Electrical and Electronics Commons^™

Study Of Interface Charges Between In-Situ Grown Dielectric And Gan/Algan Hfet Structure By Metal-Organic Chemical Vapor Deposition, Muhammad Hassan Tahir, Nifat Jahan, Md Ghulam Zakir

Faculty Publications

The integration of an oxide layer in metal-oxide-semiconductor high electron mobility transistors (MOSHFETs) plays a crucial role in minimizing gate leakage current and enabling wider gate voltage swings. In this study, we present the fabrication and characterization of GaN/AlGaN heterostructure field-effect transistors (HFETs) capped with a Ga₂O₃ dielectric layer. The oxide was deposited via an in-situ process within a single MOCVD reactor without vacuum interruption. Our findings demonstrate that the in-situ capped HFETs exhibit a significantly lower interface charge density of 4 × 10¹² cm⁻² compared to 1 × 10¹³ cm⁻²·eV⁻¹ observed in ex-situ grown counterparts. These results highlight the …

Study Of Indium-Silicon Co-Doped Gallium Oxide For Effective N-Type Doping, Muhammad Hassan Tahir, Nifat Jahan, Md Ghulam Zakir

Faculty Publications

We present the research efforts to achieve effective n-type doping in gallium oxide (Ga2O3), an ultrawide bandgap semiconductor, grown by metal-organic chemical vapor deposition (MOCVD). The application of semiconductors for power electronics requires wide and ultrawide bandgap materials that can be doped to create higher electron (n-type) or hole (p-type) densities. Ga2O3, with a bandgap of 4.9 eV, is an emerging and promising material. The bandgap of Ga2O3 is much higher than other wide bandgap material that have been adopted by or in the process of adoption by the industry for power electronics. However, the doping of Ga2O3 has some …

Gallium Oxide Based Avalanche Photo Detector, Muhammad Hassan Tahir Mr, Nifat Jahan, Md Ghulam Zakir

Faculty Publications

Gallium oxide (Ga₂O₃), an ultrawide bandgap semiconductor with a bandgap of 4.6 eV and a high critical electric field of 10.3 MV/cm, offers strong potential for high-performance avalanche photodetectors (APDs). This project explores the design and characterization of a Ga₂O₃-based APD featuring doped and undoped epitaxial layers optimized for high electric field generation and low thermal conductivity, enabling stable operation in high-temperature environments. Simulation results show a uniform electric field of 1 MV/cm under a 100 V applied bias, while material characterization confirms excellent surface smoothness with a mean roughness of ~1.1 nm and an electron mobility of 21.7 cm²/V·s …

Low Impedance, Durable, Self-Adhesive Hydrogel Epidermal Electrodes For Electrophysiology Recording, Naiyan Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditional electrodes used for electrophysiology recording, characterized by their hard, dry, and inanimate nature, are fundamentally mismatched with the soft, moist, and bioactive characteristics of biological tissues, leading to suboptimal skin-electrode interfaces. Hydrogel materials, mirroring the high water content and biocompatibility of biological tissues, emerge as promising candidates for epidermal electronic materials due to their adjustable physicochemical properties. However, challenges such as inadequate electrical conductivity, elevated skin impedance, unreliable adhesion in moist conditions, and performance decline from dehydration have significantly restricted the efficacy and applicability of hydrogel-based electrodes. In this thesis, we report a high-performance hydrogel epidermal electrode patch for …

Arkansas Tech University Modular Robotics Training System, Andrew L. Hilsdon, Jacob L. Crawford, Luke C. Hartman, Samuel E. Allen, Anthony W. Knudson, Kyle B. Mcmillan

ATU Scholars Symposium

Arkansas Tech University Modular Robotic Training System (ATUM RTS) project aims to combine two existing systems: The Georgia Tech Robotarium and the Micromouse maze-solving competition. The goal of ATUM RTS is to incorporate the challenge and excitement of maze-solving robots with the cloud-based learning system of the Robotarium. We intend to develop an automatic maze table with future remote capabilities to further student learning and engagement. By being able to create custom mazes with ATUM RTS, students will have access to a resource that will allow them to practically apply what they are learning in the classroom. The ATUM RTS …

Applications Of Supercapacitors In Robotic Systems, Charles Davis, Zachary Giese, Joseph Gober, Samuel Grisham, Avery Mahan

ATU Scholars Symposium

This project explores the utilization of a bespoke supercapacitor system to energize and propel a robot across various challenging courses. The custom supercapacitor setup serves as the primary power source, providing rapid charging capabilities and high energy density. The research investigates the integration of this innovative power solution into the robot's design, aiming to optimize its performance and endurance in competitive environments.

