| Modeling and Simulation of Nonlinear Transmission Lines |
Jan 2010 |
40 pages |
| Authors:
Frank Crowne; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
 | This technical report summarizes design work done for ARDEC Picatinny Arsenal from April to October 2009 as part of an effort to design and fabricate nonlinear transmission lines (NLTL) based on ferroelectric materials. These lines were intended to be key components in a compact source of high-power microwaves (HPM) that could be carried by artillery rounds and used to disrupt battlefield communications. The effort, which was begun in 2008, centered ... |
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| Quantum Computational Geodesics |
Jan 2010 |
38 pages |
| Authors:
Howard E Brandt; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Recent developments in the differential geometry of quantum computation offer a new approach to the analysis of quantum computation. In the Riemannian geometry of quantum computation, the quantum evolution is described in terms of the special unitary group of n-qubit unitary operators with unit determinant. The group manifold is taken to be Riemannian. The objective of this report is to mathematically elaborate on characteristics of geodesics describing possible minimal complexity ... |
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| Review of Bayer Pattern Color Filter Array (CFA) Demosaicing with New Quality Assessment Algorithms |
Jan 2010 |
42 pages |
| Authors:
Maschal; Robert A Jr; S S Young; Joe Reynolds; Keith Krapels; Jonathan Fanning; Ted Corbin; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| To address the frequent lack of a reference image or ground truth when performance testing Bayer pattern color filter array (CFA) demosaicing algorithms, we propose two new no-reference quality assessment algorithms. These new algorithms give a relative comparison of two demosaicing algorithms by measuring the presence of two common artifacts in their output images. For this purpose, we reviewed various demosaicing algorithms, especially adaptive color plane, gradient-based methods, and median ... |
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| Reflected Signal Analysis |
Jan 2010 |
32 pages |
| Authors:
Deen King-Smith; Anthony Martone; Marc Ressler; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| We present a framework for forensic identification of RF devices using specially designed probe signals. This framework applies to a broad range of devices and models. Probe signals, device models, feature selection, and classifier design are described. For the device model, we introduce a method for determining a nonlinearity based on a known diode model. Experimental results are given to verify our approach. |
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| CVD Synthesis and Characterization of Graphene Thin Films |
Jan 2010 |
|
| Authors:
Matthew O'Brien; Barbara Nichols; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
 | We demonstrated a method for producing high-quality, few-layer graphene over large areas via chemical vapor deposition (CVD). Graphene growth was achieved by the flow of methane and hydrogen gasses over a nickel thin film acting as catalyst at ambient pressure. Optimal growth conditions were found by varying the following parameters: methane flow rate, nickel film thickness, cooling rate, and temperature. A transfer process was developed through treatment with a nickel ... |
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| Through-the-Wall Small Weapon Detection Based on Polarimetric Radar Techniques |
Dec-2009 |
46 pages |
| Authors:
Traian Dogaru; Calvin Le; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| In this report, we investigate techniques for small weapon detection in the context of sensing-through-walls radar sensors. Our approach exploits the radar wave polarization in order to discriminate between a human carrying a weapon and an unarmed human. We first develop a polarization optimization procedure for a rifle-like target, but demonstrate that this technique does not perform as expected in the presence of a human. Next, we introduce a more ... |
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| EPM 2482 Power Cycling Evaluation Summary |
Dec 2009 |
16 pages |
| Authors:
Mark R Morgenstern; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| The Power Components Branch of the U.S. Army Research Laboratory's Sensors and Electron Devices Directorate has evaluated the use of NuSil's EPM 2482 as an electrical insulator in power convertor modules. There is a need for a material that electrically insulates well and does not distort in form when heated. Distorting potting material can induce mechanical stress on and break wire bond connections in packaging. During the test described in ... |
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| An Analysis of Clustering Tools for Moving Target Indication |
Nov 2009 |
34 pages |
| Authors:
