Multiple-input multiple-output (MIMO) antennas can be exploited to provide high data rate using a limited bandwidth through multiplexing gain. MIMO combined with orthogonal frequency division multiplexing (OFDM) could potentially provide high data rate and high spectral efficiency in frequency-selective fading channels. MIMO-OFDM technology has been widely employed in modern communication...
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...
Triangulateration uses geometric distance to estimate the location of user by employing techniques like received signal strength (RSS), time-of-arrival (TOA), time-difference-of-arrival (TDOA) and image processing.
Radio frequency (RF) signal positioning using TOA or TDOA techniques generally requires timing synchronization of the anchors and/or the anchors and targets. If the desired...
This work presents a novel CCRW receiver that utilizes a window of variable width, for e˙ectively mitigating multipath and ambiguity in both civil and military positioning applica-tions using Global Navigation Satellite Systems (GNSS). This CCRW receiver incorporates a single stroboscopic window, whose width is iteratively reduced until the e˙ect of...
This dissertation proposes the use of advanced time-varying approaches for modeling the dynamics of the multipath channel in wireless communication networks. These advanced time-varying approaches include linear Kalman innovation models in observable block companion form, and neural network-based models. The e˙ectiveness of these type of models is evaluated through three...
This thesis deals with target localization using multiple-input multiple-output (MIMO) radars. In the field of communications, navigation, radar, and sensing networks, one of the common and most sophisticated problems is target localization. We develop a target localization scheme in distributed MIMO radar systems using bistatic range measurements. The localization approach...
Radio frequency (RF) sensing arises as a promising option for enabling the internet of things (IoT) applications that transform our life into a world of smart homes, smart cities, and smart industries. The innovation of IoT reveals the benefits of RF sensing across cost, pervasiveness, unobtrusiveness, and privacy. However, challenges...
Movement pattern detection can be applied in a variety of applications such as assisting independent living of seniors at home, behaviour understanding in surveillance systems, sports analytics, and robotics. This project develops a scheme that fuses information from different sensors to detect movement patterns. This report contains three main parts:...
Advances in low-power digital integration and microelectro-mechanical systems (MEMS) have paved the way for micro-sensors. These sensors are equipped with data processing capabilities along with sensory circuits. Sensor data are processed on these individual sensors and transmitted to the target (sink). Lowcost integration and small sizes of these sensors have...
Pulsed ultra-wideband (UWB) radio uses extremely short pulses to transmit information. Such pulses provide very fine timing information, which has led to technological advances in high-precision localization. This thesis investigates UWB localization strategies with a focus on receiver synchronization algorithms for time-difference-of-arrival localization to achieve centimeter accuracies in a 3-dimensional...
Accurate positioning has become an active research area in recent years. It has a wide range of applications in many fields such as navigation, asset tracking, health care, proximity marketing/location-based advertising, and sport analytics. Transmitter positioning via radio frequency (RF) signals is the most widely encountered scenario, and it uses...
Traditional localization techniques rely on triangulation or trilateration, where in a set of three or more stationary known locations is used to estimate a “client” position. For inertial navigation, these techniques can estimate client positions merely using the measured data from tri-axial accelerometers and gyroscopes. However, the use of double...
In this paper, a Direction of Arrival (DOA) based system is proposed. This method searches the direction relative to the array to find where the signal source is located. The proposed system can achieve sub-meter level accuracy with a near real-time update rate. Also, we introduced several refinement methods including...
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...
Pulsed ultra-wideband (UWB) radio uses extremely short pulses to transmit
information. Such pulses provide very fine timing information, which has led to
technological advances in high-precision localization. This thesis focuses on
techniques and experiments of Time-Difference-of-Arrival (TDOA) localization of
a large number of simultaneous sources. First, common localization techniques
such...
Wearable sensors with an inertial measurement unit (IMU) are popular for indoor positioning and activity pattern detection. The IMUs can be connected to a wireless transmission module, allowing users to monitor and process motion-related parameters remotely. Because of the complexity and uncertainty of signals in indoor environments, a radio frequency...
It is well known that multipath effects cause inter-symbol interference (ISI) for high-speed signaling and ultimately limit the achievable data rate at any frequency band. In this thesis, we study several different methods to tackle this issue and provide solutions for establishing efficient wireless links that can provide several Gbps...
