Patents by Inventor John A. Wendler

John A. Wendler 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: 5162723
    Abstract: A sampling signal analyzer in which the frequency of an input signal to be measured is initially ascertained, an appropriate sampling frequency is then determined, data needed to reconstruct the wave form of the input signal is acquired, and the input signal wave shape is reconstructed with a calibrated time axis and preferably displayed. The sampling signal analyzer synthesizes a sampler drive signal to enable continuous sampling of the input signal and therefore has the advantage over known data sampling signal measurement instruments that it is not triggered directly in response to the level of the input signal to be measured. Instead, sample timing is based on numerical analysis of the intermediate frequency (IF) signal produced by the sampler. The IF frequency can be an arbitrarily low frequency, which allows digitizing and digital signal processing for aligning measurement data from sweep to sweep with precision.
    Type: Grant
    Filed: February 11, 1991
    Date of Patent: November 10, 1992
    Assignee: Hewlett-Packard Company
    Inventors: Michael S. Marzalek, Richard C. Keiter, John A. Wendler, Stephen R. Peterson, Ronald J. Hogan
  • Patent number: 4928251
    Abstract: Representations of signal edges of a repetitive signal are sampled without triggering, then sorted out based on frequency and sequence and then superimposed along a common time base of one period in order to reconstruct a signal. In a specific embodiment of a method according to the invention, a string of samples of a repetitive, input signal with high frequency components is captured without triggering with relatively low time resolution to determine an approximate waveform from the low resolution samples, then digital signal processing techniques in the form of a fast Fourier transform are applied to a reconstructed time record of the input signal to obtain an accurate frequency for each signal component, and finally the sampled waveform is reconstructed by overlaying sampled components with reference to a common time or phase reference. The FFT is employed to determine the frequency of each signal component very accurately.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: May 22, 1990
    Assignee: Hewlett-Packard Company
    Inventors: Michael S. Marzalek, Stephen R. Peterson, John A. Wendler