Electromagnetics and Photonics Commons^™

Split-Ring Resonator Waveguide Structure Characterization By Simulations, Measurements And Linear Time-Invariant Modeling, Mohamed Aziz Hmaidi

Electrical and Computer Engineering ETDs

Interest in Metamaterials has been rising drastically in the recent years as they have been used in several optical and RF applications, from antennas to perfect lenses and pulsed power devices. Nevertheless, the time-behavior of metamaterials remains opaque and poorly understood.

In this research work, characterization of a metamaterial structure in time and frequency-domain was made through simulations and experiments. The structure consists in a series of edge-side coupled Split Ring Resonators (SRRs) in a below cutoff waveguide. A linear time invariant model of distributed elements has been elaborated as well in an attempt to approach the structure’s behavior. The …

Assisted Switched Reluctance Machines, Amy Robinson

Honors Scholar Theses

Switched reluctance machine (SRM) modifications in both control schemes and physical design have been steadily increasing in academia to improve machine performance. Assisted switched reluctance machines (ASRMs) are a type of design modification for SRMs. Permanent magnets (PMs) and electromagnetic DC coils (DCC) are being added to the SRM to improve its torque output and overall efficiency. The choice for the design modification has been evolving throughout the decades. The focus has shifted from adding DCC to ASRM to adding PMs to ASRMs. This paper reviews the research trends of ASRMs and includes an analysis of the modified stator yoke …

Analysis Of Photovoltaic Energy In The Eastern Kentucky Region And The Residential Financial Feasibility, Joshua A. Johnson

Morehead State Theses and Dissertations

A thesis proposal presented to the Faculty of the College of Business and Technology Morehead State University in partial fulfillment of the requirements for the Degree Master of Science by Joshua A. Johnson on April 25, 2018.

Multiple-Photon Excitation Of Nitrogen Vacancy Centers In Diamond, Peng Ji, Ryan Balili, Jonathan Beaumariage, Silpa Mukherjee

University Faculty Publications and Creative Works

We report the observation of multiphoton photoluminescence excitation (PLE) below the resonant energies of nitrogen vacancy (NV) centers in diamond. The quadratic and cubic dependence of the integrated fluorescence intensity as a function of excitation power indicates a two-photon excitation pathway for the NV- charge state and a three-photon process involved for the neutral NV0 charge state, respectively. Comparing the total multiphoton energy with its single-photon equivalent, the PLE spectra follows the absorption spectrum of single photon excitation. We also observed that the efficiency of photoluminescence for different charge states, as well as the decay time constant, was dependent on …

Experimental Testing Of A Metamaterial Slow Wave Structure For High-Power Microwave Generation, Kevin Aaron Shipman

Electrical and Computer Engineering ETDs

Experimental Testing of a Metamaterial Slow Wave Structure for High-Power Microwave Generation

by

Kevin Aaron Shipman

B.S., Exercise Science, University of New Mexico, 2008

A.S., Mathematics, San Juan College, 2014

M.S., Electrical Engineering, University of New Mexico, 2018

Abstract

A high-power L-band microwave source has been developed using a metamaterial (MTM) to produce a biperiodic double negative slow wave structure (SWS) for interaction with an electron beam. The beam is generated by a ~700 kV, ~6 kA short pulse (~ 10 ns) electron beam accelerator. The design of the metamaterial SWS (MSWS) consists of a cylindrical waveguide, loaded with alternating …

An Exploration Of The Optical Detection Of Ionizing Radiation Utilizing Modern Optics Technology, Sean D. Fournier, Adam Hecht, Cassiano De Oliveira, Jeffrey B. Martin, Richard K. Harrison, Charles Potter

Nuclear Engineering ETDs

Modern ultraviolet (UV) cameras, when combined with UV-transmitting lenses/filter arrangements, can be used to detect radiation dose in air. Ionizing radiation excites nitrogen molecules in ambient air, the resulting decay includes weak emission of ultraviolet photons. Previous work has proven this phenomenon is detectable using highly-sensitive electronically cooled cameras traditionally used in astronomy for low-background imaging. While the ability to detect the presence of radiation (i.e. qualitative measurement) has been demonstrated at Sandia National Laboratories, there are several challenges in correlating images to known dose-fields (quantitative measurement). These challenges include: a low signal to background ratio, interferences due to electronic …

Image Processing Applications In Real Life: 2d Fragmented Image And Document Reassembly And Frequency Division Multiplexed Imaging, Houman Kamran Habibkhani

LSU Doctoral Dissertations

In this era of modern technology, image processing is one the most studied disciplines of signal processing and its applications can be found in every aspect of our daily life. In this work three main applications for image processing has been studied.