Modeling, Characterization, And Machine Learning Algorithm For Rectangular Choke Horn Antennas, Ibrahim N. Alquaydheb, Saleh A. Alfawaz, Amirreza Ghadimi Avval, Sara Ghayouraneh, Samir M. El-Ghazaly

Electrical Engineering and Computer Science Faculty Publications and Presentations

In this work, we present the design and modeling of a new type of choke horn antenna. It incorporates a rectangular waveguide and a rectangular choke acting as a parasitic element. The four-sided geometry of the antenna is applicable to systems that utilize rectangular waveguides. Also, it can overcome the need for rectangular-to-circular transition of transmission line or mode conversion. The main objective of this paper is to develop a model that calculates the far field radiation characteristics of the proposed antenna (analytical part) and to incorporate a finite element method (FEM) solver that adds to the theoretical solution (empirical …

Towards A Wearable Device For Measuring Impedance Plethysmography Of The Radial Artery, Pritom Chowdhury

Dartmouth College Master’s Theses

Recent advancements in bioimpedance technology have demonstrated significant promise in the application of cardiac health monitoring. This research explores the design and development of a forearm-based wearable bioimpedance device for non-invasive measurement of heart rate and respiratory rate at an accuracy level comparable to medical-grade monitors. It utilizes a tetrapolar electrode configuration to analyze bioimpedance changes in the radial artery due to blood flow.

An ongoing aspect of this work involves the preliminary development of an embedded framework intended to integrate signal generation, acquisition, and processing within the device to achieve compact and efficient system design, anticipated to contribute to …

Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform, Joshua W. Milford

Doctoral Dissertations and Master's Theses

Low-cost and low-size-weight-and-power (SWaP) magnetometers can provide greater accessibility for distributed simultaneous measurements in the ionosphere, either onboard sounding rockets or on CubeSats. The Space and Atmospheric Instrumentation Laboratory (SAIL) at Embry-Riddle Aeronautical University has launched a multitude of sounding rockets in recent history: one night-time mid-latitude rocket from Wallops Flight Facility in August 2022 and three mid-latitude rockets from White Sands Missile Range during the October 2023 annular solar eclipse. All rockets had a comprehensive suite of instruments for electrodynamics and neutral dynamics measurements. Among this suite was one science-grade three-axis fluxgate magnetometer (Billingsley TFM65VQS / TFM100G2) and up …

Analysis And Improvement Of Efficient Charge Recovery Logic Adiabatic Circuits, William Morell

LSU Doctoral Dissertations

Power consumption has been an ever-present concern since the dawn of electronic computing. Every operation that a device performs consumes some amount of energy and as the demand for computation increases, both in scale and ubiquity, reducing this energy loss becomes more important. While modern devices are orders of magnitude more efficient than their ancestors on a per-operation basis, they are increasingly used in more resource constrained applications. Tiny, Internet of Things (IoT) machines are prevalent these days and demanded to perform data collection and analysis at all hours of the day for days at a time on small battery. …

Uav-X Communication: Empirical Characterization And Performance Optimization, Muhammad Hashir Syed

Electrical Engineering Theses and Dissertations

In emerging wireless networks, the scalability of deploying drones presents an opportunity to design extensive aerial networks. These networks could effectively monitor large agricultural fields from the air and soil for food production with efficient resource utilization. On the one hand, unmanned aerial vehicles (UAVs) have gained interest in agricultural aerial inspection due to their ubiquity and observation scale. On the other hand, agricultural internet-of-thing devices, including buried soil sensors, have gained interest in improving natural resource efficiency in crop production. In this work, we investigate the natural interaction of these two phenomena, where UAVs can be leveraged as flying …

Design Of A Launchable Remote-Controlled Rover And Protective Aeroshell, Matthew Loewer, Colby Weeks, Lake Williams, Jackson Zazzaro

Senior Theses

Planetary rovers, vehicles that can traverse challenging terrain, have excelled in their exploration missions to other celestial bodies. They have been especially suitable for exploring Mars, as rovers such as Opportunity and Perseverance have collected valuable geological, atmospheric, seismic, and magnetic information from the Martian surface. Rovers will remain vital in future space exploration missions, and it is necessary to understand their design and functionality. This paper focuses on the design and prototyping of a miniature rover that can survive the rough Martian terrain while collecting and submitting environmental data for scientific analysis. The design is based off proven Martian …

A New Method To Start Loaded Induction Motors, Omar El-Sayed Mohammed Youssef

Journal of Engineering Research

Three-phase induction motors have a widespread use in industry, and starting of loaded induction motors is an important matter. However, there are few studies on motor starting using variable-frequency drives (VFDs). The existing control schemes, described by these studies, have disadvantages such as dependence on derived characteristics, adjustment of settings, design of controllers, or burden of calculations on the control processor. In this paper, a simple and effective control scheme of VFDs to start loaded motors is proposed. In this scheme, there is no dependence on any characteristic, adjustment of settings, controllers, and rotor speed sensor. By this scheme, the …

High Power Capacitive Wireless Power Transfer System For Future Transportation Electrification, Kodeeswaran S

Theses and Dissertations

Wireless Power Transfer (WPT) technologies, including Inductive Power Transfer (IPT) and Capacitive Power Transfer (CPT), offer promising solutions for Electric Vehicle (EV) charging applications. Compared to conventional IPT, a CPT method has no eddy current losses, lower electromagnetic interference (EMI), low system cost and weight, less misalignment problems, which gives the motivation to start this research work. The Proposed CPT method uses aluminum plates that generate electric fields by applying voltage on the plates to transfer the power from the transmitter (ground side) to the receiver (vehicle side).

