Dielectric resonator electromagnetic wave filter

• US 4,810,984 A
• Filed: 09/04/1987
• Issued: 03/07/1989
• Est. Priority Date: 09/04/1987
• Status: Expired due to Term

• Current Assignee: Celwave Systems Incorporated
• Original Assignee: Celwave Systems Incorporated
• Inventors: Gaukel, Kevin M., Arnold, Pitt W.
• Primary Examiner(s): LaRoche, Eugene R.
• Assistant Examiner(s): Lee, Benny T.
• Application Number:
  US07/093,232
• Time in Patent Office: 550 Days
• Field of Search: 333/235, 333/234, 333/232, 333/229, 333/219.1, 333/202
• US Class Current: 333/202
• CPC Class Codes: H01P 1/2084 with dielectric resonators

Abstract

A dielectric resonance electromagnetic filter for selection of a resonance frequency of a high frequency electromagnetic wave having the dielectric resonator attached directly to the shield. The filter is tunable using a tuning cylinder which moves through a cavity in the center of the resonator.

The tuning cylinder is hollow and is designed to expand thermally during heatup to counter thermal changes in the resonance frequency. The tuning cylinder may be metal or dielectric material or may have sections of both materials.

A shield geometry has been described which enables filter clusters to occupy a minimum volume.

Claims

1. A transverse electric mode dielectric resonating electromagnetic filter for the selection of a discrete frequency of an electromagnetic signal which resonates in a resonator composed of dielectric material, said resonator propagative of a transverse electric mode of said discrete frequency as a consequence of physical dimensions of said resonator derived upon selection of said discrete frequency, said resonator enclosed within an electrically conductive enclosure defined as the shield, wherein said resonator is in contact with said shield by having abutment of a first face of said resonator to a surface of said shield, providing thereby for conductive heat transfer therethrough said first face between said resonator and said shield, having a cavity therethrough said resonator and having an elongated plunger movable into and out of said cavity, and also having plunger mounting means for supporting said plunger comprising an aperture through said shield, a metal tower mounted on an outside surface of said shield, said tower in juxtaposition to said shield aperture, said tower defining an enclosing volume of elongated length outside said shield and in electromagnetic communication with the interior volume of said shield, said tower enclosing volume therefore functioning as a trap for an undesired electromagnetic frequency, said tower elongated length being appropriate to trap the undesired frequency.

2. A composite filter which is a combination of "N" transverse electric mode dielectric resonating electromagnetic filters, where "N" is defined as the number of filters in the composite filter, for the selection of a discrete frequency of an electromagnetic signal which resonates in each of "N" resonators composed of dielectric material, said resonators propagative of a transverse electric mode of said discrete frequency as a consequence of physical dimensions of said resonators derived upon selection of said discrete frequency, each of said resonators enclosed within one of "N" electrically conductive enclosures defined as its shield, wherein each resonator is in contact with its shield by having abutment of a first face of said resonator to a surface of its shield, providing thereby for conductive heat transfer therethrough said first face between said resonator and its shield, wherein each shield is geometrically a section of a right circular cylinder having an angle "C" between two intersecting shield faces equal to 360 degrees divided by "N", and all "N" filters abut at the apexes of each angle "C" to form a whole right circular cylinder shaped composite filter.

3. A transverse electric mode dielectric resonating electromagnetic filter for the selection of a discrete frequency of an electromagnetic signal which resonates in a resonator composed of dielectric material, said resonator propagative of a transverse electric mode of said discrete frequency as a consequence of physical dimensions of said resonator derived upon selection of said discrete frequency, said resonator enclosed within an electrically conductive enclosure defined as the shield, wherein the improvement is that said resonator is in contact with said shield by having abutment of a first face of said resonator to a surface of said shield, providing thereby for conductive heat transfer therethrough said first face between said resonator and said shield, wherein said shield is geometrically a wedge-shaped section of a right circular cylinder.

4. A transverse electric mode dielectric resonating electromagnetic filter for the selection of a discrete frequency of an electromagnetic signal which resonates in a resonator composed of dielectric material, said resonator propagative of a transverse electric mode of said discrete frequency as a consequence of physical dimensions of said resonator derived upon selection of said discrete frequency, said resonator enclosed within an electrically conductive enclosure defined as the shield, wherein the improvement is that said resonator is in contact with said shield by having abutment of a first face of said resonator to a surface of said shield, providing thereby for conductive heat transfer therethrough said first face between said resonator and said shield wherein said shield has attached thereto an input electrical terminal for introduction to said filter of said electromagnetic signal, a first output electrical terminal for said discrete frequency, and means for attachment to said shield for an output electrical terminal, said means located at a site on said shield remote from said first output electrical terminal and from said input electrical terminal, enabling operator installation of an alternate output terminal on said shield at said remote site.