In a power system, operators maintain voltage stability through adequate reactive reserves. Maintaining and accessing an efficient allocation of reactive reserves is prohibitively complex because of reactive line losses, the variety of reactive resources, and either limited or variable reactive outputs from renewable sources. By clustering the system into smaller...
The central focus of this thesis is the design, fabrication and characterization of amorphous oxide semiconductor (AOS) thin-film transistor (TFT) current mirrors. The thin-film deposition and circuit fabrication methods used to realize zinc tin oxide (ZTO) TFT
current mirrors are addressed in order to elucidate the processing challenges for this...
The primary objective of this thesis is to develop a process for fabricating integrated circuits based on thin-film transistors (TFTs) using zinc tin oxide (ZTO) as the channel layer. ZTO, in contrast to indium- or gallium-based amorphous oxide semiconductors (AOS), is perceived to be a more commercially viable AOS choice...
The prevalence of Internet-of-Things (IoT) applications leads to an increasing focus on the design and optimization of sensor nodes. Battery lifetime and associated costs of battery replacement often limits the long term operation and viability of sensor nodes. RF wireless energy harvesting on the other hand can be appealing since...
Bird and bat collisions with wind turbines are a problem that needs to be better quantified for its impact to be fully understood. This thesis documents portions of the design of a sensor patch module for use on wind turbines blades to detect impacts caused by birds and bats. This...
This dissertation studies two different wireless microwave sensing applications in the subjects of environmental monitoring and biomedical devices. The environmental sensing application presents a design of novel wireless sensor node configurations. These nodes are intended to be used specifically in a built environment of railroad track ballast for its health...
A wireless power transfer system using inductive coupling was designed and implemented as part of a three-member project team. The system uses coupled magnetic fields at a frequency of 606kHz to transfer electromagnetic energy from a charging base to the batteries of portable devices. It succeeded in transmitting power to...
The number of wind turbines and wind farms in the Pacific Northwest has increased dramatically in the past six years, which represents a significant amount of electrical generation capacity connected to the public electric grid. However, the variable nature of wind sometimes introduces excessive power, or conversely shortages, in power...
Low-distortion architecture is widely used in wideband discrete-time switched-capacitor delta-sigma ADC design. However, it suffers from the power-hungry active adder and critical timing for quantization and dynamic element matching (DEM). To solve this problem, this dissertation presents a delta-sigma modulator architecture with shifted loop delays. In this project, shifted loop...
Nowadays, needs for wideband and high accuracy analog-to-digital converter are increasing rapidly in manifold applications such as wireless communication, digital video and other consumer electronics. Besides, low power consumption is required to have longer battery life in portable systems. CMOS technology scaling and innovative modulator topology make the implementation much...
There is a significant need in recent mobile communication and wireless broadband
systems for high-performance analog-to-digital converters (ADCs) that have wide
bandwidth (BW>5-MHz) and high data rate (>100-Mbps). A delta-sigma ADC is
recognized as a power-efficient ADC architecture when high resolution (>12-b) is
required. This is due to several advantages...
Typical power outputs of commercially available diode lasers are on the
order of 5 milliwatts. This thesis discusses the growth, processing and
fabrication of high power (lOO's of milliwatts) diode lasers. Devices were
grown by Molecular Beam Epitaxy (MBE) and by Metal Organic Chemical
Vapor Deposition (MOCVD). The MOCVD diode...
The Amazon basin is a natural wonder of biodiversity that serves as one of the largest single carbon storage mechanisms in the world. For these reasons, preserving the Amazon and other similar forests is a worthy goal. Protecting these spaces is not possible without understanding the threats facing animal populations...
To protect the environment and save human lives, the detection of various hazardous toxins of biological or chemical origin has been a major challenge to the researchers at Oregon State University. Living fish cells can indicate the presence of a wide range of toxins by reactions such as changing color...
The influence of weather on the long range radio navigation system Loran-C was investigated. The variables analyzed over a period of 255 days were: time differences (TDs), TD signal-to-noise ratios, TD standard deviations (measured at a fixed receiver location in Corvallis, Oregon), time interval numbers (TINOs) (measured at the transmitter...
Efficient time-series analysis can impact multiple application domains such as motif discovery in gene analysis or music data, extracting spectro-temporal patterns in acoustic scene analysis, or annotating and classifying electrical bio-signals (such as ECG, EEG, and EMG) for medical applications.