Time of Arrival (TOA) is a popular technique used for geolocation. This thesis evaluates the use of TOA techniques indoors. The accuracy of measuring distances using TOA is dependent on the bandwidth of the system and the multipath conditions between the receiver and transmitter. System bandwidth has a significant effect...
Wireless power transfer (WPT) is a way to transfer power from one device to another without any wire or cable connections. Although the technology has been around for more than 100 years, it is gaining popularity in recent years due to the ever-increasing demand for faster and more frequent charging...
The purpose of this thesis is to increase the positional accuracy of Global Position System (GPS) modules using an artificial intelligence algorithm. Three basic and identical GPS modules were setup in an equilateral triangle formation with side lengths of one meter. The triangle was placed in four separate locations where...
In modern digital communication systems, error correction codes (ECC) are widely used and play an important role. The main effect of ECCs is to reduce the transmission error caused by channel noise, thereby protecting data and increasing the quality of information transmission. In addition, high spectral efficiency is desired in...
Inter-symbol interference is one of the major factors that make the realization of high-data-rate digital communications system complex. Current designs face two main challenges: how to efficiently utilize the available bandwidth and how to reduce the hardware complexity of the transmitter and receiver. Traditional solutions use a single-band architecture. When...
Relay-assisted cooperative communications are promising solutions for error-performance improvement and cell coverage extension. In this thesis, we propose several efficient cooperative relay communication schemes. First, an efficient space-time coded cooperative relay communications scheme that employs linear precoding and transmission-pattern selection is proposed. This is built upon an existing block linear...
Optical wireless communication (OWC) is an alternative to radio frequency (RF)communication with a signi cantly larger and unregulated spectrum. In OWC systems, optical orthogonal frequency division multiplexing (O-OFDM) with intensity modulation and direct detection (IM/DD) is commonly used. There are two common signal structures in most OWC systems based on...
Powerline communication (PLC), is becoming a more commonplace method for data transmission, however it is still a very new medium for data transmission, and international standards for powerline communication are still in the process of being developed and established. PLC can provide a means of simplifying the device connectivity to...
One of the key challenges in downlink multiuser multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems is the mitigation of the multi-access interference when different users share the same subcarriers. In this work, the block diagonalization (BD) algorithm for inter-user interference pre-cancelation is extended to MIMO-OFDM systems. However, in...
Ultra-wideband (UWB) radio is the transmission of data using an extremely wide bandwidth and very low power spectral density. In this thesis, the mereits and challenges of UWB architectures versus conventional narrowband architectures will be compared. Pulsed UWB systems can be implemented with very simple architectures. These advantages make UWB...
The Internet of Things (IoT) paradigm brought an ever-increasing dependence on low-power devices to collect sensor data and transmit that information to the cloud, placing greater demand on connectivity and lifespan. In response, rapid worldwide innovation demonstrates the trade-offs in processing, communication, and energy consumption with diverse approaches to low-power...
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...
Orthogonal frequency division multiplexing (OFDM), which has been very attractive for future high rate wireless communications, is very robust to channel multipath fading effect while providing high transmission data rate with high spectral efficiency.
Multiple antennas can be combined with OFDM to increase diversity gain and to improve spectral efficiency...
Designing spectral efficient, high-speed wireless links that offer high quality-
of-service and range capability has been a critical research and engineering challenge. In this thesis, we mainly address the complexity and performance issues of
channel estimation and data detection in multiple-input multiple-output (MIMO)
orthogonal frequency division multiplexing (OFDM) systems over...
Deep learning is becoming the latest trend in sensitive applications, such as healthcare, criminal justice, and finance. As these new applications emerge, adversaries are circumventing them.
Further, there have been concerns about the possibility of bias and discrimination in predictive applications.
In order to address these issues, we propose an...
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...
The quality of a digital image pipeline relies greatly on its color reproduction which should at a minimum handle the color constancy, and the final judgment of the excellence of the pipeline is made through subjective observations by humans.
This dissertation addresses a few topics surrounding the color processing of...
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...
Ultra-wideband (UWB) communication has emerged as a very promising
technology for short-range wireless applications, including
high-speed multimedia transmissions and sensor networks. UWB
system designs involve many different aspects covering analog and
digital processing, channel estimation and modeling, and
modulation and demodulation. Although UWB still faces many
challenges, significant progress has...
The US military is evaluating the capabilities of emerging technologies based on IEEE 802.16 standard as a potential commercial off-the-shelf solution to support the communication requirements of the future war.
In the last few years, development in military and telecommunication industries have focused on an intensive use of broadband systems,...
