Patents by Inventor Stephen J. J. Hirsch

Stephen J. J. Hirsch 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).

  • Dielectric constant monitor
    Patent number: 5148125
    Abstract: Monitoring of the average dielectric constant in an extended volume of a medium such as soil is achieved using an oscillator incorporating a transmission line to be embedded in the medium. The transmission line is connected as the feedback loop of an amplifier, for one-way propagation of an electrical signal with a delay determined largely by the dielectric properties of the medium, such as its moisture content. The oscillation frequency is indicative of the dielectric constant of the medium.
    Type: Grant
    Filed: June 21, 1991
    Date of Patent: September 15, 1992
    Assignee: Lincoln College
    Inventors: Ian M. Woodhead, Stephen J. J. Hirsch