Electromagnetics and Photonics Commons^™

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Directional Link Management Using In-Band Full-Duplex Free Space Optical Transceivers For Aerial Nodes, A F M Saniul Haq

Electronic Theses and Dissertations, 2020-2023

Free-space optical (FSO) communication has become very popular for wireless applications to complement and, in some cases, replace legacy radio-frequency for advantages like unlicensed band, spatial reuse, and enhanced security. Even though FSO can achieve very high bit-rate (tens of Gbps), range limitation due to high attenuation and weather dependency has always restricted its practical implementation to indoor application like data centers and outdoor application like Project Loon. Building-to-building communication, smart cars, and airborne drones are potential futuristic wireless communication sectors for mobile ad-hoc FSO networking. Increasing social media usage demands high-speed mobile connectivity for applications like video call and …

A Physics-Based Pi Pre-Layout Tool For Pcb Pdn Design, Shuang Liang

Masters Theses

"With increasingly stringent requirements for lower voltage supply, and higher density in PCB PDN design, now integrity (PI) is an increasingly important aspect that must be considered. A pre-layout tool based on the Cavity Model and Boundary Element Method is built to automatically achieve a specified target impedance for a multi-layered Printed Circuit Board (PCB) Power Distribution Network (PDN) design with a minimal number of decoupling capacitors.

The pre-work about the post-layout design and analysis is proposed and the guidelines for creating a decoupling capacitors network with better performance has been built. With limit inputs, physical limitations for the minimal …

Instrumentation, Modeling, And Sound Metamodeling Foundations For Complex Hybrid Systems, Natasha Amelia Jarus

Doctoral Dissertations

Many of our critical infrastructures, from power grids to water distribution networks, are complex hybrid systems that use software to control their non-trivial physical dynamics. These systems must be able to capably serve their purpose, while also being reliable, dependable, safe, secure, and efficient. Representation and analysis of these features requires the creation of several distinct models. These models may encode design goals or be derived from collected instrumentation data, reflecting both how a system ought to operate and how it does operate. It is essential to ensure that all of these models consistently and accurately describe the same system. …

Seed Modeling Of An Esd Gun Discharge To A Usb Cable, Yang Xu

Masters Theses

“An IC protected by a transient voltage suppression (TVS) diode may fail if the TVS device does not turn on or does not turn on quickly enough, causing the IC to take the full brunt of the electrostatic discharge (ESD) event. Transient simulation models have been developed for ESD protection devices for the purpose of system-efficient ESD design (SEED). The TVS modeling methodology has been improved to better represent the physics that occurs during the TVS response and more accurately predict the interactions between off-chip and on-chip protection devices. Moreover, a complicated test scenario -- an ESD gun discharge through …

Package Power Distribution Current Density In Applications With Large Transient Currents, Matthew Doyle, Wiren D. Becker, Matteo Cocchini, Kyle Schoneck, Samuel Connor, Layne Berge, Siqi Bai, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A method to model, measure, and characterize a high-transient current in an electrical packaging solution is described herein. These methods help overcome the challenge of generating model to hardware correlation in high current applications. A specialized test platform is developed and used to characterize current density in test hardware. The measurements are used to characterize a custom power distribution network and verify validity of current density predictions. This data is critical in high-current applications for finding and measuring current density through plane pinch points that can cause early failures in the field due to electromigration and delamination.

High-Frequency Modeling Of Permanent Magnet Synchronous Motor Considering Internal Imbalances, Yuandong Guo, Muqi Ouyang, Zhifei Xu, Minho Kim, Junesang Lee, Jungrae Ha, Hyewon Lee, Sangwon Yun, Jun Fan, Hongseok Kim

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an accurate high-frequency modeling methodology for a permanent magnet synchronous motor (PMSM) in a vehicular electrical braking system is presented, which is suitable for analyzing various electromagnetic interference problems caused by a motor drive system. The proposed modeling approach is established according to the vector fitting technique and based on the S-parameter measurements of the PMSM. The equivalent circuit model of the PMSM converted from a measured S-parameter matrix can better describe the impedance characteristics of the three-phase PMSM under study compared to the existing equivalent circuit models because the imbalances inside the motor are taken into …

