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Articles 121 - 150 of 1741

Full-Text Articles in Electrical and Computer Engineering

Fast And Accurate Automatic Design Of Spiral Inductors From High-Level Specification, Heba Ismail Jun 2024

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 …


Modeling And Optimization Of Time Delay Unit Network Architectures For Reducing Complexity Of Ultra- Wideband Phased Antenna Arrays, Daniel A. Ramirez Jun 2024

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 …


Single-Polarization And Single-Mode Hybrid Hollow-Core Anti-Resonant Fiber Design At 2 Μm, Herschel Herring, Mohammad Al Mahfuz, Md Selim Habib Jun 2024

Single-Polarization And Single-Mode Hybrid Hollow-Core Anti-Resonant Fiber Design At 2 Μm, Herschel Herring, Mohammad Al Mahfuz, Md Selim Habib

Electrical Engineering and Computer Science Faculty Publications

In this paper, to the best of our knowledge, a new
type of hollow-core anti-resonant fiber (HC-ARF) design using
hybrid silica/high-index material (HIM) cladding is presented
for single-polarization, high-birefringence, and endlessly single-
mode operation at 2 μm wavelength. We show that the inclusion
of a HIM layer in the cladding allows strong suppression of
𝑥−polarization, while maintaining low propagation loss and
single-mode propagation for 𝑦−polarization. The optimized HC-
ARF design includes a combination of low propagation loss,
high-birefringence, and polarization-extinction ratio (PER) or
loss ratio of 0.02 dB/m, 1.2×10−4, and >550 respectively, while the
loss of the 𝑥−polarization is >20 …


Design Of High Efficiency Doherty Power Amplifier, Kobi G. Kelly, Severin Pindell Jun 2024

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 Jun 2024

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 Jun 2024

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 Jun 2024

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 Jun 2024

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 …


Analysis Of Modeled 3d Solar Magnetic Field During 30 X/M-Class Solar Flares, Seth H. Garland, Vasyl B. Yurchyshyn, Robert D. Loper, Benjamin F. Akers, Daniel J. Emmons Ii May 2024

Analysis Of Modeled 3d Solar Magnetic Field During 30 X/M-Class Solar Flares, Seth H. Garland, Vasyl B. Yurchyshyn, Robert D. Loper, Benjamin F. Akers, Daniel J. Emmons Ii

Faculty Publications

Using non-linear force free field (NLFFF) extrapolation, 3D magnetic fields were modeled from the 12-min cadence Solar Dynamics Observatory Helioseismic and Magnetic Imager (HMI) photospheric vector magnetograms, spanning a time period of 1 hour before through 1 hour after the start of 18 X-class and 12 M-class solar flares. Several magnetic field parameters were calculated from the modeled fields directly, as well as from the power spectrum of surface maps generated by summing the fields along the vertical axis, for two different regions: areas with photospheric |Bz|≥ 300 G (active region—AR) and areas above the photosphere with the …


New Quantum Information Science Study At Bsu: A Theoretical Study And Research Towards Pic Generation Of Entangled Photons, Peyton Brown May 2024

New Quantum Information Science Study At Bsu: A Theoretical Study And Research Towards Pic Generation Of Entangled Photons, Peyton Brown

Honors Program Theses and Projects

The first part of this thesis explores the abstract quantum state vector space using Dirac formalism, providing a comprehensive analysis of quantum mechanics’ fundamental concepts. Emphasis is placed on the Dirac notation’s pivotal role in elucidating quantum phenomena such as superposition and entanglement. Through detailed examinations of quantum states, polarization, and the CHSH inequality, this study not only reinforces the theoretical foundations of quantum information science but also demonstrates its practical applications in quantum information and quantum computing. The discussion delves into the manipulation of qubits and quantum gates, showing the potential of quantum information theory in enhancing computational efficiencies …


Low Noise Amplifier For 5ghz Wi-Fi Applications On 22nm, Harshdeep Singh May 2024

Low Noise Amplifier For 5ghz Wi-Fi Applications On 22nm, Harshdeep Singh

Electrical Engineering Undergraduate Honors Theses

More devices than ever are being used to connect to the internet via Wi-Fi than ever before. This creates the demand for improving Wi-Fi standards and wireless transceivers. On of the most important stages of a Wi-Fi receiver is the low noise amplifier (LNA), this is because it is the very first stage after the antenna receives the signal. The LNA is responsible for boasting the incoming signal while adding a low amount of noise to boast the signal enough to make it receptible to the rest of the receiver system. This study sought to design an inductively degenerated common …


