Patents by Inventor Robert J. Fraser

Robert J. Fraser 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).

  • Varactor-tuned helical resonator filter
    Patent number: 4459571
    Abstract: A helical cavity resonator filter utilizes varactor tuning diodes positioned within each helical resonator coil. The diodes are positioned along the longitudinal axes of the coils so as not to interfere with the non-axial electromagnetic fields of the cavities associated with each helical resonator coil.
    Type: Grant
    Filed: December 20, 1982
    Date of Patent: July 10, 1984
    Assignee: Motorola, Inc.
    Inventor: Robert J. Fraser