Patents by Inventor David V. Blackham

David V. Blackham 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: 9632122
    Abstract: A method determines operating characteristics of a signal generator. The method includes performing a first set of measurements of an output signal generated by the signal generator and corresponding reflected signal, where the first set of measurements is performed over multiple frequencies and amplitudes of the output signal; applying an external signal to the output port of the signal generator; performing a second set of measurements of the output signal and corresponding reflected signal while the external signal is being applied to the output port, where the second set of measurements is performed over frequencies and amplitudes of the output signal, the external signal having the same frequency as the output signal for each measurement of the second set of measurements. A set of coefficients describing the operating characteristics of the signal generator is determined by processing results of the first and second sets of measurements through a non-linear model.
    Type: Grant
    Filed: June 23, 2014
    Date of Patent: April 25, 2017
    Assignee: Keysight Technologies, Inc.
    Inventors: Loren C. Betts, David V. Blackham, Michael C. Dobbert, Xiaolong Li, Dara Sariaslani, Lisa Shenton, Erwin F. Siegel, Bernadette Smith, Matt Todhunter, Kenneth H. Wong
  • Publication number: 20150369849
    Abstract: A method determines operating characteristics of a signal generator. The method includes performing a first set of measurements of an output signal generated by the signal generator and corresponding reflected signal, where the first set of measurements is performed over multiple frequencies and amplitudes of the output signal; applying an external signal to the output port of the signal generator; performing a second set of measurements of the output signal and corresponding reflected signal while the external signal is being applied to the output port, where the second set of measurements is performed over frequencies and amplitudes of the output signal, the external signal having the same frequency as the output signal for each measurement of the second set of measurements. A set of coefficients describing the operating characteristics of the signal generator is determined by processing results of the first and second sets of measurements through a non-linear model.
    Type: Application
    Filed: June 23, 2014
    Publication date: December 24, 2015
    Inventors: Loren C. Betts, David V. Blackham, Michael C. Dobbert, Xiaolong Li, Dara Sariaslani, Lisa Shenton, Erwin F. Siegel, Bernadette Smith, Matt Todhunter, Kenneth H. Wong
  • Patent number: 7545150
    Abstract: A measurement and correction method provides for a complete full correction of a true-mode system using only the single ended error matrix developed for 4 port correction of single ended measurements. The degree of misalignment of the balanced sources may be determined from these measurements.
    Type: Grant
    Filed: February 28, 2007
    Date of Patent: June 9, 2009
    Assignee: Agilent Technologies, Inc.
    Inventors: Keith F. Anderson, David V. Blackham, Joel P. Dunsmore, Loren C Betts, Nicholas C. Leindecker
  • Publication number: 20080204041
    Abstract: A measurement and correction method provides for a complete full correction of a true-mode system using only the single ended error matrix developed for 4 port correction of single ended measurements. The degree of misalignment of the balanced sources may be determined from these measurements.
    Type: Application
    Filed: February 28, 2007
    Publication date: August 28, 2008
    Inventors: Keith F. Anderson, David V. Blackham, Joel P. Dunsmore, Loren C. Betts, Nicholas C. Leindecker
  • Publication number: 20080020726
    Abstract: A vector network analyzer with one or more ports having each port comprising of an N-port signal separating network, where N>=6, an intermediate frequency (IF) filter interposing an RF downconverter and a power detector. The RF downconverter may be N-2 mixers or N-2 samplers. The IF downconverter (comprising N-2 IF filters and power detectors) may also be realized by an AID converter having N-2 inputs connected to a digital signal processor.
    Type: Application
    Filed: July 14, 2006
    Publication date: January 24, 2008
    Inventors: David V. Blackham, Kenneth H. Wong, Keith F. Anderson, Hassan Tanbakuchi
  • Patent number: 7148702
    Abstract: In one embodiment, a vector network analyzer (VNA) comprises a plurality of ports for coupling to a device under test (DUT), at least one reference receiver for measuring signals associated with the DUT, and logic for processing measurement data from the at least one reference receiver to compensate for transmission line effects, wherein the logic for processing evaluates a function, of several controllable variables, that is a sum of multiple transmission line models, wherein each of the controllable variables is related to a respective transmission line length associated with a corresponding transmission line model.
    Type: Grant
    Filed: March 30, 2005
    Date of Patent: December 12, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Kenneth H. Wong, David V. Blackham, Joel P. Dunsmore
  • Patent number: 7124049
    Abstract: In one embodiment, a method comprises storing parameters that are related to switch error correction terms of a vector network analyzer (VNA), and applying a calibration process of a TRL group of calibration processes to the VNA to generate calibration measurements, wherein the calibration process generates calibration measurements, calculates a switch error correction matrix using the stored parameters and a subset of the calibration measurements, and applies the switch error correction matrix to calibration measurements before solving for eight-systematic error terms associated with the calibration process.
