Skip to main content

ASU Electronic Theses and Dissertations


This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.


Subject
Date Range
2010 2015


Tracking targets in the presence of clutter is inevitable, and presents many challenges. Additionally, rapid, drastic changes in clutter density between different environments or scenarios can make it even more difficult for tracking algorithms to adapt. A novel approach to target tracking in such dynamic clutter environments is proposed using a particle filter (PF) integrated with Interacting Multiple Models (IMMs) to compensate and adapt to the transition between different clutter densities. This model was implemented for the case of a monostatic sensor tracking a single target moving with constant velocity along a two-dimensional trajectory, which crossed between regions of drastically …

Contributors
Dutson, Karl J, Papandreou-Suppappola, Antonia, Kovvali, Narayan, et al.
Created Date
2015

This dissertation aims to demonstrate a new approach to fabricating solar cells for spectrum-splitting photovoltaic systems with the potential to reduce their cost and complexity of manufacturing, called Monolithically Integrated Laterally Arrayed Multiple Band gap (MILAMB) solar cells. Single crystal semiconductor alloy nanowire (NW) ensembles are grown with the alloy composition and band gap changing continuously across a broad range over the surface of a single substrate in a single, inexpensive growth step by the Dual-Gradient Method. The nanowire ensembles then serve as the absorbing materials in a set of solar cells for spectrum-splitting photovoltaic systems. Preliminary design and simulation …

Contributors
Caselli, Derek, Ning, Cun-Zheng, Tao, Meng, et al.
Created Date
2014

Programmable metallization cell (PMC) technology is based on an electrochemical phenomenon in which a metallic electrodeposit can be grown or dissolved between two electrodes depending on the voltage applied between them. Devices based on this phenomenon exhibit a unique, self-healing property, as a broken metallic structure can be healed by applying an appropriate voltage between the two broken ends. This work explores methods of fabricating interconnects and switches based on PMC technology on flexible substrates. The objective was the evaluation of the feasibility of using this technology in flexible electronics applications in which reliability is a primary concern. The re-healable …

Contributors
Baliga, Sunil Ravindranath, Kozicki, Michael N, Schroder, Dieter K, et al.
Created Date
2011

Ever reducing time to market, along with short product lifetimes, has created a need to shorten the microprocessor design time. Verification of the design and its analysis are two major components of this design cycle. Design validation techniques can be broadly classified into two major categories: simulation based approaches and formal techniques. Simulation based microprocessor validation involves running millions of cycles using random or pseudo random tests and allows verification of the register transfer level (RTL) model against an architectural model, i.e., that the processor executes instructions as required. The validation effort involves model checking to a high level description …

Contributors
Sharma, Abhishek, Clark, Lawrence, Holbert, Keith, et al.
Created Date
2011

The tracking of multiple targets becomes more challenging in complex environments due to the additional degrees of nonlinearity in the measurement model. In urban terrain, for example, there are multiple reflection path measurements that need to be exploited since line-of-sight observations are not always available. Multiple target tracking in urban terrain environments is traditionally implemented using sequential Monte Carlo filtering algorithms and data association techniques. However, data association techniques can be computationally intensive and require very strict conditions for efficient performance. This thesis investigates the probability hypothesis density (PHD) method for tracking multiple targets in urban environments. The PHD is …

Contributors
Zhou, Meng, Papandreou-Suppappola, Antonia, Tepedelenlioglu, Cihan, et al.
Created Date
2011

Redundant Binary (RBR) number representations have been extensively used in the past for high-throughput Digital Signal Processing (DSP) systems. Data-path components based on this number system have smaller critical path delay but larger area compared to conventional two's complement systems. This work explores the use of RBR number representation for implementing high-throughput DSP systems that are also energy-efficient. Data-path components such as adders and multipliers are evaluated with respect to critical path delay, energy and Energy-Delay Product (EDP). A new design for a RBR adder with very good EDP performance has been proposed. The corresponding RBR parallel adder has a …

Contributors
Mahadevan, Rupa, Chakrabarti, Chaitali, Kiaei, Sayfe, et al.
Created Date
2011

As existing solar cell technologies come closer to their theoretical efficiency, new concepts that overcome the Shockley-Queisser limit and exceed 50% efficiency need to be explored. New materials systems are often investigated to achieve this, but the use of existing solar cell materials in advanced concept approaches is compelling for multiple theoretical and practical reasons. In order to include advanced concept approaches into existing materials, nanostructures are used as they alter the physical properties of these materials. To explore advanced nanostructured concepts with existing materials such as III-V alloys, silicon and/or silicon/germanium and associated alloys, fundamental aspects of using these …

Contributors
Dahal, Som Nath, Honsberg, Christiana, Goodnick, Stephen, et al.
Created Date
2011

All-dielectric self-supporting (ADSS) fiber optic cables are used for data transfer by the utilities. They are installed along high voltage transmission lines. Dry band arcing, a phenomenon which is observed in outdoor insulators, is also observed in ADSS cables. The heat developed during dry band arcing damages the ADSS cables' outer sheath. A method is presented here to rate the cable sheath using the power developed during dry band arcing. Because of the small diameter of ADSS cables, mechanical vibration is induced in ADSS cable. In order to avoid damage, vibration dampers known as spiral vibration dampers (SVD) are used …

Contributors
Prabakar, Kumaraguru, Karady, George G, Vittal, Vijay, et al.
Created Date
2011

A low temperature amorphous oxide thin film transistor (TFT) backplane technology for flexible organic light emitting diode (OLED) displays has been developed to create 4.1-in. diagonal backplanes. The critical steps in the evolution of the backplane process include the qualification and optimization of the low temperature (200 °C) metal oxide process, the stability of the devices under forward and reverse bias stress, the transfer of the process to flexible plastic substrates, and the fabrication of white organic light emitting diode (OLED) displays. Mixed oxide semiconductor thin film transistors (TFTs) on flexible plastic substrates typically suffer from performance and stability issues …

Contributors
Marrs, Michael Alan, Raupp, Gregory B, Vogt, Bryan D, et al.
Created Date
2011

In the late 1960s, Granger published a seminal study on causality in time series, using linear interdependencies and information transfer. Recent developments in the field of information theory have introduced new methods to investigate the transfer of information in dynamical systems. Using concepts from Chaos and Markov theory, much of these methods have evolved to capture non-linear relations and information flow between coupled dynamical systems with applications to fields like biomedical signal processing. This thesis deals with the application of information theory to non-linear multivariate time series and develops measures of information flow to identify significant drivers and response (driven) …

Contributors
Prasanna, Shashank, Jassemidis, Leonidas, Tsakalis, Konstantinos, et al.
Created Date
2011

