Patents by Inventor Francis W. Hopwood

Francis W. Hopwood 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 lock loop for a voltage controlled oscillator
    Patent number: 4009448
    Abstract: A phase lock loop configuration having a voltage controlled oscillator utilized, for example, in radar systems wherein false locking is prevented and loop bandwidth is maintained substantially constant. The voltage controlled oscillator includes a cavity resonator within which is located two tuning varactor diodes, one of which is heavily coupled to the resonator and comprises a coarse tuning port and one of which is lightly coupled and comprises the fine tuning port. The configuration is such that when the loop is locked, following a sweep mode of the coarse tuning voltage, the fine tune voltage is held constant at a predetermined DC level thereby making the fine tuning sensitivity essentially constant as the coarse tuning voltage changes the frequency over the band of interest.
    Type: Grant
    Filed: January 6, 1976
    Date of Patent: February 22, 1977
    Assignee: Westinghouse Electric Corporation
    Inventors: Francis W. Hopwood, Lester K. Staley
  • Low noise parametric varactor diode crystal oscillator
    Patent number: 3993962
    Abstract: A low noise frequency source utilizes a varactor diode to form a parametric crystal oscillator which may be frequency multiplied to the desired microwave frequency, for radar applications.
    Type: Grant
    Filed: August 18, 1975
    Date of Patent: November 23, 1976
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Francis W. Hopwood, Lester K. Staley, Thomas R. Turlington