Time-series analysis involves a variety of tasks.
To predict future...
The purpose of this thesis is to apply the wavelet transform WT to
multiresolution structures for analyzing the information content of images based on
multiresolution signal decomposition of the wavelet representation. The advantage
of the wavelet transform is the fact that it uses different building blocks than the
Fourier's sines...
The awareness of electric power quality has increased over the past decade as electronic equipment
has become more susceptible to power disturbances. The most disruptive power disturbances are voltage
sags and momentary interruptions and their effect on adjustable speed drives (ASDs) is studied in this
thesis.
Several solutions have been...
An important task of a Variable Speed Generation (VSG)
system is the capability to maintain and control the terminal
voltage at some desired value as determined by the
reactive power dispatch strategy.The main objective is to
design a sub-optimal fixed-parameter controller in the
sense that constraints with respect to practical...
Adjustable Speed Drive (ASD) systems are widely used in industry to effectively improve process efficiency and control. Typically, an ASD system consists of a motor with its speed controlled by a power electronics converter via varying the amplitude and frequency of the input voltage. However, several abnormal insulation failures of...
A new structure for the implementation of bit/serial adaptive IIR filter is
presented. The bit level system consists of gated full adders for the arithmetic
unit and data latches for the data path. This approach allows recursive
operation of the IIR filter to be implemented without any global
interconnections, minimal...
The rapid development of semiconductor technology and the increasing complexity of VLSI chips have prompted both the industry and the
academic community alike to take an indepth look at the VLSI design
problem. Many design methodologies have been proposed and associated
computer-aided tools developed. This thesis is a study of...
Pulse Oximetry is a technology used ubiquitously across the medical field for measuring oxygen saturation and heart rate monitoring. In this project a system was developed to use a new technology for pulse oximetry: single-photon avalanche diodes (SPADs). This work outlines the development process and experimental results of a SPAD...
With an increasing number of wireless applications at microwave frequencies, the frequency spectrum is becoming quite crowded. Due to this congestion, the current state of technology is leading towards upper microwave and millimeter wave spectra as they also offer other distinct advantages such as larger bandwidth and smaller component footprint....
In networked control systems (NCS) information or packets usually flow from a
sensor or a set of sensors to a remotely located controller. Then the controller
processes the received information and sends a series of control commands to the
actuators through a communication network which could be either wireless or...
Linear phase variable filters that are obtained with a frequency transformation of the form cos(ω) = P(cos(W)) were analyzed, where P is a finite degree polynomial, ω is the prototype frequency and W is the transformed filter frequency. A new transformation of third order is proposed. The new variable filter...
When the term renewable energy is mentioned in a conversation, wind, solar, and hydro energy typically come to mind. However, there is one major resource that has remained mostly untapped: wave energy. Wind and solar power technologies are well established around the world but they cannot generate electricity all the...
Real time indoor positioning awareness systems aim to add localization capabilities to upcoming wireless technologies that are quickly becoming an important feature for indoor environment. RF-based impulse-radio ultra-wideband (IR-UWB) is a promising technology for in-door positioning systems due to obstacle penetration capabilities, immunity to multi-path and fading, and high resolution....
The electrical output of solar panels is reduced when dust covers the panels, but the air movement produced by a flying drone can be used to remove this debris. This research project will study the effectiveness of a quadcopter drone in dusting a solar panel. A solar panel was covered...
The Brushless Doubly Fed Machine (BDFM) is receiving attention as a candidate for use in adjustable speed drives (ASDs) and variable speed generators (VSGs). With a large percentage of a drive or generator system's cost due to power electronics content, considerable research has been conducted to find drives in which...
Over the last decade, wind penetration in the Pacific Northwest has increased rapidly. The variable nature of this massive new resource has increased stress on the hydropower resource to the point where system limits are currently being reached. In order to cultivate continued growth of the wind energy industry both...
A Mobile Ad-hoc NETwork (MANET) is collection of wireless mobile nodes without a network infrastructure or centralized administration. Although MANETs can be used in many applications, such as mobile Internet, military communication, and disaster relief networks, a number of challenges remain. These include routing, medium access control, security, scalability, energy...
