Patents by Inventor Russel A. Christman

Russel A. Christman 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).

  • Patent number: 5226016
    Abstract: A method and apparatus are provided to adaptively form an optimum signal-free reference used to cancel near-field noise in an adaptive plate-noise cancellation system. First, second and third pressure sensors are positioned to detect any near-field plate-radiated noise. The first sensor is positioned closest to the plate, the third sensor is positioned furthest from the plate, and the second sensor is positioned between the first and third sensors. An acoustic far-field projector generates a plurality of broadband signals from a plurality of incidence angles. Each broadband signal is projected at an amplitude indicative of a noise-off condition. Outputs from the first and third sensors are combined to form a dipole responsive to each broadband signal). A feedback system is operatively associated with the dipole and the second sensor.
    Type: Grant
    Filed: April 16, 1992
    Date of Patent: July 6, 1993
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Russel A. Christman