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Search Publications by: Dylan Williams (Fed)

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Displaying 251 - 275 of 583

Identifying RF Identification Cards from Measurements of Resonance and Carrier Harmonics

May 27, 2010
Author(s)
Henry Romero, Kate Remley, Dylan Williams, Chih-Ming Wang, Timothy X. Brown
We show that careful measurements of the unloaded resonant frequency and quality factor of radio frequency identification proximity cards allow identification of different card models and, for the set of cards we studied, identification with minimal error

Electro-optic sampling for traceable high-speed electrical measurements

May 23, 2010
Author(s)
Paul D. Hale, Dylan F. Williams
We will describe how the complex frequency response of a high-speed photodiode is calibrated by use of electro-optic sampling. Our uncertainty analysis includes a unique covariance-matrix based method that allows us to transform uncertainties between the

Towards Standardized Waveguide Sizes and Interfaces for Submillimeter Wavelengths

March 22, 2010
Author(s)
Ronald A. Ginley, Dylan Williams, N M. Ridler, J L. Hesler, Anthony R. Kerr, R D. Pollard
This paper describes an activity that has begun recently to develop an international standard for rectangular metallic waveguides and their interfaces for frequencies of 110 GHz and above. The IEEE's Microwave Theory and Techniques Society (MTT-S) is

Measurement Bandwidth Extension Using Multisine Signals: Propagation of Error

February 6, 2010
Author(s)
Catherine A. Remley, Dominique Schreurs, M. Myslinski, Dylan F. Williams
We describe a post-processing technique that can extend the effective measurement bandwidth of narrowband vector receivers by phase aligning overlapping measurements. The method requires only knowledge of the desired phases of a periodic, multisine

Comparison of Large-Signal-Network-Analyzer Calibrations

February 5, 2010
Author(s)
Dylan F. Williams, Catherine A. Remley, Joe Gering, Grand Aivazian
We develop a procedure and metrics for comparing large-signal-network-analyzer calibrations. The metrics we develop provide a bound on differences between measurements obtained from large-signal-network-analyzer calibrations, as well as more specific

Stochastic Modeling of Coaxial-Connector Repeatability Errors

November 30, 2009
Author(s)
Arkadiusz C. Lewandowski, Dylan F. Williams
We propose a new description of connector or repeatability errors for coaxial one-port devices. Our approach is based on a stochastic model constructed as a luped-element equivalent circuit with randomly varying frequency-independent parameters. We

Electronic Vector-Network-Analyzer Verification

October 1, 2009
Author(s)
Dylan F. Williams, Arkadiusz C. Lewandowski, Denis X. LeGolvan, Ronald A. Ginley
The National Institute of Standards and Technology (NIST) has just introduced a fully electronic measurement verification system for microwave vector-network-analyzer (VNA) calibrations called NISTeVerify. The system allows you to quickly verify VNA

Traceable waveform calibration with a covariance-based uncertainty analysis

October 1, 2009
Author(s)
Paul D. Hale, Dylan F. Williams, Andrew M. Dienstfrey, Arkadiusz C. Lewandowski, Tracy S. Clement, Darryl A. Keenan
We describe a method for calibrating the voltage that a step-like pulse generator produces at a load at every time point in themeasured waveform. The calibration includes an equivalent-circuit model of the generator that can be used to determine how the

Uncertainty of timebase corrections

October 1, 2009
Author(s)
Chih-Ming Wang, Paul D. Hale, Dylan F. Williams
We develop a covariance matrix describing the uncertainty of a new timebase for waveform measurements determined with the National Institute of Standards and Technology's timebase correction algorithm. This covariance matrix is used with covariance

Novel nano-structured Metal-Semiconductor-Metal photodetector with high peak voltage

June 22, 2009
Author(s)
Paul D. Hale, Dylan F. Williams, Tomoko Borsa, B. J. VanZeghbroeck
A novel nano-structured metal-semiconductor-metal photodetector consisting of interdigitated metal fingers and nanodots is successfully fabricated on a semi-insulating GaAs substrate by electron beam lithography, and integrated with an on-chip ground