Recent developments in computing technology have generated a demand for more streamlined and effective test systems. By replacing traditional in-chassis wired interconnects with a broadcast wireless system, fault detection and error susceptibility will drastically improve, input/output capabilities will expand, and routing complexity will decrease. Ultra-wideband impulse radio's (UWB-IR) characteristic multipath-immunity...
Impulse-radio ultra-wide-band (IR-UWB) signaling is a promising technique
for high-speed, short-range relay communications networks. Depending on how
the relay node retransmits the signal, there are two main relay schemes: conventional
one-directional (one-way) relay model, and bi-directional (two-way) relay
model. In bi-directional relay communications, wireless network coding (WNC),
also called physical-layer...
This paper proposes a novel means of using analog correlators to improve upon existing Ultra-Wideband receiver architectures. Current architectures aim for an all-digital design for the sake of ease of implementation and conceptual simplicity. This causes some notable design challenges including an ultra-high sampling rate, and difficulty capturing multipath energy....
Indoor localization systems have a variety of applications such as tracking of assets, indoor robot navigation, and monitoring of people (e.g. patients) in hospitals or at home. Global positioning system (GPS) offers location accuracy of several meters and is mainly used for outdoor location-based applications as its accuracy degrades significantly...
As the number of autonomous data collection applications keep increasing, the demand for wireless sensor networks (WSNs) has seen explosive growth. In this dissertation, an ultra-low-energy WSN transmitter is developed to reduce the energy consumption of sensor nodes in WSNs. With an ultra-low-energy transceiver, it is possible to eliminate the...
In wireless sensor network applications, low-power operation of the wireless receiver is critical. To address this need an ultra-low power Binary Frequency Shift Keying (BFSK) receiver using the super-regenerative architecture is developed.
A prototype receiver is built and tested for operation in the 900 MHz ISM band. Lab measurements show...
Low energy design techniques for digital circuits are examined to determine their suitability for use in a digital logic controller for wireless sensor network nodes. Transistor level simulations are used to evaluate the techniques and those demonstrating an energy reduction are used to implement a digital logic controller. The digital...
This thesis presents a low-energy application specific digital controller for a battery-free 2.4 GHz wireless sensor network (WSN) node. The digital controller has been designed and fabricated in a standard 0.13 μm CMOS and implements a simple protocol for WSNs. Techniques such as supply voltage reduction and power gating have...
Silicon photonics has become the most promising platform for future large-scale optical interconnect and optical computing systems due to its inherent CMOS compatibility, which brings exclusive advantages in bandwidth density, energy efficiency, and cost effectiveness. Parallel optical interconnects based on photonic integrated circuits (PICs) have the capacity to meet the...
The major limiting factor of DRAM access time is the low transconductance of the
MOSFET's which have only limited current drive capability. The bipolar junction
transistor(BJT) has a collector current amplification factor, β, times base current and is
limited mostly by the willingness to supply this base current. This collector...
In Radio Frequency Integrated Circuits (RFIC) or high frequency digital
ICs, there is a demand to probe the internal nodes for testing. The ultra low
capacitance RFIC probe presented in his work is a flexible tool for these
applications. The probe utilizes the coupling between a tungsten needle and the...
The low thermal conductivity of gallium arsenide compared to silicon
results in self-heating effects in GaAs MESFETs that limit the electrical
performance of such devices for high power applications. To date, analytical
thermal models of self heating in GaAs MESFETs are based on the assumption
of a uniformly heated channel....
Turbo codes have been used successfully for error correction in digital communications, however, their application to wireless mobile communications is still a fresh research topic. The objective of this thesis is to present a new solution that involves the usage of turbo codes, spatial diversity, and orthogonal complementary codes in...
This thesis focuses on two aspects of transparent electronics, SnO₂ transparent thin-film transistors (TTFTs) and transparent circuits. Both depletion- and enhancement-mode SnO₂ TTFTs are realized. The maximum effective mobility for the depletion- and enhancement-mode devices are 2 cm²V⁻¹s⁻¹ and 0.8 cm²V⁻¹s⁻¹, respectively. A variety of techniques to decrease the carrier...
Hybrid automatic repeat request (HARQ) schemes combine packet retransmission with forward error correction to ensure a reliable communications. In multiple-input multiple output (MIMO) systems, interference cancellation (IC) detection is widely used where the detection and cancellation steps of the simultaneously transmitted data streams occur. In principle, the signal stream estimated...
