Electromagnetics and Photonics Commons^™

Modelling V-Band Atmospheric Loss With Deep Learning, Ralph Lyndon Gesner

Electrical and Computer Engineering ETDs

Modelling atmospheric loss is fundamental to implementation of future mm-wave terrestrial and earth space communication links. Atmospheric losses have traditionally been estimated by calculating the contributions of individual weather phenomena through in-situ meteorological measurements and statistically derived models for estimating localized atmospheric water content. Collecting data for all points along the propagation path and calculating the physical effects of gases, clouds, and precipitation individually is both time consuming and impractical for large-scale use cases.

In response to these present limitations, this work proposes the use of novel deep learning models for estimating atmospheric losses from tabular meteorological sensor data and …

Propagation Modeling Of Terahertz Reflections And Reflector Design For Mimo Channel, Thanh Ngoc Dan Le

Dissertations and Theses

Wireless communication has transformed connectivity, enabling seamless access across devices without physical constraints. Terahertz (THz) frequencies, ranging from 100 GHz to 10 THz, promise high-bandwidth channels crucial for applications like IoT and virtual reality. However, deploying THz communication faces challenges due to significant propagation limitations such as high attenuation and environmental absorption. The motivation behind this research is to develop a comprehensive understanding of THz propagation dynamics and utilize reflective surfaces to create multipath environments for an improvement in the capacity performance of MIMO channels.

This research investigates the potential of Multi-Input Multi-Output (MIMO) channels at THz frequencies to overcome …

Microwave Flow Cytometer For Single Cell Detection, Differentiation, And Drug Effect Study, Neelima Dahal

All Dissertations

New methods to rapidly detect and identify pathogens in patients’ blood are needed for timely disease treatment. In this work, a tunable microwave interferometer was used to measure single Candida cells of C. albicans, C. tropicalis, C. parapsilosis, and C. krusei at multiple frequencies between 0.265 GHz and 7.76 GHz. A Quadratic Discriminate Analysis was used to classify Candida species with an accuracy of 0.875. Likewise, a microwave device was used to measure single Escherichia coli cells of B and K-12 strains at multiple frequencies between 500 MHz and 8 GHz. A LightGBM model was developed to …

Ellipticity-Controlled Exceptional Points From Nanoscale Metasurfaces, Benjamin Goldberg

McKelvey School of Engineering Graduate Student Theses & Dissertations

Precise control over light polarization is critical for advancing technologies in telecommunica- tions, quantum computing, and image sensing. However, existing methods for manipulating polarization around exceptional points in non-Hermitian systems, have exclusively focused on circular polarization and work with reflected light. To address this limitation, we de- velop a novel metasurface platform with high-Q resonators that enables tunable control of polarization exceptional points across arbitrary ellipticity for transmitted light. Our design uses orthogonally polarized guided mode resonators in a two-layer silicon metasurface, where careful tuning of the dipolar guided mode resonances (DGMRs) and layer spacing allows us to control the …

Chipless 3d Microfluidic Rf Sensing, Sheikh Dobir Hossain

Open Access Theses & Dissertations

Effective management of the cold chain is essential to uphold the quality and safety of products vulnerability to physical factors like temperature, humidity, pressure, etc., including perishable foods, pharmaceuticals, and vaccines. Chipless Radio Frequency Identification (RFID) sensors have become increasingly favored as a viable technology for tracking, inventory, and sensing industries due to their wireless and non-line of sight (NLOS) situations, straightforward fabrication, cost efficiency, and adaptability to challenging environmental conditions. However, there is still a need for advancements in RFID sensors to make them promise for cold chain applications. Integration of flexibility and non-volatile memory into the existing RFID …

Higher Order Bessel Beams Integrated In Time (Hobbit) With Engineered Light Frequencies And Applications In Computational Imaging, Tyler Cramer

All Theses

This thesis presents an adaptive optical system which leverages the frequency shifts from an acousto-optic deflector (AOD) form an array of uniformly spaced frequency diverse beamlets. These beamlets are then spatially transformed (wrapped) into a circular array forming a non-diffracting ring with an unprecedented orbital angular momentum (OAM) mode switching rate of 50Mhz with an OAM range of ±64. Along with frequency diversity, the non-diffracting range of the beams are analyzed 6 Rayleigh ranges of an equivalently sized gaussian beam. Inherent in the frequencies superposed on the AOD are associated relative phases which can be controlled to form sets of …

