The gradient of a velocity vector field is an asymmetric tensor field which can provide critical insight that is difficult to infer from traditional trajectory-based vector field visualization techniques. I describe the structures in the eigenvalue and eigenvector fields of the gradient tensor and how these structures can be used...
The passive charge compensation (PCC) technique was introduced for switched capacitor (SC) circuit to increase the slew rate and enhance the linearity performance, as PCC techniques are used on the Delta-Sigma modulator (DSM) in ADC circuitry. The PCC technique of the project was applied to the design of a SC...
As screen resolution and video decoding capability have increased, high-definition (HD) video in resolutions as high as 1920 x 1080 is rapidly becoming the standard. Ad-hoc streaming of HD video over 802.11 wireless networks, e.g., streaming from a mobile device to a television, is convenient for users, but is hampered...
This thesis presents a novel algorithmic A/D converter to be used in a biosensor. The converter is capable of a conversion rate of 1.5 bits/phase and hence the required conversion time is reduced. The proposed architecture is analyzed for non-ideal effects and compared with existing algorithmic A/D architectures. The converter...
Ring amplification has emerged as an efficient technique to drive large capacitive loads in switched capacitor circuits. We propose circuit techniques to demonstrate the first application of a ring amplifier in a non-capacitive feedback system of a LDO. These techniques enable a simple cap-less LDO structure in 180nm CMOS that...
The increasing demand for higher data-rates is challenging to satisfy with spectrum-deficient indoor WiFi networks. A novel hybrid WiFi Free-Space Optical (WIFO) system has been proposed to enhance the wireless capacity of indoor WiFi networks. In this thesis, an integrated optical wireless receiver is designed and integrated in 65-nm CMOS...
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...
In cellular telephones, RF power amplifiers consume a significant part of the total phone current. Reducing the average PA current will extend battery life. In GSM systems the handset is commanded by the base station to transmit at power levels lower than full power much of the time. A Doherty...
It is common practice in the unsupervised anomaly detection literature to create experimental benchmarks by sampling from existing supervised learning datasets. We seek to improve this practice by identifying four dimensions important to real-world anomaly detection applications --- point difficulty, clusteredness of anomalies, relevance of features, and relative frequency of...
In this thesis, we propose a Blockchain-based distributed protocol for enabling deployment of dynamic, on-demand IoT networks. Specifically, the proposed protocol leverages Blockchain technology to: (i) enable distributed and secure authentication, registration, and management of IoT devices; (ii) provide fast discovery of IoT resources and scalable and secure instantiation of...
Various natural language processing (NLP) tasks necessitate deep models that are fast, efficient, and small based on their ultimate application at the edge or elsewhere. While significant investigation has furthered the efficiency and reduced the size of these models, reducing their downstream latency without significant trade-offs remains a difficult task....
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...
Various applications like wireless UWB communication, fast data acquisition systems and digital storage oscilloscopes needs ADCs with instantaneous input signal bandwidth from 0.1-40 GigaHertz range with 6-10 bits of resolution -- a challenging task and an impressive goal to achieve. Flash ADCs have been conventionally employed to achieve these goals...
AES (Advanced Encryption Standard), also known as Rijndael, is a symmetric key block cipher adopted as an encryption standard by the US government and used extensively in cryptographic applications worldwide. ARM is the most popular processor core used in embedded applications. This thesis surveys the available public implementations of AES...
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...
Distributed Version Control Systems (DVCS) have seen an increase in popularity relative to traditional Centralized Version Control Systems (CVCS). Yet we know little on whether VCS tools meet the needs of software developers when managing software change or whether developers are benefitting from the extra power of DVCS. Without such...
Farm machinery continues to increase in its importance to the agricultural sector. Depreciation, the decline in value of a durable asset over time, represents one of the largest costs of agricultural production. The general objectives of this study were to update and expand the number of Remaining Value (RV) functions...