Increasing threats of terrorism and contraband smuggling have led to a growing interest in millimeter wave/ THz security sensors. Recently, systems combining active and passive sensing into one unit have been proposed where the active mode provides information on range and reflectivity, and the passive mode complements the active by...
In recent years, RF (Radio Frequency) device fingerprinting using deep learning has emerged as a method of identifying devices solely by their RF transmissions. Conventional approaches to this type of device fingerprinting are not portable to different domains. That is, if a model for this purpose is trained on data...
In recent years there have been many improvements in the reliability of critical infrastructure systems. Despite these improvements and despite targeted efforts to improve the operation and control of the electric grid, the power systems industry has seen relatively small advances in this regard. For instance, today's power system is...
The suitability of discrete least-squares optimal (Wiener) filters
for deconvolution of tone-burst waveforms is studied. It is shown
that: (1) such waveforms are not well suited to these filters without
preprocessing, (2) the use of exponential weighting results in a significant
improvement in filter performance and (3) that "phase-unwrapping"
in...
While the performance gap between microprocessors and main memory is ever increasing each year, cache memory has been a bridge to alleviate this discrepancy. In this thesis proposal, we introduce three techniques to tolerate this processor and memory speed imbalance. First, we propose the bloom filter scheme to identify which...
This work presents a new energy saving technique for modern digital designs. We propose Time Interleaved Multi-Rail (TIMR) - a method for providing two dynamic supply rails to a circuit. This technique uses the first supply rail to mask the transition delay while changing the voltage of the second rail....
In the first part of this dissertation, low frequency l/f or flicker noise in the frequency range of Hz to kHz has been identified and demonstrated to be described by temperature fluctuations in heat conduction in bipolar transistors operated at higher power densities. This noise phenomenon is not described by...
In this dissertation, time-based signal processing techniques and their applications in oversampling and noise-shaping data converters are examined. These techniques demonstrate the ability to shift the burden of high performance analog circuits from the compressed voltage-domain to the augmented time-domain. First, the potential of high order noise-shaping and phase-domain feedback...
As CMOS processes size continues to shrink, a number of factors limit the ability of analog circuit performance to scale with the process. These issues include smaller transistor intrinsic gains and lower supply voltages. However, scaling continues to increase the speed and decrease the power of digital circuits. In this...
A numerical technique to compute the time domain response of multiconductor lossy
uniform and nonuniform lines terminated in general nonlinear elements is presented. The
technique is based on the generalized method of characteristics. The method transforms the
original system of transmission line equations into a system of ordinary differential
equations....
A numerical method based on the the method of characteristics for hyperbolic systems
of partial differential equations in four independent variables is developed and used
for solving time domain Maxwell's equations. The method uses the characteristic
hypersurfaces and the characteristic conditions to derive a set of independent equations
relating the...
A versatile computational technique for improved time domain modeling of electromagnetic radiative systems is demonstrated. Two computational methods are combined: the finite-difference time domain (FDTD) method, a full-wave electromagnetic field solver, and the Kirchhoff surface integral formulation, a spatial transformation technique. The combined FDTD/Kirchhoff technique is shown to increase accuracy...
Current trends in integrated circuit technology are continuing towards physically smaller components and related structures. Interconnects between circuit components have reached sub-micron dimensions which can not be modeled accurately by the current ideal microstrip analysis based techniques. These techniques often assume that the structure being modeled is perfectly conducting, smooth,...
The purpose of this study is to develop experimental techniques to
characterize typical interconnect discontinuities, including bends, steps, T
junctions, vias and pads, which are the most commonly encountered
interconnections in high speed digital integrated circuits, hybrid and
monolithic microwave circuits and electronic packages. The time domain
reflection response of...
In an industrial and consumer electronic marketplace that is increasingly demanding greater real-world interactivity in portable and distributed devices, analog to digital converter efficiency and performance is being carefully examined. The successive approximation (SAR) analog to digital converter (ADC) architecture has become popular for its high efficiency at mid-speed and...
Recent advances in wireless technologies have helped the proliferation of wireless devices, ranging from hand-held devices such as cellular phones to more powerful mobile computing platforms as such laptops [1]. Along with that, the end users’
applications running on these devices, ranging from text message to multimedia applications such as...
