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Search Publications by: Chris Long (Fed)

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Displaying 26 - 50 of 70

Updates to the traceability of mm-wave power measurements at NIST

December 17, 2021
Author(s)
Aaron Hagerstrom, Angela Stelson, Jeffrey Jargon, Chris Long
Metrological traceability helps ensure the reliability of measurements by allowing them to be compared with established international standards with well-understood uncertainties. A thorough uncertainty analysis is therefore necessary to provide traceable

Collector Series-Resistor to Stabilize a Broadband 400 GHz Common-Base Amplifier

October 14, 2021
Author(s)
Jerome Cheron, Dylan Williams, Richard Chamberlin, Miguel Urteaga, Kassi Smith, Nick Jungwirth, Bryan Bosworth, Chris Long, Nate Orloff, Ari Feldman
The indium phosphide (InP) 130 nm double-heterojunction bipolar transistor (DHBT) offers milliwatts of output power and high signal amplification in the lower end of the terahertz frequency band when the transistor is used in a common-base configuration

Electro-optically derived millimeter-wave sources with phase and amplitude control

October 12, 2021
Author(s)
Bryan Bosworth, Nick Jungwirth, Kassi Smith, Jerome Cheron, Franklyn Quinlan, Ari Feldman, Dylan Williams, Nate Orloff, Chris Long
Integrated circuits are building blocks in millimeter-wave handsets and base stations, requiring nonlinear characterization to optimize performance and energy efficiency. Today's sources use digital-to-analog converters to synthesize arbitrary electrical

Local negative permittivity and topological-phase transition in polar skyrmions

October 12, 2020
Author(s)
Sujit Das, Zijian Hong, Vladimir Stoica, Mauro A. Goncalves, Yu-Tsun Shao, Eric Parsonnet, Eric J. Marksz, Sahar Saremi, Margaret McCarter, A Reynoso, Chris Long, Aaron Hagerstrom, D Meyers, V Ravi, B Prasad, H Zhou, Z Zhang, H Wen, F Gomez-Ortiz, P Garcia-Fernandez, J Bokor, J Iniguez, J Freeland, Nate Orloff, J Junquera, Long-Qing Chen, Sayeef Salahuddin, David A. Muller, L Martin, R. Ramesh
Topological solitons such as magnetic skyrmions have drawn enormous attention as stable quasi- particle-like objects. The recent discovery of polar vortices and skyrmions in ferroelectric- oxide superlattices, exhibiting exotic physical phenomena, has

Physical Models and Dimensional Traceability of WR15 Rectangular Waveguide Standards for Determining Systematic Uncertainties of Calibrated Scattering-Parameters

August 10, 2020
Author(s)
Jeffrey A. Jargon, Dylan F. Williams, Angela C. Stelson, Christian J. Long, Aaron M. Hagerstrom, Paul D. Hale, John R. Stoup, Eric S. Stanfield, Wei Ren
In this report, we document the models and dimensional traceability of our WR15 rectangular waveguide standards for performing multiline thru-reflect-line calibrations from 50 GHz to 75 GHz using vector network analyzers. We identify the equations used in

On-Wafer Metrology of a Transmission Line Integrated Terahertz Source

May 10, 2020
Author(s)
Kassiopeia A. Smith, Bryan T. Bosworth, Nicholas R. Jungwirth, Jerome G. Cheron, Nathan D. Orloff, Christian J. Long, Dylan F. Williams, Richard A. Chamberlin, Franklyn J. Quinlan, Tara M. Fortier, Ari D. Feldman
A combination of on-wafer metrology and high-frequency network analysis was implemented to measure the response of transmission-line integrated Er-GaAs and InGaAs photomixers up to 1 THz to support the telecommunication and electronics industry.

Measurements of Nonlinear Polarization Dynamics in the Tens of Gigahertz

April 9, 2020
Author(s)
Aaron Hagerstrom, Eric J. Marksz, Xiaohang Zhang, Xifeng Lu, Christian Long, James Booth, Ichiro Takeuchi, Nathan Orloff
Frequency-dependent linear permittivity measurements are commonplace in the literature, providing key insights into the structure of dielectric materials. These measurements describe a material's dynamic response to a small applied electric eld. In

Materials Characterization With Multiple Offset Reflects at Frequencies to 110 GHz

January 8, 2020
Author(s)
Nina P. Basta, Aaron Hagerstrom, Jasper A. Drisko, James Booth, Edward Garboczi, Christian Long, Nathan Orloff
Understanding the electrical properties of materials is a necessary part of any microwave circuit design. In this article, we explore the possibility of employing multiple-offset-reflect devices for on-wafer materials characterization at frequencies up to

Targeted chemical pressure yields tuneable millimetre-wave dielectric

December 23, 2019
Author(s)
Natalie M. Dawley, Eric J. Marksz, Aaron Hagerstrom, Gerhard H. Olsen, Megan E. Holtz, Jingshu Zhang, Chris Long, Craig Fennie, David A. Muller, Darrell G. Schlom, James Booth, Nate Orloff
Tunable dielectrics are key constituents for emerging high-frequency devices in telecommunications—including tunable filters, phase shifters, and baluns—and for miniaturizing frequency-agile microwave and millimeter-wave components. Today, strained films

Optimal Series Resistors for On-Wafer Calibrations

November 8, 2019
Author(s)
Jasper A. Drisko, Richard A. Chamberlin, James C. Booth, Nathan D. Orloff, Christian J. Long
The series resistor is a common on-wafer device typically used in the series-resistor calibration and for estimating the capacitance per unit length of coplanar waveguide transmission lines. While much work has been done using series resistors, this paper