An analysis of substrate noise coupling in mixed-signal circuits has been performed in the TSMC 0.25 [mu]m lightly doped and heavily doped CMOS processes. Methods to minimize noise coupling in both the chip design and board design phases are presented along with techniques for accurate circuit simulation of noise coupling....
Three types of low noise amplifiers operating at 2.4GHz were designed. They are the commonly used single-ended and differential amplifiers as well as a new quasi-differential amplifier. The substrate noise injected into these amplifiers is examined for both heavily and lightly doped CMOS substrates. For the single-ended amplifier the noise...
Retention of engineering students is a problem for many universities, especially during the first year. The problem of introducing students to engineering while increasing retention rates has recently been addressed by many different universities. Implementing novel lab structures, adjusting the lecture to incorporate more effective teaching techniques, and using orientation...
This thesis presents a model for simulating individual pedestrian motion based on empirical data. The model keeps track of a pedestrian’s position, orientation, and body configuration and leverages motion capture data to generate plausible motion. Our model can automatically incorporate a pedestrian’s physical limitations when making movement decisions, since it...
This thesis presents a low power DC-DC converter suitable for harvesting energy from high impedance thermoelectric generators (TEGs) for the use in body powered electronics. The chip has been fabricated in a 130nm CMOS technology. To meet the power demands of body powered networks, a novel dual-path architecture capable of...
The aim of this thesis is to study past 10 years of security vulnerabilities reported against Linux Kernel and all existing mitigation techniques that prevent the exploitation of those vulnerabilities. To systematically study the security vulnerabilities, they were categorized into classes and sub-classes based on their type.
This thesis first...
This thesis addresses the problem of temporal action segmentation in videos, where the goal is to label every video frame with the appropriate action class present. We focus on the domain of NFL football videos, where action classes represent common football play types. For action segmentation, we use a temporal...
As Moore’s Law continues to give rise to ever shrinking channel lengths, circuits are becoming more digital and ever increasingly faster. Generating high frequency clocks in such scaled processes is becoming a tough challenge. Digital phase locked loops (DPLLs) are being explored as an alternative to conventional analog PLLs but...
Advances in deep learning based image processing have led to their adoption for a wide range of applications, and in tow with these developments is a dramatic increase in the availability of high quality datasets. With this comes the need to accelerate and scale deep learning applications in order to...
Functional programming is concerned with referential transparency, that is, given a certain function and its parameter, that the result will always be the same. However, it seems that this is violated in applications involving uncertainty, such as rolling a dice. This thesis defines the background of probabilistic programming and domain-specific...
Researchers at Oregon State University, focusing on the development of ocean wave energy converters, have designed and installed a unique linear test bed to aid in the characterization of these converters. Under the original control scheme, the linear test bed follows a position profile and is limited in its ability...
In this thesis, we present semantic equivalence rules for an extension of the choice calculus and sound operations for an implementation of variational lists. The choice calculus is a calculus for describing variation and the formula choice calculus is an extension with formulas. We prove semantic equivalence rules for the...
Smart home devices are becoming increasingly popular and by 2021, it is estimated to have 80 million devices in the households of the U.S. The privacy and security threats involved with devices, as a result, are also scaling up in recent years. Smart home cameras have been hacked, private conversations...
Wave energy converter (WEC) devices are complicated systems containing hydrodynamic, mechanical, and electrical elements. WEC design efforts are primarily focused in the time-domain, using frequency-based energy analyses and numerical problem solving approaches that are staples in hydrodynamic design efforts to form the basic information set used in these time-domain development...
In any biomedical signal acquisition system, a front-end amplifier is needed to amplify low amplitude bio-signals while filtering out any unwanted low-frequency artifacts. The design of low frequency poles within the sub-Hz range implies very large time-constants which goes against system integrability. In recent years, the pseudo resistor has been...
As more wind farms are connected to the grid, the variable nature of wind energy begins to influence grid stability. Energy storage could help smooth the variable nature of wind energy. Laboratory demonstration and exploration of the interaction between different energy storage devices and wind energy could help improve and...