Kenneth Ranney; Anthony Martone; Roberto Innocenti; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Previously, we developed a moving target indication (MTI) processing approach to detect and track slow-moving targets inside buildings, which successfully detected moving targets (MTs) from data collected by a low-frequency, ultrawideband radar. Our MTI processing algorithms include change detection (CD), used to identify the MT signature; automatic target detection (ATD), used to eliminate imaging artifacts and potential false alarms due to target multi-bounce effects; clustering, used to identify a centroid ... |
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| Acoustic Transient Localization: A Comparative Analysis of the Conventional Time Difference of Arrival Versus Biomimetics |
Nov 2009 |
20 pages |
| Authors:
Latasha Solomon; ALLYN HUBBARD; Yirong Pu; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Accurately localizing threats of interest remains a high priority for today's military. The conventional least-squares time difference of arrival algorithm and a novel biomimetic algorithm will be applied to acoustic transient events to localize points of origin. This report will compare the accuracy of the output of these two signal processing algorithms as it relates to that of truth data. |
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| Model-guided Examination of Human Signatures Produced by an Array-based Radar System |
Nov 2009 |
14 pages |
| Authors:
Kenneth Ranney; Calvin Le; Getachew Kirose; Anders Sullivan; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| We adapt X-patch models and processing to produce moving target indication (MTI) signatures that better represent those produced by an array-based system. We then consider the resulting data as a function of both depression angle and azimuth (or viewing) angle. |
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| Human Infrastructure Detection and Exploitation (HIDE) |
Nov 2009 |
56 pages |
| Authors:
Raju Damarla; Barry O'Brian; Matthew Thielka; Gary Chatters; Jonathan Fine; Steve Vinci; Greg Samples; Richard Gregory; Jeff Houser; Alan Edelstein; Alex Chan; Greg Fischer; Patti Gillespie; Michael Patterson; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Finding human infrastructure elements such as machinery, chemicals, radiofrequency emissions, electrical currents, or other evidence of human activity in confined enclosed spaces is a deficiency in current intelligence, surveillance, and reconnaissance (ISR) systems. In addition, operations in these places present a threat to Soldiers and detection of these manmade infrastructure elements is a needed capability. In this effort, the authors investigate and demonstrate multimodal, low-cost sensing on a mobile platform ... |
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| Performance Evaluation of Commercial CFx Materials in Lithium Batteries |
Oct-2009 |
16 pages |
| Authors:
Don Foster; Jeffrey Read; Jeffrey Wolfenstine; Michelle Marx; Sheng Zhang; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| The performance of six different commercially available carbon monofluoride (CFx) materials were evaluated at four different discharge rates. The physical and chemical properties of the CFx materials were correlated to cell performance in lithium coin cells. This study was undertaken to determine if there are specific physical or chemical properties that can be tied to performance and if modification of these properties could lead to an improved carbon monofluoride material. ... |
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| Atomic Waveguides for Atom Chips |
Oct-2009 |
38 pages |
| Authors:
William M Golding; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This report studies the quantum behavior of a spin one-half magnetic atom guided by a two-dimensional quadrupole magnetic field of infinite extent. The technique used is based on the Frobenius series technique and gives a complete understanding of the guide mode structure for small radial coordinates. Asymptotic solutions are used to establish boundary conditions for large radii. Various guide modes that have not been included in earlier studies are made ... |
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| Signal Modeling of Turbulence-Distorted Imagery |
Sep-2009 |
18 pages |
| Authors:
S S Young; Ron Driggers; Keith Krapels; Richard Espinola; Joseph Reynolds; Jae Cha; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Understanding turbulence effects on wave propagation and imaging systems has been an active research area for more than 50 years. Conventional atmospheric optics methods use statistical models to analyze image degradation effects that are caused by turbulence. In this paper, we intend to understand atmospheric turbulence effects using a deterministic signal processing and imaging theory point of view and modeling. The model simulates the formed imagery by a lens by ... |
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| Z-scan Measurement of the Upconversion Coefficient in Er:YAG |
Sep-2009 |
20 pages |
| Authors:
Jeffrey O White; Robert Dibiano; Alexander B Fick; John E McElhenny; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Solid-state laser research at the U.S. Army Research Laboratory (ARL) is currently emphasizing techniques for power scaling and achieving wavelengths in the eye-safer spectral region. We are studying erbium-doped yttrium aluminum garnet (Er:YAG), because it can be operated with a low quantum defect and has transitions around 1.6 micrometers. However, it suffers from cooperative pair upconversion, which can raise the lasing threshold, and thus lower the output power. In this ... |
