Electrical and Computer Engineering Commons^™

Negative Conductance Load Modulation Rf Power Amplifier, Cody R. Neslen

Master's Theses

The number of mobile wireless devices on the market has increased substantially over the last decade. The frequency spectrum has become crowded due to the number of devices demanding radio traffic and new modulation schemes have been developed to accommodate the number of users. These new modulation schemes have caused very poor efficiencies in power amplifiers for wireless transmission systems due to high peak-to-average power ratios (PAPR). This thesis first presents the issue with classical power amplifiers in modern modulation systems. A brief overview of current attempts to mitigate this issue is provided. A new RF power amplifier topology is …

Pulse Density Modulated Soft Switching Cycloconverter, Jesse Timothy Adamson

Master's Theses

Single stage cycloconverters generally incorporate hard switching at turn on and soft switching at turn off. This hard switching at turn on combined with the slow switching speeds of thyristors (the switch of choice for standard cycloconverters) limits their use to lower frequency applications.

This thesis explores the analysis and design of a pulse density modulated (PDM), soft switching cycloconverter. Unlike standard cycloconverters, the controller in this converter does not adjust thyristor firing angles. It lets only complete half cycles of the input waveform through to the output. This allows and requires a much greater frequency step down from the …

A Constant Conduction Angle Biased Rf Power Amplifier For Improved Linearization In Class C Operation, Greg Lacaille

Master's Theses

Class C power amplifiers offer higher efficiency than class B power amplifiers, but suffer from poor linearity. A feedback based biasing system to improve the linearity of a class C power amplifier is designed. A class B amplifier with a gain of 20 dB and 20 MHz bandwidth at 900 MHz acts as the launching point for the design. The biasing and output network of the class B power amplifier is modified to produce a class C amplifier at conduction angles of 180°, 162°, 126°, 90°, and 54°. A feedback based biasing system, which uses two matched and scaled down …

Multiple Robot Boundary Tracking With Phase And Workload Balancing, Michael Jay Boardman

Master's Theses

This thesis discusses the use of a cooperative multiple robot system as applied to distributed tracking and sampling of a boundary edge. Within this system the boundary edge is partitioned into subsegments, each allocated to a particular robot such that workload is balanced across the robots. Also, to minimize the time between sampling local areas of the boundary edge, it is desirable to minimize the difference between each robot’s progression (i.e. phase) along its allocated sub segment of the edge. The paper introduces a new distributed controller that handles both workload and phase balancing. Simulation results are used to illustrate …

Space-Time Adaptive Processing With Multi-Staged Wiener Filter And Principal Component Signal Dependent Algorithms, Zheng N. Zhou

Master's Theses

Space-time Adaptive Processing (STAP) is a two-dimensional filtering technique for antenna array with multiple spatial channels. The name "space-time" describes the coupling of these spatial channels with pulse-Doppler waveforms. Applications for STAP includes ground moving target indicator (GMTI) for airborne radar systems.

Today, there are strong interests to develop STAP algorithms for operations in “sample starved” environments, where intense environmental interference can reduce STAP capacity to detect and track ground targets. Careful applications of STAP can effectively overcome these conditions by suppressing these interferences and maximize the signal to interference plus noise ratio (SINR). The Multi-stage Wiener filter (MWF) and …

Wave Energy Converter Performance Modeling And Cost Of Electricity Assessment, Dmitri Jarocki

Master's Theses

California is experiencing a rapid increase in interest for the potential of converting ocean waves into clean electricity. Numerous applications have been submitted for the permitting of such renewable energy projects; however the profitability, practicability, and survivability have yet to be proven. Wave energy conversion technology has steadily matured since its naissance in the 1970’s, several wave energy power installations currently exist, and numerous plans for commercial power plant are in the works on the shores of multiple continents. This study aims to assess the economic viability of two proposed commercial wave energy power plant projects on the Central California …

Near Real-Time Exercise Machine Power Statistics Reporting, Brendan C. Asche

Master's Theses

Cal Poly’s Recreation Center expansion project provides an opportunity to implement Energy Harvesting From Exercise Machines (EHFEM). Part of this implementation is a system that reports the exercise machines’ energy production. Although products capable of reporting exercise machine energy harvesting statistics exist, they have limited capabilities. This thesis project defends a system capable of reporting exercise machine power statistics in near real-time.

