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Search Publications by: Dylan Williams (Fed)

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Displaying 326 - 350 of 583

Measurement of Weak Signals Using a Communications Receiver System

March 1, 2005
Author(s)
Marc Rutschlin, Kate Remley, Robert T. Johnk, Dylan Williams, Galen H. Koepke
We describe the calibration of an inexpensive, reliable system for use in weak-signal detection. The calibration procedure described allows the conversion of signals measured with the communications receiver system-which is based on a standard

Scattering-Parameter Models and Representations for Microwave Mixers

January 1, 2005
Author(s)
Dylan F. Williams, Fabien Ndagijimana, Catherine A. Remley, Joel Dunsmore, Sean Hubert
We present straight-forward models and representations for RF and image mixers, and develop simple rules for transforming electrical problems involving mixers and signals at several frequencies into equivalent single-frequency problems. We show how those

Uncertainty of the NIST Electrooptic Sampling System

December 1, 2004
Author(s)
Dylan F. Williams, Paul D. Hale, Tracy S. Clement
We present an uncertainty analysis of measurements performed with NIST's electrooptic sampling system. The system measures the voltage waveform injected by a photodetector on a coplanar waveguide fabricated on an electrooptic LiTaO3 wafer. The frequency

Multiport Investigation of the Coupling of High-Impedance Probes

November 1, 2004
Author(s)
Dylan F. Williams, Pavel Kabos, Uwe Arz
We used an on-wafer measurement technique that combines two- and three-port frequency-domain mismatch corrections in order to characterize the influence of a high-impedance probe on a device under test. The procedure quantifies the probe’s load of the

Simplifying and Interpreting Two-Tone Measurements

November 1, 2004
Author(s)
Kate Remley, Dylan Williams, Dominique Schreurs, John Wood
We develop a mathematical description of the response of systems to second-order memory mechanisms based on a time-varying gain modulation function. We show that intermodulation products arising from interactions at baseband have different phase symmetries

Extended NVNA Bandwidth for Long-Term Memory Measurements

June 11, 2004
Author(s)
Catherine A. Remley, Dominique Schreurs, Dylan F. Williams, John Wood
We present a new technique for measuring the magnitude and phase of intermodulation products outside the measurement bandwidth of our instrumentation. We apply the technique to measurements of long-term memory effects, and realte our measurements to

Vector Mixer Characterization for Image Mixers

January 1, 2004
Author(s)
Joel Dunsmore, Sean Hubert, Dylan Williams
The vector mixer characterization method first introduced by Dunsmore [1] can be used only for mixers where the Local Oscillator (LO) frequency lies between the RF input and output frequencies. Attempts to use the method for mixers with the LO greater than

An Optimal Vector-Network-Analyzer Calibration Algorithm

December 1, 2003
Author(s)
Dylan Williams, Chih-Ming Wang, Uwe Arz
We present an iterative algorithm for calibrating vector network analyzers based on orthogonal distance regression. The algorithm features a robust, yet efficient, search algorithm, a complete error analysis that includes both random and systematic errors

An Optimal Multiline TRL Calibration Algorithm

June 17, 2003
Author(s)
Dylan Williams, Jack Wang, Uwe Arz
We examine the performance of two on-wafer multiline TRL calibration algorithms, the popular multiline TRL algorithm implemented in the MultiCal software package and a newly implemented iterative algorithm designed to give optimal results in the presence

Sampling Oscilloscope Models and Calibrations

June 17, 2003
Author(s)
Kate Remley, Dylan Williams
We discuss the basic principles of operation of electrical sampling oscilloscopes and describe circuit models developed to design, characterize, and help explain their operation. We survey common oscilloscope calibration schemes that correct for finite

Phase Detrending for Measured Multisine Signals

June 13, 2003
Author(s)
Kate Remley, Dylan Williams, Dominique Schreurs, Giovanni Loglio, Cidronali Alessandro
We develop a method to detrend the phases of measured multisine signals. We find a time reference that removes the linear component of the measured phases and aligns them to their expected values to the precision specified by the user. An initial guess is
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