Threshold-based time of arrival (TOA) estimation is a technique for high-precision indoor localization. Existing threshold selection methods, such as xed thresh- old and normalized threshold methods, do not consider the signal-to-noise radio (SNR) value at the receiver. This is not desired for high-precision positioning. A proper threshold value depends on...
Brushless Doubly Fed Machines (BDFM) have potential advantages in variable
speed generation and adjustable speed drive applications. The most significant of these
advantages is a reduction in the power electronic converter rating, and therefore a
reduction in overall system cost. Presently, efforts are being directed at optimizing the
design of...
A new second order accurate nonuniform grid spacing technique which does not
depend on supraconvergence is developed for Finite Difference Time Domain (FDTD)
simulation of general three dimensional structures. The technique is useful for FDTD
simulations of systems which require finer details in small regions of the simulation space by...
In recent years, a new class of high-performance thin-film transistors (TFTs) has emerged comprising amorphous oxide channel materials composed of heavy-metal cations (HMCs) with (n-1)d¹⁰ns⁰ (n ≥ 4, where 'n' refers to the row of the periodic table) electronic configuration. This thesis is devoted to the fabrication and characterization of...
Amorphous metal thin films (AMTFs) are of potential use for metal-insulator-metal (MIM) tunnel diode applications due to their ultra-smooth surfaces, a consequence of their amorphous microstructure. The objective of this thesis is to design a thermally-stable AMTF capable of maintaining MIM tunnel diode performance after a post-deposition anneal in excess...
The purpose of this thesis is to investigate the necessity of
transposition in the construction of overhead transmission lines.
Line currents, line voltages and line losses of both the transposed
and untransposed lines were calculated and compared for two different
voltage classes. The conventional method of symmetrical components
was used...
Two-way transmission of data on broadband community cable television systems is considered in this thesis. A discussion of the data transmission environment is presented which attempts to characterize the channel noise and interference which degrades data transmission performance. The analysis considers channel degradation resulting from additive gaussian noise and various...
The question of the suitability of Walsh functions or
similar bi-valued functions used as a radar electromagnetic
carrier waveform is considered. Walsh functions are
described and effective sinusoidal steady state transfer
functions are defined for transmission elements, antenna
systems, and propagation media.
The argument is made that the unit impulse...
Previous research has shown that women are increasingly sexualized in a variety of media contexts. I conducted a content analysis of film trailers from 2018 and 2019 to examine the relationship between the sexualization and objectification of female-presenting characters to the popularity of the film and its trailer. A random...
With each generation of technology, computers become even more capable of rendering objects with an ever increasing number of polygons. As a result, the desire to add more details to a 3D model increases as well. Among the many tools provided by computer graphics software that an artist has at...
An accurate state estimation plays an essential role in power system operation and planning in energy management systems. However, existing multi-area state estimation researches have not focused on the importance of system clustering. The clustering mechanism divides or partitions a system according to user-defined criteria. Few published research works have...
Minimizing the dynamic power consumption of a circuit is becoming a more and more important issue for digital circuit design in the age of portable electronics. Among all the arithmetic circuits, addition is the most fundamental operation. Therefore, designing low power adder is an important and necessary research area.
In...
The agricultural industry in the Western United States continues to possess issues of overwatering, accounting for over 80% of consumed water per year in the country. While technologies such as satellite imaging and sensor networks have slowly improved irrigation Best Management Practices to reduce superfluous water consumption, limitations associated with...
Rapid advances in technology have seen computing move from a
large central computer to desktop microcomputers.
This advance was also
seen in the design of dedicated computers, computers designed to perform a
few specialized tasks or duties.
These computers, or microcontrollers, are
often controlled by a central computer and themselves...
The power spectral density of the acoustic signature of
Dungeness crab was calculated by the use of digital computer.
The signal produced by the Dungeness crab was an analog signal.
Therefore a conversion of the signal from analog to digital was
necessary. This was done by sampling the acoustic signature...
This thesis reports on an investigation of the growth, by
Molecular Beam Epitaxy, of III,III-V ternary compound semiconductors.
Strained and unstrained growth was studied via the deposition of InGaAs
on GaAs and InP substrates. Lattice matched InGaAs on InP was grown,
and an in situ method was developed to find...
