Patents by Inventor Van Dokas

Van Dokas 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: 6882251
    Abstract: The invention provides a method and apparatus for a adaptively predistorted filter which has a transfer function that satisfies performance criteria specified for at (east one property of the filter. The transfer function is obtained by adaptively predistorting the transfer function poles to meet the performance criteria such that at least one of the poles is shifted by a unique amount.
    Type: Grant
    Filed: December 9, 2002
    Date of Patent: April 19, 2005
    Assignee: Com Dev Ltd.
    Inventors: Ming Yu, Van Dokas, Wai-Cheung Tang
  • Publication number: 20040108920
    Abstract: The invention provides a method and apparatus for an adaptively predistortion filter which has a transfer function that satisfies performance criteria specified for at least one property of the filter. The transfer function is obtained by adaptively predistorting the transfer function poles to meet the performance criteria such that at least one of the poles is shifted by a unique amount.
    Type: Application
    Filed: December 9, 2002
    Publication date: June 10, 2004
    Applicant: Com Dev Ltd.
    Inventors: Ming Yu, Van Dokas, Wai-Cheung Tang
  • Patent number: 6549102
    Abstract: A dielectric resonator is provided having a cavity, a dielectric half disk resonator structure structure, and a support for the half disk resonator structure. The support isolates the dielectric half disk resonator structure from walls of the cavity. A straight edge wall of the dielectric half disk resonator structure couples to a dielectric/air interface within the cavity and forms an approximate magnetic wall. The approximate magnetic wall images the electric field perpendicular to the straight edge wall and supports a single-mode electric field within the half disk resonator structure. Multiple half disk resonator structures may be oriented within the cavity to support other, orthogonal electric fields. Multiple cavities may be coupled to each other through irises formed on the cavity walls.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: April 15, 2003
    Assignee: COM DEV Limited
    Inventors: Raafat R. Mansour, Van Dokas, Soeren F. Peik
  • Publication number: 20020149449
    Abstract: A dielectric resonator is provided having a cavity, a dielectric half disk resonator structure structure, and a support for the half disk resonator structure. The support isolates the dielectric half disk resonator structure from walls of the cavity. A straight edge wall of the dielectric half disk resonator structure couples to a dielectric/air interface within the cavity and forms an approximate magnetic wall. The approximate magnetic wall images the electric field perpendicular to the straight edge wall and supports a single-mode electric field within the half disk resonator structure. Multiple half disk resonator structures may be oriented within the cavity to support other, orthogonal electric fields. Multiple cavities may be coupled to each other through irises formed on the cavity walls.
    Type: Application
    Filed: June 3, 2002
    Publication date: October 17, 2002
    Inventors: Raafat R. Mansour, Van Dokas, Soeren F. Peik
  • Patent number: 5608363
    Abstract: The invention relates to a single mode multi-cavity microwave filter that includes a housing formed with a plurality of walls which define at least two rows of side-by-side dielectric loaded cavities, wherein sequential cavities are coupled to one another via slots formed in the walls therebetween and at least one pair of non-sequential adjacent cavities are coupled via a probe. The coupling via the slots is defined mathematically as positive coupling. The probe is selectively configurable to provide positive or negative coupling relative to the sign of the slot coupling. Further, at least one non-adjacent, non-sequential pair of cavities is coupled via a second probe that may be configured to provide either positive or negative coupling relative to the sign of the slot coupling. The filter housing supports a plurality of adjustable fins which extend into the slots, one fin to each slot, to selectively adjust the size of the slot.
    Type: Grant
    Filed: April 1, 1994
    Date of Patent: March 4, 1997
    Assignee: COM DEV Ltd.
    Inventors: Richard J. Cameron, Wai-Cheung Tang, Van Dokas
  • Patent number: 5585331
    Abstract: Microwave bandpass filters contain dielectric resonators mounted in dielectric blocks, which are in turn mounted in cavities. There can be more than one dielectric resonator per cavity. Significant size reduction has been achieved over prior art filters. The filters can be operated at cryogenic temperatures and since the results attainable at cryogenic temperatures are repeatable, the filters can be tuned at cryogenic temperatures and returned to room temperature before being returned to cryogenic temperatures for operating purposes. When operated at cryogenic temperatures, the filters contain shorting plates having high temperature superconducting material thereon. The filters can be constructed with various configurations and can be operated in either a single mode or a dual-mode. Previous single mode or dual-mode dielectric resonator filters are larger in size and mass than the filters of the present application.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: December 17, 1996
    Assignee: Com Dev Ltd.
    Inventors: Raafat R. Mansour, Van Dokas
  • Patent number: 5498771
    Abstract: Microwave bandpass filters contain dielectric resonators mounted in dielectric blocks, which are in turn mounted in cavities. There can be more than one dielectric resonator per cavity. Significant size reduction has been achieved over prior art filters. The filters can be operated at cryogenic temperatures and since the results attainable at cryogenic temperatures are repeatable, the filters can be tuned at cryogenic temperatures and returned to room temperature before being returned to cryogenic temperatures for operating purposes. When operated at cryogenic temperatures, the filters contain shorting plates having high temperature superconducting material thereon. The filters can be constructed with various configurations and can be operated in either a single mode or a dual-mode. Previous single mode or dual-mode dielectric resonator filters are larger in size and mass than the filters of the present application.
    Type: Grant
    Filed: December 3, 1993
    Date of Patent: March 12, 1996
    Assignee: Com Dev Ltd.
    Inventors: Raafat R. Mansour, Van Dokas