Indoor positioning systems can be used for many applications such as indoor navigation,emergence response, asset monitoring, and shopper assistance. Due to the weak received signal and multipath reflection, the global positioning system (GPS) generally does not work in indoor environments. There are a variety of radio frequency (RF) signals and...
Network coding, as the next generation of data routing protocols, enables each intermediate node in a network to process and encode its received data before forwarding it to the next nodes. Hence, the core idea in network coding is to allow a network to encode the data that is being...
The uncontrolled growth in domains such as surveillance systems, health care services, and finance produce a large amount of data and contain potentially sensitive data that can become public if they are not appropriately sanitized.
Motivated by this issue, we introduce a privacy filter (PF), a novel non-negative matrix factorization...
Due to the continued evolution of 5G standards, the need for higher rates of data, lower latency network access, and implementations that are more energy efficient have become clear. To enable wireless communications at rates over tens of Gbps, the wide bandwidth of mmWave spectrum can be exploited. Beamforming (or...
Direct sequence spread spectrum (DSSS) was initially used for anti-jamming in military applications and was later developed in other commercial applications. Walsh codes, which are a set of mutually orthogonal codes, are one type of the spreading codes used in DSSS systems. For any spreading codes of length N, these...
Error correction codes (ECCs) have been widely used in communication systems and storage devices. Nowadays, the rapid development of integrated circuit technologies makes feasible the implementation of powerful ECCs such as turbo code and low-density parity-check (LDPC) code. However, these high-performance codes require complex decoding algorithms, resulting in large hardware...
The dependence of the substrate resistance, R[subscript sub], for MOS transistor RF modeling on transistor biasing and layout is studied from device simulations and measurements. Though R[subscript sub] is found to be bias dependent, the error incurred by assuming a constant value equal to the DC resistance is not significant....
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...
The ability to accurately locate people and objects indoors will enable opportunities for control and automation of indoor environments. Current indoor localization solutions require dedicated hardware which must be custom tailored to each application. There are large technological, societal, and economic benefits in developing a more general purpose system that...
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...
Radiation is part of our life. Most people may know a radioactive source is very dangerous. But there are very few situations people are exposed to uncontrolled radionuclides above background. A radioactive source can emit gamma rays which are the highest energy type in electromagnetic radiation.[2] Gamma rays are like...
In wireless communication, channel state information (CSI) is essential for data detection. Fast fading coefficients estimation is important in order to acquire accurate CSI. Kalman filters (KF) are widely used for real time parameter estimation and can be used to estimate the fast fading coefficients of a mobile communication channel....
Massive MIMO is a promising technique for future 5G communications due to its high spectrum and energy efficiency. To realize its potential performance gain, accurate channel state information at transmitter side (CSIT) is essential. Frequency division duplex (FDD) is widely employed by the most cellular systems today. However, it requires...
Recent publications show that successive approximation register (SAR) analog to digital converters (ADC) are capable of achieving high efficiency over other ADC topologies. Furthermore, techniques have been adopted to process signals with low activity periods, such as biomedical and industrial sensors. Prior work used least- significant bit first quantization (LSBFQ)...
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...
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...
In this thesis, a novel Direct-Charge-Transfer (DCT) integrator structure is proposed, which can settle much faster than regular switch-capacitor integrators. A new Spread-Spectrum Dynamic Element Matching (SS-DEM) algorithm is also introduced, which can effectively spread or shape the nonlinearity error of multi-bit DAC in the feedback path, thus improve the...
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,...
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...
All-digital PLLs promise flexible and precise frequency modulation continous-wave(FMCW) radar signal signal for 77GHz radar applications. Such PLLs require digitally-controlled oscillators(DCO) with wide frequency tuning range and high resolution to address a range of applications and low phase noise requirements. In this thesis, novel resonator structures with ne capacitance/inductance switching...
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...
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...
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...
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...
We develop efficient coordination techniques that support inelastic traffic in large-scale distributed dynamic spectrum access DSA networks. By means of any learning algorithm, the proposed techniques enable DSA users to locate and exploit spectrum opportunities effectively, thereby increasing their achieved throughput (or "rewards" to be more general). Basically, learning algorithms...
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,...
The proliferation of body worn autometric devices has been enabled by advances in low-power electronics and fueled by the quantified-self movement. These devices range in complexity from pedometers to clinical vital sign measurement. They all share the same drawback, typically the most expensive and heaviest component, the battery. The future...