The history of a software project plays a vital role in the software development process. Version control systems enable users of a software repository to look at the evolution of the source code, and see the changes that led to newer versions. Currently, version control systems provide commands that can...
Determining the performance characteristics of various ocean wave energy converters (OWEC) has proven to be difficult due to problems replicating a baseline motion profile in the ocean or wave tank to compare these devices. The linear test bed seeks to mechanically simulate the relative linear motion between the active components...
A methodology for rapid estimation of substrate noise generated by digital circuitry in mixed-signal circuits is presented. This methodology is incorporated into the Silencer! framework, and also provides for future improvements including pre-layout noise estimation. Measurements of a test chip fabricated in the TSMC o.25[mu]m heavily doped logic process validate...
Over the last 20 years, there has been rapid growth in the amount of installed wind power in the Pacific Northwest, specifically in the Columbia River Gorge. The variable and non-dispatchable nature of this resource requires that it be balanced in some form by other sources on the grid. In...
Magnetic particle imaging (MPI) is a biomedical imaging technique which detects the presence of magnetic nanoparticles which have been introduced into the specimen prior to imaging. MPI has shown promise for real-time imaging with spatial resolution comparable to magnetic resonance imaging (MRI). MPI research has focused predominantly on the development...
In the past two years, Oregon State University (OSU) Corvallis campus suffered several power outages. The estimated cost of one of those outages was close to a million dollars worth of equipment and impact on research projects. Meanwhile, the campus grid operates with severely aging power assets. The reliability of...
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 design of a 10-bit pipelined charge redistribution DAC employing MOSCAPs biased in their accumulation mode is presented in this thesis. A switched capacitor filter and output buffer have also been designed for the system. The effect of MOSCAP nonlinearity on the performance of the pipelined charge redistribution DAC has...
This research introduces an energy storage system to deliver microgrid frequency response. A doubly-fed induction generator (DFIG) and a squirrel cage induction machine (SCIM) are coupled together as a motor/generator set to deliver an immediate inertial response to a change of frequency, and an inverter and supercapacitors deliver short term...
Is it possible to determine whether a signal violates a formula in Signal Temporal Logic (STL), if the monitor only has access to a low-resolution version of the signal? We answer this question affirmatively by demonstrating that temporal logic has a multiresolution structure, which parallels the multiresolution structure of signals....
A fully integrated CMOS latched comparator is presented for use as a wake-up circuit that is attached to an RF energy harvester in a battery free wireless sensor network. The system consumes less than 36nA static current at 20°C and dissipates 2pJ of energy per conversion. The comparator comprises of...
This work presents a new data encoding scheme: Integrated Pulse Width Modulation (iPWM) for equalizing lossy wireline channels with the aim of achieving energy efficient wireline communication. The proposed scheme is able to overcome the fundamental limitations imposed by Manchester and Pulse Width Modulation (PWM) encoding on high data rate...
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...
Ocean wave energy is rapidly becoming a field of great interest in the world of renewable energy. Significant advancements in design and technology are being made to make wave energy a viable alternative for our growing energy demands. The two major hurdles for ocean wave energy to make a significant...
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...
Interest in nanomaterials is motivated partly by their potential for sensor arrays to detect
different gases. Nanowires in particular are of interest because their high surface-to-volume
ratio promises the possibility of high sensitivity. However, because of their discrete
quasi-one-dimensional geometry, electrical integration of nanowires into photolithographically
defined devices and circuits...
High data rate transmission has become an important challenge in today digital communication systems. One of the most difficult problems faced by engineers is to transmit data at sufficiently high rates through fading channels. This is the main motivation for the research presented herein. In this thesis, we investigate a...
What are the most effective ways to improve the engineering curriculum? Improvements should result in increased student retention, undergraduates who are more industry-ready and graduates who are better prepared to be leaders. Current research suggests that the best predictor of persistence is a person’s self-efficacy. The focus of this thesis...