Optical receivers have many different uses covering simple infrared receivers, high speed fiber optic communication and light based instrumentation. All of them have an optical receiver that converts photons to current followed by a transimpedance amplifier to convert the current to a useful voltage. Different systems create different requirements for each receiver. High speed digital communication require high throughput with enough sensitivity to keep the bit error rate low. Instrumentation receivers have a lower bandwidth, but higher gain and sensitivity requirements. In this thesis an optical receiver for use in instrumentation in presented. It is an entirely monolithic design with …

Contributors
Lafevre, Kyle, Bakkaloglu, Bertan, Barnaby, Hugh, et al.
Created Date
2011

Obtaining local electrochemical (EC) information is extremely important for understanding basic surface reactions, and for many applications. Scanning electrochemical microscopy (SECM) can obtain local EC information by scanning a microelectrode across the surface. Although powerful, SECM is slow, the scanning microelectrode may perturb reaction and the measured signal decreases with the size of microelectrode. This thesis demonstrates a new imaging technique based on a principle that is completely different from the conventional EC detection technologies. The technique, referred to as plasmonic-based electrochemical imaging (PECI), images local EC current (both faradaic and non-faradaic) without using a scanning microelectrode. Because PECI response …

Contributors
Shan, Xiaonan, Tao, Nongjian, Chae, Junseok, et al.
Created Date
2011

The high penetration of photovoltaic (PV) both at the utility and at the distribu-tion levels, has raised concerns about the reliability of grid-tied inverters of PV power systems. Inverters are generally considered as the weak link in PV power systems. The lack of a dedicated qualification/reliability standard for PV inverters is a main barrier in realizing higher level of confidence in reliability. Development of a well-accepted design qualification standard specifically for PV inverters will help pave the way for significant improvement in reliability and performance of inverters across the entire industry. The existing standards for PV inverters such as UL …

Contributors
Alampoondi Venkataramanan, Sai Balasubramanian, Ayyanar, Raja, Vittal, Vijay, et al.
Created Date
2011

The long wavelength infrared region (LWIR) and mid wavelength infrared region (MWIR) are of great interest as detection in this region offers a wide range of real time applications. Optoelectronic devices operating in the LWIR and MWIR region offer potential applications such as; optical gas sensing, free-space optical communications, infrared counter-measures, biomedical and thermal imaging etc. HgCdTe is a prominent narrow bandgap material that operates in the LWIR region. The focus of this research work is to simulate and analyze the characteristics of a Hg1-xCdxTe photodetector. To achieve this, the tool `OPTODET' has been developed, where various device parameters can …

Contributors
Muralidharan, Pradyumna, Vasileska, Dragica, Wijewarnasuriya, Priyalal S, et al.
Created Date
2011

In semiconductor physics, many properties or phenomena of materials can be brought to light through certain changes in the materials. Having a tool to define new material properties so as to highlight certain phenomena greatly increases the ability to understand that phenomena. The generalized Monte Carlo tool allows the user to do that by keeping every parameter used to define a material, within the non-parabolic band approximation, a variable in the control of the user. A material is defined by defining its valleys, energies, valley effective masses and their directions. The types of scattering to be included can also be …

Contributors
Hathwar, Raghuraj, Vasileska, Dragica, Goodnick, Stephen M, et al.
Created Date
2011

The development of a Solid State Transformer (SST) that incorporates a DC-DC multiport converter to integrate both photovoltaic (PV) power generation and battery energy storage is presented in this dissertation. The DC-DC stage is based on a quad-active-bridge (QAB) converter which not only provides isolation for the load, but also for the PV and storage. The AC-DC stage is implemented with a pulse-width-modulated (PWM) single phase rectifier. A unified gyrator-based average model is developed for a general multi-active-bridge (MAB) converter controlled through phase-shift modulation (PSM). Expressions to determine the power rating of the MAB ports are also derived. The developed …

Contributors
Falcones, Sixifo Daniel, Ayyanar, Raja, Karady, George, et al.
Created Date
2011

A wireless hybrid device for detecting volatile organic compounds (VOCs) has been developed. The device combines a highly selective and sensitive tuning-fork based detector with a pre-concentrator and a separation column. The selectivity and sensitivity of the tuning-fork based detector is optimized for discrimination and quantification of benzene, toluene, ethylbenzene, and xylenes (BTEX) via a homemade molecular imprinted polymer, and a specific detection and control circuit. The device is a wireless, portable, battery-powered, and cell-phone operated device. The device has been calibrated and validated in the laboratory and using selected ion flow tube mass spectrometry (SFIT-MS). The capability and robustness …

Contributors
Chen, Cheng, Tao, Nongjian, Chae, Junseok, et al.
Created Date
2011

Demand for biosensor research applications is growing steadily. According to a new report by Frost & Sullivan, the biosensor market is expected to reach $14.42 billion by 2016. Clinical diagnostic applications continue to be the largest market for biosensors, and this demand is likely to continue through 2016 and beyond. Biosensor technology for use in clinical diagnostics, however, requires translational research that moves bench science and theoretical knowledge toward marketable products. Despite the high volume of academic research to date, only a handful of biomedical devices have become viable commercial applications. Academic research must increase its focus on practical uses …

Contributors
Choi, Seokheun, Chae, Junseok, Tao, Nongjian, et al.
Created Date
2011

A dual-channel directional digital hearing aid (DHA) front-end using a fully differential difference amplifier (FDDA) based Microphone interface circuit (MIC) for a capacitive Micro Electro Mechanical Systems (MEMS) microphones and an adaptive-power analog font end (AFE) is presented. The Microphone interface circuit based on FDDA converts the capacitance variations into voltage signal, achieves a noise of 32 dB SPL (sound pressure level) and an SNR of 72 dB, additionally it also performs single to differential conversion allowing for fully differential analog signal chain. The analog front-end consists of 40dB VGA and a power scalable continuous time sigma delta ADC, with …

Contributors
Naqvi, Syed Roomi, Kiaei, Sayfe, Bakkaloglu, Bertan, et al.
Created Date
2011

With the increasing focus on developing environmentally benign electronic packages, lead-free solder alloys have received a great deal of attention. Mishandling of packages, during manufacture, assembly, or by the user may cause failure of solder joint. A fundamental understanding of the behavior of lead-free solders under mechanical shock conditions is lacking. Reliable experimental and numerical analysis of lead-free solder joints in the intermediate strain rate regime need to be investigated. This dissertation mainly focuses on exploring the mechanical shock behavior of lead-free tin-rich solder alloys via multiscale modeling and numerical simulations. First, the macroscopic stress/strain behaviors of three bulk lead-free …

Contributors
Fei, Huiyang, Jiang, Hanqing, Chawla, Nikhilesh, et al.
Created Date
2011