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| Heat Transfer in the LCCM Thermal Reserve Battery |
Sep 2009 |
169 pages |
| Authors:
Frank C Krieger; Michael Ding; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Volumetric energy densities of the LCCM (Low Cost Competent Munition) thermal battery were increased by 25% over those of a previously miniaturized benchmark LCCM battery primarily by using improved battery construction and thermal management techniques (1,2). Experimental results and calculations indicate that the LCCM benchmark battery thermal lifetimes can be increased by 200% over the original benchmark value of 90 s, and that the volumetric energy density can be increased ... |
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| Measurement and Analysis of Upconversion Rates of Er:YAG at Room Temperature |
Aug-2009 |
14 pages |
| Authors:
M Dubinskii; G A Newburgh; T Sanamyan; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| We have measured upconversion fluorescence resulting from the excitation of room temperature 1% and 5% Er:YAG by a 1532 nm nanosecond pump source. Measurements of the fluorescence decay from the 4I13/2, 4I11/2, 4F9/2 and 4S3/2 manifolds to the 4I15/2 ground state manifold were observed over a wide range of excitation pulse fluence values. A unique set of upconversion parameters were extracted from the measurements using a modification of the traditional ... |
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| Effects of Differing Carbon Nanotube Field-effect Transistor Architectures |
Jul-2009 |
22 pages |
| Authors:
Andrew M Dorsey; Matthew H Ervin; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Single-walled carbon nanotube field-effect transistors (SWCNTFETs) were fabricated with varying device architectures. Variations on the standard back-gated architecture included varying the gate oxide material and thickness, changing source and drain contact metallization, suspending the carbon nanotubes to minimize interaction with the gate oxide, and fabricating a topgated architecture employing a thin layer of aluminum oxide (Al2O3) as the gate oxide. Devices were characterized and compared to each other based on ... |
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| Next Generation Highly Conducting Organic Films Using Novel Donor-Acceptor Molecules for Opto-Electronic Applications |
Jun-2009 |
16 pages |
| Authors:
Eric Forsythe; Jianmin Shi; David Morton; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This two-year DRI is intended to address the Army's need for two-dimensional, conformal, large-area electronics by developing techniques that will lead to the printing of conducting organic materials as a primary build-block that will enable such low-cost, large area applications. In the first year, we worked on developing novel organic based molecules using the donor-acceptor design concepts and developing a more fundamental understanding of donor acceptor molecule stacking in order ... |
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| Animating a Human Body Mesh with Maya for Doppler Signature Computer Modeling |
Jun-2009 |
20 pages |
| Authors:
Getachew Kirose; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| The Maya software package has been used by researchers at the U.S. Army Research Laboratory (ARL) to create human body motion animation for the purpose of simulating the radar signature of a moving human target. This report describes how to use Maya's powerful graphics user interface (GUI) in order to create realistic frame-by-frame animation of a human mesh in walking motion. The examples presented here also include a human equipped ... |
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| Solution Deposition Methods for Carbon Nanotube Field-Effect Transistors |
Jun-2009 |
32 pages |
| Authors:
Matthew Ervin; Natalie Salaets; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This study evaluated different methods for controlled deposition of carbon nanotubes (CNTs) from solution onto a silicon substrate to make CNT field-effect transistors (FETs). The goal of this deposition was to achieve reproducible device properties through more uniform CNT densities and other traits. This method serves as an easier, room temperature alternative to chemical vapor deposition growth. Three different types of CNT solutions were spun onto substrates: pristine tubes solubilized ... |
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| Test and Characterization of Some Zeolite Supported Gas Phase Desulfurization Sorbents |
Jun-2009 |
22 pages |
| Authors:
John Hopkins; Deryn Chu; Charles Rong; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This report presents the results of sulfidation and regeneration of mixed metal oxide supported on zeolite-Y for hydrogen sulfide (H2S) at 650 and 800 deg C, along with results for unsupported mixed metal oxide. The capacity for the unsupported oxide was higher than that for the supported oxide, but the unsupported mixed metal oxide showed evidence of sintering at higher temperatures, which resulted in a decreased desulfurization capacity. The sulfidation ... |