Remote sensors are becoming the standard for observing and recording ecological data in the field. Such sensors can record data at fine temporal resolutions, and they can operate under extreme conditions prohibitive to human access. Unfortunately, sensor data streams exhibit many kinds of errors ranging from corrupt communications to partial...
We took the back-propagation algorithms of Werbos for recurrent and feed-forward neural networks and implemented them on machines with graphics processing units (GPU). The parallelism of these units gave our implementations a 10 to 100 fold increase in speed. For nets with less than 20 neurons the machine performed faster...
Power and timing requirements are becoming more and more stringent as applications move from less mobile devices to more mobile ones. As such, it is important to optimize these applications as much as possible in order to provide the best solution that is low power and low latency. Although there...
Domain-independent automated planning is concerned with computing a sequence of actions that can transform an initial state into a desired goal state. Resource production domains form an interesting class of such problems, in that they typically require reasoning about concurrent durative-actions with continuous effects while minimizing some cost function. Although...
Modern wireless System-on-Chips (SoCs), such as mobile handsets, sensor networks, and mm-wave systems, integrate an entire RF system on a single CMOS chip. Such highly complex systems require significant on-chip digital signal processing to help improve the performance of highly sensitive analog/RF components. The IC
market being competitive, the ability...
We consider the problem of finding unknown patterns that are recurring across multiple sets. For example, finding multiple objects that are present in multiple images or a short DNA code that is repeated across multiple DNA sequences. We first consider a simple problem of finding a single unknown pattern in...
Digital phase-locked loops (PLLs) have been receiving increasing attention recently due to their ease of integration, scalability and performance comparable to their analog counterparts. In digital PLLs, increased resolution in time-to-digital conversion is desirable for improved noise performance. This work describes the design and simulation of a stochastic time-to-digital converter...
Given k terminal pairs (s₁,t₁),(s₂,t₂),..., (s[subscript k],t[subscript k]) in an edge-weighted graph G, the k Shortest Vertex-Disjoint Paths problem is to find a collection P₁, P₂,..., P[subscript k] of vertex-disjoint paths with minimum total length, where P[subscript i] is an s[subscript i]-to-t[subscript i] path. As a special case of the...
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...
Object categorization is one of the fundamental topics in computer vision research. Most current work in object categorization aims to discriminate among generic object classes with gross differences. However, many applications require much finer distinctions. This thesis focuses on the design, evaluation and analysis of learning algorithms for fine- grained...
There is a significant amount of research analyzing the effect of race, gender, and other common demographical data on student interest and performance in computer science. However, there is relatively little research concerning less common demographic populations, such as introverts, artistic students, and visual learners. This study investigates if these...
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...
Modern applications in wireless communications systems demand the capability of high transmission rate. Engineers have to find optimum solutions to transmit the signal over fading environments. In this study, we propose the combination of space-time diversity techniques and optimum QAM constellation design, in order to further improve performance. Specifically, we...
A basic tradeoff to consider when designing a distributed data-mining framework is the need for a compromise between the cost of communication and computation resources and the accuracy of the mining results. This is essentially a decision of whether it is more efficient to communicate all of the data to...
A new method is presented to compress switching information in large digital circuits. This is combined with an efficient approach of generating the noise signatures of cells in a digital library that results in an accurate and efficient approach for estimating the noise generated in digital circuits. This method provides...
A tuning technique which tunes the continuous time filter very accurately is proposed in this thesis. This technique overcomes the problem of master slave mismatch, thus tuning the filter accurately. The mismatch minimization is done on power up on foreground while the background tuning is always operational. Once the mismatch...
Significance: Movement intent decoding algorithms can interpret human bioelectrical signals to control prosthetic limbs with many degrees of freedom (DOFs). This work involves decoding volitional movement intent from surface electromyogram (sEMG) signals to control prosthetic arms. To train these algorithms, patients flex their muscles to “follow” a movement prompt, and...