This thesis pursues a method to deregulate the electric distribution system and provide support to distributed renewable generation. A locational marginal price is used to determine prices across a distribution network in real-time. The real-time pricing may provide benefits such as a reduced electricity bill, decreased peak demand, and lower emissions. This distribution locational marginal price (D-LMP) determines the cost of electricity at each node in the electrical network. The D-LMP is comprised of the cost of energy, cost of losses, and a renewable energy premium. The renewable premium is an adjustable function to compensate `green' distributed generation. A D-LMP …

Contributors
Kiefer, Brian, Heydt, Gerald T, Shunk, Dan, et al.
Created Date
2011

One of the challenges in future semiconductor device design is excessive rise of power dissipation and device temperatures. With the introduction of new geometrically confined device structures like SOI, FinFET, nanowires and continuous incorporation of new materials with poor thermal conductivities in the device active region, the device thermal problem is expected to become more challenging in coming years. This work examines the degradation in the ON-current due to self-heating effects in 10 nm channel length silicon nanowire transistors. As part of this dissertation, a 3D electrothermal device simulator is developed that self-consistently solves electron Boltzmann transport equation with 3D …

Contributors
Hossain, Arif, Vasileska, Dragica, Ahmed, Shaikh, et al.
Created Date
2011

Many products undergo several stages of testing ranging from tests on individual components to end-item tests. Additionally, these products may be further "tested" via customer or field use. The later failure of a delivered product may in some cases be due to circumstances that have no correlation with the product's inherent quality. However, at times, there may be cues in the upstream test data that, if detected, could serve to predict the likelihood of downstream failure or performance degradation induced by product use or environmental stresses. This study explores the use of downstream factory test data or product field reliability …

Contributors
Mosley, James Holton, Morrell, Darryl, Morrell, Darryl, et al.
Created Date
2011

Process variations have become increasingly important for scaled technologies starting at 45nm. The increased variations are primarily due to random dopant fluctuations, line-edge roughness and oxide thickness fluctuation. These variations greatly impact all aspects of circuit performance and pose a grand challenge to future robust IC design. To improve robustness, efficient methodology is required that considers effect of variations in the design flow. Analyzing timing variability of complex circuits with HSPICE simulations is very time consuming. This thesis proposes an analytical model to predict variability in CMOS circuits that is quick and accurate. There are several analytical models to estimate …

Contributors
Gummalla, Samatha, Chakrabarti, Chaitali, Cao, Yu, et al.
Created Date
2011

Reliable extraction of human pose features that are invariant to view angle and body shape changes is critical for advancing human movement analysis. In this dissertation, the multifactor analysis techniques, including the multilinear analysis and the multifactor Gaussian process methods, have been exploited to extract such invariant pose features from video data by decomposing various key contributing factors, such as pose, view angle, and body shape, in the generation of the image observations. Experimental results have shown that the resulting pose features extracted using the proposed methods exhibit excellent invariance properties to changes in view angles and body shapes. Furthermore, …

Contributors
Peng, Bo, Qian, Gang, Ye, Jieping, et al.
Created Date
2011

In the last few years, significant advances in nanofabrication have allowed tailoring of structures and materials at a molecular level enabling nanofabrication with precise control of dimensions and organization at molecular length scales, a development leading to significant advances in nanoscale systems. Although, the direction of progress seems to follow the path of microelectronics, the fundamental physics in a nanoscale system changes more rapidly compared to microelectronics, as the size scale is decreased. The changes in length, area, and volume ratios due to reduction in size alter the relative influence of various physical effects determining the overall operation of a …

Contributors
Joshi, Punarvasu, Thornton, Trevor J, Goryll, Michael, et al.
Created Date
2011

CMOS technology is expected to enter the 10nm regime for future integrated circuits (IC). Such aggressive scaling leads to vastly increased variability, posing a grand challenge to robust IC design. Variations in CMOS are often divided into two types: intrinsic variations and process-induced variations. Intrinsic variations are limited by fundamental physics. They are inherent to CMOS structure, considered as one of the ultimate barriers to the continual scaling of CMOS devices. In this work the three primary intrinsic variations sources are studied, including random dopant fluctuation (RDF), line-edge roughness (LER) and oxide thickness fluctuation (OTF). The research is focused on …

Contributors
Ye, Yun, Cao, Yu, Yu, Hongbin, et al.
Created Date
2011

The increased use of commercial complementary metal-oxide-semiconductor (CMOS) technologies in harsh radiation environments has resulted in a new approach to radiation effects mitigation. This approach utilizes simulation to support the design of integrated circuits (ICs) to meet targeted tolerance specifications. Modeling the deleterious impact of ionizing radiation on ICs fabricated in advanced CMOS technologies requires understanding and analyzing the basic mechanisms that result in buildup of radiation-induced defects in specific sensitive regions. Extensive experimental studies have demonstrated that the sensitive regions are shallow trench isolation (STI) oxides. Nevertheless, very little work has been done to model the physical mechanisms that …

Contributors
Sanchez Esqueda, Ivan, Barnaby, Hugh J, Schroder, Dieter, et al.
Created Date
2011

There will always be a need for high current/voltage transistors. A transistor that has the ability to be both or either of these things is the silicon metal-silicon field effect transistor (MESFET). An additional perk that silicon MESFET transistors have is the ability to be integrated into the standard silicon on insulator (SOI) complementary metal oxide semiconductor (CMOS) process flow. This makes a silicon MESFET transistor a very valuable device for use in any standard CMOS circuit that may usually need a separate integrated circuit (IC) in order to switch power on or from a high current/voltage because it allows …

Contributors
Sochacki, John J., Thornton, Trevor J, Schroder, Dieter, et al.
Created Date
2011

This research work describes the design of a fault current limiter (FCL) using digital logic and a microcontroller based data acquisition system for an ultra fast pilot protection system. These systems have been designed according to the requirements of the Future Renewable Electric Energy Delivery and Management (FREEDM) system (or loop), a 1 MW green energy hub. The FREEDM loop merges advanced power electronics technology with information tech-nology to form an efficient power grid that can be integrated with the existing power system. With the addition of loads to the FREEDM system, the level of fault current rises because of …

Contributors
Thirumalai, Arvind, Karady, George, Vittal, Vijay, et al.
Created Date
2011

Recent changes in the energy markets structure combined with the conti-nuous load growth have caused power systems to be operated under more stressed conditions. In addition, the nature of power systems has also grown more complex and dynamic because of the increasing use of long inter-area tie-lines and the high motor loads especially those comprised mainly of residential single phase A/C motors. Therefore, delayed voltage recovery, fast voltage collapse and short term voltage stability issues in general have obtained significant importance in relia-bility studies. Shunt VAr injection has been used as a countermeasure for voltage instability. However, the dynamic and …

Contributors
Salloum, Ahmed, Vittal, Vijay, Heydt, Gerald, et al.
Created Date
2011