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| Demonstration of Ethanol and JP-8 Fuel Atomization Using Micromachined Silicon Multiplexed Electrosprays |
May-2009 |
24 pages |
| Authors:
C M Waits; Israel Boniche; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This work discusses the fabrication and experimental testing of multiplexed electrospray (ESpray) devices micromachined in silicon substrates. Variations to the experimental test stands from previous work demonstrating Ethanol spraying are described for the successful demonstration of JP-8 spraying. Five different ESpray devices were microfabricated to gain an understanding of the operating limits for stable electrospraying. The microfabrication of ESpray devices consists of independently fabricating its two components (extractor and nozzle ... |
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| Growth of Low Defect Density Gallium Nitride (GaN) Films on Novel Tantalum Carbide (TaC) Substrates for Improved Device Performance |
May-2009 |
34 pages |
| Authors:
M A Derenge; K A Jones; K W Kirchner; T S Zheleva; R D Vispute; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| To potentially improve device performance, we attempted to grow gallium nitride (GaN) films with better crystalline quality (fewer mismatch dislocations) using a tantalum carbide (TaC) substrate, which is more closely lattice matched to GaN than currently used substrates. We created the TaC substrate, using pulse laser deposition (PLD) of TaC onto (0001) SiC substrates at tilde 1000 deg C, and grew GaN films, using metal organic chemical vapor deposition (MOCVD). ... |
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| Theory and Operation of Cold Field-effect Transistor (FET) External Parasitic Parameter Extraction |
May-2009 |
22 pages |
| Authors:
Romeo Rosario; Benjamin D Huebschman; Pankaj B Del Shah; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| The design of monolithic microwave integrated circuits (MMIC) is dependent on the ability to generate accurate device models. Prior knowledge of the external parasitic components is required to determine the small-signal model of the intrinsic device. In this report, we describe a technique and its implementation for extracting external device parasitics. The term cold field-effect transistor (FET) refers to measurements taken when the drain is at the same voltage as ... |
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| Rare-Earth Doped Gallium Nitride (GaN)- An Innovative Path Toward Area-scalable Solid-state High Energy Lasers Without Thermal Distortion |
Apr-2009 |
22 pages |
| Authors:
Michael Wraback; Mark Dubinskiy; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| We have demonstrated, for the first time, in situ neodymium (Nd) doping of gallium nitride GaN by plasma-assisted molecular beam epitaxy (PA-MBE). The Nd doping is controlled by the GaN growth conditions and the Nd effusion cell temperature. The Rutherford backscattering spectroscopy (RBS) and secondary ion mass spectrometry (SIMS) data indicated Nd doping as high as 8 at. %, with no evidence of phase segregation identified by x-ray diffraction (XRD) ... |
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| A Low-wear Planar-contact Silicon Raceway for Microball Bearing Applications |
Apr-2009 |
34 pages |
| Authors:
C M Waits; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| As silicon rotary micro-electromechanical systems (MEMS) devices become critical components to power generation and sensor platforms, it is crucial to develop bearing mechanisms that can achieve speed and reliability requirements without increasing cost and complexity. Microball bearings have proven simple to fabricate and capable of achieving high speeds. However, previous microball raceway implementations showed substantial degradation in performance and required cleaning steps to improve reliability. Furthermore, large surface roughness on ... |
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| Magnetic Signature: Small Arms Testing of Multiple Examples of Same Model Weapons |
Apr-2009 |
26 pages |
| Authors:
G A Fischer; J E Fine; A S Edelstein; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This report investigates identical model small arms, in particular eight same-model pistols and seven same-model shotguns. This is an adjunct to experiments to obtain statistically significant quantities of signatures of objects of military interest. Magnetic signature features were compared to find similarities and differences between all the pistols and all the shotguns tested. In the far field region, the shapes of the component curves for each weapon were similar; the ... |
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| Spin Torque Nano Oscillators as Potential Terahertz (THz) Communications Devices |
Apr-2009 |
20 pages |
| Authors:
