Patents by Inventor Vijay K. Varadan

Vijay K. Varadan 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: 6516665
    Abstract: A gyroscope comprises a piezoelectric substrate having a surface. Disposed on the surface are a resonator transducer, a pair of reflectors, a structure such as a metallic dot, and a sensor transducer. The resonator transducer creates a first surface acoustic wave on the surface. The pair of reflectors reflects the first surface acoustic wave to form a standing wave within a region of the surface between the pair of reflectors. The structure is disposed on the surface within the region, wherein a Coriolis force acting upon the structure creates a second surface acoustic wave. The sensor senses the second surface acoustic wave and provides an output indicative thereof.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: February 11, 2003
    Assignee: The Penn State Research Foundation
    Inventors: Vijay K. Varadan, Pascal B. Xavier, William D. Suh, Jose A. Kollakompil, Vasundara V. Varadan
  • Publication number: 20020149519
    Abstract: A class of antennas that comprise an electrically conductive fractal pattern disposed on a dielectric substrate and are capable of construction in a size measured in centimeters as compared to previous antennas of the same class that measured in meters. One antenna style has a ground plane that is perpendicular to the substrate and another style has a ground plane that is parallel to the substrate. The substrate has a dielectric constant of in the range of about 10 to 600 or more and may be a ferroelectric, such as barium strontium titanate. A bias voltage applied across the substrate can tune the antenna for operation in a particular frequency range. The antenna can be made especially wideband by placing an absorbing material behind the substrate. The fractal pattern may be any fractal pattern, such as Hilbert curve, Koch curve, Sierpinski gasket and Sierpinski carpet.
    Type: Application
    Filed: June 28, 2001
    Publication date: October 17, 2002
    Applicant: The Penn State Research Foundation
    Inventors: Vijay K. Varadan, Kalarickaparambil Vinoy, Jose Kollakompil, Vasundara V. Varadan
  • Patent number: 6333719
    Abstract: A multilayer tunable ferroelectric antenna assembly which includes a first laminar structure that includes a tunable ferroelectric substrate positioned on top of a conducting ground plane and a copper radiating sheet on the other side of the substrate. A second laminar structure includes a single-sided copper cladded high dielectric substrate with the copper sheet acting as the radiator. The passive second laminar structure is electromagnetically coupled to the first laminar structure via an air-gap spacing. Application of a bias voltage across the first laminar structure changes the dielectric permittivity and, hence, the resonating frequency of the antenna structure.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: December 25, 2001
    Assignee: The Penn State Research Foundation
    Inventors: Vijay K. Varadan, Peng Thian Teo
  • Patent number: 6329959
    Abstract: A multilayer tunable ferroelectric antenna assembly that includes two superimposed substrate layers. A first substrate layer consists of a low dielectric material carrying on one face an electrically ground plane, and on its opposite face an electrically conductive patch serving as an active feeder-resonator. A second substrate includes a ferroelectric material having one face positioned on top of the feeder-resonator and carrying on the opposite face an electrically conductive patch acting as a director. The upper director patch is fed through capacitve coupling of energy from the feeder-resonator. Application of bias voltage between the director and the feeder-resonator changes the permittivity of the ferroelectric substrate, thereby causing a shift in resonance frequency. A radiation null, corresponding to energy absorption, could be tuned into the resonance frequency at which the antenna is previously exhibiting a radiation characteristic.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: December 11, 2001
    Assignee: The Penn State Research Foundation
    Inventors: Vijay K. Varadan, Peng Thian Teo
  • Patent number: 5668744
    Abstract: A method for reducing noise generated by the operation of a noise-producing machine includes sensing the noise of the machine with a piezoelectric sensor, sending an activation signal, responsive to the sensed noise of the machine, to activate a piezoelectric actuator to reduce the noise of the machine, where the piezoelectric actuator is independent of a wave guide. Further, a parameter of the machine indicative of the speed of the machine is sensed with a second sensor, and the activation signal is corrected, responsive to the sensed parameter of the machine, to optimize the noise reduction of the piezoelectric material.