Spotlight mode synthetic aperture radar (SAR) imaging involves a tomo- graphic reconstruction from projections, necessitating acquisition of large amounts of data in order to form a moderately sized image. Since typical SAR sensors are hosted on mobile platforms, it is common to have limitations on SAR data acquisi- tion, storage and communication that can lead to data corruption and a resulting degradation of image quality. It is convenient to consider corrupted samples as missing, creating a sparsely sampled aperture. A sparse aperture would also result from compressive sensing, which is a very attractive concept for data intensive sen- sors such …

Contributors
Werth, Nicholas, Karam, Lina, Papandreou-Suppappola, Antonia, et al.
Created Date
2011

ABSTRACT The purpose of this study is to demonstrate that stable lipid bilayers can be set up on an array of silicon micropores and can be used as sites for self-inserting ion-channel proteins which can be studied independently of each other. In course of this study an acrylic based holder was designed and machined to ensure leak-free fluidic access to the silicon micropores and physical isolation of the individual array channels. To measure the ion-channel currents, we simulated, designed and manufactured low-noise transimpedance amplifiers and support circuits based on published patch clamp amplifier designs, using currently available surface-mount components. This …

Contributors
Ramakrishnan, Shankar, Goryll, Michael, Thornton, Trevor J, et al.
Created Date
2011

Programmable Metallization Cell (PMC) is a technology platform which utilizes mass transport in solid or liquid electrolyte coupled with electrochemical (redox) reactions to form or remove nanoscale metallic electrodeposits on or in the electrolyte. The ability to redistribute metal mass and form metallic nanostructure in or on a structure in situ, via the application of a bias on laterally placed electrodes, creates a large number of promising applications. A novel PMC-based lateral microwave switch was fabricated and characterized for use in microwave systems. It has demonstrated low insertion loss, high isolation, low voltage operation, low power and low energy consumption, …

Contributors
Ren, Minghan, Kozicki, Michael, Schroder, Dieter, et al.
Created Date
2011

For synthetic aperture radar (SAR) image formation processing, the chirp scaling algorithm (CSA) has gained considerable attention mainly because of its excellent target focusing ability, optimized processing steps, and ease of implementation. In particular, unlike the range Doppler and range migration algorithms, the CSA is easy to implement since it does not require interpolation, and it can be used on both stripmap and spotlight SAR systems. Another transform that can be used to enhance the processing of SAR image formation is the fractional Fourier transform (FRFT). This transform has been recently introduced to the signal processing community, and it has …

Contributors
Northrop, Judith, Papandreou-Suppappola, Antonia, Spanias, Andreas, et al.
Created Date
2011

Sensing and controlling current flow is a fundamental requirement for many electronic systems, including power management (DC-DC converters and LDOs), battery chargers, electric vehicles, solenoid positioning, motor control, and power monitoring. Current Shunt Monitor (CSM) systems have various applications for precise current monitoring of those aforementioned applications. CSMs enable current measurement across an external sense resistor (RS) in series to current flow. Two different types of CSMs designed and characterized in this paper. First design used direct current reading method and the other design used indirect current reading method. Proposed CSM systems can sense power supply current ranging from 1mA …

Contributors
Yeom, Hyunsoo, Bakkaloglu, Bertan, Kiaei, Sayfe, et al.
Created Date
2011

Following the success in incorporating perceptual models in audio coding algorithms, their application in other speech/audio processing systems is expanding. In general, all perceptual speech/audio processing algorithms involve minimization of an objective function that directly/indirectly incorporates properties of human perception. This dissertation primarily investigates the problems associated with directly embedding an auditory model in the objective function formulation and proposes possible solutions to overcome high complexity issues for use in real-time speech/audio algorithms. Specific problems addressed in this dissertation include: 1) the development of approximate but computationally efficient auditory model implementations that are consistent with the principles of psychoacoustics, 2) …

Contributors
Krishnamoorthi, Harish, Spanias, Andreas, Papandreou-Suppappola, Antonia, et al.
Created Date
2011

There is increasing interest in the medical and behavioral health communities towards developing effective strategies for the treatment of chronic diseases. Among these lie adaptive interventions, which consider adjusting treatment dosages over time based on participant response. Control engineering offers a broad-based solution framework for optimizing the effectiveness of such interventions. In this thesis, an approach is proposed to develop dynamical models and subsequently, hybrid model predictive control schemes for assigning optimal dosages of naltrexone, an opioid antagonist, as treatment for a chronic pain condition known as fibromyalgia. System identification techniques are employed to model the dynamics from the daily …

Contributors
Deshpande, Sunil, Rivera, Daniel E., Si, Jennie, et al.
Created Date
2011

Negative bias temperature instability (NBTI) and channel hot carrier (CHC) are important reliability issues impacting analog circuit performance and lifetime. Compact reliability models and efficient simulation methods are essential for circuit level reliability prediction. This work proposes a set of compact models of NBTI and CHC effects for analog and mixed-signal circuit, and a direct prediction method which is different from conventional simulation methods. This method is applied in circuit benchmarks and evaluated. This work helps with improving efficiency and accuracy of circuit aging prediction. Dissertation/Thesis

Contributors
Zheng, Rui, Cao, Yu, Yu, Hongyu, et al.
Created Date
2011

With tremendous increase in the popularity of networked multimedia applications, video data is expected to account for a large portion of the traffic on the Internet and more importantly next-generation wireless systems. To be able to satisfy a broad range of customers requirements, two major problems need to be solved. The first problem is the need for a scalable representation of the input video. The recently developed scalable extension of the state-of-the art H.264/MPEG-4 AVC video coding standard, also known as H.264/SVC (Scalable Video Coding) provides a solution to this problem. The second problem is that wireless transmission medium typically …

Contributors
Sundararaman, Hari, Reisslein, Martin, Seeling, Patrick, et al.
Created Date
2011

In this thesis, I present a lab-on-a-chip (LOC) that can separate and detect Escherichia Coli (E. coli) in simulated urine samples for Urinary Tract Infection (UTI) diagnosis. The LOC consists of two (concentration and sensing) chambers connected in series and an integrated impedance detector. The two-chamber approach is designed to reduce the non-specific absorption of proteins, e.g. albumin, that potentially co-exist with E. coli in urine. I directly separate E. coli K-12 from a urine cocktail in a concentration chamber containing micro-sized magnetic beads (5 µm in diameter) conjugated with anti-E. coli antibodies. The immobilized E. coli are transferred to …

Contributors
Kim, Sangpyeong, Chae, Junseok, Phillips, Stephen M., et al.
Created Date
2011

Ge1-ySny alloys represent a new class of photonic materials for integrated optoelectronics on Si. In this work, the electrical and optical properties of Ge1-ySny alloy films grown on Si, with concentrations in the range 0 ≤ y ≤ 0.04, are studied via a variety of methods. The first microelectronic devices from GeSn films were fabricated using newly developed CMOS-compatible protocols, and the devices were characterized with respect to their electrical properties and optical response. The detectors were found to have a detection range that extends into the near-IR, and the detection edge is found to shift to longer wavelengths with …

