remains arbitrary, thereby improving production yield and reliability.

Transmission lines and fabricating method thereof

A dielectric/conductive waveguide (20) includes a dielectric housing (22) having a longitudinal axis (14) and a central channel (29). A conductive layer (24, 25) is affixed to the inner surface (21) and/or the other surface (23) of the housing (22) to confine electromagnetic radiation (17) within the waveguide (20). Ribs (50, 64) protruding into the channel (29) may be used to further confine the radiation (17). Sections of waveguide (20) may be combined using connectors (30). A local area network (90) can be formed using a plurality of sections of waveguide (20), computers (94), and bi-directional couplers (92). Air gaps (98) may break up the waveguide (20) at various places.

Dielectric/conductive waveguide

A technique for forming imbedded microwave structures in a microwave circuit package is presented. In one method, windows are punched, stamped or molded into metal laminate plates. A metal laminate layer is formed by fusing each of the metal laminate plates one on top of another, preferably using a diffusion bonding technique. The metal laminate layer is fused on top of a metal base plate, which is adhered to a ceramic substrate, and a shielded cover is fused on top of the metal laminate layer to form the imbedded waveguide structure as the base plate, metal laminate plates, and cover plate are fused together. In another method, indented cavities are formed in a shielded cover. The shielded cover is then fused, preferably using a diffusion bonding technique, to a metal base plate, which is adhered to a ceramic substrate. The technique of the present invention may be used to form propagating waveguide structures which operate as transmission lines or resonant cavities, non-propagating waveguide structures which have extremely high cutoff frequencies and which are formed around microstrip transmission lines or microcircuitry to disallow energy below the cutoff frequency to propagate, a low cost, compact, efficient microcircuit-component-to-waveguide wire bond launch, and or a periscope-type waveguide in a microcircuit package.

Imbedded waveguide structures for a microwave circuit package

A method of tuning a high temperature superconductor (HTS) resonator includes the steps of providing a HTS inductor and a HTS capacitor, the HTS capacitor being electrically connected to the HTS inductor. A tuning body is provided adjacent to the HTS inductor and the HTS capacitor. The relative position of the tuning body with respect to the HTS inductor and the HTS capacitor is altered so as to tune the resonator. A tunable resonant circuit is provided that includes a substrate having a planar surface. At least one resonator formed from HTS material is disposed on the substrate, the resonator having one or more turns that when combined, turn through greater than 360°.

Tunable superconducting resonator and methods of tuning thereof

The structures for confining or guiding high frequency electromagnetic radiation have surfaces facing the radiation constructed of high temperature superconducting materials, that is, materials having critical temperatures greater than approximately 35°K. The use of high temperature superconductors removes the constraint of the relatively low energy gaps of conventional, low temperature superconductors which precluded their use at high frequencies. The high temperature superconductors also provide larger thermal margins and more effective cooling. Devices which will benefit from the structures of the invention include microwave cavities, millimeter-wave/far infrared cavities, gyrotron cavities, mode converters, accelerators and free electron lasers, and waveguides.

Ward D. Halverson

Papers

Microwave/far infrared cavities and waveguides using high temperature superconductors