Patents by Inventor Ken K. Tsai

Ken K. Tsai 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).

  • Phase locked loop with offset cancellation
    Patent number: 6680654
    Abstract: A phase locked loop (10) for generating a variable output frequency signal. The phase locked loop (10) includes a controlled oscillator (14) to generate the variable output frequency signal in response to a tune signal. A phase detector (18) is activable in response to a gating signal (20) to generate an error signal representing a difference between a reference frequency signal and the variable output frequency signal. A loop filter (12) having a filter characteristic, filters the error signal and generates the tune signal. An offset cancellation circuit (22) is coupled to the loop filter (12). In response to an error signal representing phase offset of the phase locked loop (10), the offset cancellation circuit (22) supplies a compensating signal to reduce the phase offset.
    Type: Grant
    Filed: October 24, 2001
    Date of Patent: January 20, 2004
    Assignee: Northrop Grumman Corporation
    Inventors: Gerald R. Fischer, Talley J. Allen, Ken K. Tsai
  • Phase locked loop with offset cancellation
    Publication number: 20030076175
    Abstract: A phase locked loop (10) for generating a variable output frequency signal. The phase locked loop (10) includes a controlled oscillator (14) to generate the variable output frequency signal in response to a tune signal. A phase detector (18) is activable in response to a gating signal (20) to generate an error signal representing a difference between a reference frequency signal and the variable output frequency signal. A loop filter (12) having a filter characteristic, filters the error signal and generates the tune signal. An offset cancellation circuit (22) is coupled to the loop filter (12). In response to an error signal representing phase offset of the phase locked loop (10), the offset cancellation circuit (22) supplies a compensating signal to reduce the phase offset.
    Type: Application
    Filed: October 24, 2001
    Publication date: April 24, 2003
    Inventors: Gerald R. Fischer, Talley J. Allen, Ken K. Tsai