Contributors
Mathews, Jay, Menéndez, José, Kouvetakis, John, et al.
Created Date
2011

Residue number systems have gained significant importance in the field of high-speed digital signal processing due to their carry-free nature and speed-up provided by parallelism. The critical aspect in the application of RNS is the selection of the moduli set and the design of the conversion units. There have been several RNS moduli sets proposed for the implementation of digital filters. However, some are unbalanced and some do not provide the required dynamic range. This thesis addresses the drawbacks of existing RNS moduli sets and proposes a new moduli set for efficient implementation of FIR filters. An efficient VLSI implementation …

Contributors
Chalivendra, Gayathri, Vrudhula, Sarma, Shrivastava, Aviral, et al.
Created Date
2011

The demand for handheld portable computing in education, business and research has resulted in advanced mobile devices with powerful processors and large multi-touch screens. Such devices are capable of handling tasks of moderate computational complexity such as word processing, complex Internet transactions, and even human motion analysis. Apple's iOS devices, including the iPhone, iPod touch and the latest in the family - the iPad, are among the well-known and widely used mobile devices today. Their advanced multi-touch interface and improved processing power can be exploited for engineering and STEM demonstrations. Moreover, these devices have become a part of everyday student …

Contributors
Liu, Jinru, Spanias, Andreas, Tsakalis, Kostas, et al.
Created Date
2011

Hydropower generation is one of the clean renewable energies which has received great attention in the power industry. Hydropower has been the leading source of renewable energy. It provides more than 86% of all electricity generated by renewable sources worldwide. Generally, the life span of a hydropower plant is considered as 30 to 50 years. Power plants over 30 years old usually conduct a feasibility study of rehabilitation on their entire facilities including infrastructure. By age 35, the forced outage rate increases by 10 percentage points compared to the previous year. Much longer outages occur in power plants older than …

Contributors
Kwon, Ogeuk, Holbert, Keith E, Heydt, Gerald T, et al.
Created Date
2011

Due to the growing concerns on the depletion of petroleum based energy resources and climate change; fuel cell technologies have received much attention in recent years. Proton exchange membrane fuel cell (PEMFCs) features high energy conversion efficiency and nearly zero greenhouse gas emissions, because of its combination of the hydrogen oxidation reaction (HOR) at anode side and oxygen reduction reaction (ORR) at cathode side. Synthesis of Pt nanoparticles supported on multi walled carbon nanotubes (MWCNTs) possess a highly durable electrochemical surface area (ESA) and show good power output on proton exchange membrane (PEM) fuel cell performance. Platinum on multi-walled carbon …

Contributors
Liu, Xuan, Madakannan, Arunachalanadar, Munukutla, Lakshmi, et al.
Created Date
2011

Different environmental factors, such as ultraviolet radiation (UV), relative humidity (RH) and the presence of reducing gases (acetone and ethanol), play an important role in the daily life of human beings. UV is very important in a number of areas, such as astronomy, resin curing of polymeric materials, combustion engineering, water purification, flame detection and biological effects with more recent proposals like early missile plume detection, secure space-to-space communications and pollution monitoring. RH is a very common parameter in the environment. It is essential not only for human comfort, but also for a broad spectrum of industries and technologies. There …

Contributors
Qiu, Xiaotun, Yu, Hongyu, Christen, Jennifer Blain, et al.
Created Date
2011

Social situational awareness, or the attentiveness to one's social surroundings, including the people, their interactions and their behaviors is a complex sensory-cognitive-motor task that requires one to be engaged thoroughly in understanding their social interactions. These interactions are formed out of the elements of human interpersonal communication including both verbal and non-verbal cues. While the verbal cues are instructive and delivered through speech, the non-verbal cues are mostly interpretive and requires the full attention of the participants to understand, comprehend and respond to them appropriately. Unfortunately certain situations are not conducive for a person to have complete access to their …

Contributors
Krishna, Sreekar, Panchanathan, Sethuraman, Black, John A, et al.
Created Date
2011

This thesis presents a gas sensor readout IC for amperometric and conductometric electrochemical sensors. The Analog Front-End (AFE) readout circuit enables tracking long term exposure to hazardous gas fumes in diesel and gasoline equipments, which may be correlated to diseases. Thus, the detection and discrimination of gases using microelectronic gas sensor system is required. This thesis describes the research, development, implementation and test of a small and portable based prototype platform for chemical gas sensors to enable a low-power and low noise gas detection system. The AFE reads out the outputs of eight conductometric sensor array and eight amperometric sensor …

Contributors
Kim, Hyuntae, Bakkaloglu, Bertan, Vermeire, Bert, et al.
Created Date
2011

Programmable Metallization Cell (PMC) is a resistance-switching device based on migration of nanoscale quantities of cations in a solid electrolyte and formation of a conducting electrodeposit by the reductions of these cations. This dissertation presents electrical characterization results on Cu-SiO2 based PMC devices, which due to the na- ture of materials can be easily integrated into the current Complimentary metal oxide semiconductor (CMOS) process line. Device structures representing individual mem- ory cells based on W bottom electrode and n-type Si bottom electrode were fabricated for characterization. For the W bottom electrode based devices, switching was ob- served for voltages in …

Contributors
Puthenthermadam, Sarath, Kozicki, Michael N, Diaz, Rodolfo, et al.
Created Date
2011

This thesis examines themodeling, analysis, and control system design issues for scramjet powered hypersonic vehicles. A nonlinear three degrees of freedom longitudinal model which includes aero-propulsion-elasticity effects was used for all analyses. This model is based upon classical compressible flow and Euler-Bernouli structural concepts. Higher fidelity computational fluid dynamics and finite element methods are needed for more precise intermediate and final evaluations. The methods presented within this thesis were shown to be useful for guiding initial control relevant design. The model was used to examine the vehicle's static and dynamic characteristics over the vehicle's trimmable region. The vehicle has significant …

Contributors
Khatri, Jaidev, Rodriguez, Armando Antonio, Tsakalis, Konstantinos, et al.
Created Date
2011

To extend the lifetime of complementary metal-oxide-semiconductors (CMOS), emerging process techniques are being proposed to conquer the manufacturing difficulties. New structures and materials are proposed with superior electrical properties to traditional CMOS, such as strain technology and feedback field-effect transistor (FB-FET). To continue the design success and make an impact on leading products, advanced circuit design exploration must begin concurrently with early silicon development. Therefore, an accurate and scalable model is desired to correctly capture those effects and flexible to extend to alternative process choices. For example, strain technology has been successfully integrated into CMOS fabrication to improve transistor performance …