Redirection Of Current In A Dense Plasma Focus, Rocky Gonzalez May 2024

Redirection Of Current In A Dense Plasma Focus, Rocky Gonzalez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mission Support & Test Services (MSTS) reports that significant amounts of energy needed for generating high energy neutrons is lost within a Dense Plasma Focus between its pinch-end of the anode stalk and at its base near the insulating sleeve. It is their mission and the goal of this research effort to both experimentally and theoretically study current redirection in a DPF during and after pinch dynamics. It is hypothesized that current redirection, due to restrike, behind the dynamic sheath of a dense plasma focus will result in a measurable change in the magnetic field along the longitudinal axis …


Mems Optical Cavities For Low Power Communication., Jacob Schopp May 2024

Mems Optical Cavities For Low Power Communication., Jacob Schopp

Electronic Theses and Dissertations

This thesis discusses the use of MEMS (microelectromechanical systems) optical cavities for use in low power communication. MEMS optical cavities are thin air gaps between an actuated MEMS mirror and a fixed glass encapsulation. By moving the MEMS mirror the reflectivity of the MEMS optical cavity can be changed. This change in reflectivity can be used to transmit information passively by modulating reflected light intensity instead of generating new light using a light source. These MEMS optical cavities are demonstrated using optical fibers for illumination delivery and reflected light collection. In addition to being reflected for communication, the illuminating light …


4-Channel Spatially Multiplexed Communication System In Single-Core Optical Fibers, Ce Su May 2024

4-Channel Spatially Multiplexed Communication System In Single-Core Optical Fibers, Ce Su

Theses and Dissertations

This dissertation delves into exploring and advancing spatial domain / space division multiplexing (SDM) technologies within single-core optical fibers, a frontier in optical fiber communications poised to meet the burgeoning global demand for data transmission. At the heart of this research is the pursuit to significantly enhance the capacity and efficiency of optical fiber communication systems without necessitating additional fiber infrastructure. This work unveils a new paradigm in optical fiber communications characterized by a pioneering 4-channel SDM system through a meticulous process encompassing theoretical modeling, computational simulations, design innovations, and rigorous experimental validations. Theoretical contributions include the development of refined …


Design, Fabrication, And Characterization Of Advanced High-Power Single-Mode 9xxnm Semiconductor Lasers, Xiaolei Zhao May 2024

Design, Fabrication, And Characterization Of Advanced High-Power Single-Mode 9xxnm Semiconductor Lasers, Xiaolei Zhao

All Dissertations

This thesis presents the comprehensive design, fabrication, and demonstration of advanced high-power, high-efficiency single-mode semiconductor lasers operating at a wavelength of 9xxnm. We begin with the design of the laser epitaxial structure, serving as the cornerstone for achieving high-power high-efficiency lasers. Our methodology integrates a semi-analytical calculation model, which accounts for Longitudinal Spatial Hole Burning (LSHB) and Two-Photon Absorption (TPA) effects, facilitating a thorough exploration of how design parameters influence output power and conversion efficiency. This approach offers an effective and time-efficient epitaxial structure optimization strategy compared to conventional full 3D simulation models.

Subsequently, we demonstrate high-power, high-efficiency ridge waveguide …


Plasma Diagnostics For Anode Cathode Plasmas And High Energy Density Physics On A Linear Transformer Driver, Robert Beattie-Rossberg Apr 2024

Plasma Diagnostics For Anode Cathode Plasmas And High Energy Density Physics On A Linear Transformer Driver, Robert Beattie-Rossberg

Electrical and Computer Engineering ETDs

A twelve-brick air insulated linear transformer driver (LTD) was characterized by charging to voltages ranging from 30 to 70 kV and delivering energy to two separate resistive loads. Various plasma diagnostics were built and fielded with an emphasis on the design, implementation and analysis of a Mach Zehnder interferometer, a moiré deflectometer and a spectroscopy system providing information on the temporal evolution of plasma electron density and atomic composition. Rogowski coils, XRD radiation detectors, framing camera images and time integrated DSLR images are used to further understand load conditions where current data, x ray radiation data, velocity data and instability …