Semi-supervised clustering aims to improve clustering performance by considering user supervision in the form of pairwise constraints. In this paper, we study the active learning problem of selecting pairwise must-link and cannot-link constraints for semisupervised clustering. We consider active learning in an iterative manner where in each iteration queries are...
The broadband wireless interference in a computer platform is resulted by multiple electro-magnetic emission sources. This non-Gaussian interference is proved to be double-sided K-distributed in previous research. With the limitation of transmission power and dimension of the device, interference mitigation is an efficient way to improve received signal bit error...
This thesis presents an adaptive modulation scheme using a Walsh-code modulator. The Walsh-code modulator consists of a dynamic demultiplexer and predetermined sets of orthogonal Walsh-Hadamard codes. The demultiplexer can demultiplex the input bit stream into a maximum of thirty-two sub-streams. The Walsh- Hadamard codes are used to spread the spectrum...
Movement intent decoders, which interpret volitional movement intent from human bioelectric signals, can be incorporated into modern neuroprostheses to offer people living with limb loss or paralysis the potential to regain their lost motor control. Machine learning methods have become the research standard for continuous decoders with high degrees of...
Rapid advances in wireless networking have led to more mobile phones, PDAs, and other digital mobile devices becoming ubiquitously connected to the Internet. As the demand of delay sensitive real-time applications for these portable devices increases, providing seamless connectivity to wireless networks becomes a critical issue. For this reason, a...
Heatmap regression has became one of the mainstream approaches to localize facial landmarks. As Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN) are becoming popular in solving computer vision tasks, extensive research has been done on these architectures. However, the loss function for heatmap regression is rarely studied. In...
The Internet is growing rapidly in terms of websites, users and uses. People use the Internet for reference, shopping, social networking, communications, business and much more. Though the Internet is useful, there are many risks associated with its use, like malicious websites, identity theft, hateful content and fraudulent practices. Online...
Markov Decision Process (MDP) is a well-known framework for devising the optimal decision making strategies under uncertainty. Typically, the decision maker assumes a stationary environment which is characterized by a time-invariant transition probability matrix. However, in many real-world scenarios, this assumption is not justified, thus the optimal strategy might not...
Question Answering in natural language processing has achieved significant progress in recent years. Yet, training and testing set methodology to evaluate the language models has proved inadequate. Adversarial examples aid us in finding loopholes inside these models and provide insights into their inner workings. In this work, an evaluation based...
We consider the problem of strategic adversarial planning in a Real-Time Strategy (RTS) game. Strategic adversarial planning is the generation of a network of high-level tasks to satisfy goals while anticipating an adversary's actions. In this thesis we describe an abstract state and action space used for planning in an...
Increased penetration of renewable energy sources results in higher operating reserve requirements, due to the inherent variability and uncertainty of these resources. Many studies, primarily focusing on wind and solar, have determined that geographic diversity of variable renewables substantially reduces system variability and uncertainty. The Pacific Northwest is well suited...
The aim of the research undertaken for this thesis was to develop a new high-performance amorphous oxide semiconductor (AOS) for use as a channel layer in a thin-film transistor (TFT). AOS TFTs offer higher electron mobility than the established amorphous silicon based technology. A new channel material comprised of aluminum...
This thesis presents algorithms and tools for the automated design of RF LC CMOS voltage controlled oscillators (VCOs) with low phase noise given a set of specifications. The electromagnetic solver, ASITIC, combined with the circuit simulator, SpectreRF, allows optimization of the VCO circuit parameters and inductor layout. This approach gives...
The research presented herein represents an effort to combine the ultra-smooth surface of an amorphous metal thin film (AMTF) with a solution-processed dielectric synthesized via prompt inorganic condensation (PIC). Analysis of dielectric film quality is carried out via electrical measurements of metal-insulator-metal (MIM) diodes. Anneals at 500 and 700 °C...