Contributors
Wang, Chi-Chao, Cao, Yu, Chakrabarti, Chaitali, et al.
Created Date
2011

Programmable Metallization Cell (PMC) technology has been shown to possess the necessary qualities for it to be considered as a leading contender for the next generation memory. These qualities include high speed and endurance, extreme scalability, ease of fabrication, ultra low power operation, and perhaps most importantly ease of integration with the CMOS back end of line (BEOL) process flow. One area where detailed study is lacking is the reliability of PMC devices. In previous reliability work, the low and high resistance states were monitored for periods of hours to days without any applied voltage and the results were extrapolated …

Contributors
Kamalanathan, Deepak, Kozicki, Dr. Michael, Schroder, Dr. Dieter, et al.
Created Date
2011

In this work, a high resolution analog-to-digital converter (ADC) for use in harsh environments is presented. The ADC is implemented in bulk CMOS technology and is intended for space exploration, mining and automotive applications with a range of temperature variation in excess of 250°C. A continuous time (CT) sigma delta modulator employing a cascade of integrators with feed forward (CIFF) architecture in a single feedback loop topology is used for implementing the ADC. In order to enable operation in the intended application environments, an RC time constant tuning engine is proposed. The tuning engine is used to maintain linearity of …

Contributors
Anabtawi, Nijad, Barnaby, Hugh, Vermeire, Bert, et al.
Created Date
2011

This dissertation builds a clear understanding of the role of information in wireless networks, and devises adaptive strategies to optimize the overall performance. The meaning of information ranges from channel/network states to the structure of the signal itself. Under the common thread of characterizing the role of information, this dissertation investigates opportunistic scheduling, relaying and multicast in wireless networks. To assess the role of channel state information, the problem of opportunistic distributed opportunistic scheduling (DOS) with incomplete information is considered for ad-hoc networks in which many links contend for the same channel using random access. The objective is to maximize …

Contributors
Paataguppe Suryanarayan Bhat, Chandrashekhar Thejaswi, Zhang, Junshan, Cochran, Douglas, et al.
Created Date
2011

This research work illustrates the use of software packages based on the concept of nu-merical analysis technique to evaluate the electric field and voltage distribution along composite insulators for system voltages ranging from 138 kV up to 1200 kV ac. A part of the calculations was made using the 3D software package, COULOMB 8.0, based on the concept of Boundary Element Method (BEM). The electric field was calculated under dry and wet conditions. Compo-site insulators experience more electrical stress when compared to porcelain and are also more prone to damage caused by corona activity. The work presented here investigates the …

Contributors
Doshi, Tanushri, Gorur, Ravi S, Vittal, Vijay, et al.
Created Date
2010

Composite insulators on overhead lines are frequently subjected to corona discharges due to increased electric field intensities under various conditions. These discharges can cause localized heating on the surface and affect the hydrophobicity of the insulator. A study has been undertaken to quantify and evaluate the thermal degradation that composite insulation is subjected to from corona discharges. This has been conducted primarily at the power frequency (60 Hz) and at the low frequency range (37 kHz). Point to plane corona discharge experiments have been performed in the laboratory at both the frequencies and varying levels of thermal degradation has been …

Contributors
Sangaraju Venkateshwara, Pradeep Varma, Gorur, Ravi S, Farmer, Richard, et al.
Created Date
2010

Optical Instrument Transformers (OIT) have been developed as an alternative to traditional instrument transformers (IT). The question "Can optical instrument transformers substitute for the traditional transformers?" is the main motivation of this study. Finding the answer for this question and developing complete models are the contributions of this work. Dedicated test facilities are developed so that the steady state and transient performances of analog outputs of a magnetic current transformer (CT) and a magnetic voltage transformer (VT) are compared with that of an optical current transformer (OCT) and an optical voltage transformer (OVT) respectively. Frequency response characteristics of OIT outputs …

Contributors
Kucuksari, Sadik, Karady, George G, Heydt, Gerald T, et al.
Created Date
2010

A systematic top down approach to minimize risk and maximize the profits of an investment over a given period of time is proposed. Macroeconomic factors such as Gross Domestic Product (GDP), Consumer Price Index (CPI), Outstanding Consumer Credit, Industrial Production Index, Money Supply (MS), Unemployment Rate, and Ten-Year Treasury are used to predict/estimate asset (sector ETF`s) returns. Fundamental ratios of individual stocks are used to predict the stock returns. An a priori known cash-flow sequence is assumed available for investment. Given the importance of sector performance on stock performance, sector based Exchange Traded Funds (ETFs) for the S&P; and Dow …

Contributors
Chitturi, Divakar, Rodriguez, Armando, Tsakalis, Konstantinos S, et al.
Created Date
2010

The thesis focuses on cost-efficient integration of the electro-chemical residue sensor (ECRS), a novel sensor developed for the in situ and real-time measurement of the residual impurities left on the wafer surface and in the fine structures of patterned wafers during typical rinse processes, and wireless transponder circuitry that is based on RFID technology. The proposed technology uses only the NMOS FD-SOI transistors with amorphous silicon as active material with silicon nitride as a gate dielectric. The proposed transistor was simulated under the SILVACO ATLAS Simulation Framework. A parametric study was performed to study the impact of different gate lengths …

Contributors
Pandit, Vedhas, Vermeire, Bert, Barnaby, Hugh, et al.
Created Date
2010

The exponential rise in unmanned aerial vehicles has necessitated the need for accurate pose estimation under any extreme conditions. Visual Odometry (VO) is the estimation of position and orientation of a vehicle based on analysis of a sequence of images captured from a camera mounted on it. VO offers a cheap and relatively accurate alternative to conventional odometry techniques like wheel odometry, inertial measurement systems and global positioning system (GPS). This thesis implements and analyzes the performance of a two camera based VO called Stereo based visual odometry (SVO) in presence of various deterrent factors like shadows, extremely bright outdoors, …

Contributors
Dhar, Anchit, Saripalli, Srikanth, Li, Baoxin, et al.
Created Date
2010

The constant scaling of supply voltages in state-of-the-art CMOS processes has led to severe limitations for many analog circuit applications. Some CMOS processes have addressed this issue by adding high voltage MOSFETs to their process. Although it can be a completely viable solution, it usually requires a changing of the process flow or adding additional steps, which in turn, leads to an increase in fabrication costs. Si-MESFETs (silicon-metal-semiconductor-field-effect-transistors) from Arizona State University (ASU) on the other hand, have an inherent high voltage capability and can be added to any silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) CMOS process free of cost. This …

Contributors
Lepkowski, William, Thornton, Trevor, Bakkaloglu, Bertan, et al.
Created Date
2010

