Patents by Inventor John Thomson Douglass

John Thomson Douglass 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: 9229026
    Abstract: An accelerometer system can include a sensor element comprising first and second proofmasses, the first proofmass accelerating in a first direction and the second proofmass accelerating in a second direction opposite the first direction in response to an external acceleration. A force rebalance controller applies control signals to at least one control element to provide a first force to accelerate the first proofmass toward a first null position and to at least one control element to provide a second force to accelerate the second proofmass toward a second null position. The force rebalance controller can also generate opposite polarity first and second output signals associated with respective displacements of the first and second proofmasses relative to the respective first and second null positions. An acceleration component calculates the external acceleration based on the first and second output signals.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: January 5, 2016
    Assignee: Northrop Grumman Guaidance and Electronics Company, Inc.
    Inventors: Robert E. Stewart, Daryl Sakaida, Michael D. Bulatowicz, Ming Li, John Thomson Douglass
  • Publication number: 20120265481
    Abstract: An accelerometer system can include a sensor element comprising first and second proofmasses, the first proofmass accelerating in a first direction and the second proofmass accelerating in a second direction opposite the first direction in response to an external acceleration. A force rebalance controller applies control signals to at least one control element to provide a first force to accelerate the first proofmass toward a first null position and to at least one control element to provide a second force to accelerate the second proofmass toward a second null position. The force rebalance controller can also generate opposite polarity first and second output signals associated with respective displacements of the first and second proofmasses relative to the respective first and second null positions. An acceleration component calculates the external acceleration based on the first and second output signals.
    Type: Application
    Filed: April 13, 2011
    Publication date: October 18, 2012
    Inventors: ROBERT E. STEWART, Daryl Sakaida, Michael D. Bulatowicz, Ming Li, John Thomson Douglass
  • Patent number: 7095963
    Abstract: An optical receiver system for processing signals output from a polarization diversity detector that includes a plurality of photodetector cells. Each cell provides an signal that includes a phase generated carrier signal having a modulation frequency ? and a sensor signal that has an in-phase component I and a quadrature phase component Q superimposed on the phase generated carrier signal. A plurality of variable gain amplifiers are arranged to produce a plurality of amplified signals. A feedback circuit is connected to the plurality of variable gain amplifiers for controlling the gains thereof. A plurality of demodulator circuits are arranged to receive the amplified signals. The demodulator circuits are arranged to provide for each photodetector cell an I signal output that indicates an amplitude of the in-phase component I and a Q signal output that indicates an amplitude of the quadrature phase component Q.
    Type: Grant
    Filed: July 30, 2001
    Date of Patent: August 22, 2006
    Assignee: Litton Systems, Inc.
    Inventors: William Christopher Knaack, John Thomson Douglass, IV, Eugene Louis Ferraro
  • Publication number: 20040047640
    Abstract: An optical receiver system for processing signals output from a polarization diversity detector that includes a plurality of photodetector cells. Each cell provides an signal that includes a phase generated carrier signal having a modulation frequency &ohgr; and a sensor signal that has an in-phase component I and a quadrature phase component Q superimposed on the phase generated carrier signal. A plurality of variable gain amplifiers are arranged to produce a plurality of amplified signals. A feedback circuit is connected to the plurality of variable gain amplifiers for controlling the gains thereof. A plurality of demodulator circuits are arranged to receive the amplified signals. The demodulator circuits are arranged to provide for each photodetector cell an I signal output that indicates an amplitude of the in-phase component I and a Q signal output that indicates an amplitude of the quadrature phase component Q.
    Type: Application
    Filed: January 23, 2003
    Publication date: March 11, 2004
    Inventors: William Christopher Knaack, John Thomson Douglass, Eugene Louis Ferraro