In chapter 1, frequency division multiplexed imaging (FDMI), a novel idea in the field of computational photography, has been introduced. Using FDMI, multiple images are captured simultaneously in a single shot and can later be extracted from the multiplexed image. This is achieved by spatially modulating the images so that they are placed at different locations in the …

Plasmonic Structures For Subwavelength Guiding And Enhanced Light-Matter Interactions, Amirreza Mahigir

LSU Doctoral Dissertations

In this dissertation we design and analyze nanostructures for subwavelength guiding and enhanced light-matter interactions.

We first investigate three-dimensional plasmonic waveguide-cavity structures, built by side-coupling stub resonators that consist of plasmonic coaxial waveguides of finite length, to a plasmonic coaxial waveguide. These structures are capable of guiding and manipulating light in deep-subwavelength volumes. We show that three-dimensional plasmonic coaxial waveguides offer a platform for practical realization of deep-subwavelength optical waveguides.

We then introduce compact wavelength-scale slit-based structures for coupling free space light into the fundamental mode of plasmonic coaxial waveguides. We consider single-, double-, and triple-slit structures optimized at the …

Circularly Polarized Two-Dimensional Microstrip Standing-Wave Array Antenna, Yang Fan

Electrical Engineering Theses and Dissertations

This dissertation reviews current designs of single-fed circularly polarized microstrip antennas and proposes a novel design concept with improved performance. The structure is similar to a regular microstrip patch antenna and the design procedure is relatively simple. By extending this SF scheme to an array structure based on the standing-wave array concept, a novel circular polarized array antenna can be realized by using one SF CP patch with standing-wave feeding networks. The standing-wave array antenna developed at SMU has a low-profile planar configuration and a simple feeding network structure and thus can be fabricated easily and cheaply with relatively high …

Non-Invasive Picosecond Pulse System For Electrostimulation, Ross Aaron Petrella

Electrical & Computer Engineering Theses & Dissertations

Picosecond pulsed electric fields have been shown to have stimulatory effects, such as calcium influx, activation of action potential, and membrane depolarization, on biological cells. Because the pulse duration is so short, it has been hypothesized that the pulses permeate a cell and can directly affect intracellular cell structures by bypassing the shielding of the membrane. This provides an opportunity for studying new biophysics. Furthermore, radiating picosecond pulses can be efficiently done by a compact antenna because the antenna size is comparable to the pulse width. However, all of the previous bioelectric studies regarding picosecond pulses have been conducted in …

Quantification Of The Impact Of Photon Distinguishability On Measurement-Device- Independent Quantum Key Distribution, Garrett K. Simon, Blake K. Huff, William M. Meier, Logan O. Mailloux, Lee E. Harrell

Faculty Publications

Measurement-Device-Independent Quantum Key Distribution (MDI-QKD) is a two-photon protocol devised to eliminate eavesdropping attacks that interrogate or control the detector in realized quantum key distribution systems. In MDI-QKD, the measurements are carried out by an untrusted third party, and the measurement results are announced openly. Knowledge or control of the measurement results gives the third party no information about the secret key. Error-free implementation of the MDI-QKD protocol requires the crypto-communicating parties, Alice and Bob, to independently prepare and transmit single photons that are physically indistinguishable, with the possible exception of their polarization states. In this paper, we apply the …

Three Dimensional Direct Print Additively Manufactured High-Q Microwave Filters And Embedded Antennas, Derar Fayez Hawatmeh

USF Tampa Graduate Theses and Dissertations

The need for miniaturized, and high performance microwave devices has focused significant attention onto new fabrication technologies that can simultaneously achieve high performance and low manufacturing complexity. Additive manufacturing (AM) has proven its capability in fabricating high performance, compact and light weight microwave circuits and antennas, as well as the ability to achieve designs that are complicated to fabricate using other manufacturing approaches. Direct print additive manufacturing (DPAM) is an emerging AM process that combines the fused deposition modeling (FDM) of thermoplastics with micro-dispensing of conductive and insulating pastes. DPAM has the potential to jointly combine high performance and low …

Dual Source Excitation Rectangular Waveguide Design And Evaluation For The Measurement Of Electromagnetic Material Properties, Daniel K. Koch

Theses and Dissertations

Broadband material parameter measurements are essential in understanding how materials interact with electromagnetic waves. Traditional rectangular waveguide material measurement systems are bandwidth limited. This results in multiple rectangular waveguides of different sizes used to conduct broadband material parameter extraction. Efforts to produce a broadband rectangular waveguide have focused on the inclusion of different guiding structures in the waveguide body. These designs have the drawback of requiring precise machining and time-consuming sample preparation. This research proposes a new broadband rectangular waveguide design which uses a dual source excitation design. This is enabled by the fact that rectangular waveguides are linear time …

