Gregory T Schaeffer

US Patent:

20030061791, Apr 3, 2003

Filed:

Oct 2, 2001

Appl. No.:

09/968018

Inventors:

Richard Barbier - Montgomery PA, US
Thomas Bemis - Montoursville PA, US
Gregory Schaeffer - Cogan Station PA, US
Michael Worthington - Unityville PA, US

Assignee:

Litton Systems, Inc.

International Classification:

B01D046/00

US Classification:

055/282300, 055/523000

Abstract:

A silicon carbide filter includes a filter body and has a cavity formed therein. A microwave RF energy source is coupled to the cavity. A lossy media is disposed in the cavity for absorbing microwave energy. A reflective screen is spaced a predetermined distance from the input screen to define an input lossy volume and to define an output lossy volume between the reflective screen and the output screen. The input lossy volume includes a central less lossy section and an outer more lossy section, wherein in the outlet lossy volume the lossy media is less lossy than in the input lossy volume.

US Patent:

45311048, Jul 23, 1985

Filed:

Nov 29, 1982

Appl. No.:

6/445122

Inventors:

Gregory T. Schaeffer - Williamsport PA

Assignee:

Litton Systems, Inc. - Beverly Hills CA

International Classification:

H03B 910
H01J 2550

US Classification:

331 90

Abstract:

A tunable, coaxial-vacuum magnetron is shown having a cathode surrounded by an anode within a surrounding evacuated anode cavity. Located between the cathode-anode interaction space and an output from the anode cavity is a tuning mechanism which includes a single symmetrical ceramic tuning rod that is adjusted along its axis into and out of the anode cavity. The adjustment mechanism includes a tuning nut rotatably mounted in a tuning housing which turns to move a threaded shaft along the axis thereof. Separating the threaded shaft from the anode cavity is a bellows attached to the tuning housing and to which is attached the symmetrical tuning rod for sealing the vacuum cavity.

US Patent:

49756567, Dec 4, 1990

Filed:

Mar 31, 1989

Appl. No.:

7/332628

Inventors:

Gregory T. Schaeffer - Williamsport PA
John C. Cipolla - Trout Run PA
Guilford R. MacPhail - Williamsport PA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

H03F 354
H01J 132
H01J 904

US Classification:

330 42

Abstract:

The present invention discloses an enhanced secondary electron emitter cathode suitable for use in a typical crossed-field amplifiers. The emitter surfaces of the cathode are formed into protuberances or knurls. The cathode's secondary emission characteristics are enhanced by providing protuberances with more surface area for electrons to bombard and for electrons to be emitted from. The protuberances increase the variety of angles of incidence of bombarding electrons thereby increasing the probability that bombarded electrons can escape the cathode's surfaces.

US Patent:

54336406, Jul 18, 1995

Filed:

May 23, 1994

Appl. No.:

8/247317

Inventors:

Gregory T. Schaeffer - Williamsport PA

Assignee:

Litton Systems, Inc. - Beverly Hills CA

International Classification:

H01J 902

US Classification:

445 58

Abstract:

An improved low power pulsed anode magnetron is provided having a cylindrical cathode centrally disposed within a plurality of radial anode vanes. An interaction region is provided between the surface of the cathode and the anode vane tips. A ratio of the anode-to-cathode space over the center-to-center distance between adjacent vane tips is within a range between 0. 95 and 1. 05. The cathode is joined to a magnetic polepiece assembly which channels magnetic flux to the interaction region. Both the cathode and the polepiece are mechanically adjustable from external to the magnetron to reposition the cathode and polepiece with respect to the anode vanes. The cathode surface is formed from an active nickel alloy which is cleaned by a chemical process followed by a high temperature and vacuum firing. An emissive surface is applied over the cleaned cathode surface. The output spectrum of the magnetron is calibrated by applying a sequential pulsed input of increasing amplitude, and adjusting the relative cathode-anode position until the frequency spectrum remains constant.

US Patent:

54225426, Jun 6, 1995

Filed:

Feb 9, 1993

Appl. No.:

8/015549

Inventors:

Gregory T. Schaeffer - Williamsport PA

Assignee:

Litton Systems, Inc. - Beverly Hills CA

International Classification:

H01J 2305
H01J 2550

US Classification:

315 3971

Abstract:

An improved low power pulsed anode magnetron is provided having a cylindrical cathode centrally disposed within a plurality of radial anode vanes. An interaction region is provided between the surface of the cathode and the anode vane tips. A ratio of the anode-to-cathode space over the center-to-center distance between adjacent vane tips is within a range between 0. 95 and 1. 05. The cathode is joined to a magnetic polepiece assembly which channels magnetic flux to the interaction region. Both the cathode and the polepiece are mechanically adjustable from external to the magnetron to reposition the cathode and polepiece with respect to the anode vanes. The cathode surface is formed from an active nickel alloy which is cleaned by a chemical process followed by a high temperature and vacuum firing. An emissive surface is applied over the cleaned cathode surface. The output spectrum of the magnetron is calibrated by applying a sequential pulsed input of increasing amplitude, and adjusting the relative cathode-anode position until the frequency spectrum remains constant.

US Patent:

55370845, Jul 16, 1996

Filed:

Sep 27, 1994

Appl. No.:

8/312609

Inventors:

Gregory T. Schaeffer - Williamsport PA

Assignee:

Litton Systems, Inc. - Woodland Hills CA

International Classification:

H03B 104
H03B 910

US Classification:

331 44

Abstract:

An improved low power pulsed anode magnetron is provided having a cylindrical cathode centrally disposed within a plurality of radial anode vanes. An interaction region is provided between the surface of the cathode and the anode vane tips. A ratio of the anode-to-cathode space over the center-to-center distance between adjacent vane tips is within a range between 0. 95 and 1. 05. The cathode is joined to a magnetic polepiece assembly which channels magnetic flux to the interaction region. Both the cathode and the polepiece are mechanically adjustable from external to the magnetron to reposition the cathode and polepiece with respect to the anode vanes. The cathode surface is formed from an active nickel alloy which is cleaned by a chemical process followed by a high temperature and vacuum firing. An emissive surface is applied over the cleaned cathode surface. The output spectrum of the magnetron is calibrated by applying a sequential pulsed input of increasing amplitude, and adjusting the relative cathode-anode position until the frequency spectrum remains constant.