Engineering Commons^™

Nanoplasmonic Sensors Based On Periodic Arrays Of Gold Nanoparticles, Hao Jiang

Electronic Thesis and Dissertation Repository

Nanoplasmonic sensors use the localized surface plasmon resonance (LSPR) of metal nanostructures to sense the refractive index change in a surface-bound layer caused by biomolecular interactions or changing chemical environment. In this thesis, four types of sensor configurations based on gold nanoparticle arrays are thoroughly investigated.

The first configuration is a periodic array of gold nanoparticles excited by the evanescent field of an optical waveguide mode. Since light carried by a waveguide mode propagates along the same plane of the periodicities, the coupling of nanoparticles are strongly affected by the photonic crystal lattice. This configuration is investigated both in simulations …

Design Of Wireless Power Transfer And Data Telemetry System For Biomedical Applications, Ashraf Bin Islam

Doctoral Dissertations

With the advancement of biomedical instrumentation technologies sensor based remote healthcare monitoring system is gaining more attention day by day. In this system wearable and implantable sensors are placed outside or inside of the human body. Certain sensors are needed to be placed inside the human body to acquire the information on the vital physiological phenomena such as glucose, lactate, pH, oxygen, etc. These implantable sensors have associated circuits for sensor signal processing and data transmission. Powering the circuit is always a crucial design issue. Batteries cannot be used in implantable sensors which can come in contact with the blood …

Short Distance Ground Wave Propagation Modeling In Irregular And Forested Environments, Zachary Michael Crane

Masters Theses

A model for the phase of a ground wave propagating over irregular and forested terrain has been developed and tested for a transmission system operating at 3.315 MHz.

In this model, the time delay induced beyond that of the standard velocity of radio waves in air is modeled as a combination of 3 effects: the finite conductivity of the earth, the irregularity of the terrain over which the wave is propagating, and the forestation of the terrain.

The finite conductivity model is based on a small curvature formula developed by Van Der Pol and Bremmer. The terrain irregularity model models …

Wavelength Dependence Of Transverse Mode Coupling With/Without E-Block Of Gan Laser Cavity, Krishneel Lal

Electrical Engineering

No abstract provided.

902–928mhz Uhf Rfid Tag Antenna Design, Fabrication And Test, Chiweng Kam

Master's Theses

Radio Frequency Identification (RFID) uses RF radiation to identify physical objects. With decreasing integrated circuit (IC) cost and size, RFID applications are becoming economically feasible and gaining popularity. Researchers at MIT suggest that RFID tags operating in the 900 MHz band (ultrahigh frequency, UHF) represent the best compromise of cost, read range, and capabilities [1]. Passive RFID tags, which exclude radio transmitters and internal power sources, are popular due to their small size and low cost [1].

This project produced Cal Poly’s first ever on-campus printed, assembled, and operational UHF (902 to 928 MHz) passive RFID tag. Project goals include …

Fem-Fct Based Dynamic Simulation Of Trichel Pulse Corona Discharge In Point-Plane Configuration, Paria Sattari

Electronic Thesis and Dissertation Repository

In this thesis, a new two-dimensional numerical solver is presented for the dynamic simulation of the Trichel pulse regime of negative corona discharge in point-plane configuration. The goal of this thesis is to simulate the corona discharge phenomenon and to improve the existing models so that the results have an acceptable compatibility with the experimentally obtained data. The numerical technique used in this thesis is a combination of Finite Element Method (FEM) and Flux Corrected Transport (FCT). These techniques are proved to be the best techniques, presented so far for solving the nonlinear hyperbolic equations that simulate corona discharge phenomenon. …

Optical Power Splitting Techniques Using Photonic Crystal Line Defect Waveguides, Rajat Dey

Electronic Thesis and Dissertation Repository

“Photonic Crystals (PCs)” are dielectric or metallo-dielectric structures with periodic spatial alternations of refractive index on the scale of the wavelength of light. Many optical devices, based on PCs, have been proposed. There are multiple ways by which equal amount of power of incoming signals can be divided into two, three and four output channels; for example using multiple coupled photonic crystal waveguides, directional coupling and cascaded multimode PC waveguides. Ideally, the splitter should divide the input power equally into the output channels without significant reflection or radiation losses and should be compact in size. In this thesis we have …

Planar Photonic Crystal For Biosensor Applications, Anil Kumar Mudraboyina

Electronic Thesis and Dissertation Repository

Photonic crystals are the subject of intense study due to their capability to provide precise control of optical transmission characteristics through the choice of their periodic lattice parameters and the material with which they are fabricated. The sensitivity of photonic crystal band structure and defect transmission states to refractive index changes either at planar boundaries of a 2-D crystal or at individual lattice sites, make these structures potentially attractive for integrated point detection biosensor devices.

