Patents Represented by Attorney, Agent or Law Firm Thomas F. Lenihan
  • Patent number: 8224613
    Abstract: An Arbitrary Waveform Generator has a controller programmed to generate a sequence of test waveforms using previously-defined waveform data files. The controller generates this series of test waveforms by direct synthesis to cause each waveform to contain a respective different predetermined amount of Rj, Sj and ISI jitter components. In this way, the Arbitrary Waveform Generator produces a sequence of waveforms incorporating varying amounts of ISI to sweep the ISI jitter components from an initial amount of ISI, for example, zero ISI, and continually increment the amount of ISI to a full unit interval of ISI in predetermined increments, for example, 0.1 UI steps.
    Type: Grant
    Filed: March 13, 2008
    Date of Patent: July 17, 2012
    Assignee: Tektronix, Inc.
    Inventors: John C. Calvin, Gary K. Richmond
  • Patent number: 8223151
    Abstract: A method of analysis of long record length data using mark duration includes displaying together with a portion of the long record length data each mark that identifies a specified feature of interest together with the mark duration. Associated with the mark may be text identifying the feature of interest, measurement values associated with the duration of the mark, or a combination thereof. Multiple sets of marks may be generated for the long record length data, which sets may be combined to generate new marks with duration. The marks also may be filtered to further refine the marks to be displayed according to user specified criteria. In this way analysis of long record length data representing an acquired signal may be readily automated so a user may move from one interesting event to another without having to pan through the long record length data.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: July 17, 2012
    Assignee: Tektronix, Inc.
    Inventors: Keith D. Rule, Thomas L. Freeman, Daniel E. Taylor, Timothy D. Margeson, Scott R. Ketterer
  • Patent number: 8165184
    Abstract: An Arbitrary Waveform Generator (AWG) synthesizes and generates an SSC modulated signal by generating a modulating waveform with a frequency of an SSC modulation frequency, calculating the number of samples per data bit (SPUI) as a ratio of an upsampling frequency to a data rate of a data stream, calculating an amplification factor as the ratio of SSC deviation frequency to data rate of the data stream, generating the array of SSC Edges containing the edge variation with respect to single sample per bit, multiplying the amplification factor to the modulating waveform, generating an array of SSC Edges Upsampled, containing edge variations with respect to an Upsample factor per bit, and multiplying SSC Edges with SPUI; calculating the resultant bit duration SSC Bit Duration as the sum of SSC Edges Upsampled and SPU, and calculating the successive summation of SSC Bit Duration, to get SSC Bit Position.
    Type: Grant
    Filed: January 17, 2009
    Date of Patent: April 24, 2012
    Assignee: Tektronix, Inc.
    Inventors: Ramachandra Cv, Mark L. Guenther, John C. Calvin
  • Patent number: 8023729
    Abstract: A method of reducing color smearing or color artifacts in a low resolution picture that is subjected to chrominance downsampling prior to display on a display device first upsamples the pixels in each row of the picture to double the picture width, then downsamples the chrominance values to produce a compressed data stream for transmission to the display device, and finally decompresses the compressed data stream for display. In order to maintain the aspect ration of the original picture, each doubled row may be repeated prior to transmission to the display device.
    Type: Grant
    Filed: August 2, 2007
    Date of Patent: September 20, 2011
    Assignee: Tektronix, Inc.
    Inventor: Craig H. Nelson
  • Patent number: 8000919
    Abstract: A method useful for the characterization of a fixture splits a partially symmetric THRU structure into portions which may then be mathematically removed from both ports of a 2-port measured structure, leaving only the desired device under test (DUT).
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: August 16, 2011
    Assignee: Tektronix, Inc.
    Inventor: Kan Tan
  • Patent number: 7994801
    Abstract: A new methodology for the measurement of the S-parameters of a high impedance probe allows obtaining a full two port S-parameter set for the high impedance probe. The measured probe S-parameters are then used for characterization of probes. An alternative method characterizes half of the fixture and termination as a one-port network and expanding it into a two-port error box. The two-port error box is then cascaded with the probe input.
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: August 9, 2011
    Assignee: Tektronix, Inc.
    Inventors: William A. Hagerup, Laudie Doubrava
  • Patent number: 7929461
    Abstract: A method of measuring bus traffic on a controller area network (CAN) is described. Accordingly, in one embodiment, a digital oscilloscope acquires the CAN bus signal in the form of a waveform in real-time. The waveform is converted into a bit stream, and the bitstream is analyzed to carry out various measurements in a CAN measurement system. The method may be used for continuous monitoring of bus traffic and measuring of various parameters related thereto, such as bus occupancy by a particular node. The acquired data may be analyzed for measuring bus occupancy by various types of CAN message frames. The user is presented with a data display and a graphical display of the measurements. Also, the user is allowed to enter an identifier for a node to obtain measurements relating to that particular node.