Using robotics in education allows students to become familiar with multiple topics in science, technology, engineering, and mathematics (STEM). With the use of robotic educational tools in the 8th – 12th grade classrooms, such as Sphero, Anki Cozmo, and Lego Mindstorms, few devices allow students to build the robots’ electrical...
Artificial Intelligence has gained resurgence in popularity through machine learning methods. This thesis investigates the current use of AI, the impact it will have on the economy and the ethical considerations for developing this technology. In the coming decade AI could increase global economic output over $10 Trillion. AI will...
General purpose computer systems have seen increased performance potential through the parallel processing capabilities of multicore processors. Yet this potential performance can only be attained through parallel applications, thus forcing software developers to rethink how everyday applications are designed. The most readily form of Thread Level Parallelism (TLP) within any...
This dissertation investigates diverse techniques to support multithreading in modern high performance processors. The mechanisms studied expand the architecture of a high performance superscalar processor to control efficiently the interaction between software-controlled and hardware-controlled multithreading. Additionally, dynamic speculative mechanisms are proposed to exploit thread-level-parallelism (TLP) and instruction-level-parallelism (ILP) on a...
The doubly-excited machine can be used as a variablespeed
generator or as a variable-speed-drive motor. In
this thesis the focus is on the aspects associated with
generating electric power (real and reactive) from erratic
energy resources such as water or wind. In such cases,
the power input to the prime...
Basic operation, as well as successful development, of the Brush less Doubly-fed Machine (BDFM) has been documented, and research has turned from proof of concept and early development to the more practical direction of increased manufacturability to prove industrial viability. Previous research centered on using standard induction motor stators along...
The clean cookstove sector has long sought the tools and analysis methods needed to accurately quantify social, environmental, and economic impacts of projects in diverse settings. To respond to this need, Climate Solutions Consulting and Oregon State University have developed a novel integrated suite of sensors to collect fuel usage...
The transition from second-generation (2G) to third-generation (3G) wireless cellular and cordless telephone systems requires multi-standard adaptability in a single RF receiver equipment. An important answer to this request is the use of Delta-Sigma modulators for IF-to-baseband conversion, which will satisfy the dynamic range requirements for digital signal processing, and...
CP1100/GPIB Interface is an interface between the "General
Purpose Interface Bus", which is an implementation of the Universal
Bus described in IEEE Standard 488-1975, and Unibus. This interface
enables TEKTRONIX CP1100 series controllers to operate
GPIB- compatible instruments connected to the General Purpose
Interface Bus. The designer can now incorporate...
Information security is an important concern in today’s communication and business world. To achieve these security functions, cryptography is utilized. RSA and the Diffie Hellman key exchange are some examples of cryptography algorithms that use modular multiplication to compute modular exponentiations. Modular multiplication requires division operations which becomes very time...
This thesis describes the design of a single-chip
logic analyzer. The utility of such a chip in measuring
and recording digital system parameters is illustrated.
Possibilities for future applications of this chip in
performance monitoring of computer systems are discussed.
The objective of this thesis is to describe the design and
implementation of a VSLI reduced instruction set computer (RISC).
The RISC machine constitutes a new style of computer architecture.
It differs significantly from the complex instruction set computer
architectures (CISC) of the past. RISC architectures are
characterized by their...
This thesis describes the design and implementation of a motor controller that is a customizable and cost effective replacement for the motor controllers used by Edwards Robotics Company (ERC). Extensive research of comparable products available in the market was conducted. The research formed the basis for the design specifications of...
This work describes the development of an accurate, low-cost, expandable and wearable health and activity monitoring platform. Wearable monitors used to track physical activity are becoming an increasingly popular and effective way to combat our dangerously sedentary lifestyles. Unfortunately most existing wearable solutions are either costly, inaccurate or cumbersome. The...
In the past, multimedia technology focused mainly on designing high quality audio and graphical imagery as well as providing adequate performance levels that the users demand for multimedia applications. However, the concept of multimedia has expanded into New-Media that involves variety use of multimedia data in consumer-oriented applications, such as...
The complexity of designing and testing today's system on chip (SOC) is increasing due to greater integrated circuit (IC) density and higher IO and memory frequencies. SOCs for the mobile phone and tablet market have the unique challenge of short product development windows, at times less than six months, and...