Saturation Behaviors In Deep Turbulence, Jeffrey R. R. Beck

Dissertations, Master's Theses and Master's Reports

Distributed-volume atmospheric turbulence near the ground significantly limits the performance of incoherent imaging and coherent beam projection systems operating over long horizontal paths. Defense, military and civilian surveillance, border security, and target identification systems are interested in terrestrial imaging and beam projection over very long horizontal paths, but atmospheric turbulence can blur the imagery and aberrate the laser beam such that they are beyond usefulness. While many post-processing and adaptive optics techniques have been developed to mitigate the effects of turbulence, many of these techniques do not work as expected in stronger volumetric turbulence, or in many cases don't work …

Novel Liquid Crystal Photonic Devices Enabled By Liquid Crystal Alignment Engineering, Ziqian He

Electronic Theses and Dissertations, 2020-2023

Liquid crystals (LCs) are self-assembled soft materials composed of certain anisotropic molecules with orientational orders. Their widespread applications include information displays and photonic devices, such as spatial light modulators for laser beam steering and tunable-focus lens, where achieving desired LC alignment is pivotal. In general, LC alignment is influenced by several factors, including chemical bonding, dipolar interactions, van der Waals interactions, surface topographies, and steric factors. Here, we focus on three alignment techniques for aligning rod-like LC molecules and highlights the photonic devices enabled by these techniques: 1) Two-photon polymerization direct-laser writing-induced alignment, 2) Weigert effect-based reversible photoalignment, and 3) …

Ieee Access Special Section Editorial: Trends And Advances In Bio-Inspired Image-Based Deep Learning Methodologies And Applications, Peter Peer, Carlos M. Travieso-Gonzalez, Vijayan K. Asari, Malay Kishore Dutta

Electrical and Computer Engineering Faculty Publications

Many of the technological advances we enjoy today have been inspired by biological systems due to their ease of operation and outstanding efficiency. Designing technological solutions based on biological inspiration has become a cornerstone of research in a variety of areas ranging from control theory and optimization to computer vision, machine learning, and artificial intelligence. Especially in the latter few areas, biologically relevant solutions are becoming increasingly important as we look for new ways to make artificial systems more efficient, intelligent, and overall effective.

Transform Based Approaches For The Detection Of Astrophysical Signals, Marwan Mahfud Alkhweldi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Development of new algorithms for the detection of isolated astrophysical pulses is of interest to radio astronomers. Both Fast Radio Bursts (FRBs) and several Rotating Radio Transients (RRATs) were detected through the application of a single pulse search algorithm. The conventional approach to detect astronomical pulses requires an exhaustive search for the correct dispersion measure. Its accelerated versions involve signal processing in Fourier transform space.

In this dissertation, we present several new transform-based approaches for the detection and analysis of astrophysical signals with the latest being the most effective and advanced of all. It is implemented in several steps. First, …

Wavefront-Selective Fano Resonant Metasurface, Adam C. Overvig, Andrea Alù

Publications and Research

Fano resonances are conventionally understood as sharp spectral features with selectivity in the momentum-frequency domain, implying that they can be excited only by plane waves with specific frequencies and incident angles. We demonstrate that Fano resonances can be made generally selective in the space-frequency domain. They can be tailored to resonate only when excited by a frequency, polarization, and wavefront of choice. This generalization reveals that Fano systems are characterized by eigenwaves that scatter to their time-reversed image upon reflection. Although in conventional Fano systems this trivially occurs for normally incident plane waves, we show that, in general, the selected …

Boundary Integral Equation Method For Electrostatic Field Prediction In Piecewise-Homogeneous Electrolytes, Christopher Keith Pratt

Theses and Dissertations--Electrical and Computer Engineering

This thesis presents a method to predict electrostatic fields, potentials, and currents in regions containing piecewise-homogeneous electrolytes. Additionally, an efficient electric field calculation is presented. A boundary integral equation is formulated for the boundary potentials and currents and is discretized using the Locally Corrected Nyström method. Solution convergence with respect to the mesh discretization and basis order is investigated. The techniques are validated through analysis of problems with either analytic solutions, with published data, or with other solution methods.