    Type: Grant
    Filed: May 5, 1995
    Date of Patent: September 16, 1997
    Assignee: Owens-Corning Fiberglas Technology Inc.
    Inventors: Vijay K. Varadan, Vasundara V. Varadan, Xiao-Qi Bao, Kenneth B. Carney, John L. Olinger, Fred S. Coffey
  • Patent number: 5557286
    Abstract: An improved BST dielectric powder is created used a sol-gel procedure. Addition of graphite to the powder, followed by a firing of the mixture results in a highly porous BST substrate, with the included graphite being burned off. By adjustment of the amount of added graphite, the porosity of the BST substrate is widely adjustable and enables achievement of a low bulk dielectric constant. A low dielectric filler is added to the fired substrate so as to provide a composite substrate with physical rigidity. Conductive layers are then adhered to the composite substrate to enable a tuning of the dielectric constant in accordance with applied DC voltage potentials. Antenna and other applications of the improved composite BST substrate are described.
    Type: Grant
    Filed: June 15, 1994
    Date of Patent: September 17, 1996
    Assignee: The Penn State Research Foundation
    Inventors: Vijay K. Varadan, Fathi Selmi, Vasundara V. Varadan
  • Patent number: 5366664
    Abstract: The present invention provides for conductive electromagnetic shielding (EMS) compositions which can be formulated to provide effective shielding over a broad range of frequencies, e.g. 30 MHz. to 110 GHz. which is based on a mixture of a polymeric or liquid matrix material and a synergestic combination of conductive powders, fibers and optional flake components. The invention also provides for formulations containing the above composition which are adapted for EMS applications such as pliable caulking, thermoformable shaped articles such as housings and cabinetry, flexible gasket material, shielding curtains, coatings and paints which may be applied to substrates such as glass, plastic or metal, structural composites, conformal coatings for printed circuit boards and like applications.
    Type: Grant
    Filed: May 4, 1992
    Date of Patent: November 22, 1994
    Assignee: The Penn State Research Foundation
    Inventors: Vijay K. Varadan, Vasundara V. Varadan, Neil R. Williams, Joseph W. Cresko
  • Patent number: 5296666
    Abstract: A system is provided for heating non-metallic material or a discrete layer of the non-metallic material. Microwave energy is introduced into an enclosure defining a first cavity and capable of substantially containing the microwave energy. A semiconductive sheet is positioned at the bottom of the first cavity. Thermal insulation overlies the semiconductive sheet. A second cavity is defined by the undersurface of the semiconductive sheet and flexible microwave shielding in the form of a skirt which is attached to, and depends from, the enclosure. The flexible shielding is composed of a material which also substantially contains the microwave energy. The semiconductive sheet is effective to convert some of the microwave energy into thermal energy and to transmit the thermal energy into the second cavity while transmitting the remainder of the microwave energy directly to the discrete layer, thereby rapidly heating the discrete layer.
    Type: Grant
    Filed: May 4, 1992
    Date of Patent: March 22, 1994
    Assignee: The Pennsylvania Research Corporation
    Inventors: Vijay K. Varadan, Vasundara V. Varadan, Thomas L. Schaffer
  • Patent number: 4948922
    Abstract: A material having a matrix and a plurality of inclusions which are chiral is effective as a coating to reduce incident reflections and absorptions of microwave frequency electromagnetic energy. The matrix can use an electrically conductive polymeric material as the base as well as any other low loss dielectric material. Chiral inclusions may be in the form of helices or any other small object displaying handedness. Moreover, it is possible to use electrically conductive polymeric materials by themselves as absorbers of electromagnetic energy. There are a variety of uses for these materials and the unique properties including gaskets for controlling the emission of microwave energy from electronic enclosures.
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: August 14, 1990
    Assignee: The Pennsylvania State University
    Inventors: Vijay K. Varadan, Vasundara V. Varadan