Nowcasting Solar Euv Irradiance With Photospheric Magnetic Fields And The Mg Ii Index, Kara L. Kniezewski, Samuel J. Schonfeld, Carl J. Henney Apr 2024

Nowcasting Solar Euv Irradiance With Photospheric Magnetic Fields And The Mg Ii Index, Kara L. Kniezewski, Samuel J. Schonfeld, Carl J. Henney

Student Publications

A new method to nowcast spectral irradiance in extreme ultraviolet (EUV) and far ultraviolet (FUV) bands is presented here, utilizing only solar photospheric magnetograms and the Mg II index (i.e., the core-to-wing ratio). The EUV and FUV modeling outlined here is a direct extension of the SIFT (Solar Indices Forecasting Tool) model, based on Henney et al. (2015, https://doi.org/10.1002/2014sw001118). SIFT estimates solar activity indices using the earth-side solar photospheric magnetic field sums from global magnetic maps generated by the ADAPT (Air Force Data Assimilative Photospheric Flux Transport) model. Utilizing strong and weak magnetic field sums from ADAPT maps, Henney …


Wireless Power Transfer Using Cavity With Height Discontinuities, Linsheng Zhang Apr 2024

Wireless Power Transfer Using Cavity With Height Discontinuities, Linsheng Zhang

Electrical Engineering Theses and Dissertations

A novel device for efficient wireless power transfer (WPT) system is presented. The proposed WPT system utilizes modified microstrip antennas with height discontinuities (MAHDs) to achieve power transfer. Similar to the conventional WPT system using inductive devices, the power transmission relies on the magnetic field coupling in the near field region. However, the researcher can treat the isolated transmitter or receiver as a modified microstrip antenna, which resembles a capacitive device. Like a capacitive antenna, we can utilize the cavity model, which significantly simplifies field analysis, design and impedance matching process, reduces the overall space requirement, and potentially increases the …


Longitudinal Solid Polarized Target For Clas12 And Study Of Spin Structure Of Nucleons, Pushpa Pandey Apr 2024

Longitudinal Solid Polarized Target For Clas12 And Study Of Spin Structure Of Nucleons, Pushpa Pandey

Physics Theses & Dissertations

A suite of experiments measuring target-spin observables in electron-nucleon scattering (dubbed Run Group C) was conducted at Jefferson Lab’s Hall B in Newport News, VA with a new polarized nuclear target known as ‘APOLLO’ (Ammonia Polarized Longitudinally). This innovative target is engineered to seamlessly integrate with the advanced 12 GeV CEBAF (Continuous Electron Beam Accelerator Facility) accelerator and the Hall B CLAS12 (12 GeV CEBAF Large Acceptance Spectrometer) detector array. The ‘APOLLO’ target harnesses the power of Dynamic Nuclear Polarization (DNP) to achieve longitudinal polarization of solid ammonia, thereby creating a net polarization in both protons (NH3) and …


Broadband Dielectric Spectroscopic Detection Of Volatile Organic Compounds With Zinc Oxide And Metal-Organic Frameworks As Solid-State Sensor Materials, Papa Kojo Amoah Apr 2024

Broadband Dielectric Spectroscopic Detection Of Volatile Organic Compounds With Zinc Oxide And Metal-Organic Frameworks As Solid-State Sensor Materials, Papa Kojo Amoah

Electrical & Computer Engineering Theses & Dissertations

The industrial revolution drove technological progress but also increased the release of harmful pollutants, posing significant risks to human health and the environment. Volatile organic compounds (VOCs), which have various anthropogenic and natural sources, are particularly concerning due to their impact on public health, especially in urban areas. Addressing these adverse effects requires comprehensive strategies for mitigation as traditional gas sensing techniques have limitations and there is a need for innovative approaches to VOC detection.