Optical Metasurfaces, Fatih Balli

Theses and Dissertations--Physics and Astronomy

Traditional optical elements, such as refractive lenses, mirrors, phase plates and polarizers have been used for various purposes such as imaging systems, lithographic printing, astronomical observations and display technology. Despite their long-term achievements, they can be bulky and not suitable for miniaturization. On the other hand, recent nanotechnology advances allowed us to manufacture micro and nanoscale devices with ultra-compact sizes. Metasurfaces, 2D engineered artificial interfaces, have emerged as candidates to replace traditional refractive lenses with ultra-thin miniaturized optical elements. They possess sub-wavelength unit cell structures with a specific geometry and material selection. Each unit cell can uniquely tailor the phase, …

Ultrafast Thermal Modification Of Strong Coupling In An Organic Microcavity, Bin Liu, Vinod M. Menon, Matthew Y. Sfeir

Publications and Research

There is growing interest in using strongly coupled organic microcavities to tune molecular dynamics, including the electronic and vibrational properties of molecules. However, very little attention has been paid to the utility of cavity polaritons as sensors for out-of-equilibrium phenomena, including thermal excitations. Here, we demonstrate that non-resonant infrared excitation of an organic microcavity system induces a transient response in the visible spectral range near the cavity polariton resonances. We show how these optical responses can be understood in terms of ultrafast heating of electrons in the metal cavity mirror, which modifies the effective refractive index and subsequently the strong …

Morphology-Dependent Resonances In Two Concentric Spheres With Variable Refractive Index In The Outer Layer: Analytic Solutions, Umaporn Nuntaplook, John A. Adam

Mathematics & Statistics Faculty Publications

In many applications constant or piecewise constant refractive index profiles are used to study the scattering of plane electromagnetic waves by a spherical object. When the structured media has variable refractive indices, this is more of a challenge. In this paper, we investigate the morphology dependent resonances for the scattering of electromagnetic waves from two concentric spheres when the outer shell has a variable refractive index. The resonance analysis is applied to the general solutions of the radial Debye potential for both transverse magnetic and transverse electric modes. Finally, the analytic conditions to determine the resonance locations for this system …

Reflection And Transmission Of Electromagnetic Pulses At A Planar Dielectric Interface: Theory And Quantum Lattice Simulations, Abhay K. Ram, George Vahala, Linda Vahala, Min Soe

Electrical & Computer Engineering Faculty Publications

There is considerable interest in the application of quantum information science to advance computations in plasma physics. A particular point of curiosity is whether it is possible to take advantage of quantum computers to speed up numerical simulations relative to conventional computers. Many of the topics in fusion plasma physics are classical in nature. In order to implement them on quantum computers, it will require couching a classical problem in the language of quantum mechanics. Electromagnetic waves are routinely used in fusion experiments to heat a plasma or to generate currents in the plasma. The propagation of electromagnetic waves is …

Analysis Of Miniaturized, Circularly Polarized Antennas For Bidirectional Propagation, Mason C. Moore

College of Graduate Studies: Theses & Dissertations

Size reduction is necessary to fit the recent demand for small sized communication systems in consumer electronics. Wireless communication systems rely on antennas for long range transmission of signals, so size reduced antennas have been sought after in recent years. Also, not many antennas are designed for use in bidirectional scenarios like subways, tunnels, bridges, etc. Three sized reduced antennas with circular polarization are presented for use in bidirectional communication systems. An electrically small pattern reconfigurable array, an electrically small two-sided printed cross dipole, and a size reduced printed wideband antenna are introduced within this thesis. All antennas’ results are …

The Application Of Leaky Wave Antennas For Medical Hyperthermia Treatment And Beamformer In Fmcw Automotive Radar Systems, Masoud Sarabi

Dissertations, Master's Theses and Master's Reports

Thousands of years ago human discovered that if a slice of amber is rubbed against fur, it would absorb light-weight objects. Hundreds of years after that the ancient people figured out that there are actually two different characteristics of attraction and repulsion. Another 2000 years passed when human discovered that these two wonders of nature, magnetism and electricity are actually linked together like the two sides of the same coin. Since then, in the early 19th century great huge achievements were made in antennas and propagation by scientists such as Hans Christen Oersted, Heinrich Hertz, Alexander Popov and Marconi. Since …

Magnetic Field Sensors For Detection Of Trapped Flux In Superconducting Radio Frequency Cavities, Ishwari Prasad Parajuli, Gianluigi Ciovati, Jean R. Delayen

Physics Faculty Publications

Superconducting radio frequency (SRF) cavities are fundamental building blocks of modern particle accelerators. They operate at liquid helium temperatures (2–4 K) to achieve very high quality factors (10¹⁰–10¹¹). Trapping of magnetic flux within the superconductor is a significant contribution to the residual RF losses, which limit the achievable quality factor. Suitable diagnostic tools are in high demand to understand the mechanisms of flux trapping in technical superconductors, and the fundamental components of such diagnostic tools are magnetic field sensors. We have studied the performance of commercially available Hall probes, anisotropic magnetoresistive sensors, and flux-gate magnetometers with …