Patents by Inventor Stephen R. Maddox

Stephen R. Maddox 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).

  • Portable microwave instrument for non-destructive evaluation of structural characteristics
    Patent number: 5384543
    Abstract: A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member.
    Type: Grant
    Filed: November 9, 1992
    Date of Patent: January 24, 1995
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventors: Don W. Bible, Richard I. Crutcher, Carl W. Sohns, Stephen R. Maddox