    Type: Grant
    Filed: June 5, 2006
    Date of Patent: April 19, 2011
    Assignee: Tekronix, Inc.
    Inventors: PE Ramesh, Godfree Coelho, RN Prasanna
  • Patent number: 7839792
    Abstract: A system and a method for simultaneous measurement and analysis of network signals on multiple communication networks are described. Accordingly, in one embodiment, the system accepts signals from two communication networks. The two networks may be following different protocols. A time-correlated measurement of corresponding frames of two protocols may be provided. Information pertaining to message frames of different networks may be displayed simultaneously.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: November 23, 2010
    Assignee: Tektronix, Inc.
    Inventor: RN Prasanna
  • Patent number: 7729872
    Abstract: Selectable portions of a display on a display screen allow a user to select bits of a digital signal. A mode selection menu changes the bit selection to select bits in different ways. If an individual bit designation mode is selected, objects are displayed that correspond to the respective bits of the digital signal. A user selects the object corresponding to a desired bit by use of a mouse. After bit selection, an eye pattern, derived from only selected bits, is displayed. Additionally, jitter analysis results derived from only the selected bits are displayed.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: June 1, 2010
    Assignee: Tektronix, Inc.
    Inventor: Toshiaki Obata
  • Patent number: 7620509
    Abstract: A frequency hopping pattern of a frequency hopping signal is detected by use of spectrogram-generating software in a digital storage oscilloscope. By using a spectrogram, a hopping pattern can be determined without having to demodulate the signal, recover the phase or frequency of the carrier, determine optimal sample timing, or determine system timing. A block of data that contains at least one repetition of the hopping pattern in analyzed with respect to known hopping patterns as well as with respect to the duration in time of the relevant symbols of that data.
    Type: Grant
    Filed: October 23, 2006
    Date of Patent: November 17, 2009
    Assignee: Tektronix, Inc.
    Inventor: Richard A. Cameron
  • Patent number: 7404679
    Abstract: A terminal element for fiber optic communication has an elongated body defining a body axis and having a first end from which an optical fiber extends along the body axis. The body has a second end with an angled surface offset at an angle from the body axis. The fiber extends partly through the length of the body, and terminates at a fiber end surface. The second portion has an optical entry surface registered with the fiber end surface such that light emitted from the fiber end surface enters the optical entry surface. At least one of the fiber end surface, angled surface and optical entry surface has a figured optical form with a non-planar shape.
    Type: Grant
    Filed: December 14, 2006
    Date of Patent: July 29, 2008
    Assignee: Tektronix, Inc.
    Inventors: Ralph Ebbutt, Talapker Imanbayev
  • Patent number: 7379830
    Abstract: A method and apparatus for determining the period Tp of a signal representing a digitally modulated waveform using NRZ coding with a discrete/integer number of a clock periods between signal transitions, where a periodic sequence of logic “1s” and logic “0s” is transmitted. The method samples an input periodic signal, constructs an estimate of the autocorrelation sequence rk of the sequence of samples, constructs a sequence of peaks pk, and computes the period Tp to be the time between the first pk sample (k=0), and the time location of the maximum value of pk based on the known Ts spacing of the pk sequence samples.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: May 27, 2008
    Assignee: Tektronix, Inc.
    Inventor: Dan Onu
  • Patent number: 7373263
    Abstract: A logic analyzer that performs analog-type measurements on digital data includes circuitry in its acquisition system that is programmable to search through acquired data to detect analog-type signal characteristics. In a first embodiment, the logic analyzer includes a graphical user interface employing a drag-and-drop operation to apply one or more selected analog-type measurements to selected portions of the digital data record. In a second embodiment, a user may designate a particular waveform or data listing by means of a mouse-click. Each of the choices of analog-type measurements can be represented by an icon, or text, or both icon and text.
    Type: Grant
    Filed: May 16, 2006
    Date of Patent: May 13, 2008
    Assignee: Tektronix, Inx.
    Inventors: Robert C. Cohn, Susan C. Adam, Mark A. Briscoe, Andrew Loofburrow, Eric E. Thums
  • Patent number: 7369604
    Abstract: Apparatus according to the subject invention includes two independent acquisition systems, wherein one of the two independent acquisition systems acquires the acquisition clock of the other acquisition system along with a signal from a known acquisition reference point. In general, the first independent acquisition system is a logic analyzer, and the second independent acquisition system can be an ILA, a second logic analyzer, an oscilloscope, or other sampling device.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: May 6, 2008
    Assignee: Tektronix, Inc.