Estimating the carrier frequency from a modulated waveform is one of the most important functions of a coherent signal receiver. Good performance and low bit error rates are obtained by coherent demodulation. Therefore, exact knowledge of the received signal carrier frequency is critical for communication systems. Also due to the...
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....
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...
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...
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,...
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...
The design of mobile wireless devices has always focused on reducing power, area, and cost. This dissertation proposes two techniques that are leveraged to save power and area and therefore cost. The first techniques reduces the noise in the receiver and results in a relaxed power requirement. The second technique...
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 electrical behavior of on-chip interconnects has become a dominant factor in silicon-based high speed, RF, and mixed-signal integrated circuits. In particular, the frequency-dependent loss mechanisms in heavily-doped silicon substrates can have a large influence on the transmission characteristics of on-chip interconnects. To optimize the performance of the integrated circuit,...
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...
Routing from a single source node to multiple destination nodes using node disjoint paths (NDP) has many important applications in parallel systems. For example, if a source node wants to send distinct messages to distinct destination nodes, then the one-to-many NDP routing is useful.
Unlike parallel systems with shared-memory, each...
Harvesting energy from the environment for powering micro-power devices have been increasing in popularity. These types of devices can be used in embedded applications or in sensor networks where battery replacement is impractical. In this dissertation, different methods of energy harvesting from the environment are explored as alternative sources of...
Advancements in power electronics to higher power levels and faster switching times allow new machine and systems designs, but also create higher stresses on electric machinery insulation. High performance, pulse-width modulated (PWM) inverters are now available for medium voltage drive systems, and are being considered by the U.S. Navy as...
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...
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...
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...
Data converters are essential interface circuits between the analog world that people live in and the digital processors that people live with. Linearity, which often is a tradeoff against other performance criteria, is one of the major performance demands from applications for both analog-to-digital converts (ADC) and digital-to-analog converters (DAC)....
This work demonstrates correlation of microwave signals encoded with 16-bit codes using the parametric interaction of spin waves. Signal processing correlators are devices that compare two signals, such as a reference code and a received code, where the output indicates the similarity between the signals. Correlators are used in communication...
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...
The Focused Ion Beam (FIB) tool is a versatile instrument for nano-machining in
circuit editing. Circuit editing is one of the most important steps in the design of an
electronic circuit on a chip. Circuit editing can be improved by imaging of silicon
plates and analyzing the resultant images. However...
Phase Locked Loops(PLLs) are an integral part of almost every electronic system. Systems involving low frequency clocks often require PLLs with low bandwidth. The area occupied by the large loop filter capacitor and resistor in a low bandwidth PLL design makes the realization of traditional charge-pump PLL architecture impractical on...
Complex digital circuits such as microprocessors typically require support circuitry that has traditionally been realized using analog or mixed-signal macros. PLL circuits are used in many integrated applications such as frequency synthesizers and inter-chip communication interfaces. As process technologies advance and grow in complexity, the challenge of maintaining required analog...
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...
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...
The imperfections of the propagation channel due to channel fading and the self-generated noise from the RF front-end of the receiver cause errors in the received signal in electronic communication systems. When network coding is applied, more errors occur because of error propagation due to the inexact decoding process. In...
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...
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....
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,...
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...
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...
This dissertation presents a low-power high-resolution delta-sigma ADC. Two new architectural design techniques are proposed to reduce the power dissipation of the ADC. Compared to the conventional active adder, the direct charge transfer (DCT) adder greatly saves power by keeping the feedback factor of the active adder unity. However, the...
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...
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...
This dissertation focuses on the development of ultra-compact optical devices for free-space modulation. We propose a surface-normal modulator using metallic photonic crystals for free-space optical interconnects. The active control of light intensity is achieved by engineering the Fano resonances in metallic photonic crystals. Both thermo-optic modulation and electro-optic modulation of...
This thesis proposes a novel fully digital technique for the estimation and correction of the DAC error in multi-bit delta sigma ADCs. The structure of the DAC error is indicated through a simple model for unit-element based DACs. The impact of the DAC error on the performance of ADC is...
Ultra-high-speed (>10GS/s), medium-resolution (5~6bit), low-power (<50mW) analog-to-digital converter can find it application in the areas of digital oscilloscopes and next-generation serial link receivers. There are several challenges to enable a successful design, however. First, the time-interleaved architecture is required in order to achieve over 10GS/s sampling rate, with the trade-off...