Mathematical Model For Helically Propagating Spatially Multiplexed Mimo Channels Inside Single Core Optical Fibers, Ibrahim Barka

Theses and Dissertations

It all started when our curiosity was sparked by observing light beams from a Multi-Channel Laser Source precisely coupled into a single-core optical fiber positioned on an optical bench in the lab. The multiplexed light beams, characterized by different spatial azimuthal angles, were guided by the fiber, tracing helical paths and producing a bright central spot with concentric rings depending on the launched angles, a phenomenon we came to call Spatial Domain Multiplexing (SDM). Conventional concepts of hybrid and LP modes couldn’t fully explain the behavior of SDM modes, leading us to the question of the types of field configurations …

Nanostructured Silicon Meta-Waveguides And Surfaces For Enhanced Light-Matter Interaction, Saddam Gafsi

All Dissertations

In this study, we tackle the challenge of light-matter interaction engineering and local field enhancement using various silicon photonic platforms based on three different approaches. (i) The first approach is based on boundary condition engineering where we present and show through simulation and experimental results, a silicon nanodisk “diabolo” configuration able to support significant local field enhancement levels in the range ~102 to 104 in the high index medium through proper structural modifications at the nanoscale. We show that the presented optical behavior is consistent with the anapole modes characterized by the observed near-field enhancement and coinciding with far-field suppression. …

Photophoretic Optical Particle Trapping Improvements Using Beam Reflection, Ian A. Garcia, Xiaomin Jin Phd., Kun Hua Phd.

Master's Theses

Current research has shown that photophoretic optical trapping (POT) is a promising method for creating true three-dimensional holograms. A landmark study by Smalley et. al. at BYU was able to generate a full hologram within a 2 cm edge cube with remarkable success. However, a key drawback to this method is its poor ability to hold trapped particles within the focal point of the laser for an extended period of time. An investigation from our group presented at SPIE Photonics West 2023 sought to improve these results by varying the focal length of the trapping and the wavelength of the …

Measuring Soil Salinity, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

To make sound decisions on managing saline sites, you need to know the source of salt, how salinisation is occurring, the landscape context, and most importantly, the actual salt concentration of the soil.

The most common 'measures' of salt concentration are actually estimates based on electrical conductivity of a soil and water solution. Soil salt content can be measured in a laboratory by measuring the total dissolved solids in a sample. In the field, salt concentration can also be estimated using electromagnetic induction-based soil sensors.

Global Empirical Model Of Sporadic-E Occurrence Rates, Eli V. Parsch, Anthony L. Franz, Eugene V. Dao, Dong L. Wu, Nimalan Swarnalingam, Cornelius C. J. H. Salinas, Daniel J. Emmons

Faculty Publications

Intense ionization enhancements in the Earth’s ionosphere, known as sporadic-E (E_s), can degrade and severely disrupt the propagation of radio signals. Although many previous studies have analyzed the characteristics and morphologies of sporadic-E, few efforts have attempted to model global E_s occurrence rates (ORs) at high time resolutions. This study develops a global empirical model of blanketing sporadic-E occurrence rates using a Karhunen–Loéve Expansion (KLE) of a global OR climatology built with Global Navigation Satellite System radio occultation (GNSS-RO) and ionosonde observations. Using an fbE ≥ threshold of 3 MHz, the model outputs a blanketing sporadic-E …

Enhancing Radiation Performance Of A 0.18 Μm Cmos 60 Ghz On-Chip Double-Slot Vivaldi Antenna, Elsayed Ibrahim Elsaidy Mr., Amr H. Hussein Prof.Dr., Mustafa M. Abd Elnaby Prof. Dr.