    Inventor: Robert J. Heath
  • Patent number: 7340656
    Abstract: The subject invention facilitates the efficient operation of the disassembly of the microprocessor bus by providing an apparatus and method for detecting and correcting a strobe phase inversion and predrive filtering in a 2× source synchronous data transfer bus. Apparatus according to the subject invention detects a data strobe inversion in a source synchronous 2× data bus and corrects for this inversion by reordering the received data as well as filtering predrive effects in real time. Specifically, this apparatus according to the subject invention monitors bus traffic in a multiprocessor environment and correctly captures all double data rate exchanges regardless of the source IC or destination IC in the system.
    Type: Grant
    Filed: July 8, 2004
    Date of Patent: March 4, 2008
    Assignee: Tektronix, Inc.
    Inventors: James M. Fenton, Kevin Taylor, Gene L. Markozen
  • Patent number: 7272528
    Abstract: A test and measurement instrument such as a Logic Analyzer, or the like, has at least one Reloadable Word Recognizer whose reference value can be loaded by a trigger machine with a current acquired data sample while data is being acquired. In a second embodiment useful for performing memory testing, the reloadable word recognizer is used in cooperation with two conventional word recognizers. In a third embodiment, a delay unit is employed to provide delayed input data words as reference words. In a fourth embodiment, an offset register and adder are used to modify the input data words before storing them. A fifth embodiment provides for substantially immediate use of base addresses of relocatable subroutines and stack-based variables recovered from a data stream acquired from a system under test.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: September 18, 2007
    Assignee: Tektronix, Inc.
    Inventors: David A. Holaday, Gary K. Richmond, Donald C. Kirkpatrick
  • Patent number: 7271337
    Abstract: A security block for securing I/O ports of an electronic instrument physically prevents any breach of data through a protected I/O port, such as a USB port, by securing cables that may be plugged into the port by means of a locked cover. The cables are prevented from being removed and USB memory devices are prevented from being connected in their place. In a second aspect, a portion of the security block covers unused I/O ports thereby preventing USB memory devices and other devices from being connected to unoccupied I/O ports. The locking mechanism can be either a padlock, or a locking screw, or the like.
    Type: Grant
    Filed: November 23, 2005
    Date of Patent: September 18, 2007
    Assignee: Tektronix, Inc.
    Inventor: Lawrence M. Le Mon
  • Patent number: 7246267
    Abstract: A logic analyzer according to the subject invention includes a disassembler for disassembling object code. The disassembler automates the process of locating op-code addresses by utilizing information derived from an object file corresponding to the code whose execution is being disassembled. The object file includes addresses for the starting location of op-codes corresponding to individual source code lines. When the disassembler cannot determine the correct starting location for an op-code, it uses information from the object file to obtain the address of an op-code within a specified range of interest.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: July 17, 2007
    Assignee: Tektronix, Inc.
    Inventors: David L. Bennett, Robert J. Heath, Mark L. Millard
  • Patent number: 7236900
    Abstract: A method and apparatus for synchronizing presentation of multi-domain measurements using actual or quasi 3-D representation. The synchronization between data streams acquired in different measurement domains is performed by using timestamps, a common trigger event, or a common clock, or a combination of any or all of them. In this way, for example, a transient anomaly in the RF spectrum of a communications signal may be correlated with, and displayed with, a related corrupted data communications packet.
    Type: Grant
    Filed: April 20, 2004
    Date of Patent: June 26, 2007
    Assignee: Tektronix, Inc.
    Inventors: Michael S. Hagen, Wendell W. Damm
  • Patent number: 7222034
    Abstract: An oscilloscope performs an in-circuit measurement of voltage across, and current through, a core winding of an inductor, and derives the actual B and H values with n number of turns, receives data indicative of the magnetic length of the circuit, and plots the B_H curve. The oscilloscope then derives the value of Saturation flux density (Bsat), Remnant flux density (Br), Permeability (?), and Coercivity (Hc) from this B-H plot. Characterizing the operating region of the magnetic component while it operates in a Switch Mode Power Supply (SMPS) under test, provides information concerning the stability of the power supply that was heretofore unavailable.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: May 22, 2007
    Assignee: Tektronix, Inc.
    Inventors: P. E. Ramesh, Godfree Coelho