Engineering Commons^™

Development Of An Electrical Interface For A Lateral Field Excited Sensor System, Thomas J. Leighton

Electronic Theses and Dissertations

Sensor systems are utilized to provide critical information to an end user which may range from a physician in a heath care facility to a soldier in a battle field environment. The "heart" of the sensor system is the sensing platform, examples of which include semiconductor, piezoelectric and optical devices. The responses of these sensors must be converted into a format that the user can read and interpret. This conversion is achieved through integrating the sensing platform with an electrical interface.

The focus of this thesis is the development of the first electrical interface for Quartz Crystal Microbalance (QCM) sensors …

Analysis, Design And Efficiency Optimization Of Power Converters For Renewable Energy Applications, Xi Chen

Electronic Theses and Dissertations

DC-DC power converters are widely used in renewable energy-based power generation systems due to the constant demand of high-power density and high-power conversion efficiency. DC-DC converters can be classified into non-isolated and isolated topologies. For non-isolated topologies, they are typically derived from buck, boost, buck-boost or forth order (such as Cuk, Sepic and Zeta) converters and they usually have relatively higher conversion efficiency than isolated topologies. However, with the applications where the isolation is required, either these topologies should be modified, or alternative topologies are needed. Among various isolated DC-DC converters, the LLC resonant converter is an attractive selection due …

Reconfigurable Reflectarray Antennas With Bandwidth Enhancement For High Gain, Beam-Steering Applications, Michael Trampler

Electronic Theses and Dissertations

Reconfigurable reflectarrays are a class of antennas that combine the advantages of traditional parabolic antennas and phased array antennas. Chapter 1 discusses the basic operational theory of reflectarrays and their design. A review of previous research and the current status is also presented. Furthermore the inherent advantages and disadvantages of the reflectarray topography are presented. In chapter 2, a BST-integrated reflectarray operating at Ka band is presented. Due to the monolithic integration of the tuning element, this design is then extended to V band where a novel interdigital gap configuration is utilized. Finally to overcome loss and phase limitations of …

Frequency-Reconfigurable Microstrip Patch And Cavity-Backed Slot Espars, Wei Ouyang

Electronic Theses and Dissertations

Wireless communication systems have rapidly evolved over the past decade which has led to an explosion of mobile data traffic. Since more and more wireless devices and sensors are being connected, the transition from the current 4G/LTE mobile network to 5G is expected to happen within the next decade. In order to improve signal-to-noise ratio (SNR), system capacity, and link budget, beam steerable antenna arrays are desirable due to their advantage in spatial selectivity and high directivity. Electronically steerable parasitic array radiator (ESPAR) that can achieve low-cost continuously beamsteering using varactor diodes have attracted a lot of attention. This dissertation …

Programmable Low Loss Orthogonal Frequency Coded Surface Acoustic Wave Correlator Filters, Marshall Smith

Electronic Theses and Dissertations

Simultaneous Transmit and Receive (STAR) communication is being developed as a means of improving spectral efficiency in wireless communication systems. If the obstacle of self-interference can be sufficiently overcome, it is possible to double the spectral efficiency of an equivalent time or frequency division duplexed system. Spread spectrum techniques can reduce self-interference by using orthogonal or pseudo-orthogonal codes to encode the transmit signal and decode the receive signal. Hardware correlator filters are developed for use with STAR radio systems using orthogonal frequency coded (OFC) surface acoustic wave (SAW) devices. OFC is a type of spread spectrum communication that can be …

Semiconductor Device Modeling, Simulation, And Failure Prediction For Electrostatic Discharge Conditions, Hang Li

Electronic Theses and Dissertations

Electrostatic Discharge (ESD) caused failures are major reliability issues in IC industry. Device modeling for ESD conditions is necessary to evaluate ESD robustness in simulation. Although SPICE model is accurate and efficient for circuit simulations in most cases, devices under ESD conditions operate in abnormal status. SPICE model cannot cover the device operating region beyond normal operation. Thermal failure is one of the main reasons to cause device failure under ESD conditions. A compact model is developed to predict thermal failure with circuit simulators. Instead of considering the detailed failure mechanisms, a failure temperature is introduced to indicate device failure. …

Control Strategy For A Small-Scale Microgrid Based On Battery Energy Storage System-Virtual Synchronous Generator (Bess-Vsg), Wei Gao

Electronic Theses and Dissertations

As one of widely deployed renewable energy resources, PV power is playing a very important role in microgrids today. It has advantages such as making the best of natural solar energy and being friendly to our environment. In this thesis, solar PV based microgrid is studied using modeling and simulation. Microgrid can run in either grid-connected-mode or islanded-mode. However, there are also some disadvantages for solar power. For solar panel, its output is influenced by weather conditions such as illumination intensity and temperature. In addition, during the control process of grid-connected mode, it is hard to guarantee its output power …

Sparse Signal Recovery Under Sensing And Physical Hardware Constraints, Davood Mardaninajafabadi

Electronic Theses and Dissertations

This dissertation focuses on information recovery under two general types of sensing constraints and hardware limitations that arise in practical data acquisition systems. We study the effects of these practical limitations in the context of signal recovery problems from interferometric measurements such as for optical mode analysis. The first constraint stems from the limited number of degrees of freedom of an information gathering system, which gives rise to highly constrained sensing structures. In contrast to prior work on compressive signal recovery which relies for the most part on introducing additional hardware components to emulate randomization, we establish performance guarantees for …

A Study On Distributed Generation With A Focus On Solar Power, Shravan Kumar Tomar

Electronic Theses and Dissertations

Centralized generation is when electric power is produced in a large scale of tens of MWs and is located away from the end user. This kind of production is connected to a series of high-voltage transmission lines. Electricity is then delivered to the end user through a network of distribution grids. Centralized generation tend to have multiple end user with multiple user profiles.

Distributed Generation is when is produced in a small scale and is located at the site of or very close to the end user. There are many ways distributed generation can be achieved, Solar power being the …

Danger-Aware Resource Management In V2x Network, Tsigigenet Dessalgn

Electronic Theses and Dissertations

IEEE 802.11p is one of the key technologies that enable dedicated short-range communications (DSRC) in intelligent transportation system (ITS) for safety on the road. The main challenge in vehicular communication is the large amount of data to be processed. As vehicle density and velocity increases, the data to be transmitted also increases. We proposed a protocol that reduces the number of data to be transmitted at every second according to the level of danger that the transmitter vehicle experiences. The proposed protocol measures inter-vehicle distance, as the representative of the danger of a vehicle, to determine the priority for transmission. …