Journal of Engineering Research

This paper presents the design of a 60-GHz double-slot Vivaldi antenna (DSVA) using standard 0.18 µm CMOS technology. The antenna's two slots are uniformly excited in both amplitude and phase by a coplanar waveguide (CPW) power divider. A double-Y balun feeding structure is also used to transition from the CPW to the coplanar slot line (CPS). Two techniques are investigated to enhance the antenna's radiation characteristics. The first technique involves incorporating equal corrugations along the edges of the flare aperture, resulting in a significant gain enhancement of 0.9 dBi and an improvement in radiation efficiency by 7%. The second technique …

Gratings In Optical Waveguides And Lasers, Weida Zhang

Electrical Engineering Theses and Dissertations

Gratings play a crucial role in Distributed Bragg reflector (DBR) lasers, influencing their performance and characteristics. The focus of this work is aimed at the design of DBR lasers that significantly impact the laser's spectral and temporal behavior, making it a key component in optimizing DBR laser functionality.

The SMU developed grating software, compared with commercially available photonics software, has improved accuracy and much smaller computation times. The improved accuracy and reduced computation times compared with commercial photonics software occur because commercial software is typically based on numerical methods such as finite-difference time-domain (FDTD), eigenmode expansion and beam propagation methods …

Optical Investigation Of A Low-Pressure Plasma In A Superconducting Radio-Frequency Cavity, Zachary A. Caudell

Electrical & Computer Engineering Theses & Dissertations

The state-of-the-art cryomodules for particle accelerators use superconducting radio-frequency (SRF) cavities. It is known that accumulation of hydrocarbon impurities reduces the cavity surface work function, decreasing cryomodule performance metrics such as field emission, thermal stability, and accelerating gradients. An in-situ method of plasma processing has recently been developed to clean the cavities and restore cryomodule performance [1]. This study is to understand the properties of the low-pressure plasmas generated in a C100 SRF cavity and ultimately to improve the performance of plasma surface cleaning using optical emission spectroscopy. Using a 500 mm focal length Czerny-Turner monochromator coupled with a photomultiplier …

Electromagnetic Theory And Applications, 2nd Edition, Nicholas Madamopoulos, George Kliros

Open Educational Resources

This book intends to provide both the fundamentals of Electromagnetics but also some practical applications of the concepts covered. Having taught electromagnetics for several years, the authors feel that many times the field of electromagnetics comes as “old” and often times students do not appreciate the concepts and their importance in everyday applications. The authors intend to accompany the EM concepts with life applications. Hence, students may see the direct impact of the knowledge they acquire through the study of the field of electromagnetics and better appreciate the field.

Patterning Synthesis Of Lead Halide Perovskites Toward Photonic Application, S. M. Nayeem Arefin

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Lead halide perovskites (LHPs) are a fascinating class of photonic materials with the potential to revolutionize various optoelectronic applications. Their diverse crystal structures, ranging from 0D to 3D configurations, offer a unique combination of properties, including high tunability and ease of synthesis. However, their inherent instability and the difficulty of patterning them into sophisticated photonic structures using conventional methods present a significant hurdle to their widespread applications. This thesis addresses these challenges by proposing a novel synthesis method that combines soft lithography and self-assembly. By utilizing a patterned template with controlled wettability, precise manipulation of LHP crystal formation is achieved, …

Impacts Of High-Frequency Operation On Magnetics And Performance On Isolated Power Electronic Converter Design, David Arturo Porras Fernandez

Graduate Theses and Dissertations

The pursuit of high-power density and high switching frequency is a central theme in the advancement of power electronic converters. While these parameters offer significant benefits in terms of compactness and performance, they also introduce challenges related to efficiency and thermal management. This doctoral dissertation aims to provides a design framework to analyze the implications of high-frequency operation (> 100 kHz) on magnetics design and performance in power electronic converters, particularly when integrating silicon carbide (SiC) power modules. It examines the advantages and disadvantages of high-frequency operation and delves into its effects on the performance of the converter, focusing on …

A Broadband, Dual Polarized Antenna For The Radio Neutrino Observatory In Greenland, Danny Maas

Master's Theses

The Radio Neutrino Observatory in Greenland (RNO-G) is a multidisciplinary, multinational collaboration which uses antennas to detect neutrino interactions with arctic ice sheets. Neutrinos are formed from nuclear reactions; predominant sources include nuclear reactors, stars, supernovae, and the big bang. They rarely interact with normal matter and thus travel from origin to destination relatively unimpeded, with applications including tracking nuclear weapons tests and supernovae. Measurements of galactic neutrino flux can provide information about how the universe developed and its current evolution. Neutrino interactions produce signals from 100 to 1000MHz. Current RNO-G antennas operate over only a portion of this band; …

