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Search Publications by: Yicheng Wang (Fed)

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Displaying 1 - 25 of 139

A digital four-arm bridge for the comparison of resistance with capacitance

September 11, 2024
Author(s)
Yicheng Wang, Stephan Schlamminger
A digital four-arm bridge for the comparison of resistance with capacitance has been designed and demonstrated. The digital bridge mimics the classical quad bridge in the digital domain with three balances: the source balance, the detector balance, as well

Four terminal-pair measurements of ceramic capacitors

June 28, 2024
Author(s)
Stephan Schlamminger, Yicheng Wang, Andrew Koffman, Jordan Love
Expanding on our previous work on four terminal-pair air capacitors, we present a model for the frequency-dependent capacitance of ceramic capacitors for values ranging from 10 nF to 10 uF. Two measurements are necessary for the complete model. First, the

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