Electrical and Computer Engineering Commons^™

Long Term Field Emission Current Stability Characterization Of Planar Field Emitter Devices, Ranajoy Bhattacharya, Marco Turchetti, P. Donald Keathley, Karl K. Berggren, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Lateral field emission devices have been characterized and degradation tested for >1000 h to study stability and reliability. Two types of planar device structures, diode and bowtie, were studied. These nanoscale devices have 10–20 nm tip to tip or tip to collector dimensions with the tips fabricated from Au/Ti. Typical currents of 2–6 nA at 6 V were measured. The devices were placed on lifetime tests in a vacuum of < 10⁻⁸ Torr and biased at 6 V DC for >1000 h. Seven total devices were tested with one failing at 300 h. and three of the devices showed < 5% degradation in current until 1400 h when testing was stopped, and three other devices showed a sudden drop of ≈20% ranging from 700 to 900 h. Optical microscope images of one of the devices that failed catastrophically at 350 h show physical arc damage where the bond pad narrows to the emitter trace. Scanning electron microscope images of a bowtie part that completed 1400 h of operation showed no obvious erosion or damage to the tips.

A New Feature Extraction Approach For Script Invariant Handwritten Numeral Recognition, Pawan Kumar Singh, Iman Chatterjee, Ram Sarkar, Elisa Barney Smith, Mita Nasipuri

Electrical and Computer Engineering Faculty Publications and Presentations

Handwritten numeral recognition is a challenging research problem because of the enormous varieties of styles in which human beings write the numerals. Several researchers have tried to find solutions to this problem with exceptional recognition accuracies. However, most of these solutions have been dedicated to single script numerals. Such methods are inappropriate for multi-lingual nations such as India where a large number of scripts are used. Keeping this issue in mind, a new feature descriptor named symbolization of binary images (SBI) is introduced here for the recognition of handwritten numerals of different scripts. Effectiveness of SBI is supported …

Space-Charge Limited Current In Planar And Cylindrical Crossed-Field Diodes Using Variational Calculus, Adam M. Darr, Ranajoy Bhattacharya, Jim Browning, Allen L. Garner

Electrical and Computer Engineering Faculty Publications and Presentations

No abstract provided.

Lemons Into Lemonade!, Thad B. Welch, Cameron H. G. Wright, Michael G. Morrow

Electrical and Computer Engineering Faculty Publications and Presentations

This paper discusses a trial of offering two senior/first-year graduate classes in a 7-week format, one following the other. Thus, a student could complete two courses (6-credits), dealing with two closely related topics, in one semester. In this case, the courses were Digital Communication Systems and Wireless Communications.

During the first week of the first 7-week course, all of the in-class demonstrations and hands-on experiences needed to be shifted to online/remote delivery. This was primarily accomplished using the Amazon Web Services (AWS) AppStream, cloud computing system.

The planned real-world signal capture and analysis project changed to an optional attendance …

Effects Of Memristive Synapse Radiation Interactions On Learning In Spiking Neural Networks, Sumedha Gandharava Dahl, Robert C. Ivans, Kurtis D. Cantley

Electrical and Computer Engineering Faculty Publications and Presentations

This study uses advanced modeling and simulation to explore the effects of external events such as radiation interactions on the synaptic devices in an electronic spiking neural network. Specifically, the networks are trained using the spike-timing-dependent plasticity (STDP) learning rule to recognize spatio-temporal patterns (STPs) representing 25 and 100-pixel characters. Memristive synapses based on a TiO₂ non-linear drift model designed in Verilog-A are utilized, with STDP learning behavior achieved through bi-phasic pre- and post-synaptic action potentials. The models are modified to include experimentally observed state-altering and ionizing radiation effects on the device. It is found that radiation interactions tend …

Seabed Observations At The New England Mud Patch: Reflection And Scattering Measurements And Direct Geoacoustic Information, Charles W. Holland, Chad M. Smith, Zackary Lowe, Jim Dorminy

Electrical and Computer Engineering Faculty Publications and Presentations

Seabed reflection and scattering measurements were conducted at the New England Mud Patch to better understand the acoustic properties of fine-grained (muddy) sediments. The measurement philosophy and the measurements themselves are summarized. In addition, geoacoustic information accessed directly from the data in the time and frequency domains is presented. The main result is the existence of an angle of intromission. This observation proves that the mud sound speed is less than that of the water and yields a sediment sound speed ratio 0.9865 with outer bounds {0.985 0.989}. Another result is the observation of strong scattered arrivals from within the …