Radiation hardening by design (RHBD) has become a necessary practice when creating circuits to operate within radiated environments. While employing RHBD techniques has tradeoffs between size, speed and power, novel designs help to minimize these penalties. Space radiation is the primary source of radiation errors in circuits and two types of single event effects, single event upsets (SEU), and single event transients (SET) are increasingly becoming a concern. While numerous methods currently exist to nullify SEUs and SETs, special consideration to the techniques of temporal hardening and interlocking are explored in this thesis. Temporal hardening mitigates both SETs and SEUs …

Contributors
Matush, Bradley, Clark, Lawrence T, Allee, David, et al.
Created Date
2010

An advantage of doubly fed induction generators (DFIGs) as compared to conventional fixed speed wind turbine generators is higher efficiency. This higher efficiency is achieved due to the ability of the DFIG to operate near its optimal turbine efficiency over a wider range of wind speeds through variable speed operation. This is achieved through the application of a back-to-back converter that tightly controls the rotor current and allows for asynchronous operation. In doing so, however, the power electronic converter effectively decouples the inertia of the turbine from the system. Hence, with the increase in penetration of DFIG based wind farms, …

Contributors
Gautam, Durga, Vittal, Vijay, Heydt, Gerald, et al.
Created Date
2010

Ethernet switching is provided to interconnect multiple Ethernets for the exchange of Ethernet data frames. Most Ethernet switches require data buffering and Ethernet signal regeneration at the switch which incur the problems of substantial signal processing, power consumption, and transmission delay. To solve these problems, a cross bar architecture switching system for 10GBASE-T Ethernet is proposed in this thesis. The switching system is considered as the first step of implementing a multi-stage interconnection network to achieve Terabit or Petabit switching. By routing customized headers in capsulated Ethernet frames in an out-of-band control method, the proposed switching system would transmit the …

Contributors
Luo, Haojun, Hui, Joseph, Zhang, Junshan, et al.
Created Date
2010

Silicon carbide (SiC), long touted as a material that can satisfy the specific property requirements for high temperature and high power applications, was studied quantitatively using various techniques. The electronic band structure of 4H SiC is examined in the first half of this dissertation. A brief introduction to band structure calculations, with particular emphasis on the empirical pseudopotential method, is given as a foundation for the subsequent work. Next, the crystal pseudopotential for 4H SiC is derived in detail, and a novel approach using a genetic algorithm search routine is employed to find the fitting parameters needed to generate the …

Contributors
Ng, Garrick, Schroder, Dieter K, Vasileska, Dragica, et al.
Created Date
2010

There is a growing interest in the creation of three-dimensional (3D) images and videos due to the growing demand for 3D visual media in commercial markets. A possible solution to produce 3D media files is to convert existing 2D images and videos to 3D. The 2D to 3D conversion methods that estimate the depth map from 2D scenes for 3D reconstruction present an efficient approach to save on the cost of the coding, transmission and storage of 3D visual media in practical applications. Various 2D to 3D conversion methods based on depth maps have been developed using existing image and …

Contributors
Li, Jinjin, Karam, Lina J, Chakrabarti, Chaitali, et al.
Created Date
2010

After a power system blackout, system restoration is the most important task for the operators. Most power systems rely on an off&ndashline; restoration plan and the experience of operators to select scenarios for the black start path. Using an off&ndashline; designed restoration plan based on past experience may not be the most reliable approach under changing network configurations and loading levels. Hence, an objective restoration path selection procedure, including the option to check constraints, may be more responsive in providing directed guidance to the operators to identify the optimal transmission path to deliver power to other power plants or to …

Contributors
Wang, Chong, Vittal, Vijay, Tylavsky, Daniel, et al.
Created Date
2010

The U.S. Navy is interested in evaluating the dielectric performance of SF6 at 30 kHz in order to develop optimal bushing designs and to ensure reliable operation for the Very Low Frequency/ Low Frequency (VLF/LF) transmitting stations. The breakdown experiments of compressed SF6 at 30 kHz in the pressure range of 1-5 atm were conducted in both the uniform field (plane-plane gap) and the non-uniform field (rod-plane gap). To understand the impact of pressure on the breakdown voltage of SF6 at VLF/LF, empirical models of the dielectric strength of SF6 were derived based on the experimental data and regression analysis. …

Contributors
Han, Jian, Gorur, Ravi S, Farmer, Richard G, et al.
Created Date
2010

A dual-channel directional digital hearing aid (DHA) front end using Micro Electro Mechanical System (MEMS) microphones and an adaptive-power analog processing signal chain is presented. The analog front end consists of a double differential amplifier (DDA) based capacitance to voltage conversion circuit, 40dB variable gain amplifier (VGA) and a continuous time sigma delta analog to digital converter (CT - ΣΔ ADC). Adaptive power scaling of the 4th order CT - ΣΔ achieves 68dB SNR at 120μW, which can be scaled down to 61dB SNR at 67μW. This power saving will increse the battery life of the DHA. Dissertation/Thesis

Contributors
Deligoz, Ilker, Kiaei, Sayfe, Bakkaloglu, Bertan, et al.
Created Date
2010

Silicon Carbide (SiC) junction field effect transistors (JFETs) are ideal for switching high current, high voltage loads in high temperature environments. These devices require external drive circuits to generate pulse width modulated (PWM) signals switching from 0V to approximately 10V. Advanced CMOS microcontrollers are ideal for generating the PWM signals but are limited in output voltage due to their low breakdown voltage within the CMOS drive circuits. As a result, an intermediate buffer stage is required between the CMOS circuitry and the JFET. In this thesis, a discrete silicon-on-insulator (SOI) metal semiconductor field effect transistor (MESFET) was used to drive …

Contributors
Summers, Nicholas Burton, Thornton, Trevor J, Goryll, Michael, et al.
Created Date
2010

Photovoltaic (PV) modules appear to have three classifications of failure: Infant mortality, normal-life failure, and end-of-life failure. Little is known of the end-of-life failures experienced by PV modules due to their inherent longevity. Accelerated Life Testing (ALT) has been at the crux of this lifespan prediction; however, without naturally failing modules an accurate acceleration factor cannot be determined for use in ALT. By observing modules that have been aged in the field, a comparison can be made with modules undergoing accelerated testing. In this study an investigation on about 1900 aged (10-17 years) grid-tied PV modules installed in the desert …

Contributors
Suleske, Adam Alfred, Tamizhmani, Govindasamy, Rogers, Bradley, et al.
Created Date
2010

The RADiation sensitive Field Effect Transistor (RADFET) has been conventionally used to measure radiation dose levels. These dose sensors are calibrated in such a way that a shift in threshold voltage, due to a build-up of oxide-trapped charge, can be used to estimate the radiation dose. In order to estimate the radiation dose level using RADFET, a wired readout circuit is necessary. Using the same principle of oxide-trapped charge build-up, but by monitoring the change in capacitance instead of threshold voltage, a wireless dose sensor can be developed. This RADiation sensitive CAPacitor (RADCAP) mounted on a resonant patch antenna can …