The system consists of display, database, and power measurement modules. The display module presents statistics in an interactive, graphical, and widely-accessible way. The database module provides an efficient way of organizing and accessing stored statistics. Multiple power measurement …

High Voltage Resonant Self-Tracking Current-Fed Converter, Scott Logan Mcclusky

Master's Theses

High voltage power supply design presents unique requirements, combining safety, controllability, high performance, and high efficiencies. A new Resonant Self-Tracking Current-Fed Converter (RST-CFC) is investigated as a proof-of-concept of a high voltage power supply particularly for an X-ray system. These systems require fast voltage rise times and low ripple to yield a clear image.

The proposed converter implements high-frequency resonance among discrete components and transformer parasitics to achieve high voltage gain, and the self-tracking nature ensures operation at maximum gain while power switches achieve zero-voltage switching across the full load range. This converter exhibits an inherent indefinite short-circuit capability. Theoretical …

Receive Sensitivity Characterization Of The Polysat Satellite Communication System, Ivan M. Bland

Master's Theses

Following the successful launch of CP3 and CP4, the PolySat team noticed an unreliable uplink to both satellites. A significant problem with the PolySat COMM system is poor receive sensitivity of the communications system. Efforts have been made to improve the uplink margin, but without proper characterization of the receiver sensitivity, the problem cannot be fully addressed. By developing an accurate method of measuring receive sensitivity, a methodical approach can be used to properly diagnose the communication system and link budget. Two revisions of the PolySat COMM system will be measured and compared. An in-depth study of the PolySat COMM …

Charge Injection And Clock Feedthrough, Jonathan Yu

Master's Theses

Turning off a transistor introduces an error voltage in switched-capacitor circuits. Circuits such as analog-to-digital converters (ADC), digital-to-analog converters (DAC), and CMOS image sensor pixels are limited in performance due to the effects known as charge injection and clock feedthrough. Charge injection occurs in a switched-capacitor circuit when the transistor turns off and disperses channel charge into the source and drain. The source, which is the sampling capacitor, experiences an error in the sampled voltage due to the incoming channel charge. Simultaneously, the coupling due to gate-source overlap capacitance also contributes to the total error voltage, which is known as …

Denoising Of Natural Images Using The Wavelet Transform, Manish Kumar Singh

Master's Theses

A new denoising algorithm based on the Haar wavelet transform is proposed. The methodology is based on an algorithm initially developed for image compression using the Tetrolet transform. The Tetrolet transform is an adaptive Haar wavelet transform whose support is tetrominoes, that is, shapes made by connecting four equal sized squares. The proposed algorithm improves denoising performance measured in peak signal-to-noise ratio (PSNR) by 1-2.5 dB over the Haar wavelet transform for images corrupted by additive white Gaussian noise (AWGN) assuming universal hard thresholding. The algorithm is local and works independently on each 4x4 block of the image. It performs …

The Design And Manufacture Of A Light Emitting Diode Package For General Lighting, Michael S. Krist

Master's Theses

Lighting technologies have evolved over the years to become higher quality, more efficient sources of light. LEDs are poised to become the market standard for general lighting because they are the most power efficient form of lighting and do not contain hazardous materials. Unfortunately, LEDs pose unique problems because advanced thermal management is required to remove the high heat fluxes generated by such relatively small devices. These problems have already been overcome with complex packaging and exotic materials, but high costs are preventing this technology from displacing current lighting technologies.