Demonstration Of Versatile Whispering-Gallery Micro-Lasers For Remote Refractive Index Sensing, Lei Wan, Hengky Chandrahalim, Jian Zhou

Faculty Publications

We developed chip-scale remote refractive index sensors based on Rhodamine 6G (R6G)-doped polymer micro-ring lasers. The chemical, temperature, and mechanical sturdiness of the fused-silica host guaranteed a flexible deployment of dye-doped polymers for refractive index sensing. The introduction of the dye as gain medium demonstrated the feasibility of remote sensing based on the free-space optics measurement setup. Compared to the R6G-doped TZ-001, the lasing behavior of R6G-doped SU-8 polymer micro-ring laser under an aqueous environment had a narrower spectrum linewidth, producing the minimum detectable refractive index change of 4 x 10⁻⁴ RIU. The maximum bulk refractive index sensitivity (BRIS) …

Coaxial Magnetic Gearbox With A Flux Concentration Halbach Rotor And Consequent Pole Rotor Typology, Ho Yin Wong

Electrical and Computer Engineering PhD Day

This paper presents the performance comparison between a flux concentration and triple permanent magnet consequent pole magnetic gear rotor typology with the same 7.5:1 gear ratio. The triple permanent magnet consequent pole magnetic gear is unique in that it can create torque change through two field heterodyning pole combinations. The performance with respect to volumetric and mass torque density is considered. It is shown that the flux concentration typology can operate with a higher mass and volumetric higher torque density, even when using a low flux concentration ratio rotor.

Navigation Using Vector And Tensor Measurements Of The Earth's Magnetic Anomaly Field, Lauren A. Mount

Theses and Dissertations

This research explores the viability of using a navigation system that relies on measurements of the magnetic anomaly field as an alternative to GPS navigation. Previous research has been conducted on developing a navigation system using the intensity of the Earth's magnetic anomaly field as an alternative signal. This research focuses on using vector and tensor measurements, as opposed to scalar measurements of the anomaly field, as a means of obtaining accurate position and orientation solutions. This paper presents two navigation systems. The first uses an Extended Kalman Filter (EKF) with vector measurements of the magnetic anomaly field to aid …

Techniques For Low-Latency In Software-Defined Radio-Based Networks, Daniel D. Hart

Theses and Dissertations

Decreased budgets have pushed the United States Air Force towards using existing systems in new ways. The use of unmanned aerial vehicle swarms is one example of reuse of existing systems. One problem with the increased utilization of these swarms is the congestion of the electromagnetic spectrum. Software-defined or cognitive radios have been proposed as a basis for a potential robust communications solution. The present research aims to develop and test a genetic algorithm-based cognitive engine to begin looking at real-time engines that could be used in future swarms. Here, latency is the optimization objective of primary importance. In testing …

Measuring 3d Molecular Orientation And Rotational Mobility Using A Tri-Spot Point Spread Function, Oumeng Zhang, Tianben Ding, Jin Lu, Hesam Mazidi, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

We present a method to measure the molecular orientation and rotational mobility of single-molecule emitters by designing and implementing a Tri-spot point spread function. It can measure all degrees of freedom related to molecular orientation and rotational mobility. Its design is optimized by maximizing the theoretical limit of its measurement precision. We evaluate the precision and accuracy of the Tri-spot PSF by measuring the orientation and effective rotational mobility of single fluorescent molecules embedded in a polymer matrix.

Antennas For Wv Band Applications, Firas Ayoub

Electrical and Computer Engineering ETDs

This dissertation focuses on designing, fabricating and testing antennas that are suitable for operation within the V/W bands. In particular, this work focuses on the design of slotted rectangular waveguide antenna arrays and cross slotted waveguide fed horn antennas. These structures are known for their high efficiency and high circularly polarized gain that can be implemented in satellite and terrestrial communication links. In addition, such designs can be implemented in radar applications that operate infrequency bands around 72 GHz or 84 GHz bands. Such antenna structures are inexpensive to fabricate since they can simply be machined using high precision conventional …

Monte Carlo Simulations Of Three-Dimensional Electromagnetic Gaussian Schell-Model Sources, Milo W. Hyde Iv, Santasri Bose-Pillai, Olga Korotkova

Faculty Publications

This article presents a method to simulate a three-dimensional (3D) electromagnetic Gaussian-Schell model (EGSM) source with desired characteristics. Using the complex screen method, originally developed for the synthesis of two-dimensional stochastic electromagnetic fields, a set of equations is derived which relate the desired 3D source characteristics to those of the statistics of the random complex screen. From these equations and the 3D EGSM source realizability conditions, a single criterion is derived, which when satisfied guarantees both the realizability and simulatability of the desired 3D EGSM source. Lastly, a 3D EGSM source, with specified properties, is simulated; the Monte Carlo simulation …