Magnetic Sensor Compensation Utilizing Factor Graph Estimation, Frederic W. Lathrop, Clark N. Taylor, Aaron Nielsen

Faculty Publications

Recently, there has been significant interest in the ability to navigate without GPS using the magnetic anomaly field of the Earth (magnav). One of the key technical bottlenecks to achieving magnav is obtaining an accurate magnetic sensor calibration, taking into account own-ship and sensor effects. The Tolles-Lawson magnetic calibration method continues to be the industry standard and was developed when airborne magnetic survey aircraft were first employed over 70 years ago. In this paper, we present a magnetic calibration algorithm based on a factor graph optimization using inertial measurements as well as inputs from both a vector and scalar magnetometer. …

Fabrication And Characterization Of A Monolithic Photonic Integrated Circuit With High-Aspect Ratio Photonic Device Structures, Sami A. Nazib

Optical Science and Engineering ETDs

The focus of this work was to create a process to fabricate an InP-based Photonic Integrated Circuit (PIC). The design of the PIC required the photonic components of this device to be created by deep etching of an epitaxially-grown multilayer structure. Therefore, a novel dry etching process was developed to produce very high aspect- ratio (HAR) features. This process not only involved the development of dry etch chemistry but also the engineering of a metal mask structure. The next step of the challenge was to use a polymer-based material that would have two functions: cladding for the etched photonic components …

Multisensory System For Probing Scattering Media, Muralidhar Madabhushi Balaji

Electrical Engineering Theses and Dissertations

There are numerous problems in the physical sciences wherein the scattering of light fundamentally limits our ability to perceive and reason about objects within the visual field. Examples include navigation in foggy weather, detecting hidden contraband/explosives, detecting diseased regions in agricultural produce, and detecting tumors within tissue. In all these scenarios, the scrambling of light paths due to scattering reduces the ability to locate embedded objects and identify their spatial or spectral features.

Existing approaches address the challenge by augmenting optical sensing modalities with complementary techniques that do not rely on optical phenomenology, such as Magnetic Resonance Imaging (MRI) or …

Parallel Communications In Single-Core Optical Fibers Utilizing Spatial Domain Multiplexing And Wavelength Division Multiplexing, Mingxuan Tu

Theses and Dissertations

This endeavor proposes a hybrid parallel optical communication architecture in single-core fibers combining WDM in O-band (1270 nm, 1310 nm, 1310 nm, and 1330 nm) and two-channel SDM. The proposed architecture applies carefully designed delays in each propagating channel to achieve synchronization and, therefore, realizes parallel transmission in single-core fibers without the help of Serializer/De-serializers (SerDes). A mathematical model of SDM, calculations on delays between each optical channel, simulation of the hybrid architecture, experimental setup, and the testing and analysis of channel performance have been provided. A design of a photonic integrated circuit based on thin film lithium niobate electro-optic …

Fast And Accurate Automatic Design Of Spiral Inductors From High-Level Specification, Heba Ismail

Theses and Dissertations

Integrated on-chip planar spiral inductors are widely employed in communication circuit blocks and other various electronic devices, thus becoming an essential passive component of RF integrated circuits (RFICs). A common vital spiral inductor design problem is determining the optimum layout parameters of spiral inductors that yield the desired inductance value and achieve highest quality factor at the intended operating frequency. Various approaches tackle this difficulty, but the most prevalent approaches for designing inductors are using an electromagnetic simulator or a library of pre-designed inductors. The latter approach requires an extensive amount of time and computational resources, whereas the former restricts …

Evaluation Of Reduced Graphene Oxide For Advanced Thermal Management In Microwave Electronics Packaging, Utkarsh Misra

USF Tampa Graduate Theses and Dissertations

The continuous push towards making electronic devices smaller and denser, largely driven by the demand for higher power capabilities, has led to a critical need for innovative and comprehensive methods for managing the heat these devices generate. Traditional cooling solutions for electronics often rely on methods such as copper-based layers or channels to distribute and dispel heat. However, these conventional methods and materials are becoming increasingly insufficient, especially for Radio Frequency (RF) and millimeter-wave electronics. These components are becoming ever more compact while requiring more power, thus presenting unique challenges for thermal management in their packaging.

