Patents by Inventor Ajay I. Sreenivas

Ajay I. Sreenivas 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: 7026995
    Abstract: Dielectric materials having modified dielectric constants and methods for modifying the dielectric constant of a dielectric material are provided. Generally, the dielectric constant of a dielectric material is modified by providing relieved portions within the dielectric material. The relieved portions may comprise holes formed in the dielectric material. In connection with dielectric material that is incorporated into an antenna apparatus, the size and/or arrangement of holes or other relieved portions in the dielectric material can be determined with reference to the operating wavelengths of the antenna apparatus.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: April 11, 2006
    Assignee: Ball Aerospace & Technologies Corp.
    Inventors: Ajay I. Sreenivas, Farzin Lalezari
  • Patent number: 6795020
    Abstract: A dual band coplanar microstrip interlaced array antenna is provided. The antenna may be confined to a relatively small area, while providing dual band operation with no or minimal grating lobes and losses. According to the present invention, first and second arrays are interlaced with one another to minimize the surface area of the antenna. A maximum spacing between array elements is selected based on the operating wavelengths and scan range for each of the arrays. A first dielectric constant of a material underlying elements of the first array is calculated from the selected element spacing and the operating wavelength of the first array. A second dielectric constant of a material underlying elements of the second array is calculated from the first dielectric constant and the operating frequencies of the first and second arrays. The present invention provides a dual band coplanar microstrip interlaced array antenna capable of efficient operation at two center frequencies.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: September 21, 2004
    Assignee: Ball Aerospace and Technologies Corp.
    Inventors: Ajay I. Sreenivas, Farzin Lalezari
  • Publication number: 20040155820
    Abstract: A dual band coplanar microstrip interlaced array antenna is provided. The antenna may be confined to a relatively small area, while providing dual band operation with no or minimal grating lobes and losses. According to the present invention, first and second arrays are interlaced with one another to minimize the surface area of the antenna. A maximum spacing between array elements is selected based on the operating wavelengths and scan range for each of the arrays. A first dielectric constant of a material underlying elements of the first array is calculated from the selected element spacing and the operating wavelength of the first array. A second dielectric constant of a material underlying elements of the second array is calculated from the first dielectric constant and the operating frequencies of the first and second arrays. The present invention provides a dual band coplanar microstrip interlaced array antenna capable of efficient operation at two center frequencies.
    Type: Application
    Filed: January 23, 2004
    Publication date: August 12, 2004
    Inventors: Ajay I. Sreenivas, Farzin Lalezari
  • Publication number: 20030137456
    Abstract: A dual band coplanar microstrip interlaced array antenna is provided. The antenna may be confined to a relatively small area, while providing dual band operation with no or minimal grating lobes and losses. According to the present invention, first and second arrays are interlaced with one another to minimize the surface area of the antenna. A maximum spacing between array elements is selected based on the operating wavelengths and scan range for each of the arrays. A first dielectric constant of a material underlying elements of the first array is calculated from the selected element spacing and the operating wavelength of the first array. A second dielectric constant of a material underlying elements of the second array is calculated from the first dielectric constant and the operating frequencies of the first and second arrays. The present invention provides a dual band coplanar microstrip interlaced array antenna capable of efficient operation at two center frequencies.
    Type: Application
    Filed: January 24, 2002
    Publication date: July 24, 2003
    Inventors: Ajay I. Sreenivas, Farzin Lalezari
  • Patent number: 5838282
    Abstract: The present invention relates to an antenna system which is capable of multiband operation from a single antenna aperture. The system provides a high degree of design freedom for achieving desired antenna pattern shapes for all relevant frequency bands. The system achieves this pattern shaping ability by utilizing a unique array configuration which is highly adaptable. The array configuration may include a center array element for each of the relevant frequency bands. In one embodiment of the present invention, a dual frequency band antenna is provided which includes a stacked patch element as the center element in a first frequency band and a crossed dipole element, mounted on top of the stacked patch, as the center element in the second frequency band.
    Type: Grant
    Filed: March 22, 1996
    Date of Patent: November 17, 1998
    Assignee: Ball Aerospace and Technologies Corp.
    Inventors: Farzin Lalezari, J. Mark Rogers, Ajay I. Sreenivas
  • Patent number: 5821908
    Abstract: The invention relates to an antenna system which is capable of producing multiple, high-gain, independently steerable antenna beams from a single antenna aperture. The system accomplishes this, in part, by utilizing a separate phased array antenna as the feed element of a spherical lens for each desired beam. In this fashion, the beam(s) produced by the antenna system can each be electronically steered (independently of the other beams, if any) and physical movement of the feed element(s) is not required. The invention may also use multiple spherical lenses, wherein each lens includes at least one phased array feed.
    Type: Grant
    Filed: March 22, 1996
    Date of Patent: October 13, 1998
    Assignee: Ball Aerospace and Technologies Corp.
    Inventor: Ajay I. Sreenivas
  • Patent number: 5382959
    Abstract: An efficient, lightweight, broadband antenna, having high quality circular polarization capabilities, is disclosed for use in a variety of applications. In one embodiment, signals are fed to, or received by, an array of electromagnetically coupled patch pairs arranged in sequential rotation by an interconnect network which is coplanar with the coupling patches of the patch pairs. The interconnect network includes phase transmission line means, the lengths of which are preselected to provide the desired phase shifting among the coupling patches. The complexity of the array and the space required are thus reduced. In one described embodiment, two such arrays are employed, each having four patch pairs. The two arrays are arranged in sequential rotation to provide normalization of the circularly polarized transmitted or received beam. In another embodiment, a lightweight material having a dielectric constant less than about 1.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: January 17, 1995
    Assignee: Ball Corporation
    Inventors: Todd A. Pett, Steven C. Olson, Ajay I. Sreenivas
  • Patent number: 5231406
    Abstract: A broadband, circular polarization antenna is disclosed for use on a satellite. In one embodiment, signals are fed to, or received by, an array of electromagnetically coupled patch pairs arranged in sequential rotation by an interconnect network which is coplanar with the coupling patches of the patch pairs. The interconnect network includes phase transmission line means, the lengths of which are preselected to provide the desired phase shifting among the coupling patches. The complexity of the array and the space required are thus reduced. In the described embodiment, two such arrays are employed, each having four patch pairs. The two arrays are arranged in sequential rotation to provide normalization of the circularly polarized transmitted or received beam.
    Type: Grant
    Filed: April 5, 1991
    Date of Patent: July 27, 1993
    Assignee: Ball Corporation
    Inventor: Ajay I. Sreenivas