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Search Publications by: Dylan Williams (Fed)

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Displaying 251 - 275 of 294

LRM Probe-Tip Calibrations Using Nonideal Standards

February 1, 1995
Author(s)
Dylan F. Williams, Roger Marks
The line-reflect-match calibration is enhanced to accommodate imperfect match standards and lossy lines typical of monolithic microwave integrated circuits. We characterize the match and line standards using an additional line standard of moderate length

Compensation for Substrate Permittivity in Probe-Tip Calibration

December 1, 1994
Author(s)
Dylan F. Williams, Roger Marks
We demonstrate a method of compensation for the effect of substrate permittivity on coplanar waveguide probe-tip scattering parameter calibrations, modeling the effect as a capacitance at the probe tip. Comparison to on-wafer multiline TRL calibration

On-Wafer Impedance Measurement on Lossy Substrates

June 1, 1994
Author(s)
Dylan F. Williams, Roger Marks
This paper introduces a new method for measuring impedance parameters in transmission lines fabricated on lossy or dispersive dielectrics. The method, which uses an independent calibration to provide an impedance reference, compares well with conventional

LRM Probe-Tip Calibrations with Imperfect Resistors and Lossy Lines

December 1, 1993
Author(s)
Dylan F. Williams, Roger Marks
The line-reflect-match calibration is extended, without significant loss of measurement accuracy, to accommodate imperfect match standards and lossy lines typical of monolithic microwave integrated circuits. We characterize the match and line standards

Verification of Commercial Probe-Tip Calibrations

December 1, 1993
Author(s)
Roger Marks, Dylan F. Williams
We present results of a verification procedure useful in evaluating the accuracy of probe-tip scattering parameter measurements. The procedure was applied to calibrations and measurements performed in industrial laboratories. Actual measurement

Accurate Transmission Line Characterization

August 1, 1993
Author(s)
Dylan F. Williams, Roger Marks
This letter introduces a new method for the characterization of transmission lines fabricated on lossy or dispersive dielectrics. The method, which is more accurate than conventional techniques, is used to examine the resistance, inductance, capacitance

Reciprocity Relations in Waveguide Junctions

July 1, 1993
Author(s)
Dylan F. Williams, Roger Marks
The Lorentz reciprocity condition is applied to junctions composed of reciprocal media which connect uniform but otherwise arbitrary waveguides. An expression relating the forward and reverse transmission coefficients is derived and factored into two terms

Calibrating On-Wafer Probes to the Probe Tips

December 1, 1992
Author(s)
Dylan F. Williams, Roger Marks
This paper investigates the accuracy of on-wafer scattering-parameter calibrations at the probe tips. Data show the extent to which certain probe-tip calibrations are consistent with one another and applicable to the characterization of devices or circuits

Interconnection Transmission Line Parameter Characterization

December 1, 1992
Author(s)
Roger Marks, Dylan Williams
This paper introduces a new method for the characterization of transmission lines fabricated on lossy or dispersive dielectrics. The method, which is more accurate than conventional techniques, is used to examine the resistance, inductance, capacitance

Planar Resistors for Probe Station Calibration

December 1, 1992
Author(s)
Dave K. Walker, Dylan F. Williams, Nicole Morgan
This paper investigates the effects of variations in sheet resistance, geometry, distance from the probe tip, and fabrication processes on the impedance of planar nickel-chromium resistors. Resistor reactance is a strong function of film resistance, but

A General Waveguide Circuit Theory

October 1, 1992
Author(s)
Roger Marks, Dylan F. Williams
This work generalizes and extends the classical circuit theory of electromagnetic waveguides. Unlike the conventional theory, the present formulation applies to all waveguides composed of linear, isotropic material, even those involving lossy conductors

Wafer Probe Transducer Efficiency

October 1, 1992
Author(s)
Dylan F. Williams, Roger Marks, Dave K. Walker, Fred R. Clague
Experimental evidence is presented that shows the conventional expression relating the transducer efficiency of a two-port to measured scattering parameters is incorrect when the characteristic impedance at one of the ports is complex. This evidence is

Frequency-Dependent Transmission Line Parameters

April 1, 1992
Author(s)
Dylan F. Williams, Roger Marks
Recent theoretical developments have resulted in the rigorous definition of equivalent circuit parameters for non-TEM transmission lines. This summary provides a brief review of the theory and presents calculated and measured results illustrating the

Reciprocity Relations for On-Wafer Power Measurements

December 5, 1991
Author(s)
Roger Marks, Dylan F. Williams
The implications of expressions relating the forward and reverse transmission coefficients of a waveguide junction derived from the Lorentz reciprocity condition are explored. The two terms in the relation, the phase of the reference impedance in the guide

Benchmark for the Verification of Microwave CAD Software

December 1, 1991
Author(s)
R. Furlow, R. Y. Shimoda, Dylan Williams, Roger Marks, Kuldip Gupta
A set of microstrip structures which constitute a comprehensive benchmark for the verification of microwave Computer Aided Design (CAD) software has been developed in a collaborative effort. The benchmark is designed to exhibit a wide range of physical