In this thesis we …

Modeling And Optimization Of Time Delay Unit Network Architectures For Reducing Complexity Of Ultra- Wideband Phased Antenna Arrays, Daniel A. Ramirez

USF Tampa Graduate Theses and Dissertations

This dissertation presents a systematic technique for modeling and optimization of the hierarchical time delay unit (TDU) architectures of ultra-wideband (UWB) phased antenna arrays (PAAs). The first major contribution of this dissertation is the optimization of a linear PAA by casting the problem in the standard form of integer linear programming (ILP) optimization with an objective function that targets minimizing the total number of TDUs within the RF feed network fanout while maintaining phase error and manufacturability constraints. This optimization can significantly reduce the cost, power, and complexity of UWB PAAs in contrast to prior methods that iteratively converge on …

Design Of High Efficiency Doherty Power Amplifier, Kobi G. Kelly, Severin Pindell

Electrical Engineering

The project includes design and fabrication of a high efficiency power amplifier for a student design competition held at International Microwave Symposium (IMS) 2023. Efficient power amplifiers are critical for base station communication requiring efficient use of available power. The final design optimizes power added efficiency (PAE) and linearity. The amplifier will operate at 2.45 GHz. Competitive PAE above 50%, and C/I above 30 dB is achieved by leveraging a Doherty class amplifier using accurate discrete CGH4006P transistor models to simulate an efficient and linear design. Unique design features include optimal transistor bias point selection and power split ratios between …

Multi-Hop And Automated Testing Of Wide-Area Network Radio Systems, Zachary C. Numa, Joseph S. Nuccio

Electrical Engineering

Requests for low-power and versatile wide-area Internet-of-Things (IoT) networks are becoming more prevalent with upcoming research in low-data rate ad-hoc mesh networks. Connections to terrestrial satellites have proven promising methods for increasing range capabilities for wide area networks (WAN). As research in communication with IoT networks and satellites progresses, reliable multi-hop mesh networks for Earth-based communication are still necessary to develop the base for satellite communication. These multi-hop communication mesh networks are being developed to allow communication where Line-of-Sight (LOS) from A to B is incapable due to environmental barriers. Hence, communication is possible without LOS by providing an intermediate …

2-Bit Schiffman Phase Shifter, Tavita Dayton, Enrique Ruiz

Electrical Engineering

Phase shifters are found in microwave/RF applications such as defense or wireless communications for their ability to control the relative phase of a system which allows for alignment of signals to obtain constructive interference. Typical phase shifters are chip level (digital and analog) which require a DC bias therefore restricting PCB use unless allowance for air gaps. The paper analyzes a passive and low-profile 2-bit phase shifter using the Schiffman architecture, which outputs a near-constant 90 degree shift over a wide band of frequencies. The design process initially confirmed a proper 90 degree phase shift over the desired WiFi band, …

Unconventional Computing With Photonic Oscillator Networks, Mostafa Honari Latifpour

Dissertations, Theses, and Capstone Projects

The ever-increasing demand for data processing and the challenges in scaling traditional computing architectures are driving intensive research into alternative computing paradigms. Optical computing has garnered renewed attention since the 2010s, driven by its potential to accelerate specialized computational tasks such as combinatorial optimization and neural networks.

Coherent light sources including lasers and parametric oscillators have been around for decades and become indispensable tools in modern technology, but these photonic oscillators are also nonlinear dynamical systems that can exhibit emergent, complex phenomena, especially when coupled in arrays. These nonlinear optical systems have recently been shown to be capable of doing …

Design And Characterization Of A Broadband Rf Switch Utilizing Surface Mount Devices, Daniel Bracamontes

Master's Theses

High frequency solid-state switches are critical elements in communication systems, radio frequency (RF) systems and instrumentation. Key parameters to an RF switch include insertion loss while on and off-state isolation. Power handling and linearity are important to consider for a cost-effective construction. This becomes a design challenge into K-band frequencies as components required need to be small, dielectric losses and transmission lines need to be physically matched for proper isolative and through states. This thesis presents a novel single pole eight throw (SP8T) hybrid design composed of commercially available surface mount technology solutions to achieve high isolation and low insertion …