Patents by Inventor Stuart A. Ridgway

Stuart A. Ridgway 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).

  • EMI reduction using tunable delay lines
    Patent number: 7333527
    Abstract: The clock signal is the dominant source of electromagnetic interference (EMI) for many digital electronic devices. EMI generated by these electronic devices must be suppressed to avoid interference with other electronic devices and to satisfy FCC regulations. The present invention seeks to reduce EMI emissions by phase-modulating the clock signal using tunable delay lines. Phase modulation causes a spreading of the energy spectrum of the clock signal thereby reducing EMI emissions. In addition, the present invention is capable of generating a wide energy spectrum in a short time interval. Furthermore, the present invention can be similarly applied to other signals which exhibit a periodic or timing nature due to a correlation with the clock signal.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: February 19, 2008
    Assignee: Sun Microsystems, Inc.
    Inventors: Mark R. Greenstreet, Robert J. Bosnyak, Stuart A. Ridgway
  • EMI reduction using tunable delay lines
    Publication number: 20030169838
    Abstract: The clock signal is the dominant source of electromagnetic interference (EMI) for many digital electronic devices. EMI generated by these electronic devices must be suppressed to avoid interference with other electronic devices and to satisfy FCC regulations. The present invention seeks to reduce EMI emissions by phase-modulating the clock signal using tunable delay lines. Phase modulation causes a spreading of the energy spectrum of the clock signal thereby reducing EMI emissions. In addition, the present invention is capable of generating a wide energy spectrum in a short time interval. Furthermore, the present invention can be similarly applied to other signals which exhibit a periodic or timing nature due to a correlation with the clock signal.
    Type: Application
    Filed: November 27, 2002
    Publication date: September 11, 2003
    Applicant: Sun Microsystems, Inc.
    Inventors: Mark R. Greenstreet, Robert J. Bosnyak, Stuart A. Ridgway