Alma E Wickenden; Chris Fazi; Ben Huebschman; Roger Kaul; Andrew C Perrella; William H Rippard; Matthew R Pufall; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| In this report, we describe the complex impedance of spin torque nano oscillator (STNO) devices. We determined that the STNO is a nonreactive, real-resistance device with single-valued resistance in the broadband frequency range of 500 MHz to 10 GHz (the limit of our test conditions), and that STNOs do not require an external circuit or conjugate matching to operate in a transmitter configuration. We report the first demonstration of the ... |
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| Optimizing Uncertainty in Dempster-Shafer Detectors Fusing Multi-Sensor Data |
Mar-2009 |
18 pages |
| Authors:
Nasser M Nasrabadi; Kenneth I Ranney; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| Fusion algorithms based on the Dempster-Shafer (DS) Theory of Evidence lack a universally standard method for automatically assigning probability mass to the don't know hypothesis for a particular input. For example, when fusing automatic target detection (ATD) algorithm outputs from multiple sensors, one must associate a measure of uncertainty with the output from the ATD algorithm of each sensor. We describe such a fusion algorithm, developed using the DS formalism, ... |
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| Four-Channel Threshold Detector With Optical Isolation |
Feb-2009 |
26 pages |
| Authors:
Mark R Morgenstern; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| The four-channel window comparator discussed in this report is a safety switch that can be used to limit a range of test variables such as voltages, currents, temperatures or other values that can be scaled to a voltage within +-13 V. This device is simple, reliable, rugged, and requires no external control hardware or software. This module is scalable and reconfigurable to support nearly any test apparatus. |
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| Exploratory Corrugated Infrared Hot-Electron Transistor Arrays |
Feb-2009 |
18 pages |
| Authors:
Kwong-Kit Choi; Richard Fu; Kimberly Olver; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| In this study, we investigated a 5x8 corrugated infrared hot-electron transistor (IHET) array with a common base configuration. We found the IHET structure improved the photocurrent-to-dark current ratio by a maximum factor of six compared to the basic quantum well infrared photodetector (QWIP) structure. This improvement is consistent with the hot-electron distributions created by the thermal and photo-excitations within the detectors. The study also showed that there is no electrical ... |
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| Architectures and Devices for Millimeter Wave Imaging |
Feb-2009 |
18 pages |
| Authors:
Mark Mirotznik; David A Wikner; Joseph N Mait; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| A research effort was conducted to explore the ways in which sub-wavelength gratings can be used to reduce the reflections from the optics of millimeter-wave imaging systems. A moth-eye lens is sometimes used at optical and infrared frequencies for this purpose, but it is too fragile to be applied directly to the plastic lenses used in the millimeter-wave. A modification of this structure, called the inverse moth-eye lens, was designed, ... |
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| Time-Frequency Analysis of a Moving Human Doppler Signature |
Feb-2009 |
34 pages |
| Authors:
Traian Dogaru; Calvin Le; Getachew Kirose; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| In this report we analyze the Doppler signature of a moving human with the purpose of finding temporal change patterns that would allow detection and classification of movers. The analysis is based on computer models that simulate the operation of a pulse-Doppler radar. We start with an animated human mesh in walking motion and compute the frame-by-frame radar return using electromagnetic solvers such as the Finite Difference Time Domain (FDTD). ... |
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| Quantum Computer Circuit Analysis and Design |
Feb-2009 |
16 pages |
| Authors:
Howard E Brandt; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Recent developments in the Riemannian geometry of quantum computation offer a new approach to the analysis of quantum computation. A geodesic equation defined on the SU(2n) group manifold, representing quantum gate operations on n qubits, may be used to determine optimal quantum evolutions and minimum-complexity quantum circuits. The geodesic equation is a first order nonlinear differential matrix equation of the Lax type. This report gives derivations of the Levi-Civita connection, ... |
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| Characterization and Improvements to Porous Silicon Processing for Nanoenergetics |
Feb-2009 |
20 pages |
| Authors:
Luke Currano; Collin Becker; Wayne Churaman; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Nano-porous silicon offers a large surface area to volume ratio typical of nano materials and contains a network of pores that can be filled with oxidant. When a silicon fuel source is combined with an oxidant on the nano-scale, kinetic limitations of silicon oxidation are overcome and an explosive reaction is realized. We present a characterization of lightly doped p-type silicon for nanoenergetic porous silicon (PS) applications. Using gas adsorption ... |