1-D Photonic crystal (PC) and 2-D PC based sensors were developed and studied in terms of sensitivity with different types materials functionalized on the surface. …

Comparison Of A High Purity Germanium Gamma Ray Spectrometer And A Multidimensional Nai(T1) Scintillation Gamma Ray Spectrometer, Greg Stratton

Aerospace Engineering

This report compares two different gamma ray spectrometers in terms of performance, operation, and apparatus and also investigates the design and integration challenges of using gamma ray spectrometers in space. The first spectrometer is a one-dimensional high purity germanium (HPGe) spectrometer and the second is a multidimensional NaI(Tl) scintillation spectrometer (MGRS). The key results show that the HPGe exhibits 15 to 27 times better energy resolution than the MGRS, but the MGRS is 52 times more sensitive and removes 177 % more of the background radiation.

Design, Fabrication, And Testing Of An Electromagnetic Rail Gun For The Repeated Testing And Simulation Of Orbital Debris Impacts, Jeff Maniglia, Jordan Smiroldo, Alex Westfall, Guy Zohar

Aerospace Engineering

An Electromagnetic Railgun (EMRG) was designed, built, and tested, capable of firing a projectile a 1 gram projectile at 650 m/s muzzle velocity. The EMRG utilizes an injector, a high voltage power supply, a capacitor bank, inductors and rails. The injector fires 2300 psig Nitrogen gas into the system to provide an initial velocity. The high voltage power supply charges the capacitor bank. The capacitor bank discharges the electric potential built up through the projectile while inside the rails in order to create the EMRG’s force. The inductors are used to pulse form the capacitor bank in order to get …

Rfid Techniques For Passive Electronics, Ryan Behr, David Cobos

Electrical Engineering

No abstract provided.

Design And Analysis Of Substrate-Integrated Cavity-Backed Antenna Arrays For Ku-Band Applications, Mohamed Hamed Awida Hassan

Doctoral Dissertations

Mobile communication has become an essential part of our daily life. We love the flexibility of wireless cell phones and even accept their lower quality of service when compared to wired links. Similarly, we are looking forward to the day that we can continue watching our favorite TV programs while travelling anywhere and everywhere. Mobility, flexibility, and portability are the themes of the next generation communication. Motivated and fascinated by such technology breakthroughs, this effort is geared towards enhancing the quality of wireless services and bringing mobile satellite reception one step closer to the market. Meanwhile, phased array antennas are …

Mathematical Modeling Of Metamaterials, Valjean Elizabeth Elander

UNLV Theses, Dissertations, Professional Papers, and Capstones

Metamaterials are artificially structured nano materials with negative refraction index. The successful construction of such metamaterials in 2000 triggered a great interest in study of metamaterials by researchers from different areas. The discovery of metamaterials opened a wide potential for applications in diverse areas such as cloaking, sub-wavelength imaging, solar cell design and antennas.

In this thesis, we investigate the most popular Drude metamaterial model. More specifically, we first present a brief overview of metamaterials and their potential applications, then we discuss the well-posedness of this model, and develop several numerical schemes to solve it. We implement our schemes using …

Compensation Techniques In Accelerator Physics, Hisham Kamal Sayed

Physics Theses & Dissertations

Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two …

Evaluation Of The Single Keybit Template Attack, Eric W. Garcia

Theses and Dissertations

Side Channel leakage is a serious threat to secure devices. Cryptographic information extraction is possible after examining any one of the various side channels, including electromagnetic. This work contributes a new method to achieve such a purpose. The Single Keybit Template Attack (SKTA) is introduced as a means to extract encryption keys from embedded processors and other integrated circuit devices performing DES encryptions by passively monitoring and exploiting unintentional RF emissions. Key extraction is accomplished by creating two templates for each bit value of the key based on instantaneous amplitude responses as a device executes DES operations. The resultant templates …

Direction Finding With Mutually Orthogonal Antennas, David F. Chick

Theses and Dissertations

Estimating the direction-of-arrival of incident electromagnetic plane waves (a.k.a. direction finding or DF) has typically been accomplished in the past using arrays of spatially separated antennas. The spatial separation produces a delay in each antenna's measured voltage due to the finite propagation time as the wave strikes each antenna in succession. In this thesis, we approach the problem differently by using three antennas that have been oriented in orthogonal directions but are co-located at the origin of a coordinate system. Being co-located, this mutually orthogonal arrangement of antennas cannot detect the propagation phase delay and must rely solely on the …

Electromagnetic Modeling And Measurement Of Adaptive Metamaterial Structural Elements, Matthew E. Jussaume

