David W Applegate

US Patent:

20020196099, Dec 26, 2002

Filed:

Jun 26, 2001

Appl. No.:

09/891747

Inventors:

Stephen Remillard - Evanston IL, US
Piotr Radzikowski - Chicago IL, US
Sean Cordone - Chicago IL, US
David Applegate - Wheeling IL, US
J. Kokales - Schaumburg IL, US
Arun Mehrotra - Schaumburg IL, US

International Classification:

H01P001/20

US Classification:

333/09900S, 333/202000

Abstract:

A resonator is provided comprising a conductive element, and a closed-slot in the conductive element, where the length of the closed slot dictates the resonating properties of the resonator. The closed slot generally confines the electromagnetic field resonated by the resonator in a direction perpendicular to a plane of the resonator, providing greater flexibility in the placement of the closed-slot resonator within the filter housing. Further, where three-dimensional resonators are used, compact resonator configuration such as spiral resonator configurations may be securely mounted within the filter without incurring severe filter losses due to the mounting mechanism, allowing filters designed with closed-slot resonators to be more compact in size than filters designed with prior art three-dimensional resonator configurations.

US Patent:

58050361, Sep 8, 1998

Filed:

May 15, 1995

Appl. No.:

8/440829

Inventors:

James D. Hodge - Lincolnwood IL
Qiang Huang - Glen Ellyn IL
David S. Applegate - Wheeling IL

Assignee:

Illinois Superconductor - Mt. Prospect IL

International Classification:

H01F 100

US Classification:

335216

Abstract:

A magnetically-activated switch including a high temperature superconductor. The magnetic switch includes a high temperature superconductor coupled at both ends to a rigid beam, a thermal shield structure is disposed adjacent to the superconductor and a magnetic field source is positioned near the superconductor to allow transitioning of the superconductor in and out of the superconducting state.

US Patent:

57610177, Jun 2, 1998

Filed:

Jun 15, 1995

Appl. No.:

8/490943

Inventors:

James D. Hodge - Lincolnwood IL
Lori J. Klemptner - Lincolnwood IL
David S. Applegate - Wheeling IL

Assignee:

Illinois Superconductor Corporation - Mount Prospect IL

International Classification:

H02H 900

US Classification:

361 19

Abstract:

A high temperature superconductor fault current limiter and a method of using same. The fault current limiter comprises a high temperature superconductor material structure at least partially encapsulated in an epoxy having thermal conductivity properties that enable the superconductor to heat rapidly during a fault condition while preventing thermal runaway. The epoxy encapsulation decreases the critical current density of the superconductor material structure and increases the rate at which resistance increases with increasing current once the critical current density is exceeded. Preferably, the epoxy has thermal expansion properties approximately equal to the thermal expansion properties of the superconductor material structure.