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| Hot-Pressed Versus Sintered LiTi2(PO4)3 |
Feb-2009 |
28 pages |
| Authors:
Jeff Wolfenstine; Jan L Allen; James Sumner; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| The electrical and mechanical properties of hot-pressed versus sintered LiTi2(PO4)3 were investigated. The hot-pressed LiTi2(PO4)3 had a higher density and larger average grain size than the sintered material. As a result of these microstructural differences, the hot-pressed material exhibited a higher total ionic conductivity and lower hardness. The electronic conductivity of both materials was the same, and increased by a factor of about 107 when the hot-pressed and sintered materials ... |
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| Evaluation of Saft Ultra High Power Lithium Ion Cells (VL5U) |
Feb-2009 |
24 pages |
| Authors:
Sonya Gargies; Jeff Read; Wishvender Behl; Wesley Tipton; Thomas Salem; Donald Porschet; Jan L Allen; Jeff Wolfenstine; Kang Xu; T R Jow; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| We evaluated Saft Ultra High Power (UHP) cells (Saft designation VL5U) to determine their rate capability, low temperature performance, storage, and cycle life. The energy and power density at 5 A (1C) were 45 Wh/kg and 55 W/kg, respectively; at 1000 A (200C) were 25 Wh/kg and 10 kW/kg, respectively; and at a 500 A rate, the energy densities were 35, 29, and 29 Wh/kg at 20, -20, and -40 ... |
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| Flip Chip Bonding of 68 x 68 MWIR LED Arrays |
Jan-2009 |
6 pages |
| Authors:
Naresh C Das; Monica Taysing-Lara; Kimberley A Olver; Fouad Kiamilev; J P Prineas; J T Olesberg; E J Koerperick; L M Murray; Tom F Boggess; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| The flip chip bonding process is optimized by varying the bonding pressure, temperature, and time. The 68 68 mid wave infrared (MWIR) LED array was hybridized onto Si-CMOS driver array with same number of pixels. Each pixel has two indium bumps, one for cathode and another for anode. Both LED array and CMOS drivers have 15- m-square Indium bump contact pads. We used Karl Suss FC150 flip chip machine for ... |
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| Continuous System-Level Scale for Comparing Laser Gain Media |
Dec-2008 |
24 pages |
| Authors:
Jeffrey O White; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Several quantities are proposed for facilitating a quantitative comparison of laser gain media, operating temperatures, pump, and laser wavelengths. They are based on the occupation probability of absorbing and emitting pump and laser levels. The system level, l, has a numerical value coinciding with conventional usage of the terms two-, three-, and four-level systems. The occupation factor has a value from -1 to +1, and is appropriate for describing an ... |
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| Direct Methanol Fuel Cell Systems for Future Force Warriors: From Experimental and Simulations for Water and Methanol Crossover and Recycling to High Performance Fuel Cell Systems |
Dec-2008 |
9 pages |
| Authors:
Deryn Chu; Rongzhong Jiang; Scott Feldman; Joseph Kowal; Dave Schimmel; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| To produce a high power and high energy density direct methanol fuel cell (DMFC) system, it must use neat methanol as a fuel, and water produced at the cathode must be recycled. Based on Faradic reactions for DMFC, a series of theoretical equations over the entire discharge current ranges were explored and developed to model and simulate water and methanol crossover in a DMFC stack. The performance of the DMFC ... |
|
| Ultra-wideband Radar for Building Interior Imaging |
Dec-2008 |
9 pages |
| Authors:
Traian Dogaru; Calvin Le; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This paper presents both numeric simulations and radar measurements related to through the wall imaging technologies. We present synthetic aperture radar (SAR) images obtained by the Army Research Laboratory (ARL) Forward-Looking Radar system during field experiments and compare those with the results of our Xpatch computer models. We also demonstrate a computational approach based on the Finite Difference Time Domain (FDTD) algorithm in order to obtain the SAR images of ... |
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| Characterization of Perovskite Films Grown by a Novel Low-Temperature Process for Uncooled IR Detector Applications |
Dec-2008 |
8 pages |
| Authors:
W L Sarney; J W Little; A R Tao; D E Morse; F E Livingston; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Many Army applications, such as driver vision enhancement (DVE), rifle sights, seekers, physical security, target acquisition, and fire control, would benefit from affordable, passive uncooled infrared (IR) sensor options. The main considerations for uncooled IR sensors are cost, weight, and power. We have begun a three-year effort to develop a novel approach to the fabrication of uncooled IR focal-plane array (FPA) detectors using bio-inspired, low-temperature, multimetallic perovskite nanoparticle deposition, direct-write ... |