The objective of this thesis is to provide an initial demonstration of two-terminal and three-terminal electronic devices employing amorphous multi-component metallic film
(AMMF) electrodes. Such a demonstration is successfully achieved in the fabrication of metal-insulator-metal (MIM) diode and hot electron transistor (HETs) structures employing ZrCuAlNi AMMF electrodes. The ultra-smooth surface...
Amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) constitute the central theme of this thesis. Within this theme, three primary areas of focus are pursued.
The first focus is the realization of a transparent three-stage ring oscillator with buffered output and an output frequency in the megahertz range. This leads to...
The focus of this thesis is the investigation of thin-film transistors (TFTs) based on amorphous oxide semiconductors (AOSs) in two circuit applications. To date, circuits implemented with AOS-based TFTs have been primarily enhancement-enhancement inverters, ring oscillators based on these inverters operating at peak frequencies up to ~400 kHz, and two-transistor...
In this thesis, convergence of time inhomogeneous Markov chains is studied using an adiabatic approach. The adiabatic framework considers slowly changing systems and the adiabatic time quantifies the time required for the change such that the final state of the system is close to some equilibrium state. This approach is...
Renewable energy, particularly wind power, has increased dramatically over the past two decades. In the Pacific Northwest, the power system has accommodated a large amount of new wind power. The variability of wind power has introduced many challenges, requiring additional reserve generation to be available to maintain system stability. The...
Students’ success is one of the foremost objectives in higher education, and their self-efficacy plays a prominent role in students’ achieving their full potentials. It is especially important in STEM fields, which often suffer from higher attrition rates. Therefore, it is important to understand students’ self-efficacy levels at an early...
This thesis considers the problem of training convolutional neural networks for online visual tracking. A major challenge for single object visual tracking is that most training sets with frame-level track annotations are quite small, due to the prohibitive cost of manual annotation. Current training approaches either supplement the annotations with...
Smart home devices, such as voice assistants, smart lights, and smart video doorbells have become a part of end users' daily lives. Many of these devices combine their features with other services and smart devices to create a simple and efficient user experience. This is partly because of the contribution...
Protecting end-users privacy and building trust are the two most important factors needed to support the growth of ecommerce. The increased dependence on the Internet for a wide variety of daily transactions causes a corresponding loss in privacy for many users, as virtually all websites collect data from users directly...
This thesis presents a Z-parameter based model to predict the substratenoise coupling between two contacts in a heavily doped substrate for frequenciesless than 2 GHz. The empirical model is scalable with contact size and spacingsbetween the contacts and model parameters can be readily extracted from simu-lated or measured data. The...
As more features are being integrated into mobile platforms, the demand for
long battery life during standby mode has been increasing. Light load efficiency
becomes one of essential features in today's DC-DC converter. The most effective
method to improve light load efficiency is to operate the DC-DC converter under
pulse-frequency-modulation...
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...
Macrosomia is a medical term describing a new baby born with an excessive birth weight (greater than 4000g). Fetal macrosomia may lead to both pregnancy complications, and increased risk of mother's and baby's health problems after birth. But the potential complications may be mitigated by a cesarean delivery. As such,...
There is a growing interest in bringing online and streaming content to the television. Gaming platforms such as the PS3, Xbox 360 and Wii are at the center of this digital convergence; platforms for accessing new media services. This presents a number of interface challenges, as controllers designed for gaming...
Forward Error Correction and retransmission are two approaches used to reliably broadcast data in a network with poor quality of service. Taking some assumptions, it has been suggested that a retransmission based reliable broadcasting scheme using network coding should in theory provide an increase in bandwidth efficiency by combining packets...
This work presents an inductor less switched capacitor based energy harvester, which can simultaneously harvest from 2 energy sources (Solar + Piezo). The proposed harvester employs 2D maximum power point tracking algorithm, by changing the conversion ratios of the charge pumps for piezo and solar sources, and 1D voltage regulation...
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...
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...