Theses and Dissertations

This document addresses two major obstacles facing metamaterial development: uncertainty in the characterization of electromagnetic field behavior in metamaterial structures and the relatively small operational bandwidth of metamaterial structures. To address the first obstacle, a method of prediction aided measurement is developed and exploited to examine the field interactions within metamaterial devices. The fusion of simulation and measurement techniques enhances the understanding of the physical interactions of fields in the presence of metamaterials. To address the second obstacle, this document characterizes the effectiveness of an adaptive metamaterial design that incorporates a microelectromechanical systems (MEMS) variable capacitor. Applying voltages to the …

Ultra High Density Spectral Beam Combining By Thermal Tuning Of Volume Bragg Gratings In Photo-Thermo-Refractive Glass, Derrek Drachenberg

Electronic Theses and Dissertations

High power lasers with diffraction limited beam quality are desired for many applications in defense and manufacturing. A lot of applications require laser beams at the 100 kW power level along with divergence close to the diffraction limit. The figure of merit for a beam used in such applications should be radiance which determines the laser power delivered to a remote target. One of the primary limiting factors is thermal distortion of a laser beam caused by excessive heat generated in the laser media. Combination of multiple laser beams is usually considered as a method to mitigate these limitations. Spectral …

Theoretical Study Of Beam Transformations By Volume Diffraction, Sergiy V. Mokhov

Electronic Theses and Dissertations

Laser beams can be manipulated by volume diffractive elements in addition to conventional optical elements like mirrors, lenses, and beam splitters. Conventional optical elements can be described by applying the basic laws of reflection and refraction at the surfaces of the elements. Even diffraction by surface gratings utilizes relatively simple mathematics. This is to be contrasted with the volume diffraction, which requires coupled wave theory in the slowly varying envelope approximation (SVEA) to obtain accurate results. Efficient spatially distributed diffraction of laser beams is possible due to the high coherence of laser light, and it occurs at specific resonant Bragg …

Characterization Of The Nonlinear Refractive Index Of Carbon Disulfide Over An Extended Spectral And Temporal Range, Marcus Seidel

Electronic Theses and Dissertations

The intensity dependent refractive index change of a medium is frequently described in terms of the product n₂ · I where n₂ is the nonlinear refractive index and I the light intensity. The nonlinear refractive index is often treated as constant which is a reasonable assumption if the light interacts only with bound electrons. In the case of carbon disulfide (CS₂) however, nuclear motions contribute to n₂. These motions occur on the sub picosecond time scale and thus become especially relevant for ultrashort laser pulses. The neat liquid CS₂ is studied because it exhibits a large nonlinear refractive index in …

Perceptual Image Quality Of Launch Vehicle Imaging Telescopes, Joshua K. Lentz

Electronic Theses and Dissertations

A large fleet (in the hundreds) of high quality telescopes are used for tracking and imaging of launch vehicles during ascent from Cape Canaveral Air Force Station and Kennedy Space Center. A maintenance tool has been development for use with these telescopes. The tool requires rankings of telescope condition in terms of the ability to generate useful imagery. It is thus a case of ranking telescope conditions on the basis of the perceptual image quality of their imagery. Perceptual image quality metrics that are well-correlated to observer opinions of image quality have been available for several decades. However, these are …

Few-Cycle Pulses Amplification For Attosecond Science Applications Modeling And Experiments, Michael Hemmer

Electronic Theses and Dissertations

The emergence of mode-locked oscillators providing pulses with durations as short as a few electric-field cycles in the near infra-red has paved the way toward electric-field sensitive physics experiments. In addition, the control of the relative phase between the carrier and the pulse envelope, developed in the early 2000’s and rewarded by a Nobel price in 2005, now provides unprecedented control over the pulse behaviour. The amplification of such pulses to the millijoule level has been an on-going task in a few world-class laboratories and has triggered the dawn of attoscience, the science of events happening on an attosecond timescale. …

Design, Fabrication, And Testing Of High-Transparency Deep Ultra-Violet Contacts Using Surface Plasmon Coupling In Subwavelength Aluminum Meshes, Clarisse Mazuir

Electronic Theses and Dissertations

The present work aims at enhancing the external quantum efficiencies of ultra-violet (UV) sensitive photodetectors (PDs) and light emitting diodes (LEDs)for any light polarization. Deep UV solid state devices are made out of AlGaN or MgZnO and their performances suffer from the high resistivity of their p-doped regions. They require transparent p-contacts; yet the most commonly used transparent contacts have low transmission in the UV: indium tin oxide (ITO) and nickel-gold (Ni/Au 5/5 nms) transmit less than 50% and 30% respectively at 300 nm. Here we investigate the use of surface plasmons (SPs) to design transparent p-contacts for AlGaN devices …

Multilayered Planar Periodic Subwavelength Microstructures For Generating And Detecting Circularly Polarized Thermal Infrared Radiation, Samuel Lanning Wadsworth

