Patents by Inventor Gerald Shearer

Gerald Shearer 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).

  • Variable frequency system having linear combination of charge pump and voltage controlled oscillator
    Patent number: 5126692
    Abstract: A phase locked loop system having a non-linear voltage controlled oscillator (VCO) is provided with a variable gain charge pump. The charge pump supplies a pump current to an integrating network which transforms the pump current into a frequency-modulating input voltage. The frequency-modulating input voltage is applied to an input of the VCO. The frequency-modulating input voltage is also coupled to a gain control input of the variable gain charge pump so that the magnitude of the pump current will be a function of the absolute value of the frequency-modulating voltage.A substantially constant loop gain may be obtained in the phase locked loop system by arranging the gain function of the variable gain charge pump in counterposed relation to the slope of a VCO transfer function defining the nonlinear relation between the frequency-modulating input voltage of the VCO and the output frequency of the VCO.
    Type: Grant
    Filed: July 21, 1989
    Date of Patent: June 30, 1992
    Assignee: Western Digital Corporation
    Inventors: Gerald Shearer, Karl M. Lofgren, Kenneth W. Ouyang
  • Variable frequency system having linear combination of charge pump and voltage controlled oscillator
    Patent number: 4871979
    Abstract: A phase locked loop system having a non-linear voltage controlled oscillator (VCO) is provided with a variable gain charge pump. The charge pump supplies a pump current to an integrating network which transforms the pump current into a frequency-modulating input voltage. The frequency-modulating input voltage is applied to an input of the VCO. The frequency-modulating input voltage is also coupled to a gain control input of the variable gain charge pump so that the magnitude of the pump current will be a function of the absolute value of the frequency-modulating voltage.A substantially constant loop gain may be obtained in the phase locked loop system by arranging the gain function of the variable gain charge pump in counterposed relation to the slope of a VCO transfer function defining the nonlinear relation between the frequency-modulating input voltage of the VCO and the output frequency of the VCO.
    Type: Grant
    Filed: August 3, 1987
    Date of Patent: October 3, 1989
    Assignee: Western Digital Corporation
    Inventors: Gerald Shearer, Karl M. Lofgren, Kenneth W. Ouyang