Numerical Analysis Of Radiation Effects On Fiber Optic Sensors, Sohel Rana, Harish Subbaraman, Austin Fleming, Nirmala Kandadai

Electrical and Computer Engineering Faculty Publications and Presentations

Optical fiber sensors (OFS) are a potential candidate for monitoring physical parameters in nuclear environments. However, under an irradiation field the optical response of the OFS is modified via three primary mechanisms: (i) radiation-induced attenuation (RIA), (ii) radiation-induced emission (RIE), and (iii) radiation-induced compaction (RIC). For resonance-based sensors, RIC plays a significant role in modifying their performance characteristics. In this paper, we numerically investigate independently the effects of RIC and RIA on three types of OFS widely considered for radiation environments: fiber Bragg grating (FBG), long-period grating (LPG), and Fabry-Perot (F-P) sensors. In our RIC modeling, experimentally calculated refractive index …

Sound Speed Gradients In Mud, Charles W. Holland

Electrical and Computer Engineering Faculty Publications and Presentations

Various methods have been used to estimate sound speed profiles in mud at the New England Mud Patch. Some of these methods show large sound speed gradients of order 10 s−1. New measurements of the seabed reflection coefficient exhibit an angle of intromission over three octaves in frequency; these data constrain the range of possible sound speed gradient values. The data indicate that sound speed gradients must be quite weak, i.e., much smaller than |10 s−1|. This conclusion is supported by core data which indicate nearly constant porosity in most of the mud layer.

On Compressional Wave Attenuation In Muddy Marine Sediments, Charles W. Holland, Stan E. Dosso

Electrical and Computer Engineering Faculty Publications and Presentations

A method for measuring in situ compressional wave attenuation exploiting the spectral decay of reflection coefficient Bragg resonances is applied to fine-grained sediments in the New England Mud Patch. Measurements of layer-averaged attenuation in a 10.3 m mud layer yield 0.04 {0.03, 0.055} dB/m/kHz (braces indicate outer bounds); the attenuation is twice as large at a site with 3.2 m mud thickness. It is shown that both results are heavily influenced by a ∼1 m sand-mud transition interval created by geological and biological processes that mix sand (at the base of the mud) into the mud. Informed by the observations, …

On Ip2 Impact To Nonlinear Distortion Of Rf Amplifiers, Xianzhen Yang, Shiyu Li, Siyuan Yan, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

The second-order distortion, often using second-order intercept point (IP2) as an indicator, has been considered easy to be filtered in narrowband radio frequency (RF) communications because it is located far away from the passband of transmitted signals. However, with rapidly increased applications in wideband RF communications, the secondorder intermodulation (IM) might become important, partially evidenced by the increased appearances of IP2 in the amplifier datasheets in recent years. In this article, a power spectrum model of the second-order IM is derived to quantify the second-order distortion using the IP2. This model could be used to determine under what conditions, in …

Temperature Effects On Gated Silicon Field Emission Array Performance, Ranajoy Bhattacharya, Nedeljko Karaulac, Winston Chern, Akintunde Ibitayo Akinwande, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Silicon field emitter arrays (Si FEAs) are being explored as an electron source for vacuum channel transistors for high temperature electronics. Arrays of 1000 × 1000 silicon tip based gated field emitters were studied by measuring their electrical characteristics up to 40 V of DC gate bias with a 1.3 mA emission current at different temperatures from 25 to 400 °C. At ∼350 °C, residual gas analyzer measurements show that water desorption and carbon dioxide partial pressures increase significantly, the gate to emitter leakage current decreases by more than ten times, and the collector current increases by more than ten …

Chalcogenide Glass-Capped Fiber-Optic Sensor For Real-Time Temperature Monitoring In Extreme Environments, Bahareh Badamchi, Al-Amin Ahmed Simon, Maria Mitkova, Harish Subbaraman

Electrical and Computer Engineering Faculty Publications and Presentations

We demonstrate a novel chalcogenide glass (ChG)-capped optical fiber temperature sensor capable of operating within harsh environment. The sensor architecture utilizes the heat-induced phase change (amorphous-to-crystalline) property of ChGs, which rapidly (80–100 ns) changes the optical properties of the material. The sensor response to temperature variation around the phase change of the ChG cap at the tip of the fiber provides abrupt changes in the reflected power intensity. This temperature is indicative of the temperature at the sensing node. We present the sensing performance of six different compositions of ChGs and a method to interpret the temperature profile between 440 …