This research introduces novel advancements in CPT systems to enhance power transfer …

A Reliable Optimal Electric Vehicle Charging Stations Allocation, Mohamed Abdelaziz, A.A. Ali, R.A. Swief, Rasha Elazab

Renewable Electrical Energy Engineering

This paper presents a new and effective approach for optimally allocating Electric Vehicle (EV) stations in a distribution network by integrating electrical and road constraints. The proposed methodology, a two-stage optimization technology, addresses the challenges posed by the increasing energy demand caused by the adoption of EVs. In the first stage, the stochastic demand load of EVs is simulated considering the probability and hierarchic clustering of EV load based on the travelling distance of users. This stage focuses on emulating the uncertainty of EV user travel patterns, time of arrival and departure, and their impact on the EV load profile. …

Design And Analysis Of Zero Voltage Switching Hybrid Voltage Divider, Stephen Ulysses Alvarado Estrada

Master's Theses

This work explores the design, construction, and analysis of a novel DC-DC converter which incorporates combinations of switching capacitors and inductors to achieve an integer voltage divider function, without the need for a feedback loop controller to achieve the desired output voltage. The proposed Hybrid Voltage Divider additionally provides zero voltage switching (ZVS) at turn on transitions which yields improved overall efficiency of the converter. Besides a proof-of-concept via computer simulations, another primary goal of this thesis is to demonstrate the functionalities of the proposed Zero Voltage Switching Hybrid Voltage Divider (ZVS-HVD) through hardware prototyping. The proposed ZVS-HVD was designed …

Plc Course Development, Leonard Hernandez, Jacqueline Grace Radding

Electrical Engineering

The goal of this project is to design and construct the first lab experiment for the newly developed EE435 laboratory course. The experiment entails PLC programming to automate LED lighting in a simulated building. Starting with why PLCs are used, how to use the interface of EcoStruxure Control Expert V15.0 and practice using logic to control the dimming of a Light Emitting Diode (LED) to sustain a certain number of lumens consistent in a zone. Through the lab manual developed in this project, students will gain experience of creating logic designs using Function Block Diagram (FBD) and learn the layout …

Improvements Of Hybrid Ac/Dc House Prototype, Arden Abude

Electrical Engineering

This is an iteration from previous designs of the Hybrid AC/DC House with a systematic addition of a portable AC power supply unit. This iteration for the Hybrid AC/DC House is an innovation of independence for sustainable housing solutions. It will serve as an alternative for rural communities needing power to rely on self-sustainable microgrids rather than large-scale AC electric grids. The addition of a portable AC power supply would allow the microgrid to remove its reliance on AC power from the larger grid and would elevate the system to complete energy independence. The microgrid has DC power generated from …

Reconstruction Of Radar Range Profiles Using Dropped Channel Polarimetric Compressive Sensing, Nat Thomason

Theses and Dissertations

This thesis documents the design, construction and testing of a bench-top level measurement system and verifies previously established Dropped Channel Polarimetric Synthetic Aperture Radar Compressive Sensing (DCPCS) simulation results. Compressive Sensing is a mathematical technique which can capture and represent compressible signals at sampling rates significantly below the Nyquist rate. DCPCS is a technique which enhances Compressive Sensing techniques using known physical antenna crosstalk values. The DCPCS technique enables reconstruction of fully polarimetric signals whilst only measuring part of the signal, reducing data capture requirements.

Generalized Characterization Of Biaxial Media Using Ultra-Wideband Multi-Static Focused Beam System With Polarimetric Calibration, Jeffrey P. Massman

Theses and Dissertations

Novel metamaterial and metasurface realizations provide unique control of the electromagnetic wave dispersion but present many challenges for accurate constitutive parameter extraction. One measurement approach commonly employed is a freespace non-destructive focus beam system. Modern implementations are configured with multi-static dual-polarized capabilities for characterizing complex materials and offer many advantages by enabling ultra-wideband sampling, multiple measurement degrees of freedom and larger sample sizes. Practical electromagnetic material characterization of complex bianisotropic media requires the advancement of wave propagation analysis and calibration schemes. This research focuses on generalized biaxial media characterization and multi-static focused beam system metrology with polarimetric calibration schemes and …