    Type: Grant
    Filed: January 3, 2005
    Date of Patent: October 17, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Kenneth H. Wong, David V. Blackham, James C. Liu, Keith F. Anderson
  • Patent number: 7019536
    Abstract: In one embodiment, a method of calibrating a multi-port vector network analyzer (VNA) includes (i) performing two-port calibrations on pairs of ports to determine forward and reverse systematic error terms associated with each pair of ports, wherein the pairs of ports are selected such that each port's systematic error terms (directivity, source match, reflection tracking, and load match) are determined, (ii) generating a switch error correction matrix using data from the two-port calibrations, and (iii) performing unknown thru calibration for at least one pair of ports that was not utilized in step (i), wherein the unknown thru calibration comprises applying the switch error correction matrix to measurement data and determining transmission tracking error terms using the corrected measurement data.
    Type: Grant
    Filed: January 3, 2005
    Date of Patent: March 28, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Keith F. Anderson, David V. Blackham, Brad R. Hokkanen, Kenneth H. Wong
  • Patent number: 6995571
    Abstract: In one embodiment, a method comprises applying a stimulus signal to a reference frequency translation device (FTD) by a vector network analyzer during a calibration mode, wherein the reference FTD possesses equal conversion efficiency in forward and reverse directions and the reference FTD possesses unknown input and output reflection characteristics; measuring a response of the reference FTD; and determining forward and reverse transmission tracking error terms using data from the measured response and single-port error calibration terms.
    Type: Grant
    Filed: January 3, 2005
    Date of Patent: February 7, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: James C. Liu, Kenneth H. Wong, David V. Blackham
  • Patent number: 6836743
    Abstract: A method and a vector network analyzer compensate for unequal source match and load match of a test port of the vector network analyzer. The method characterizes the source match and the load match, computes a delta-match factor from the characterized source match and load match, and uses the delta-match factor to compensate for the difference. The method compensates S-parameter data for a device under test measured by the vector network analyzer. The vector network analyzer comprises a computer program that, when executed by a controller, implements a calibration compensation.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: December 28, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: David V. Blackham, Douglas K. Rytting
  • Patent number: 6823276
    Abstract: A system and method are disclosed which provide for flexible and accurate test apparatus error value calculation. Error value calculation of a testing apparatus requires at least one unique measurement for each unknown error value using the equation that relates the measured response, the predicted response and the error value. When more equations than unknowns can be acquired, the system of equations is over-determined and an improvement of accuracy is possible, but accuracy may be lost when the predicted responses are not trusted to the same degree. The disclosed system and method provide the increased accuracy of an over-determined system, while accounting for predicted responses of varying degrees of trust.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: November 23, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: David V. Blackham, Kenneth H. Wong
  • Publication number: 20040199350
    Abstract: A system and method are disclosed which provide for flexible and accurate test apparatus error value calculation. Error value calculation of a testing apparatus requires at least one unique measurement for each unknown error value using the equation that relates the measured response, the predicted response and the error value. When more equations than unknowns can be acquired, the system of equations is over-determined and an improvement of accuracy is possible, but accuracy may be lost when the predicted responses are not trusted to the same degree. The disclosed system and method provide the increased accuracy of an over-determined system, while accounting for predicted responses of varying degrees of trust.
    Type: Application
    Filed: April 4, 2003
    Publication date: October 7, 2004
    Inventors: David V. Blackham, Kenneth H. Wong
  • Patent number: 6060888
    Abstract: An error correction method improves measurement accuracy of a vector network analyzer by reducing reflection measurement errors for a broad class of devices, such as filters, switches, cables, couplers, attenuators, and other passive devices tested by vector network analyzers (VNAs) that are reciprocal, having a forward transmission coefficient S.sub.21 and a reverse transmission coefficient S.sub.12 that are equal. Errors due to impedance mismatches at the load port of a transmission/reflection (T/R) test set are corrected without impacting the measurement speed of the VNA. The source port of the T/R test set is calibrated and a reflection measurement is performed while an impedance matched thruline standard of known electrical length is coupled between the source port and load port of the T/R test set. The reflection measurement is corrected for the electrical length of the thruline standard to obtain a reflection measurement of the load port of the T/R test set.
    Type: Grant
    Filed: April 24, 1998
    Date of Patent: May 9, 2000
    Assignee: Hewlett-Packard Company
    Inventors: David V. Blackham, Jason Chodora, Joel P. Dunsmore