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Search Publications by: Yicheng Wang (Fed)

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Displaying 1 - 25 of 69

Comparison of a 1 nF Capacitor with a 1 kO Resistor Using a Digital Impedance Bridge

March 27, 2024
Author(s)
Yicheng Wang, Stephan Schlamminger, Dean G. Jarrett, Alireza Panna, Andrew D. Koffman
This paper reports our effort to improve a digital impedance bridge. The limit of the bridge resolution and stability is less than 3 parts in 10^9 for the nominal 1:1 impedance comparison of two 100 pF capacitors. The type-A uncertainty for comparison of a

New Method for Determining Time Constant of Resistors

March 21, 2023
Author(s)
Yicheng Wang, Dean G. Jarrett, Andrew D. Koffman, Stephan Schlamminger
We report a new method for determining the time constant of ac resistors with values around 10 kΩ, using a digital impedance bridge for comparison of two nominally equal resistors. The method involves adding a probing capacitor in parallel to one of the

Evaluations of a Detector-Limited Digital Impedance Bridge

April 6, 2021
Author(s)
Mona Feige, Stephan Schlamminger, Yicheng Wang
We tested a simple digital impedance bridge using two nominally equal resistors to form a 1:1 ratio. We focused on resolution and stability of the detectors. Fluctuations of the source voltages were largely removed through postprocessing of the digitized

Graphene quantum Hall effect devices for AC and DC resistance metrology

August 28, 2020
Author(s)
Mattias Kruskopf, Dinesh K. Patel, Chieh-I Liu, Albert Rigosi, Randolph Elmquist, Yicheng Wang, Stefan Bauer, Yefei Yin, Klaus Pierz, Eckard Pesel, Martin Goetz, Jurgen Schurr
The frequency dependence of the quantized Hall resistance at alternating current results from capacitive losses inside the sample as well as between the sample and external parts. In this joint effort we report on ac quantum Hall measurements of a graphene

Alignment and testing of the NIST Calculable Capacitor

August 24, 2014
Author(s)
Yicheng Wang, Felipe Guzman, Corey A. Stambaugh, Radek Smid, Hugo Zuniga Calvo, Andrew D. Koffman, Jon R. Pratt, John R. Lawall
This paper reports progress on the NIST effort to develop a new calculable capacitor, focusing on improvement of the guard electrode motion control as well as issues associated with the overall electrode alignment. Design of a multi-wavelength Fabry-Perot

Eddy Current Rail Inspection Using AC Bridge Techniques

February 26, 2013
Author(s)
Andrew D. Koffman, Bryan C. Waltrip, Yicheng Wang
AC bridge techniques commonly used for precision impedance measurements have been adopted to develop an eddy current sensor for rail defect detection. By using two detection coils instead of just one in a conventional sensor, we can balance out the large

Accurate Gouy phase measurement in an astigmatic optical cavity

September 14, 2012
Author(s)
John R. Lawall, Mathieu Durand, Yicheng Wang
We present measurements of the Gouy phase accumulation for the fundamental mode of an astigmatic Fabry-Perot cavity over 70 % of its stability range. The method is based on simultaneous measurement of the resonant frequencies of the fundamental mode and

High-accuracy Fabry-Perot displacement interferometry using fiber lasers

August 8, 2011
Author(s)
Mathieu Durand, John R. Lawall, Yicheng Wang
We describe ongoing work in a Fabry-Perot interferometry system designed to measure displacements over a range of 50~mm with sub-pm uncertainty. The apparatus involves probing two nearby modes of the Fabry-Perot cavity with narrow-linewidth fiber telecom

Advanced Capacitance Metrology for Nanoelectronic Device Characterization

October 5, 2009
Author(s)
Curt A. Richter, Joseph J. Kopanski, Yicheng Wang, Muhammad Y. Afridi, Xiaoxiao Zhu, D. E. Ioannou, Qiliang Li, Chong Jiang
We designed and fabricated a test chip (consisting of an array of metal-oxide-semiconductor (MOS) capacitors and metal-insulator-metal (MIM) capacitors ranging from 0.3 fF to 1.2 pF) for use in evaluating the performance of new measurement approaches for

AC Power Standard Using a Programmable Josephson Voltage Standard

April 1, 2009
Author(s)
Bryan C. Waltrip, Bo Gong, Thomas L. Nelson, Yicheng Wang, Charles J. Burroughs, Alain Rufenacht, Samuel Benz, Paul Dresselhaus
This paper describes the implementation of a new quantum-based system for the generation of 120 V rms, 5 A rms, sinusoidal, active and reactive power over the 50 Hz to 400 Hz frequency range. The system accurately relates the spectral amplitudes and phases

Evaluation of a Capacitance Scaling System

December 1, 2007
Author(s)
Svetlana Avramov-Zamurovic, Andrew D. Koffman, Bryan C. Waltrip, Yicheng Wang
A capacitance scaling system from 10 nF to 100 mF [1], [2] has been implemented at the National Institute of Standards and Technology (NIST). Standard four-terminal-pair (4TP) capacitors are characterized using a capacitance scaling calibration procedure

Dissipation Factors of Fused-Silica Capacitors in the Audio Frequency Range

April 1, 2007
Author(s)
Yicheng Wang, Andrew D. Koffman, Gerald FitzPatrick
We describe dissipation factor measurements of 10 pF fused-silica capacitance standards from 50 Hz to 20 kHz, using a toroidal cross capacitor and a 10 pF nitrogen-filled capacitor as the references. The relative combined standard uncertainties are 0.56x10

An Upper Bound to the Frequency Dependence of the Cryogenic Vacuum-Gap Capacitor

September 6, 2006
Author(s)
Neil M. Zimmerman, Brian Simonds, Yicheng Wang
In attempting to develop a capacitance standard based on the charge of the electron, one question which has been open for many years is the frequency dependence of the vacuum-gap cryogenic capacitor. In this paper, we succeed in putting an upper bound on

A digitally programmable capacitance standard

April 1, 2004
Author(s)
Yicheng Wang, Lai H. Lee
We constructed a digitally programmable capacitance standard by modifying a commercial temperature-stabilized 100 pF capacitance standard which consists of 23 binary-weighted capacitor elements on a single fused-silica disk. The variable capacitor can be

Frequency dependence of capacitance standards

September 1, 2003
Author(s)
Yicheng Wang
We measured the frequency dependence of a 10 pF transportable fused-silica capacitor from 50 Hz to 20 kHz. The results have a relative standard uncertainty of 0.32x10^(-6), 0.15x10^(-6), and 0.37x10(-6) at 100 Hz, 400 Hz, and 20 kHz, respectively. This

Measurements of frequency dependence of fused-silica capacitors

August 1, 2003
Author(s)
Yicheng Wang
In order to improve the capacitance calibration services at the National Institute of Standards and Technology, we need to determine the frequency dependence of all the reference capacitance standards over the audio frequency range. The value of a standard

C 4 F 6 1,3 Hexafluorobutadiene - A New Etching Gas: Studies on Material Compatibility, Behavior in Inductively Coupled Plasma and Etch Processes Performance

June 1, 2003
Author(s)
A Nicoletti, P Srinivasan, M Riva, Eric C. Benck, A N. Goyette, Yicheng Wang, J M. Kim, P Hsieh, A Athayde, Abhay Joshi
Hexafluoro-1,3-butadiene (C 4F 6) is a relatively new etch gas for the manufacturing of semiconductor devices, especially in critical etch processes that need high aspect ratios and selectivity. It is able to combine very high performance with a benign