Ferrites have been used for various high frequency applications as bulk
materials. These applications, however, are limited to large dimension devices. In
this thesis, thin film ferrites were deposited from a low temperature solution-based
deposition process that is suitable for micro-scale high frequency applications. The
low temperature nature of this...
With the ever-increasing demand for portable devices used in applications
such as wireless communication, mobile computing, consumer electronics, etc.,
the scaling of the CMOS process to deep submicron dimensions becomes more
important to achieve low-cost, low-power and high-performance digital systems.
However, this downscaling also requires similar shrinking of the supply...
Recently, continuous-time ΔΣ modulators are appearing increasingly often in both the literature and the marketplace due to their features of inherent antialiasing and relaxed requirements for opamp and so on. However, several nonideal factors such as clock jitter, excess loop delay, inter-symbol interference and so on, degrade the SNR performance...
There is a large and growing market for portable consumer audio products
with very small size. As the size of these products is reduced, the area occupied
by batteries becomes significant and hence limits the number of batteries to one.
In order to build such small products, high levels of...
Traditionally linear actuator applications are addressed by the use of hydraulic systems. The high maintenance cost and poor reliability will always be the most critical problem in the real applications. Benefited from both the high mechanical advantage of the roll screw and the simple structure of the switched reluctance motor,...
This thesis presents a channelized digital receiver design for UWB sytems in a multipath indoor environment. The UWB technology has been used for commercial and military purposes due to a number of advantages such as low-power consumption, noise-like and carrier free. The energy of UWB signal is spread over a...
The demand for portable electronic systems and the continued
down-scaling of device dimensions resulted in rapid improvement in
the performance of integrated systems. Several low-voltage design
techniques have been proposed to operate analog circuits with sub-1V
supply. However, these techniques require higher power consumption
to achieve large dynamic range while...
Accurate scaled modeling and simulation are critical to advancing ocean wave linear generator buoys. A 100th scaled model of ocean wave generator buoy systems is analyzed by solving the Navier-Stokes equations. These equations are numerically solved using Computational Fluid Dynamics (CFD) by implementing the front capturing method. In this thesis,...
Achieving sharpened (enhanced detail) features of a multi-dimensional data source using the linear prediction (LP) bandwidth extrapolation (BWE) technique in the transform domain is the main objective of this research. The evolution of sensor technology has provided acquisition scenarios in which the data format is inherently multi-dimensional, including hyperspectral imaging...
The amount of instruction level parallelism (ILP) that can be exploited depends
greatly on the size of the instruction window and the number of in-flight instructions
the processor can support. However, this requires a register file with a large set of
physical registers for renaming and multiple ports to provide...
Low-Density Parity-check (LDPC) codes have attracted considerable attention due to their capacity approaching performance over AWGN channel and highly parallelizable decoding schemes. They have been considered in a variety of industry standards for the next generation communication systems. In general, LDPC codes achieve outstanding performance with large codeword lengths (e.g.,...
Multiple-input multiple-output (MIMO) communication systems have recently been considered as one of the most significant technology breakthroughs for modern wireless communications, due to the higher spectral efficiency and improved link reliability. The sphere decoding algorithm (SDA) has been widely used for maximum likelihood (ML) detection in MIMO systems. It is...
Analog-to-Digital Data Converters (ADCs) used in instrumentation and measurements often require high absolute accuracy, including excellent linearity and negligible dc offset. Incremental data converters (IDCs) provide a solution for such measurement applications. Since IDCs are essentially delta-sigma converters with reset operation before each conversion, they retain most of the advantages...
Recently, delta-sigma modulation has become a widely applied technique for high-performance analog-to-digital conversion of narrow-band signals. Most of the early designs used discrete-time structure for good accuracy and good linearity. The transfer functions are independent of the clock frequency. However, high unity-gain bandwidths of the opamps are required to satisfy...
