Patents by Inventor Usha Varshney

Usha Varshney has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6433299
    Abstract: Magnetic modules and a process for manufacturing magnetic modules are provided wherein magnetic material is deposited into one or more cavities patterned into a non-magnetic substrate die to form a plurality of magnetic cores. The patterned substrate board, which may be a composite of graphite, a composite of alumina or other non-magnetic ceramic, provides a surface for winding windows, inductor air gaps, isolations, and a mounting surface for other system components.
    Type: Grant
    Filed: January 23, 1996
    Date of Patent: August 13, 2002
    Assignee: American Research Corporation of Virginia
    Inventor: Usha Varshney
  • Patent number: 5850089
    Abstract: Modulated-structure polycrystalline or heteroepitaxial multilayers of PZT/PT ferroelectric thin films are deposited on a substrate, preferably by laser ablation. The laser ablation of the PZT/PT layers onto a prepared substrate occurs while maintaining the substrate at a temperature between 380.degree. C. to about 650.degree. C. The target source for the PZT/PT laser ablated film may be either bulk PZT and PT ceramics or powders or individual metal oxides or metal pellets. The ferroelectric thin film device may be used for a random access memory.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: December 15, 1998
    Assignee: American Research Corporation of Virginia
    Inventors: Usha Varshney, Angus Ian Kingon
  • Patent number: 5626670
    Abstract: A method for developing large area highly oriented polycrystalline ferroelectric thin films using spin-on sol-gel deposition and laser crystallization techniques that allow for precise control of temperature distribution. The present invention improves quality, reliability, performance and cost effective production of ferroelectric non-volatile random access memory (FNVRAM) on thermally sensitive silicon and gallium arsenide semiconductor substrates compatible with very large scale integrated circuit technologies. The method is time effective, as crystallization is performed in three seconds as compared to thirteen hours in a conventional furnace for 1 cm.times.1 cm wafer. In addition, crystallization of the film is further achieved without exposing the underneath device structure to detrimental high temperature annealing conditions.
    Type: Grant
    Filed: October 3, 1994
    Date of Patent: May 6, 1997
    Assignee: American Research Corporation of Virginia
    Inventors: Usha Varshney, Angus I. Kingon
  • Patent number: 5626789
    Abstract: An improved NiZnCo ferrimagnetic core material which may further contain elements from the group Cr, Mn or Li. The invention permits enhancement of magnetic properties and results in core materials capable of efficient operation at high frequencies on the order of 1-100 MHz over a wide range of magnetic flux densities, on the order of 1-2500 Gauss. The composition of base NiZnCo ferrites are adjusted through ionic substitution. The magnetic properties of the ferrite are further enhanced through Bi.sub.2 O.sub.3 and SiO.sub.2 additions and controlled sintering. Methods of manufacturing the core material are also disclosed.
    Type: Grant
    Filed: September 11, 1991
    Date of Patent: May 6, 1997
    Assignee: American Research Corp. of Virginia
    Inventor: Usha Varshney
  • Patent number: 5534071
    Abstract: A laser ablation deposition system includes a movable platform for supporting ferroelectric target material and a support structure for supporting a thermally sensitive semiconductor substrate within a chamber mounted on a moveable cabinet, and a laser for ablating the material mounted on a support frame along with various control components. The cabinet with the chamber may be moved away from the laser and support frame to allow the chamber to be raised to provide access to the components within the chamber. The system may be used to fabricate a multilayer thin film device using multicomponent oxides.
    Type: Grant
    Filed: May 10, 1994
    Date of Patent: July 9, 1996
    Assignee: American Research Corporation
    Inventors: Usha Varshney, Lawrence H. Decker
  • Patent number: 5427823
    Abstract: Alumino-silicate glass-ceramic coated carbon-carbon composite and graphitic substrates having resistance to oxidation and thermal cycling. The coatings are fabricated from plasma-sprayed powders of beta-spodumene, cordierite, beta-eucryptite or beta-quartz and are rapidly recrystallized by laser processing.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: June 27, 1995
    Assignee: American Research Corporation of Virginia
    Inventors: Usha Varshney, Howard P. Groger, Jesse J. Brown, Jr.
  • Patent number: 5407119
    Abstract: The laser brazing of the present invention offers the unique advantage of producing a high temperature hermetic bond while limiting the heat affected zone to the region of the joint. Laser brazing joins infrared (IR) and radio frequency (RF) ceramic materials to metals for radome applications. Using AG--Cu--Ti brazing alloys, zinc sulfide (ZnS) infrared windows were laser brazed to cylindrical titanium housings with no thermal degradation observed in crystalline properties of ZnS. Innovative glass-ceramic materials were also used as braze filler to produce over 30 ceramic-to-metal couples, including titanium Zns, Pyroceram/Kovar and niobium/sapphire. Benefits are in the production of strong, high temperature, hermetically sealed joints in aircraft and high velocity missile systems. An optimized laser brazing system is provided.
    Type: Grant
    Filed: December 10, 1992
    Date of Patent: April 18, 1995
    Assignee: American Research Corporation of Virginia
    Inventors: Russell J. Churchill, Usha Varshney, Howard P. Groger, James M. Glass