Carbon Nanotube Thin Film Patch Antennas for Wireless Communications

May 24, 2019
Author(s)
E. A. Bengio, Damir Senic, Lauren W. Taylor, Robert J. Headrick, Michael King, Peiyu Chen, Charles A. Little, John M. Ladbury, Chris Long, Christopher L. Holloway, Aydin Babakhani, James Booth, Nate Orloff
Early work on carbon nanotube (CNT) antennas indicated that their performance could not match that of metals such as copper. However, recent improvements in fluid phase CNT processing have yielded macroscopic CNT materials with better alignment and

NONDESTRUCTIVE, NONCONTACT QUANTIFICATION OF CARBON FIBER ALIGNMENT AND ORIENTATION BY HIGH-SPEED MICROWAVE ELLIPSOMETRY FOR TAILORABLE FEEDSTOCK

May 20, 2019
Author(s)
Nina Popovic, Shridar Yarlagadda, Dirk Heider, Edward Garboczi, Christian Long, Nathan Orloff
Novel short-fiber composites facilitate the manufacture of tailorable feedstock for small formed parts. In these composites, the alignment and orientation of the short fibers must be controlled to achieve the desired composite properties. While there are

Measuring Ion-Pairing and Hydration in Variable Charge Supramolecular Cages with Microwave Microfluidics

May 17, 2019
Author(s)
Angela C. Stelson, Cynthia M. Hong, Mitchell C. Groenenboom, Charles A. Little, James C. Booth, Nathan D. Orloff, Robert G. Bergman, Kenneth N. Raymond, Kathleen A. Schwarz, F. D. Toste, Christian J. Long
MetaMetal–organic supramolecular cages can act as charged molecular containers that mediate reactions, mimic enzymatic catalysis, and selectively sequester chemicals.1,2 The hydration of these cages in solution plays a crucial role in their interactions

Label-Free Detection of Conformational Changes in Switchable DNA Nanostructures with Microwave Microfluidics

March 12, 2019
Author(s)
Angela C. Stelson, Minghui Lu, Charles A. Little, Christian J. Long, Nathan D. Orloff, Nicolas Stephanopolous, James C. Booth
Detection of conformational changes in biomolecular assemblies provides critical information into biological and self-assembly processes. State-of-the-art in situ conformation detection techniques rely on fluorescent labels or protein-specific binding

Impedance tuning with photoconductors to 40 GHz

January 22, 2019
Author(s)
Jasper A. Drisko, Ari D. Feldman, Franklyn J. Quinlan, James C. Booth, Nathan D. Orloff, Christian J. Long
Light has been widely used to control a variety of microwave devices, including switches, antennas, and detectors. Here, we present a photoconductive device integrated into a coplanar waveguide to tune complex impedances at microwave frequencies with

Measurement of Ion-Pairing Interactions in Buffer Solutions with Microwave Microfluidics

January 1, 2019
Author(s)
Charles A. Little, Angela C. Stelson, Nathan D. Orloff, Christian J. Long, James C. Booth
Broadband microwave microfluidics is an emerging technique for quantifying the frequency dependent electrical response of fluids in the microwave regime. This technique can access important physical properties including interfacial polarization, ion

Determining Carbon Fiber Composite Loading by Flip-Chip on a Coplanar Waveguide to 110GHz

November 22, 2018
Author(s)
Nina P. Basta, Jasper A. Drisko, Aaron M. Hagerstrom, Joshua A. Orlicki, Jennifer M. Sietins, Daniel B. Knorr, Jr., Edward J. Garboczi, Christian J. Long, Nathan D. Orloff
The electrical properties of materials are a necessary part of any circuit design. As applications at millimeter-wave frequen-cies increase, there is a growing need to develop new materials with low loss and multiple functionalities. Unfortunately, many

Optimizing linearity in high-speed photodiodes

November 7, 2018
Author(s)
Josue Davila-Rodriguez, X. Xie, J. Zang, Christian J. Long, Tara M. Fortier, Holly F. Leopardi, Takuma Nakamura, J. C. Campbell, Scott A. Diddams, Franklyn J. Quinlan
Analog photonic links require high fidelity, high speed optical-to-electrical conversion for applications such as radio-over-fiber, synchronization at kilometer-scale facilities, and low- noise electronic signal generation. Nonlinearity is a particularly

Determining Carbon Fiber Composite Loading with Flip-Chip Measurements to 110 GHz

September 1, 2018
Author(s)
Nina P. Basta, Aaron Hagerstrom, Jasper A. Drisko, James Booth, Edward Garboczi, Christian Long, Nathan Orloff
— Electrical properties of materials are a necessary part of any circuit design. With emerging applications at millimeter- wave frequencies, there is a need to characterize new materials before they come to market. At frequencies below about 67 GHz, it is

Sub-nanosecond Tuning of Microwave Resonators Fabricated on Ruddlesden-Popper Dielectric Thin Films

July 9, 2018
Author(s)
Aaron M. Hagerstrom, Xifeng Lu, Natalie Dawley, H. Nair, Jordi Mateu, Robert D. Horansky, Charles A. Little, James C. Booth, Christian J. Long
Voltage-tunable dielectric materials are widely used for microwave-frequency signal processing. Among tunable dielectric thin films, (SrTiO3)nSrO Ruddlesden-Popper (RP) superlattices have exceptionally low loss at high frequencies. This paper reports the
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