Enabled by continued device scaling in CMOS technology, more and more functions that were previously realized in separate chips are getting integrated on a single chip nowadays. Integration on silicon has opened the door to new portable wireless applications, and initiated a widespread use of these devices in our common...
The Advent of multi-cores allows programs to be executed much faster than before. Cryptoalgorithms use long-bit words thus parallelizing these operations on multi-cores will achieve significant performance improvement. However, not all long-bit word operations in cryptosystems are suitable for parallel execution on multi-cores. In particular, long-bit words used in Elliptic...
A two-channel data acquisition system for simultaneous detection and discrimination of beta particles and gamma rays has been developed. Each channel measures and analyzes the input pulses resulting from the absorption of radiation in the layers of the detector. The detector is a triple-layer phoswich (phosphor sandwich) scintillation detector followed...
A fully integrated CMOS GPS receiver RF front end optimized for low power operation is presented. The system operates with a supply voltage down to 250 mV. A prototype has been fabricated in a 0.13μm CMOS process and includes a low voltage LNA, quadrature oscillators, and quadrature mixers. It exhibits...
An enhanced swing differential Colpitts VCO (ESDC-VCO) dramatically improves
the swing of a Colpitts VCO by allowing the signal to swing below ground and above the
supply voltage. Fabricated in a 1P8M 0.13 um CMOS process, the ESDC-VCO operates
at 4.9GHz with a 0.475-V supply and consumes 2.7mW. The measured...
This thesis proposes a novel technique for the design of pipelined and cyclic ADCs utilizing generalized radix gain stages. Several models have been proposed for the optimization of high performance pipelined ADCs by various researchers. This work builds upon them, using a simple but accurate model to estimate the optimal...
The exponential rate of advances in modern communication devices in the last several years have brought us higher levels of functionality and performance as well as reductions in physical size and power consumption. To continue this rate of advancement, next generation systems require wider bandwidth and higher resolution ADCs. Additionally,...
Dynamic CMOS circuits are commonly used in high-performance memory arrays to implement wide-NOR logic functions for their read and search operations. This is because dynamic circuits have significantly higher speed and lower area compared to static circuits for performing similar operations. Register File (RF) arrays are located at the top...
An ultra low power crystal oscillator that provides a frequency reference for battery
powered timekeeping applications is presented. An amplitude control circuit is employed to ensure that minimum current is consumed. A subthreshold voltage regulator provides a supply voltage for the oscillator with minimum current consumption. The oscillator and regulator...
Evolution of the mobile communication standards and proliferation of hand-held devices mandate stringent Analog-to-Digital Converter (ADC) specifications. Among various ADCs, a ∆Σ ADC is best known as a power-efficient ADC when more than 12b is required. However, a conventional discrete-time (DT) ∆Σ Modulator (∆ΣM) is inadequate for low-power wideband applications...
With the increasing effort to identify alternative methods of energy generation, extraction of ocean energy has gathered a large interest. Research and industry have begun considering wave energy as the next new alternative energy. The unique challenges of ocean energy requires a wave energy converter to be both robust and...
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...
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...
This thesis presents two new approaches for the broadband, time-domain modeling of lossy transmission lines. Each approach is based on an alternative derivation of delay extraction in order to separate the line's linear phase from its
attenuation and dispersion. Augmentation networks represent the derived attenuation networks as rational function approximations....
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...
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...
Medical imaging technologies play a vital role in early diagnosis of disease by providing internal images of the human body to medical professionals. Computed Tomography (CT) is currently the most commonly used medical imaging technology because it is easy to use, detectors and scanners are constantly improving, and more importantly,...
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...
Advances in process technologies have led to the development of low-power high speed digital signal processing blocks that occupy small areas. These advances are critical in the development of portable electronic devices with small feature size and long battery life. However, the design of analog and mixed-signal
building blocks, especially...
