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Search Publications

NIST Authors in Bold

Displaying 901 - 925 of 1560

Accurate Electrical Measurement of Coupled Lines on Lossy Silicon

October 1, 2000
Author(s)
Uwe Arz, Dylan F. Williams, Dave K. Walker, Hartmut Grabinski
In this paper we apply a measurement method designed for asymmetric coupled lines to determine the broadband propagation characteristics of symmetric coupled lines fabricated on a highly conductive silicon substrate. We show that the matrices of frequency

Antenna Range Imaging

October 1, 2000
Author(s)
Ronald C. Wittmann, Michael H. Francis
We present a preliminary evaluation of a microwave measurement system that has been designed to determine electromagnetic fields in the quiet-zone of an antenna measurement range and to produce an image of the sources, intended and unintended, of the

Contact-Pad Design for High-Frequency Silicon Measurements

October 1, 2000
Author(s)
Dylan Williams, A. C. Byers, V. C. Tyree, Dave K. Walker, J. J. Ou, X. Jin, M. Piket-Moy, C. Hu
We measure and compare the electrical parasitics of contact pads of different designs fabricated on silicon integrated circuits and develop a strategy for reducing the parasitics.

Evaluation of an EMC Compliance Chamber Using an Ultrawideband Measurement System

October 1, 2000
Author(s)
Robert T. Johnk, David R. Novotny, Claude Weil, Marlene Taylor, T. J. O'Hara
This paper summarizes a joint NIST-Industry measurement effort. The purpose of this effort was to use a NIST-developed altrawide band measurement system to assess the performance imporvement of ferrite tile anechoic chamber after a partial retrofit

Low-Cost, Broadband Absorber Measurements

October 1, 2000
Author(s)
David R. Novotny, Robert T. Johnk, Arthur Ondrejka
We present a method for evaluating broadband absorber in a non-ideal testing environment. Using broadband, short impulse TEM horns, a frequency-rich spectrum (equivalent pulse length 0.5 ns) illuminates a sample of material under test and the reflections

Uncertainties in Dynamic Sphere Radar Cross Section Data

October 1, 2000
Author(s)
Lorant A. Muth, W. Sefcik
This is a report on work in progress to understand the wide variations in sphere calibration data observed on dynamic radar cross section measurement ranges. The magnitude of these fluctuations indicate an uncertainty of greater than 2 dB in some cases

On-Wafer Measurement of Transmission Lines On Lossy Silicon Substrates

September 25, 2000
Author(s)
Uwe Arz, Dylan Williams, Hartmut Grabinski
This paper examines broadband measurement techniques for electrical properties of planar transmission lines built on lossy silicon substrates. We start by investigating the performance of a new formulation of the calibration com-parison method which is

A New IEC Standard on the Measurement of Power Quality Parameters

September 1, 2000
Author(s)
Francois D. Martzloff
Following an initiative from the French and the U.S. National Committees, the IEC Technical Committee TC77 charged its Subcommittee 77A (Low-Frequency Phenomena) with the development of a new standard on the measurement of power quality parameters. The

Current Density Limitations of Spin Valves

September 1, 2000
Author(s)
Stephen E. Russek, Terry J. Gaffron, S. L. Burkett
As spin valve technology evolves, understanding the limitations and design constraints is a critical consideration. Choosing the correct materials combination, aspect ratio and size depends upon careful device characterization. Analysis of spin valves in

Ground Wave of an Idealized Lightning Return Stroke

September 1, 2000
Author(s)
J. R. Wait, David A. Hill
We model a lightning return stroke by a vertical traveling wave of current with a complex propagation constant. The Sommerfeld-integral analysis is similar to that of a vertical electric dipole over a lossy earth except that the source is distributed in

Metastable States in Large Angle Magnetization Rotations

September 1, 2000
Author(s)
Pavel Kabos, Shehzaad F. Kaka, Stephen E. Russek, Thomas J. Silva
Large angle rotations were studied in Permalloy thin films and spin valve devices. It is shown that edge effects or inhomogeneities strongly influence the magnetization behavior under certain initial conditions. Complicated intermediate states can form

Micromechanical Detectors for Ferromagnetic Resonance Spectroscopy

September 1, 2000
Author(s)
John M. Moreland, Pavel Kabos, Albrecht Jander, M. Loehndorf, Robert McMichael, C G. Lee
We demonstrate micromechanical detection of ferromagnetic resonance (FMR) in thin magnetic films. FMR spectroscopy is performed on nanometer scale samples integrated with a micromachined silicon cantilever. We present several techniques by which the FMR

On the Dispersion of Lightning Current After a Direct Flash to a Building

September 1, 2000
Author(s)
Francois D. Martzloff
Simplifications often made when simulating the dispersion of lightning current can yield results that depart too much from the complex reality of a direct lightning flash to a building. The unpredictable occurrence of side-flashes increases even more the

Some Enlightening Case Histories on Lightning Damage

September 1, 2000
Author(s)
T. S. Key, D. Nastasi, K. O. Phipps, Francois D. Martzloff
Lightning related damage stories abound, but it is not always possible to document precisely the mechanisms and scenarios involved when timely, first-hand knowledge is not obtainable. From a collection of case histories accumulated by the authors, three

The Trilogy Update of IEEE Std. C62.41

September 1, 2000
Author(s)
Francois D. Martzloff
Progress report on the restructuring of two IEEE standards concerned with surges in low-voltage a.c. power circuits into a Trilogy of three documents. First a basic Guide describes the surge environment, then a Recommended Practice proposes a limited set

Assessing the Effects of an OATS Shelter; Is ANSI C63.7 Enough?

August 1, 2000
Author(s)
Robert T. Johnk, David R. Novotny, Claude Weil, H. W. Medley
This paper summarizes a recent measurement effort by NIST researchers at an open-area test site (OATS), operated by a large information technology equipment manufacturer. The purpose of this effort was to assess the effects on emissions measurements of a

Ferromagnetic Resonance Spectroscopy with a Micromechanical Calorimeter Sensor

August 1, 2000
Author(s)
John M. Moreland, M. Loehndorf, Pavel Kabos, Robert McMichael
We describe a new type of ferromagnetic resonance (FMR) spectroscopy that is based on a calorimeter sensor. We use an atomic force microscopy cantilever coated with a ferromagnetic thin film as a bimaterial sensor to measure absorption of microwaves at 9
Displaying 901 - 925 of 1560