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We report on the development of a microwave power limiter based on high-temperature superconductor technology. The power limiter takes the form of a 50 ohm coplanar waveguide transmission line that can be reversibly driven from the low-loss superconducting
Michael D. Janezic, James R. Baker-Jarvis, Edward Kuester
We summarize a theoretical model for the split-cylinder resonator, based on the mode-matching method, for nondestructively measuring permittivity and loss tangent with the split-cylinder resonator. This new model correctly accounts for the fringing
We propose two verification methods for measurements of noise parameters of amplifiers, particularly low-noise amplifiers (LNAs). One method is a direct measurement of the parameter Trev, the noise temperature from the amplifier input, and the comparison
Donald C. DeGroot, Yves Rolain, Rik Pintelon, Johan Schoukens
A new 16-term statistical calibration is developed for the correction of vector network analyzer (VNA) data. The method uses multiple measurments of gneric transmission line and reflection standards. Using a functional model of the system and transmission
Catherine A. Remley, Dominique Schreurs, Dylan F. Williams, John Wood
We present a new technique for measuring the magnitude and phase of intermodulation products outside the measurement bandwidth of our instrumentation. We apply the technique to measurements of long-term memory effects, and realte our measurements to
We introduce nonlinear large-signal scattering parameters, a new type of frequency-domain mapping that relates incident and reflected signals for sparse-tone inputs. We present a general form of nonlinear large-signal scattering parameters and show that
A near-ambient, variable-temperature noise standard whose physical temperature can be accurately measured was constructed and then measured with the NIST total-power radiometer to test the accuracy of radiometer measurements in the temperature range of 263
Lan Gao, D. Q. Feng, L. Yuan, T. Yokota, R. Sabirianov, Sy-Hwang Liou, Michelle Chabot, Daniel Porpora, John M. Moreland
We have successfully fabricated single and paired 300 nm × 1.5 υm × 32 nm Ni 80Fe 20 bars on a microcantilever using focused ion beam milling. Magnetic interactions of these paired bars were studied by using magnetic force microscopy, microcantilever
D. Das, Atanu Saha, Stephen E. Russek, Rishi Raj, D. Bahadur
The magnetic and electrical transport properties of La 0.67Cad0.33^MnO 3(LCMO): xSiCN (x=0-40 vol%) composites, synthesized by mechanical mixing of citrate gel derived LCMO and polymer derived ceramics SiCN, have been investigated as a function of
A plan is presented for developing a standard for brightness temperature at microwave frequencies, as well as two different methods for transferring this standard to the microwave remote-sensing community. The standard will be based on existing NIST
Donald R. Larson, Nicholas Paulter, David I. Bergman
The pulse parameters of amplitudes and transition duration (10% to 90%) are examined as a function of the epoch and position of the transition edge in the epoch. The primary explanations for the observed variations are the pulse aberrations and the finite
Claude Weil, Dennis G. Camell, David R. Novotny, Robert T. Johnk
We discuss simulator units for calibrating across-the-road Doppler traffic radar transceivers used in enforcement of highway speed limits. Two units of very similar design were developed, one operating at K-band (24 GHz) and the other at Ka-band (35 GHz)
The sheet conductances of top-pinned spin valves and single-material films were measured in situ as the thin-film layers were grown. The data were fit to a Boltzmann transport calculation. The electrical conductivity and electron mean free paths were
Li-Anne Liew, Svenja A. Knappe, John M. Moreland, Hugh Robinson, David C. Larbalestier, John Kitching
We describe the fabrication of chip-sized alkali atom vapor cells using silicon micromachining and anodic bonding technology. Such cells may find use in highly miniaturized atomic frequency references or magnetometers. The cells consist of cavities etched
We report extensive measurements of transport characteristics and low-frequency resistance noise of c-axis yttrium-barium-copper-oxide (YBCO)/Au junctions. The dominant conduction mechanism is tunneling at low temperatures. The conductance characteristic
Elizabeth Mirowski, John M. Moreland, Stephen E. Russek, Michael J. Donahue
We have developed a micromachined fluid-cell platform that consists of patterned magnetic thin-film elements supported on a thin silicon-nitride membrane. In the presence of an external magnetic field, the field gradients near the magnetic elements are
Li-Anne Liew, Svenja A. Knappe, John M. Moreland, Hugh Robinson, Leo W. Hollberg, John Kitching
This paper describes the fabrication of chip-sized alkali atom vapor cells, for use in highly miniaturized atomic frequency references, using silicon micromachining and anodic bonding technology. The cells consist of silicon cavities with internal volume
William Rippard, Matthew Pufall, Shehzaad F. Kaka, Stephen E. Russek, Thomas J. Silva
We have directly measured coherent high-frequency magnetization dynamics in ferromagnetic films induced by a spin-polarized dc current. The precision frequency can be tuned over a range of several gigahertz by varying the applied current. The frequencies
Michael D. Janezic, Raian K. Kaiser, James R. Baker-Jarvis, George Free
In this paper we examine a measurement method for characterizing the dc conductivity of metal alloys commonly-used in hand weapons. From accurate measurements of the voltage and current across a cylindrical metal sample, we calculate the metal's dc
P. Termsuksawad, S. Niyomsoan, Ronald B. Goldfarb, V I. Kaydanov, David Olson, B. Mishra, Z Gavra
As demonstrated in this paper, magnetic and electronic measurements can be used to quantify hydrogen availability, absorption, and desorption in materials for nickel metal-hydride batteries and hydrogen storage. The ability of a metal alloy to absorb and
James R. Baker-Jarvis, Pavel Kabos, Christopher L. Holloway
In this paper we study the electrodynamics of materials using an exact Liouville-Hamiltonian-based statistical-mechanical theory where the magnetization, polarization, and strain density may depend on both the applied electric, magnetic, and stress fields
M G. Pini, A Retlori, David P. Pappas, A. V. Anisimov, Alexander Popov
The zero temperature equilibrium configuration of a nonuniform system made of a ferromagnetic (FM) monolayer on top of a semi-infinite FM film is calculated using a nonlinear mapping formulation of mean-field theory, where the surface is taken into account
We review the evolution of the global standards system and its relationship to industry. We then discuss some of the approaches that governments have taken in order to modify the system for the benefit of domestic and worldwide economic development. We use
This paper describes how to correct for systematic errors in one-port vector network analyzer calibrations that are caused by modeling errors in the one-port calibration standards. The paper shows how to correct an open-short-load calibration that was made
Jeffrey Jargon, Donald C. DeGroot, Vecchia Dominic
In this paper, we present the first published repeatability study of commercial harmonic phase standards (HPS) measured by a nonlinear vector network analyzer. Specifically, we measure two harmonic phase standards, one of which is specified to 20 GHz and