Particle-In-Cell Simulation Of An Industrial Magnetron With Electron Population Analysis, Andong Yue, Marcus Pearlman, Mike Worthington, John Cipolla, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Results from a particle-in-cell simulation study of L3Harris CWM-75 kW are presented; the continuous wave cooker magnetron typically operates at 18 kV, 5 A, 1900 G, 896–929 MHz. The startup process of the device has been simulated in 3D by using the PIC code VSim. The startup behavior was examined with (1) no priming, (2) RF priming, and (3) cathode modulation. Under no priming, the simulated device failed to oscillate in a simulation time of 1000 ns. Oscillations were achieved with both RF priming (150 ns) and cathode modulation (180 ns). Half (∼40 kW) of the device’s typical operating power …

Demonstration Of Three True Random Number Generator Circuits Using Memristor Created Entropy And Commercial Off-The-Shelf Components, Scott Stoller, Kristy A. Campbell

Electrical and Computer Engineering Faculty Publications and Presentations

In this work, we build and test three memristor-based true random number generator (TRNG) circuits: two previously presented in the literature and one which is our own design. The functionality of each circuit is assessed using the National Institute of Standards and Technology (NIST) Statistical Test Suite (STS). The TRNG circuits were built using commercially available off-the-shelf parts, including the memristor. The results of this work confirm the usefulness of memristors for successful implementation of TRNG circuits, as well as the ease with which a TRNG can be built using simple circuit designs and off-the-shelf breadboard circuit components.

Utilizing A Fully Optical And Reconfigurable Puf As A Quantum Authentication Mechanism, H. Shelton Jacinto, A. Matthew Smith, Nader I. Rafla

Electrical and Computer Engineering Faculty Publications and Presentations

In this work, the novel usage of a physically unclonable function composed of a network of Mach-Zehnder interferometers for authentication tasks is described. The physically unclonable function hardware is completely reconfigurable, allowing for a large number of seemingly independent devices to be utilized, thus imitating a large array of single-response physically unclonable functions. It is proposed that any reconfigurable array of Mach-Zehnder interferometers can be used as an authentication mechanism, not only for physical objects, but for information transmitted both classically and quantumly. The proposed use-case for a fully-optical physically unclonable function, designed with reconfigurable hardware, is to authenticate messages …

Icdar 2021 Competition On Time-Quality Document Image Binarization, Rafael Dueire Lins, Rodrigo Barros Bernardino, Elisa Barney Smith, Ergina Kavallieratou

Electrical and Computer Engineering Faculty Publications and Presentations

The ICDAR 2021 Time-Quality Binarization Competition assessed the performance of 12 new and 49 other previously published binarization algorithms for scanned document images. Four test sets of “real-world” documents with different features were used. For each test set, the top twenty algorithms in the quality of the resulting two-tone images had their average processing time presented, yielding an account of their time complexity.

Cyber-Physical Security Assessment And Resilience Of A Microgrid Testbed, Said Ahmed-Zaid, Sin Ming Loo, Andres Valdepena-Delgado, Theron Beam

Electrical and Computer Engineering Faculty Publications and Presentations

In order to identify potential weakness in communication and data in transit, a microgrid testbed is being developed at Boise State University. This testbed will be used to verify microgrid models and communication methods in an effort to increase the resiliency of these systems to cyber-attacks. If vulnerabilities are found in these communication methods, then risk mitigation techniques will be developed to address them.

A Low-Cost, Wireless, Multi-Channel Deep Brain Stimulation System For Rodents, F. N. U. Tala, Jordan Leiber, Hayden Fisher, Naga Spandana Muppaneni, Benjamin C. Johnson

Electrical and Computer Engineering Faculty Publications and Presentations

We present a small (43mm x 24mm x 15mm), off-the-shelf wireless neurostimulator for rodent deep brain stimulation research. Our device enables researchers to wirelessly configure stimulator settings, such as amplitude, pulse width, channel selection, and frequency, via a phone app. The system uses impedance-independent current-mode stimulation and steers current to a selected channel. In addition to monophasic and biphasic stimulation, the system also supports arbitrary waveform stimulation using pre-stored lookup tables. The system uses a configurable grounding phase to clear residual charge and a stimulation compliance monitor to ensure safe operation. The compliance monitor wirelessly reports the current during stimulation, …