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| Toward Three Dimensional Circuits Formed by Molten-Alloy Driven Self-Assembly |
Dec-2008 |
6 pages |
| Authors:
Madan Dubey; Christopher J Morris; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Self-assembly opens new possibilities in three-dimensional (3-D) device structures, and here we report on our progress toward a self-assembling 3-D circuit. A major challenge to such a system has been the fabrication of large numbers of free-standing, microfabricated parts, and we have overcome this challenge by developing a new wafer-bond and release process. We present this process on 100 mm diameter wafers, and finally show initial assembly results. |
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| Investigations of Transition Metal Oxide with the Perovskite Structure as Potential Multiferroics |
01-Oct-2008 |
40 pages |
| Authors:
Virginia L Miller; Steven C Tidrow; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Materials that exhibit both magnetism and ferroelectricity are often termed magnetoelectric multiferroics and are of recent interest because of their potential use in various microelectronic devices. There are many oxides that crystallize in the perovskite structure (ABO3) which are either ferromagnetic or ferroelectric, but relatively few that display both types of properties. This research effort focused on transition metal oxides that crystallize in the perovskite structure as a potential source ... |
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| Investigation into the Effect of Reagent Choice on the Dielectric Properties of the Ferroelectric Oxides Ba(MTa)0.05Ti0.9O3 (where M=Sc, Er, Ho or Y) |
01-Oct-2008 |
24 pages |
| Authors:
Virginia L Miller; Steven C Tidrow; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| This report investigates the effects of reagent choice on the physical properties of ferroelectric oxides of the composition Ba(MTa)0.05Ti0.9O3 (M=Sc, Er, Ho or V). These materials are of particular interest because they possess relatively low to medium dielectric constants and improved tunabilities. In this project, samples of Ba(MTa)0.05Ti0.9O3 (M=Sc, Er, Ho or Y) were prepared using two different synthetic methods. The first method consisted of heating a stoichiometric mixture of ... |
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| Low Temperature Photoluminescence and Leakage Current Characteristics of InAs-GaSb Superlattice Photodiodes |
01-Sep-2008 |
20 pages |
| Authors:
P A Folkes; J Little; S Svensson; K Olver; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| We report the results of a study of the temperature-dependent photoluminescence (PL) and leakage current characteristics of a set of type II idium arsenide (InAs)-gallium antimonide (GaSb) superlattice (SL) photodiode structures. We find that the PL efficiency of high-quality structures is determined by Shockley-Read and trap-assisted tunneling nonradiative recombination processes. Our results suggest a possible correlation between trap-assisted tunneling in some SL structures and an anomalous decrease in the PL ... |
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| Imaging With Magnification Test Procedure |
01-Sep-2008 |
18 pages |
| Authors:
Michael J Ferry; Shensky; William III; Andrew G Mott; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| Although modern cameras have advanced to the point where pixel size approaches 4 microns, we have yet to achieve the submicron size necessary to accurately resolve focused laser beams. Present methods such as pinhole scans and knife edge scans assume spatial wave forms to fit the transmission, and those assumptions may be erroneous. This technical note details a method of imaging with calibrated magnification and commercial laser beam profiling software ... |
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| Colloidal CdTe Nano Crystals Synthesis and Characterization |
01-Sep-2008 |
16 pages |
| Authors:
Fred Semendy; Gomatam Jaganathan; Nibir Dhar; Sudhir Trivedi; Ishwara Bhat; Yuanping Chen; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| Synthesis of CdTe nano crystals (NCs) in uniform sizes and in good quality was performed in our nano lab and further characterized by absorption spectra, photoluminescence (PL), and atomic force microscopy (AFM). In this growth procedure, CdTe nano crystal band gap is strongly dependent on the growth time and not on the injection temperature or organic ligand concentration. This is very attractive because the nano crystal size can be easily ... |
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| Development of a Profiling Scanner |
01-Sep-2008 |
38 pages |
| Authors:
ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| This report describes the design, operation, and performance of a two-dimensional (2-D) profiling scanner system using 16 laser diodes, 16 photo sensors, and a personal computer (PC) controller. A profiling scanner provides output images that reveal the size, height, and outline or shape of an object. This information can be useful in various military and related applications. The Radiometric Sensor Development and Applications Team of the Sensors and Electron Devices ... |
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