The purpose of this study is to develop a low-cost …

Design Techniques To Improve Time Dependent Dielectric Breakdown Based Failure For Cmos Circuits, Emanuel S. Tarog

Master's Theses

This project investigates the failure of various CMOS circuits as a result of Time Dependent Dielectric Breakdown (TDDB) and explores design techniques to increase the mean time to failure (MTTF) of large-scale circuits. Time Dependent Dielectric Breakdown is a phenomenon where the oxide underneath the gate degrades as a result of the electric field in the material. Currently, there are few well documented design techniques that can increase lifetime, but with a tool chain I created called the MTTF Analyzing Program, or MAP, I was able to test circuits under various conditions in order to identify weak links, discover relationships, …

Swept-Frequency Sampled Grating Distributed Bragg Reflector Lasers Optimized For Optical Coherence Tomography Applications, Brandon J. George

Master's Theses

Swept Frequency Source Optical Coherence Tomography (OCT) requires high repetition rate and wide spectral width wavelength tunable sources at a low cost. The sampled grating distributed Bragg reflector (SG-DBR) laser provides wide wavelength tuning range while exhibiting a wavelength switching speed that is among the fastest currently available. The SG-DBR laser is used to generate linear frequency ramps with high repetition rates. Since the SG-DBR laser is currently used for the telecommunications industry in high volume, the price of the system is much lower than current OCT sources. Therefore the SG-DBR laser provides a practical solution for Swept Source OCT. …

Galvanic Vestibular Stimulation Applied To Flight Training, Joel D. Hanson

Master's Theses

Between 1994 and 2003 spatial disorientation resulted in at least 202 aircraft

accidents, 184 of them resulting in fatalities. Galvanic Vestibular Stimulation (GVS)

provides a cost effective and safe way to simulate spatial disorientation and

potentially test pilot’s vestibular system prior to aircraft operation. This experiment

investigates the use of GVS as an indicator of motion sensitivity and explores the

effects of GVS on flight simulation performance. Bilateral bipolar rectangular pulse

electrical stimulations were given to subjects via skin-mounted electrodes placed over

each mastoid process to stimulate the vestibular system with roll and yaw sensations.

Two studies were conducted in …

Detection And Tracking Of Stealthy Targets Using Particle Filters, Philip M. Losie

Master's Theses

In recent years, the particle filter has gained prominence in the area of target tracking because it is robust to non-linear target motion and non-Gaussian additive noise. Traditional track filters, such as the Kalman filter, have been well studied for linear tracking applications, but perform poorly for non-linear applications. The particle filter has been shown to perform well in non-linear applications. The particle filter method is computationally intensive and advances in processor speed and computational power have allowed this method to be implemented in real-time tracking applications. This thesis explores the use of particle filters to detect and track stealthy …

Sensor Integration For Low-Cost Crash Avoidance, Stephane M. Roussel

Master's Theses

This report is a summary of the development of sensor integration for low-cost crash avoidance for over-land commercial trucks. The goal of the project was to build and test a system composed of low-cost commercially available sensors arranged on a truck trailer to monitor the environment around the truck. The system combines the data from each sensor to increase the reliability of the sensor using a probabilistic data fusion approach. A combination of ultrasonic and magnetoresistive sensors was used in this study. In addition, Radar and digital imaging were investigated as reference signals and possible candidates for additional sensor integration. …

Traffic Signal Control With Ant Colony Optimization, David T. Renfrew

Master's Theses

Traffic signal control is an effective way to improve the efficiency of traffic networks and reduce users’ delays. Ant Colony Optimization (ACO) is a metaheuristic based on the behavior of ant colonies searching for food. ACO has successfully been used to solve many NP-hard combinatorial optimization problems and its stochastic and decentralized nature fits well with traffic flow networks. This thesis investigates the application of ACO to minimize user delay at traffic intersections. Computer simulation results show that this new approach outperforms conventional fully actuated control under the condition of high traffic demand.

