Patents by Inventor Peter Anthony Rigby

Peter Anthony Rigby 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).

  • Patent number: 3970926
    Abstract: A method and an apparatus for measuring group delay characteristics of a transmission path is disclosed wherein a test signal is fed to the input of the transmission path and the test signal is amplitude modulated by a split frequency. The carrier frequency of the test signal is interchanged periodically between a measuring frequency and a standard reference frequency. The output measuring and reference signals of the transmission path are sensed by noting the positions in time of specified points of the envelope waveform that occur during the periods of the reference type signal and the measurement type signal. A digital pulse counter is provided for measuring a first time interval between a specified point during a period of a first type signal and a specified point during the subsequent period of the second type of signal, and for measuring a second time interval between the latter specified point and a specified point during the subsequent period of the first type of signal.
    Type: Grant
    Filed: February 21, 1975
    Date of Patent: July 20, 1976
    Assignee: Hewlett-Packard Limited
    Inventors: Peter Anthony Rigby, Ralph Hodgson, David Hubert Guest