Patents by Inventor Kalev Sepp

Kalev Sepp 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: 10073750
    Abstract: A serial data link measurement and simulation system for use on a test and measurement instrument presents on a display device. A main menu having elements representing a measurement circuit, a simulation circuit and a transmitter. The main menu includes processing flow lines pointing from the measurement circuit to the transmitter and from the transmitter to the simulation circuit. The main menu includes a source input to the measurement circuit and one or more test points from which waveforms may be obtained. The simulation circuit includes a receiver. The measurement and simulation circuits are defined by a user, and the transmitter is common to both circuits so all aspects of the serial data link system are tied together.
    Type: Grant
    Filed: February 4, 2013
    Date of Patent: September 11, 2018
    Assignee: Tektronix, Inc.
    Inventors: John J. Pickerd, Kan Tan, Kalev Sepp, Sarah R. Boen
  • Publication number: 20130332101
    Abstract: A serial data link measurement and simulation system for use on a test and measurement instrument presents on a display device a main menu having elements representing a measurement circuit, a simulation circuit and a transmitter. The main menu includes processing flow lines pointing from the measurement circuit to the transmitter and from the transmitter to the simulation circuit. The main menu includes a source input to the measurement circuit and one or more test points from which waveforms may be obtained. The simulation circuit includes a receiver. The measurement and simulation circuits are defined by a user, and the transmitter is common to both circuits so all aspects of the serial data link system are tied together.
    Type: Application
    Filed: February 4, 2013
    Publication date: December 12, 2013
    Applicant: TEKTRONIX, INC.
    Inventors: John J. Pickerd, Kan Tan, Kalev Sepp, Sarah R. Boen
  • Patent number: 7912117
    Abstract: A method of measuring transport delay and jitter with a realtime oscilloscope using cross-correlation acquires waveforms from two test points in a system under test. Clock recovery is run on both waveforms to obtain respective rates and offsets. A time offset between the two waveforms is computed. The jitter from the two test points is filtered and a mean-removed cross-correlation coefficient is computed from the filtered jitters. A fractional delay is computed using interpolation based on LMS error, and the respective computational components are summed to compute a transport delay between the two test points. The transport delay may be used to adjust clock edges from one waveform for comparison with data transition edges of the other waveform to measure jitter.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: March 22, 2011
    Assignee: Tektronix, Inc.
    Inventors: Kan Tan, John C. Calvin, Kalev Sepp
  • Patent number: 7623581
    Abstract: A method for recovering a clock from a serial data stream for use in producing “eye” diagram measurements includes determining an initial recovered clock from the serial data stream based upon transition edges. Time interval error values are then determined as a function of the transition edges and corresponding initial recovered clock times. Time interval error values are interpolated for initial recovered clock times not associated with transition edges to produce a complete set of time interval error values. The complete set of time interval error values are lowpass filtered to produce a filtered set of time interval error values. The clock for the serial data stream is reconstructed from the filtered set of time interval error values.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: November 24, 2009
    Assignee: Tektronix, Inc.
    Inventors: Srikrishna H. Nadig, Kalev Sepp
  • Publication number: 20090121762
    Abstract: Timebase variation compensation in a measurement instrument is achieved by simultaneously acquiring both a signal under test and a reference signal. The reference signal is derived from a source that has very stable timing with respect to the timebase. Timing variations are measured from the acquired signals. Timing variations detected in the reference signal are deemed to reflect variations in the timebase of the test and measurement instrument. The timing variations in the reference signal are used to detect, and compensate for, timebase variation in the signal under test to produce a corrected signal under test that reflects the actual timing variations present in the signal under test.
    Type: Application
    Filed: November 9, 2007
    Publication date: May 14, 2009
    Applicant: TEKTRONIX, INC.
    Inventor: Kalev SEPP
  • Publication number: 20080080605
    Abstract: A method of measuring transport delay and jitter with a realtime oscilloscope using cross-correlation acquires waveforms from two test points in a system under test. Clock recovery is run on both waveforms to obtain respective rates and offsets. A time offset between the two waveforms is computed. The jitter from the two test points is filtered and a mean-removed cross-correlation coefficient is computed from the filtered jitters. A fractional delay is computed using interpolation based on LMS error, and the respective computational components are summed to compute a transport delay between the two test points. The transport delay may be used to adjust clock edges from one waveform for comparison with data transition edges of the other waveform to measure jitter.
    Type: Application
    Filed: September 28, 2006
    Publication date: April 3, 2008
    Inventors: Kan Tan, John C. Calvin, Kalev Sepp
  • Publication number: 20070133726
    Abstract: A method for recovering a clock from a serial data stream for use in producing “eye” diagram measurements includes determining an initial recovered clock from the serial data stream based upon transition edges. Time interval error values are then determined as a function of the transition edges and corresponding initial recovered clock times. Time interval error values are interpolated for initial recovered clock times not associated with transition edges to produce a complete set of time interval error values. The complete set of time interval error values are lowpass filtered to produce a filtered set of time interval error values. The clock for the serial data stream is reconstructed from the filtered set of time interval error values.
    Type: Application
    Filed: September 15, 2005
    Publication date: June 14, 2007
    Inventors: Srikrishna Nadig, Kalev Sepp
  • Patent number: 6836738
    Abstract: A first method for rendering an eye diagram synchronized to a recovered clock and based on a single shot acquisition of a digital storage oscilloscope, acquires a waveform and measures the timing of its edges. It then estimates the symbol rate of the waveform and derives clock signals in accordance with the edge timing and the estimated symbol rate. The waveform data is then sliced into frames with respect to the derived clock signals, and the frames are partially overlapped and aligned to form an eye diagram. In a second embodiment of the invention, the frames are aligned, without being overlapped, to form an eye diagram.
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: December 28, 2004
    Assignee: Tektronix, Inc.
    Inventors: Kalev Sepp, John C. Calvin
  • Publication number: 20040002826
    Abstract: A first method for rendering an eye diagram synchronized to a recovered clock and based on a single shot acquisition of a digital storage oscilloscope, acquires a waveform and measures the timing of its edges. It then estimates the symbol rate of the waveform and derives clock signals in accordance with the edge timing and the estimated symbol rate. The waveform data is then sliced into frames with respect to the derived clock signals, and the frames are partially overlapped and aligned to form an eye diagram. In a second embodiment of the invention, the frames are aligned, without being overlapped, to form an eye diagram.
    Type: Application
    Filed: March 14, 2003
    Publication date: January 1, 2004
    Inventors: Kalev Sepp, John C. Calvin