Electronic Theses and Dissertations

Generation and detection of circularly-polarized (CP) radiation in the 8- to 12-μm band of the infrared (IR) spectrum is crucial for polarization sensing and imaging scenarios. There is very little naturally occurring CP radiation in the long-wave IR band, so that useful functionalities may be obtained by exploiting preferential radiation and transmission characteristics of engineered metamaterials. Conventional CP devices in the IR utilize birefringent crystals, which are typically bulky and expensive to manufacture. The operation of these devices is generally optimized at a single wavelength. Imaging in the long-wave IR is most often broadband, so that achromatic CP-device behavior is …

Electromagnetic Propagation Anomalies In Waveguiding Structures And Scattering Systems, Alessandro Salandrino

Electronic Theses and Dissertations

The effects related to diffraction and interference are ubiquitous in phenomena involving electromagnetic wave propagation, and are accurately predicted and described within the framework of classical electrodynamics. In the vast majority of the cases the qualitative features of the evolution of a propagating wave can be inferred even without detailed calculations. A field distribution will spread upon propagation, will accumulate phase along the direction of power flow, will exert mechanical forces upon scattering objects in the direction of propagation etc. When such predictions fail, counterintuitive effects and new functionalities can be engineered. In this work a series of exceptional cases …

Magneto-Dielectric Polymer Nanocomposite Engineered Substrate For Rf And Microwave Antennas, Cesar A. Morales

USF Tampa Graduate Theses and Dissertations

This dissertation presents the first reported systematic investigation on the implementation of multilayer patch antennas over Fe3O4-based polymer nanocomposite (PNC) magneto-dielectric substrates. The PNC substrate is created by the monodispersion of Fe3O4 nanopthesiss, with mean size of 7.5nm, in a polymeric matrix of Polydimethylsiloxane (PDMS).

Recently, magneto-dielectric substrates have been proposed by several researchers as a means for decreasing the size and increasing the bandwidth of planar antennas. Nevertheless, factors such as high loss and diminished control over magnetic and dielectric properties have hindered the optimal performance of antennas. In addition, the incompatibility and elevated complexity prevents integration of conventional …

Log-Periodic Microstrip Patch Antenna Miniaturization Using Artificial Magnetic Conductor Surfaces, Ahmad Tariq Almutawa

USF Tampa Graduate Theses and Dissertations

Microstrip patch antennas are attractive for numerous military and commercial applications due to their advantages in terms of low-profile, broadside radiation, lowcost, low-weight and conformability. However, the inherent narrowband performance of patch antennas prohibits their use in systems that demand wideband radiation. To alleviate the issue, an existing approach is to combine multiple patch antennas within a log-periodic array configuration [1]. These log-periodic patch antennas (LPMAs) are capable of providing large bandwidths (>50%) with stable broadside radiation patterns. However, they suffer from electrically large sizes. Therefore, their miniaturization without degrading the bandwidth performance holds promise for extending their use …

Guiding Electric Fields For Electroporation Applications, Jose Rey

USF Tampa Graduate Theses and Dissertations

Electroporation is the critical step in an electric field mediated drug or gene delivery protocol. Electroporation based protocols have been successfully demonstrated in cancer clinical trials, however, its impact in other applications is still under investigation. A significant roadblock to long term functioning of implantable biosensors in vivo is the tissue reaction in the form of fibrous encapsulation that results in reduced transport to the sensing element of the biosensor. In vivo gene electroporation has a great potential as a means to modify the transport properties of tissues in the proximity of the sensing element of implantable biosensors.

This dissertation …

Computationally Efficient Digital Backward Propagation For Fiber Nonlinearity Compensation, Likai Zhu

Electronic Theses and Dissertations

The next generation fiber transmission system is limited by fiber nonlinearity. A distributed nonlinearity compensation method, known as Digital Backward Propagation (DBP), is necessary for effective compensation of the joint effect of dispersion and nonlinearity. However, in order for DBP to be accurate, a large number of steps are usually required for long-haul transmission, resulting in a heavy computational load. In real time DBP implementation, the FIR filters can be used for dispersion compensation and account for most of the computation per step. A method of designing a complementary filter pair is proposed. The individual errors in the frequency response …

Low Noise, Narrow Optical Linewidth Semiconductor-Based Optical Comb Source And Low Noise Rf Signal Generation, Ibrahim Tuna Ozdur

Electronic Theses and Dissertations

Recently optical frequency combs and low noise RF tones are drawing increased attention due to applications in spectroscopy, metrology, arbitrary waveform generation, optical signal processing etc. This thesis focuses on the generation of low noise RF tones and stabilized optical frequency combs. The optical frequency combs are generated by a semiconductor based external cavity mode-locked laser with a high finesse intracavity etalon. In order to get the lowest noise and broadest bandwidth from the mode-locked laser, it is critical to know the free spectral range (FSR) of the etalon precisely. First the etalon FSR is measured by using the modified …