Patents by Inventor David P Haworth

David P Haworth 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).

  • Method and apparatus for locating the source of unknown signal
    Patent number: 6677893
    Abstract: A method of locating the source of an unknown signal of varying frequency received by receive antennas (16, 18) via relay satellites (12, 14) involves downconversion of received signals to a first intermediate frequency (IF) and band-limiting the downconverted signals. The band-limited signals are constrained to lie within a prearranged acquisition signal bandwidth by adjustment of local oscillator (LO) downconversion frequency to counteract frequency change in the unknown signal. Downconverted signals are offset in time relative to one another using trial values of differential time offset and their correlation is determined for each trial value to provide actual time offset. Compensation is provided for change in correlation phase angle, which results from signals being downconverted experiencing different LO frequencies during the time interval of the trial offset.
    Type: Grant
    Filed: November 19, 2002
    Date of Patent: January 13, 2004
    Assignee: QinetiQ Limited
    Inventors: Robert M Rideout, Paul R Edmonds, Simon R Duck, David P Haworth, Christopher Griffin
  • Method and apparatus for locating the source of unknown signal
    Publication number: 20030117319
    Abstract: A method of locating the source of an unknown signal of varying frequency received by receive antennas (16, 18) via relay satellites (12, 14) involves downconversion of received signals to a first intermediate frequency (IF) and band-limiting the downconverted signals. The band-limited signals are constrained to lie within a prearranged acquisition signal bandwidth by adjustment of local oscillator (LO) downconversion frequency to counteract frequency change in the unknown signal. Downconverted signals are offset in time relative to one another using trial values of differential time offset and their correlation is determined for each trial value to provide actual time offset. Compensation is provided for change in correlation phase angle, which results from signals being downconverted experiencing different LO frequencies during the time interval of the trial offset.
    Type: Application
    Filed: November 19, 2002
    Publication date: June 26, 2003
    Inventors: Robert M Rideout, Paul R Edmonds, Simon R Duck, David P Haworth, Christopher Griffin