Design And Development Of Rapid Battery Exchange Systems For Electric Vehicles To Be Used As Efficient Student Transportation, Jonathan A. Bevier

Master's Theses

Rapid battery exchange systems were built for an electric van and pedal assist electric bike as a method of eliminating the need to recharge the vehicles batteries in order to increase the feasibility of using electric propulsion as a method of efficient student transportation. After selecting proper materials it was found that the systems would need a protective coating to ensure consistent operation. 1020 cold rolled steel samples coated with multiple thicknesses of vinyl resin paint, epoxy resin paint, and powder coating were subjected to environmental wear tests in order to determine if the type and thickness of common protective …

Robust Unconstrained Face Detection And Lip Localization Using Gabor Filters, Robert E. Hursig

Master's Theses

Automatic speech recognition (ASR) is a well-researched field of study aimed at augmenting the man-machine interface through interpretation of the spoken word. From in-car voice recognition systems to automated telephone directories, automatic speech recognition technology is becoming increasingly abundant in today’s technological world. Nonetheless, traditional audio-only ASR system performance degrades when employed in noisy environments such as moving vehicles. To improve system performance under these conditions, visual speech information can be incorporated into the ASR system, yielding what is known as audio-video speech recognition (AVASR). A majority of AVASR research focuses on lip parameters extraction within controlled environments, but these …

A Study Of Dempster-Shafer's Theory Of Evidence In Comparison To Classical Probability Combination, Scott J. Seims

Master's Theses

ABSTRACT

A Study of Dempster-Shafer’s Theory of Evidence in Comparison to Classical Probability Combination

Scott J. Seims

This thesis is an assessment on the effectiveness of Dempster-Shafer’s Theory of Evidence in comparison to Classical Probabilistic Combination as it applies to Synthetic Aperture Radar (SAR) Automatic Target Recognition (ATR). A three feature based classifier (peaks, corners and edges) ATR system is presented. These classifiers are assumed to be independent. The results of both the weight-based Maximum Likelihood and Dempster-Shafer’s Theory of Evidence data fusion techniques are presented.

Using Dempster-Shafer an accuracy of 77.50 percent is obtained, which is less than the …

Affine Region Tracking And Augmentation Using Mser And Adaptive Sift Model Generation, Matthew James Marano

Master's Theses

Relatively complex Augmented Reality (AR) algorithms are becoming widely available due to advancements in affordable mobile computer hardware. To take advantage of this a new method is developed for tracking 2D regions without a prior knowledge of an environment and without developing a computationally expensive world model. In the method of this paper, affinely invariant planar regions in a scene are found using the Maximally Stable Extremal Region (MSER) detector. A region is selected by the user to define a search space, and then the Scale Invariant Feature Transform (SIFT) is used to detect affine invariant keypoints in the region. …

An Approach Based On Wavelet Decomposition And Neural Network For Ecg Noise Reduction, Suranai Poungponsri

Master's Theses

Electrocardiogram (ECG) signal processing has been the subject of intense research in the past years, due to its strategic place in the detection of several cardiac pathologies. However, ECG signal is frequently corrupted with different types of noises such as 60Hz power line interference, baseline drift, electrode movement and motion artifact, etc. In this thesis, a hybrid two-stage model based on the combination of wavelet decomposition and artificial neural network is proposed for ECG noise reduction based on excellent localization features: wavelet transform and the adaptive learning ability of neural network. Results from the simulations validate the effectiveness of this …

Novel Current-Fed Boundary-Mode Parallel-Resonant Push-Pull Converter, Jonathan David Paolucci

Master's Theses

The inherent difficulty in designing high voltage power supplies is often compounded by demands of high reliability, high performance, and safe functionality. A proposed high step-up ratio DC-DC converter meets the exacting requirements of applications such as uninterruptible power systems, radar, and pulsed power systems. The proposed DC-DC converter topology combines a multi-phase buck input stage with a novel self-tracking zero-voltage-switching (ZVS) resonant output stage. Traditionally, the inclusion of multiple power processing stages within a power supply topology severely degrades the overall converter efficiency. Due to the inherent high efficiency per stage, however, this effect is minimized. The self-tracking switching …

Multidisciplinary Design Optimization Of An Extreme Aspect Ratio Hale Uav, Bryan J. Morrisey