Contributors
Srinivasan Gopalan, Madusudanan, Barnaby, Hugh, Holbert, Keith, et al.
Created Date
2010

Market acceptability of distributed energy resource (DER) technologies and the gradual and consistent increase in their depth of penetration have generated significant interest over the past few years. In particular, in Arizona and several other states there has been a substantial in-crease in distributed photovoltaic (PV) generation interfaced to the power distribution systems, and is expected to continue to grow at a significant rate. This has made integration, control and optimal operation of DER units a main area of focus in the design and operation of distribution systems. Grid-connected, distributed PV covers a wide range of power levels ranging from …

Contributors
Narayanan, Anand, Ayyanar, Raja, Vittal, Vijay, et al.
Created Date
2010

Implantable medical device technology is commonly used by doctors for disease management, aiding to improve patient quality of life. However, it is possible for these devices to be exposed to ionizing radiation during various medical therapeutic and diagnostic activities while implanted. This commands that these devices remain fully operational during, and long after, radiation exposure. Many implantable medical devices employ standard commercial complementary metal-oxide-semiconductor (CMOS) processes for integrated circuit (IC) development, which have been shown to degrade with radiation exposure. This necessitates that device manufacturers study the effects of ionizing radiation on their products, and work to mitigate those effects …

Contributors
Schlenvogt, Garrett James, Barnaby, Hugh J, Goodnick, Stephen, et al.
Created Date
2010

In this thesis two methodologies have been proposed for evaluating the fault response of analog/RF circuits. These proposed approaches are used to evaluate the response of the faulty circuit in terms of specifications/measurements. Faulty response can be used to evaluate important test metrics like fail probability, fault coverage and yield coverage of given measurements under process variations. Once the models for faulty and fault free circuit are generated, one needs to perform Monte Carlo sampling (as opposed to Monte Carlo simulations) to compute these statistical parameters with high accuracy. The first method is based on adaptively determining the order of …

Contributors
Subrahmaniyan Radhakrishnan, Gurusubrahmaniyan, Ozev, Sule, Blain Christen, Jennifer, et al.
Created Date
2010

Magnetic resonance (MR) imaging with data acquisition on a non-rectangular grid permits a variety of approaches to cover k-space. This flexibility can be exploited to achieve clinically relevant characteristics -- fast yet full coverage for short scan times, center out schemes for short Te, over-sampled k-space for robustness to motion, long acquisition time for improved signal-to-noise (SNR) performance and benign under-sampling (aliasing) artifact. This dissertation presents advances in Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction (PROPELLER) trajectory design and improved reconstruction for spiral imaging. Scan time in PROPELLER imaging can be reduced by tailoring the trajectory to the required …

Contributors
Devaraj, Ajit, Pipe, James G, Karam, Lina J, et al.
Created Date
2010

As the world energy demand increases, semiconductor devices with high energy conversion efficiency become more and more desirable. The energy conversion consists of two distinct processes, namely energy generation and usage. In this dissertation, novel multi-junction solar cells and light emitting diodes (LEDs) are proposed and studied for high energy conversion efficiency in both processes, respectively. The first half of this dissertation discusses the practically achievable energy conversion efficiency limit of solar cells. Since the demonstration of the Si solar cell in 1954, the performance of solar cells has been improved tremendously and recently reached 41.6% energy conversion efficiency. However, …

Contributors
Wu, Songnan, Zhang, Yong-Hang, Menendez, Jose, et al.
Created Date
2010

ABSTRACT Ongoing research into wireless transceivers in the 60 GHz band is required to address the demand for high data rate communications systems at a frequency where signal propagation is challenging even over short ranges. This thesis proposes a mixer architecture in Complementary Metal Oxide Semiconductor (CMOS) technology that uses a voltage controlled oscillator (VCO) operating at a fractional multiple of the desired output signal. The proposed topology is different from conventional subharmonic mixing in that the oscillator phase generation circuitry usually required for such a circuit is unnecessary. Analysis and simulations are performed on the proposed mixer circuit in …

Contributors
Martino, Todd Jeffrey, Kiaei, Sayfe, Bakkaloglu, Bertan, et al.
Created Date
2010

Graphene, a one atomic thick planar sheet of carbon atoms, has a zero gap band structure with a linear dispersion relation. This unique property makes graphene a favorite for physicists and engineers, who are trying to understand the mechanism of charge transport in graphene and using it as channel material for field effect transistor (FET) beyond silicon. Therefore, an in-depth exploring of these electrical properties of graphene is urgent, which is the purpose of this dissertation. In this dissertation, the charge transport and quantum capacitance of graphene were studied. Firstly, the transport properties of back-gated graphene transistor covering by high …

Contributors
Xia, Jilin, Tao, N.J., Ferry, David, et al.
Created Date
2010

Distributed inference has applications in fields as varied as source localization, evaluation of network quality, and remote monitoring of wildlife habitats. In this dissertation, distributed inference algorithms over multiple-access channels are considered. The performance of these algorithms and the effects of wireless communication channels on the performance are studied. In a first class of problems, distributed inference over fading Gaussian multiple-access channels with amplify-and-forward is considered. Sensors observe a phenomenon and transmit their observations using the amplify-and-forward scheme to a fusion center (FC). Distributed estimation is considered with a single antenna at the FC, where the performance is evaluated using …

Contributors
Banavar, Mahesh Krishna, Tepedelenlioglu, Cihan, Spanias, Andreas, et al.
Created Date
2010

An investigation of phase noise in amplifier and voltage-controller oscillator (VCO) circuits was conducted to show that active direct-current (DC) bias techniques exhibit lower phase noise performance than traditional resistive DC bias techniques. Low-frequency high-gain amplifiers like those found in audio applications exhibit much better 1/f phase noise performance and can be used to bias amplifier or VCO circuits that work at much higher frequencies to reduce the phase modulation caused by higher frequency devices. An improvement in single-side-band (SSB) phase noise of 15 dB at offset frequencies less than 50 KHz was simulated and measured. Residual phase noise of …

Contributors
Baldwin, Jeremy Bart, Aberle, James, Bakkaloglu, Bertan, et al.
Created Date
2010

Electronic devices are gaining an increasing market share in the medical field. Medical devices are becoming more sophisticated, and encompassing more applications. Unlike consumer electronics, medical devices have far more limitations when it comes to area, power and most importantly reliability. The medical devices industry has recently seen the advantages of using Flash memory instead of Read Only Memory (ROM) for firmware storage, and in some cases to replace Electrically Programmable Read Only Memories (EEPROMs) in medical devices for frequent data storage. There are direct advantages to using Flash memory instead of Read Only Memory, most importantly the fact that …

Contributors
Hag, Eslam E., Kozicki, Michael N, Schroder, Dieter K, et al.
Created Date
2010