Virtual Head Waves In Ocean Ambient Noise: Theory And Modeling, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan

Electrical and Computer Engineering Faculty Publications and Presentations

The Green's function retrieval in media with horizontal boundaries usually only considers the extraction of direct and reflected waves but ignores the virtual head waves, which have been observed experimentally from ocean ambient noise and used to invert for geometric and environmental parameters. This paper derives the extraction of virtual head waves from ocean ambient noise using a vertically spaced sensor pair in a Pekeris waveguide. Ocean ambient noise in the water column is a superposition of direct, reflected, and head waves. The virtual head waves are produced by the cross-correlations between head waves and either reflected waves or other …

Distributed Energy Resource Aggregation Using Customer-Owned Equipment: A Review Of Literature And Standards, Manasseh Obi, Tylor Slay, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Large-scale deployment of renewable energy resources, both utility-scale and distributed, create reliability concerns for electrical power system operators. The weather-dependent, non-dispatchable nature of renewable resources decreases the ability of operators to match supply with demand. Concurrently, distributed energy resources, defined as small-scale loads, generation sources, and storage systems, are becoming ubiquitous within modern electrical systems. This literature review presents the grid services that utilities use to alleviate power systems reliability concerns, particularly those caused by renewable resources, and how aggregations of residential-scale distributed energy resources can be used to provide these services.

By aggregating distributed energy resources en masse to …

A Simplified Accuracy Enhancement To The Saleh Am/Am Modeling And Linearization Of Solid-State Rf Power Amplifiers, Haider Al-Kanan, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

The Saleh behavioral model exhibits high prediction accuracy for nonlinearity of traveling-wave tube power amplifiers (TWT-PAs). However, the accuracy of the Saleh model degrades when modeling solid-state power amplifiers (SSPAs) technology. In addition, the polynomial expansion of the Saleh model consists of only odd-order terms as analyzed in this work. This paper proposes a novel model accuracy enhancement for the Saleh amplitude-to-amplitude (AM/AM) model when applied to radio frequency (RF) SSPAs. The proposed model enhancement accounts for the second-order intermodulation distortion, which is an important nonlinearity challenge in wideband wireless communications. The proposed static AM/AM model is a three-parameter rational …

Inkjet-Printed Graphene-Based 1 × 2 Phased Array Antenna, Mahmuda Akter Monne, Peter Mack Grubb, Harold Stern, Harish Subbaraman, Ray T. Chen, Maggie Yihong Chen

Electrical and Computer Engineering Faculty Publications and Presentations

Low-cost and conformal phased array antennas (PAAs) on flexible substrates are of particular interest in many applications. The major deterrents to developing flexible PAA systems are the difficulty in integrating antenna and electronics circuits on the flexible surface, as well as the bendability and oxidation rate of radiating elements and electronics circuits. In this research, graphene ink was developed from graphene flakes and used to inkjet print the radiating element and the active channel of field effect transistors (FETs). Bending and oxidation tests were carried out to validate the application of printed flexible graphene thin films in flexible electronics. An …

A Cathode Support Structure For Use In A Magnetron Oscillator Experiment, Daylon Black, Ryan Harper, Patrick Ward, Jacob Davlin, Omar Bentancourt, Donald Plumlee, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

A Low Temperature Cofired Ceramic (LTCC) material system has been used to develop a protype field emission cathode structure for use in an experimental magnetron oscillator. The structure is designed for used with 30 Gated Field Emission Array (GFEA) die electrically connected through silver metal traces and electrical vias. To approximate a cylinder, the cathode structure (48 mm long and 13.7 mm in diameter) is comprised of 10 faceted plates which cover the GFEA dies. Slits in the facet plates allow electron injection. The GFEA die (3 mm x 8 mm) are placed in axial columns of 3 and spaced …

Image Object Extraction Based On Semantic Segmentation And Label Loss, Xiaoru Wang, Peirong Xu, Zhihong Yu, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