VOCs encompass a diverse group of chemicals with high volatility, emitted from various human activities and natural sources. These compounds play a crucial role in …


6d Single-Fluorogen Orientation-Localization Microscopy For Elucidating The Architecture Of Beta-Sheet Assemblies And Biomolecular Condensates, Tingting Wu, Weiyan Zhou, Jai S. Rudra, Rohit V. Pappu, Matthew D. Lew Mar 2024

6d Single-Fluorogen Orientation-Localization Microscopy For Elucidating The Architecture Of Beta-Sheet Assemblies And Biomolecular Condensates, Tingting Wu, Weiyan Zhou, Jai S. Rudra, Rohit V. Pappu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

We develop six-dimensional single-molecule orientation-localization microscopy (SMOLM) to measure the 3D positions and 3D orientations simultaneously of single fluorophores. We show how careful optimization of phase and polarization modulation components can encode phase, polarization, and angular spectrum information from each fluorescence photon into a microscope’s dipole-spread function. We used the transient binding and blinking of Nile red (NR) to characterize the helical structure of fibrils formed by designed amphipathic peptides, KFE8L and KFE8D, and the pathological amyloid-beta peptide Aβ42. We also deployed merocyanine 540 to uncover the interfacial architectures of biomolecular condensates.


The Effects Of A Non-Uniform Magnetic Field On Solar Cell Efficiency, Jason A. Burdette Mar 2024

The Effects Of A Non-Uniform Magnetic Field On Solar Cell Efficiency, Jason A. Burdette

Theses and Dissertations

Commercial-grade silicon-based solar cells have an efficiency in the 20-30% range. The addition of a non-uniform magnetic field manipulates the movement of charge carriers within the silicon of a solar cell. With this manipulation, one hypothesis is that the magnetic field increases the current produced by the solar cell which helps to increase the power and efficiency of the solar cell. Measuring a solar cell’s output current and voltage both with and without the presence of a non-uniform magnetic field tests this theory. Voltage multiplied by current gives output power, and to be calculated, efficiency needs maximum output power. The …


Analyzing The Effects Of Atmospheric Turbulence On Polarization-Entangled Photon Pairs Using Quantum State Tomography, Noah S. Everett Mar 2024

Analyzing The Effects Of Atmospheric Turbulence On Polarization-Entangled Photon Pairs Using Quantum State Tomography, Noah S. Everett

Theses and Dissertations

To help in building a quantum-based communication link, we experimentally designed a system to simulate atmospheric turbulence and characterize its effects on a polarization-entangled photon-pair source. The simulated turbulence is constructed using two afocal optical systems with a phase plate inserted in each to mimic both weak and strong atmospheric turbulence respectively. After propagation, quantum state tomography (QST) is performed on each pair to reconstruct the density matrix of the pair’s overall polarization state. In characterization of the simulated turbulence, we were able to reach strengths up to a D/r0 of 18.2, which begins to approach the strong turbulent regime. …


Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density, Natalie R. Wirth Mar 2024

Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density, Natalie R. Wirth

Theses and Dissertations

High frequency (HF) communication is a vital aspect of military communication and is highly reliant upon ionospheric conditions. The variation in electron density within the lowest echelon of the ionosphere, the D-region, can significantly impact HF signals, making communication inconsistent and unreliable for these wavelengths. Despite the D-region’s important, research in this area mainly focuses on understanding the impact of space weather anomalies on the upper ionosphere, particularly its higher layers, with relatively little exploration of the D-region. This region, situated closest to the troposphere and stratosphere, has been definitively linked to solar weather events like solar flares and geomagnetic …


Development Of An Electromagnetic System For Wireless Magnetic Manipulation Of Soft Capsule Endoscope For Drug Delivery Applications, Nada Ashraf Hussein Mahmoud Jan 2024

Development Of An Electromagnetic System For Wireless Magnetic Manipulation Of Soft Capsule Endoscope For Drug Delivery Applications, Nada Ashraf Hussein Mahmoud

Theses and Dissertations

Wireless capsule endoscopy (WCE) is a remarkable diagnostic device that examines the gastrointestinal (GI) tract. The WCE is a small capsule integrated with a camera that is used to visualize the inner mucosa of the GI tract. WCE has been proven to be the most effective method to diagnose GI diseases and GI cancers. The procedure reduces the discomfort and risk compared to conventional endoscopy methods. However, current WCEs lack the ability to take a biopsy or deliver a drug to a specific location. Those therapeutic functions can be introduced by wirelessly controlled WCEs. This thesis introduces an electromagnetic system …


Mechanical And Electromagnetic Properties Of Incorporating Graphene Oxide In Cementitious Mixtures, Cherif Khalil Jan 2024

Mechanical And Electromagnetic Properties Of Incorporating Graphene Oxide In Cementitious Mixtures, Cherif Khalil

