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).
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Patent number: 9632122Abstract: 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: GrantFiled: June 23, 2014Date of Patent: April 25, 2017Assignee: 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
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Publication number: 20150369849Abstract: 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: ApplicationFiled: June 23, 2014Publication date: December 24, 2015Inventors: 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
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Patent number: 7545150Abstract: 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: GrantFiled: February 28, 2007Date of Patent: June 9, 2009Assignee: Agilent Technologies, Inc.Inventors: Keith F. Anderson, David V. Blackham, Joel P. Dunsmore, Loren C Betts, Nicholas C. Leindecker
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Publication number: 20080204041Abstract: 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: ApplicationFiled: February 28, 2007Publication date: August 28, 2008Inventors: Keith F. Anderson, David V. Blackham, Joel P. Dunsmore, Loren C. Betts, Nicholas C. Leindecker
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Publication number: 20080020726Abstract: 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: ApplicationFiled: July 14, 2006Publication date: January 24, 2008Inventors: David V. Blackham, Kenneth H. Wong, Keith F. Anderson, Hassan Tanbakuchi
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Patent number: 7148702Abstract: 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: GrantFiled: March 30, 2005Date of Patent: December 12, 2006Assignee: Agilent Technologies, Inc.Inventors: Kenneth H. Wong, David V. Blackham, Joel P. Dunsmore
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Patent number: 7124049Abstract: 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: GrantFiled: January 3, 2005Date of Patent: October 17, 2006Assignee: Agilent Technologies, Inc.Inventors: Kenneth H. Wong, David V. Blackham, James C. Liu, Keith F. Anderson
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Patent number: 7019536Abstract: 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: GrantFiled: January 3, 2005Date of Patent: March 28, 2006Assignee: Agilent Technologies, Inc.Inventors: Keith F. Anderson, David V. Blackham, Brad R. Hokkanen, Kenneth H. Wong
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Patent number: 6995571Abstract: 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: GrantFiled: January 3, 2005Date of Patent: February 7, 2006Assignee: Agilent Technologies, Inc.Inventors: James C. Liu, Kenneth H. Wong, David V. Blackham
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Patent number: 6836743Abstract: 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: GrantFiled: October 15, 2002Date of Patent: December 28, 2004Assignee: Agilent Technologies, Inc.Inventors: David V. Blackham, Douglas K. Rytting
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Patent number: 6823276Abstract: 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: GrantFiled: April 4, 2003Date of Patent: November 23, 2004Assignee: Agilent Technologies, Inc.Inventors: David V. Blackham, Kenneth H. Wong
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Publication number: 20040199350Abstract: 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: ApplicationFiled: April 4, 2003Publication date: October 7, 2004Inventors: David V. Blackham, Kenneth H. Wong
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Patent number: 6060888Abstract: 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: GrantFiled: April 24, 1998Date of Patent: May 9, 2000Assignee: Hewlett-Packard CompanyInventors: David V. Blackham, Jason Chodora, Joel P. Dunsmore