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...
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...
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...
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...
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...
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...
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...
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...
p-type conducting films of α- BaCu₂S₂ have been deposited onto glass and KBr substrates, yielding a conductivity of 17 S/cm and a Hall mobility of 3.5 cm²/Vs. For a 430-nm-thick film, the optical transparency approaches 90% in the visible portion of the spectrum at 650 nm, and a transparency of...
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...
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...
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...
We present the results of embedding a multigrid solver for Poisson's equation
into the parallel 3D Monte Carlo device simulator, PMC-3D. First we compare
the sequential multigrid implementation to the sequential Successive Overrelaxation
(SOR) Monte Carlo code used previously in PMC-3D. Depending on the convergence
threshold, we obtain significant speedups...
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...
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...
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...
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...
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...
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...
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...
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 multimedia capabilities of computers have recently become the focus of computer developers due to the increasing demand for advanced computer graphics and new media capabilities, such as video conferencing, 3-D visualization, and animation. To support these multimedia capabilities, specialized graphics hardware, such as MPEG encoding/decoding card, 3-D graphics card,...
Sorting is typically a compute intensive operation used in many
areas of industry. With improved technology, both in the VLSI and CAE
areas, we can afford to develop hardware based database computers to
move the work load off the main computer. In this thesis the
architecture of a VLSI parallel...
The objective of this thesis is to present the architecture and
design of a neural network-based pattern classifier. The classifier
detects textual characters which have been translated, rotated, and
corrupted by noise. This form of pattern classifier differs
significantly from traditional pattern classifiers. The neural network
architecture used in implementing...
This thesis is concerned with the development of a unique
parallel sort-merge system suitable for implementation in VLSI.
Two new sorting subsystems, a high performance VLSI sorter and a
four-way merger, were also realized during the development
process. In addition, the analysis of several existing parallel sorting
architectures and algorithms...
In microwave network analysis, proper matching of the measurement system is necessary to prevent measurement errors and provide a
proper terminating impedance for the device-under-test. To obtain
this matching, a buffer amplifier is often used in the first stage of
the network analyzer.
This study describes the design and analysis...