Theses and Dissertations

This multidisciplinary study aimed at investigating the impact of incorporating graphene oxide (GO) on the mechanical properties and electromagnetic (EM) shielding effectiveness of cementitious mixtures, as well as critically examining the mechanism with which GO affects their microstructure properties. Analysis of the literature review showed that there are discrepancies in reporting the impact of GO on the mortar mix. Consequently, this study focuses on exploring the cause for such discrepancies and identifies three main factors which are thoroughly investigated. The factors were the different sonication energies applied to the GO (Shear Mixing, 1.5 kJ/ml, 3 kJ/ml and 6 kJ/ml), the …


Employing Frequency Independent Structure For Ultra-Wide Band Antenna, Hassan Ali Ragheb, Mostafa Salah Jan 2024

Employing Frequency Independent Structure For Ultra-Wide Band Antenna, Hassan Ali Ragheb, Mostafa Salah

Electrical Engineering

The paper presents a novel and compact design for an ultra-wideband antenna based on frequency independent ethos. It consists of a Log-Periodic monopole structure with specific angle for the radiating patch with a defected ground plane. The antenna is fed using microstrip line feed and is designed on an FR4 substrate with a thickness of 1.6 mm, a relative permittivity of 4.4, and a loss tangent of 0.02. The Finite Element Method (FEM) of the Ansoft HFSS software is used during the design process. The proposed antenna covers the frequency range from 5.3 GHz up to 14 GHz for multiple …


Detection And Classification Of Sporadic E Using Convolutional Neural Networks, J. A. Ellis, Daniel J. Emmons, M. B. Cohen Jan 2024

Detection And Classification Of Sporadic E Using Convolutional Neural Networks, J. A. Ellis, Daniel J. Emmons, M. B. Cohen

Faculty Publications

In this work, convolutional neural networks (CNN) are developed to detect and characterize sporadic E (Es), demonstrating an improvement over current methods. This includes a binary classification model to determine if Es is present, followed by a regression model to estimate the Es ordinary mode critical frequency (foEs), a proxy for the intensity, along with the height at which the Es layer occurs (hEs). Signal-to-noise ratio (SNR) and excess phase profiles from six Global Navigation Satellite System (GNSS) radio occultation (RO) missions during the years 2008–2022 are used as the inputs of the model. Intensity (foEs) and the …


Side Lobe Level Reduction And Array Thinning Of Concentric Circular Antenna Arrays, Alzahraa H. Nosier, Ahmed M. Elkhawaga, Mohamed E. Nasr, Nessim M. Mahmoud, Amr H. Hussein Jan 2024

Side Lobe Level Reduction And Array Thinning Of Concentric Circular Antenna Arrays, Alzahraa H. Nosier, Ahmed M. Elkhawaga, Mohamed E. Nasr, Nessim M. Mahmoud, Amr H. Hussein

Mansoura Engineering Journal

This paper presents a new beamforming technique based on the hybrid combination of the convolution algorithm (CA) and the genetic algorithm (GA) for reducing side lobe level (SLL) and array thinning of concentric circular antenna arrays (CCAA), which is denoted as C/GA technique. The CA determines the excitations of the elements, while the GA optimizes the radii of the circular arrays to adjust the half-power beamwidth (HPBW). For CCAA consisting of uniform feeding circular arrays, we assume that there are excitation coefficients that are distributed symmetrically around the array center and arranged in a vector. The excitation vector is convolved …


Semiconductor Mode-Locked Lasers For Applications In Multi-Photon Imaging And Microwave Photonics, Srinivas Varma Pericherla Jan 2024

Semiconductor Mode-Locked Lasers For Applications In Multi-Photon Imaging And Microwave Photonics, Srinivas Varma Pericherla

Graduate Thesis and Dissertation 2023-2024

Semiconductor lasers are considered essential for the advancement in the field of photonics where compact and energy-efficient lasers are necessary. Advancements in integrated photonic technologies will help push the performance of semiconductor lasers in the coming years and expand the technology to several other applications. Semiconductor lasers offer several key features such as high energy efficiency, mass production, availability at a myriad of wavelengths, and high integration capabilities. However, limitations in noise performance, pulse energy, and duration hold back semiconductor lasers from being utilized to their full potential. This dissertation reviews the utilization and development of external techniques that enable …