Object extraction refers to the operation of obtaining an object area from an image based on a small amount of mark information given by users, which is a key step in image processing. In order to obtain a complete object profile, current methods usually require a large number of manual annotations, especially for objects with irregular contours. Since traditional algorithms rely on low-level pixel features without semantic information, and are based on obvious mathematical assumptions (ie, strong inductive bias), it is difficult to completely identify objects. At present, in order to improve the integrity of object extraction, semantic segmentation-based methods …

A Unified Spectrum Formulation For Ofdm, Fbmc, And F-Ofdm, Xianzhen Yang, Siyuan Yan, Xiao Li, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

Although orthogonal frequency division multiplexing (OFDM) has been standardized for 5G, filter bank multi-carrier (FBMC) and filtered orthogonal frequency division multiplexing (F-OFDM) remain competitive as candidates for future generations of wireless technologies beyond 5G, due to their reduced spectrum leakage and thus enhanced spectrum efficiency. In this article, we developed a unified spectrum expression for OFDM, FBMC, and F-OFDM, which provides comparative insights into those techniques. A representative sideband quantification is included at the end of this article.

A Novel Tri-Band Reconfigurable Microstrip Patch Antenna, Wen Tao Li, Meng Wei, Bahareh Badamchi, Harish Subbaraman, Xiaowei Shi

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper, a novel tri-band reconfigurable patch antenna with simple structure is presented. By changing the on-off state of only two PIN diodes, the antenna can operate in three bands, namely X-band, Ku-band, and Ka-band. The overall size of the antenna is 0.24λ_L × 0.5λ_L × 0.019λ_L, where λ_L is the free-space wavelength of the lowest operating frequency. A prototype is fabricated and measured to verify the design. The measurement results are in good agreement with the simulation results, which indicate that the proposed antenna can be flexibly switched between three …

Continuous Learning In A Single-Incremental-Task Scenario With Spike Features, Ruthvik Vaila, John Chiasson, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

Deep Neural Networks (DNNs) have two key deficiencies, their dependence on high precision computing and their inability to perform sequential learning, that is, when a DNN is trained on a first task and the same DNN is trained on the next task it forgets the first task. This phenomenon of forgetting previous tasks is also referred to as catastrophic forgetting. On the other hand a mammalian brain outperforms DNNs in terms of energy efficiency and the ability to learn sequentially without catastrophically forgetting. Here, we use bio-inspired Spike Timing Dependent Plasticity (STDP) in the feature extraction layers of the network …

A Self Controlled Rdp Approach For Feature Extraction In Online Handwriting Recognition Using Deep Learning, Sukhdeep Singh, Vinod Kumar Chauhan, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

The identification of accurate features is the initial task for benchmarked handwriting recognition. For handwriting recognition, the objective of feature computation is to find those characteristics of a handwritten stroke that depict the class of a stroke and make it separable from the rest of the stroke classes. The present study proposes a feature extraction technique for online handwritten strokes based on a self controlled Ramer-Douglas-Peucker (RDP) algorithm. This novel approach prepares a smaller length feature vector for different shaped online handwritten strokes without preprocessing and without any control parameter to RDP. Thus, it also overcomes the shortcomings of the …

Cyber-Physical Systems Security Introductory Course For Stem Students, Sin Ming Loo, Liljana Babinkostova

Electrical and Computer Engineering Faculty Publications and Presentations

We are witnessing the rapid development and adoption of Cyber-Physical Systems (CPS). CPS refers to the integration of digital and internetworked components, and physical devices in systems that affect nearly everyone in society. These devices are always connected to the internet. This connectivity gives CPS devices the capability of being in continuous monitoring mode where data and information are delivered to device owners through a proxy server. These capabilities open up all kinds of security issues for a device that has been built with such features with little regard for security considerations. At present, many Science, Technology, Engineering, and Mathematics …

Student Perception Of Mathematical Modeling Before And After Completing A Two Joint Robot Computer Simulation Task (Rtp), Laurel Johnston, Noah Salzman

Electrical and Computer Engineering Faculty Publications and Presentations

Engineers frequently utilize computer simulation as part of their design processes to model and understand the behavior of complex systems. Simulation is also an important tool for developing students’ understanding of modeling and strengthening their intuition for problem solving in complex domains. This project uses a two-joint robot arm problem and accompanying computer simulation to demonstrate to AP BC Calculus students how and why we would use calculus concepts simultaneously in Cartesian and polar coordinate systems. We developed the simulation in a way that allows students to experience mathematical modeling in an applications-based engineering context. A small cohort of students …