Patents by Inventor Robert R. Greenwood

Robert R. Greenwood 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: 5091699
    Abstract: A frequency division network is disclosed in which a sinusoidal signal is converted to a digital format for frequency division and then converted back to the sinusoidal format, the sinusoidal output waveform having low phase noise. In a preferred embodiment the frequency conversion takes place in an m-fold plurality of edge triggered flip-flops, connected to divide by two, and clocked by the sinusoidal waveform. Each flip-flop is subject to jitter causing phase noise, which is minimized when the output of two sets of four flip-flops are averaged, and then filtered to obtain the sinusoidal fundamental. When a crystal filter having a very narrow pass band is employed, the phase noise is further reduced. The frequency division network uses low cost components and the phase noise of the output waveform approaches that of a stable crystal oscillator.
    Type: Grant
    Filed: November 14, 1990
    Date of Patent: February 25, 1992
    Assignee: General Electric Company
    Inventors: Bert K. Erickson, Robert R. Greenwood, Wilbert C. Kennedy, David W. Michel, David C. Allen, Victor J. Jacek