Patents by Inventor Charles Richard Hill

Charles Richard Hill 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).

  • Electromagnetic intruder detector sensor cable
    Patent number: 5834688
    Abstract: A sensor cable formed of a center conductor surrounded by dielectric material and first and second layers. The first layer is formed of a gapped conductive material surrounding the dielectric material. The second layer has predetermined conductivity and at least covers the gaps in the conductive material of the first layer. The predetermined conductivity and thickness of the second layer is such that the skin depth in the second layer at an operating frequency of the cable is much greater than the thickness of the second layer, and inductive coupling into or out of the cable through gaps in the second layer is at least an order of magnitude greater than capacitive coupling into or out of the cable through gaps in the second layer.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: November 10, 1998
    Assignee: Senstar Stellar Corporation
    Inventors: Charles Richard Hill, Melvin Clive Maki