Master's Theses

ABSTRACT

Multidisciplinary Design Optimization of an Extreme Aspect Ratio HALE UAV

Bryan J. Morrisey

Development of High Altitude Long Endurance (HALE) aircraft systems is part of a vision for a low cost communications/surveillance capability. Applications of a multi payload aircraft operating for extended periods at stratospheric altitudes span military and civil genres and support battlefield operations, communications, atmospheric or agricultural monitoring, surveillance, and other disciplines that may currently require satellite-based infrastructure. Presently, several development efforts are underway in this field, including a project sponsored by DARPA that aims at producing an aircraft that can sustain flight for multiple years and …

Advanced Thermosonic Wire Bonding Using High Frequency Ultrasonic Power: Optimization, Bondability, And Reliability, Minh-Nhat Ba Le

Master's Theses

Gold wire bonding typically uses 60 KHz ultrasonic frequency. Studies have been reported that increasing ultrasonic frequency from 60KHz to 120KHz can decrease bonding time, lower bonding temperature, and/or improve the bondability of Au metalized organic substrates. This thesis presents a systematic study of the effects of 120 KHz ultrasonic frequency on the reliability of fine pitch gold wire bonding. Two wire sizes, 25.4 and 17.8 μm in diameter (1.0 and 0.7 mil, respectively) were used. The gold wires were bonded to metalized pads over organic substrates with five different metallization. The studies were carried out using a thermosonic ball …

Time-Frequency Analysis Of Intracardiac Electrogram, Erik Brockman

Master's Theses

The Cardiac Rhythm Management Division of St. Jude Medical specializes in the development of implantable cardioverter defibrillators that improve the quality of life for patients diagnosed with a variety of cardiac arrhythmias, especially for patients prone to sudden cardiac death. With the goal to improve detection of cardiac arrhythmias, this study explored the value in time-frequency analysis of intracardiac electrogram in four steps. The first two steps characterized, in the frequency domain, the waveforms that construct the cardiac cycle. The third step developed a new algorithm that putatively provides the least computationally expensive way to identifying cardiac waveforms in the …

Synthetic Aperture Radar Imaging Simulated In Matlab, Matthew Schlutz

Master's Theses

This thesis further develops a method from ongoing thesis projects with the goal of generating images using synthetic aperture radar (SAR) simulations coded in MATLAB. The project is supervised by Dr. John Saghri and sponsored by Raytheon Space and Airborne Systems. SAR is a type of imaging radar in which the relative movement of the antenna with respect to the target is utilized. Through the simultaneous processing of the radar reflections over the movement of the antenna via the range Doppler algorithm (RDA), the superior resolution of a theoretical wider antenna, termed synthetic aperture, is obtained. The long term goal …

Analysis & Design Of Improved Multiphase Interleaving Dc-Dc Converter With Input-Output Bypass Capacitor, Rudi Rudianto

Master's Theses

As the transistor count per chip in computer microprocessors surpasses one billion, the semiconductor industry has become more and more concerned with meeting processor’s power requirements. This poses a design challenge for the power supply module, especially when the processor operates at low voltage range. For example, the electrical requirement for the newest Intel microprocessors has exceeded 100A with an input voltage of approximately 1V. To overcome this problem, multiphase DC-to-DC converters encased in a voltage regulator module (VRM) have become the standard means of supplying power to computer microprocessor.

This study proposes a new topology for the multiphase DC-to-DC …

Application Of Pv Panels In Large Multi-Story Buildings, Sara Kayal

Master's Theses

Application of PV Panels in Large Multi-Story Buildings Feasibility Study Sara Kayal

The awareness of global warming along with an ever increasing demand for a new source of energy has brought a strong interest in harnessing natural resources such as solar energy. This thesis evaluates the viability of applying photovoltaic (PV) panels in high-rise commercial buildings of around 20 stories. Specifically, the thesis is intended to provide a pre-planning tool during the early design stage for architects and designers who are considering the deployment of PV panels in new multi-story construction.

The first three chapters cover a comprehensive literature review …