Patents by Inventor Calvin R. Graf

Calvin R. Graf 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).

  • Privacy communication method and system
    Patent number: 4244053
    Abstract: A privacy communication method and system which utilizes coherent, continuously changing frequencies for keyed, pulsed, and voice communications. A synthesized swept frequency or "chirp" signal imparts a privacy or secure communications capability to the communications signal by virtue of the random or pseudo-random nature of the transmitted signals which is programmed.
    Type: Grant
    Filed: September 10, 1970
    Date of Patent: January 6, 1981
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Marvin R. Clinch, Calvin R. Graf, Paul E. Martin, Robert B. Fenwick