With the recent interest in increasing the penetration of renewable energy sources onto the power grid, there has been an unprecedented rapid deployment of wind generation, especially in the US Pacific Northwest. While wind farm developers have continued to expand their operations, power system operators are left to deal with...
The enormous success of wireless technology has recently led to an explosive demand for, and hence a shortage of, bandwidth resources. This expected shortage problem is reported to be primarily due to the inefficient, static nature of current spectrum allocation methods. As an initial step towards solving this shortage problem,...
Ultra-wideband (UWB) radio has become an attractive alternative for wireless communications due to the robustness to multipath fading, low power transmission, mostly-digital implementation, and low cost. Furthermore, short-range, high data-rates applications are possible with UWB radios due to the wide spectral
allocations at 3.1 - 10.6 GHz.
This thesis presents...
Short-range wireless communications continually attract interest from both industry and academia, and it is changing our life in every aspect in the last decade. The design of wireless transceivers is the bottleneck for variety applications, due to RF modeling inaccuracy, stringent FCC regulations over the transmitted power spectrum, interference, multi-path...
As the number of mobile devices accessing large-scale WLANs such as campus
and metropolitan area networks increases, the need for load balancing among the
cells becomes crucial. In addition, the network must also support some minimum
handoff tolerance defined by an application.
A number of load balancing techniques have been...
Dual referencing has been garnering a lot of attention in the power integrity community, specifically in the voltage mode driver application because it shows a lower overall power delivery noise (PDN) compared to other signal referencing types. Additionally, the increasing push to drive down package and board manufacturing costs is...
Multi-layer optically coupled scintillation based radiation detectors, known as phoswich detectors, have rapidly evolved in recent years. During the same time, digital signal processing has improved radiation discrimination accuracy and enhanced reliability, while reducing complexity and size of traditional analog signal processing methods. A new generation of high-speed radiation detectors...
Given a video, we would like to recognize group activities, localize video parts where these activities occur, and detect actors involved in them. To this and, we propose a novel, mid-level feature, called control point, for representing group activities. The control points are aimed at summarizing visual cues, lifting from...
The decrease of switching times accompanied by the corresponding increase of
clock speeds and data rates, contributes to improve the overall system
computational performance. At the same time, they also affect wireless
communications due to an increment in the emissions of electromagnetic
radiation on the radio bands.
In this dissertation...
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...
Two aspects of ADC system performance are addressed in this work. First, the combination of the ADC and its associated reference are co-designed for an energy constrained remote sensing system. Second, sampling linearity is mathematically analyzed as a function of frequency to provide enhanced understanding into an ADC's requisite sampling...
High speed serial links are critical components for addressing the growing demand for I/O bandwidth in next-generation computing applications, such as many-core systems, backplane and optical data communications. Due to continued process scaling and circuit innovations, today's CMOS serial link transceivers can achieve tens of Gb/s per pin. However, most...
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....
Physical-Layer Network Coding (PNC) is a promising technique that has great potentials for improving the achievable data rates of end-to-end flows through higher packet transmission rates, thereby increasing the overall network throughput. In this thesis, we study the performance of the PNC transmission techniques for unidirectional end-to-end flows in multi-hop...
This dissertation investigates the use of a hardware mechanism called Eager Data Transfer (EDT) for achieving the reduction of communication latency for user-level network protocol. To reach the goal, the dissertation addresses the following research issues. First, the development of a communication system performance evaluation tool called Linux/SimOS is presented....
The stupendous growth in wireless and mobile devices in the recent years has prompted researchers to look at innovative approaches that enable effective use of the available resources. In this thesis, we propose a medium access control (MAC) protocol, referred to as EM-MAC, that enables wireless devices with multi-channel access...
In some practical systems, most of the errors are of 1 → 0 type and 0 → 1
errors occur very rarely. In this thesis, first, the capacity of the asymmetric
channel is derived. The capacity of the binary symmetric channel (BSC) and the
Z-channel can be derived from this...