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Full-Text Articles in Engineering

Passive Harmonic Generation At Spring Contacts, Sen Yang Jan 2019

Passive Harmonic Generation At Spring Contacts, Sen Yang

Doctoral Dissertations

"In the first paper, the RF passive harmonic generation phenomenon on the spring contact is studied. A spring contact harmonic generation measurement system is developed. The factors that may have an impact on the spring contact harmonic generation, such as contact material, contact force, and contact resistance are characterized by the measurement system. The gold-to-gold contact is found to be much superior to the stainless-steel contacts. It is also found that the passive nonlinearity at the spring contact is the semiconductor-like junction formed by the surface oxide film.

In the second paper, we show that the maximum E-field coupling occurs ...


The Tabu Ant Colony Optimizer And Its Application In An Energy Market, David Donald Haynes Jan 2019

The Tabu Ant Colony Optimizer And Its Application In An Energy Market, David Donald Haynes

Doctoral Dissertations

"A new ant colony optimizer, the 'tabu ant colony optimizer' (TabuACO) is introduced, tested, and applied to a contemporary problem. The TabuACO uses both attractive and repulsive pheromones to speed convergence to a solution. The dual pheromone TabuACO is benchmarked against several other solvers using the traveling salesman problem (TSP), the quadratic assignment problem (QAP), and the Steiner tree problem. In tree-shaped puzzles, the dual pheromone TabuACO was able to demonstrate a significant improvement in performance over a conventional ACO. As the amount of connectedness in the network increased, the dual pheromone TabuACO offered less improvement in performance over the ...


Underwater Acoustic Communications And Adaptive Signal Processing, Mohammadhossein Behgam Jan 2019

Underwater Acoustic Communications And Adaptive Signal Processing, Mohammadhossein Behgam

Doctoral Dissertations

"This dissertation proposes three new algorithms for underwater acoustic wireless communications. One is a new tail-biting circular MAP decoder for full tail-biting convolution (FTBC) codes for very short data blocks intended for Internet of Underwater Things (IoUT). The proposed algorithm was evaluated by ocean experiments and computer simulations on both Physical (PHY) and Media access control (MAC) layers. The ocean experimental results show that without channel equalization, the full tail-biting convolution (FTBC) codes with short packet lengths not only can perform similarly to zero-tailing convolution (ZTC) codes in terms of bit error rate (BER) in the PHY layer. Computer simulation ...


Non-Invasive Microwave And Millimeter Wave Reflectometry And Imaging For Human Skin Diagnosis And Materials Characterization, Yuan Gao Jan 2019

Non-Invasive Microwave And Millimeter Wave Reflectometry And Imaging For Human Skin Diagnosis And Materials Characterization, Yuan Gao

Doctoral Dissertations

"Microwave and millimeter wave reflectometry and synthetic aperture radar (SAR) imaging techniques have been successfully applied in many applications, such as nondestructive testing and evaluation (NDT&E), security inspection and medical diagnosis. In this dissertation, the feasibility of using microwave and millimeter reflectometry and SAR imaging for burn diagnosis is investigated through both simulations and measurements, with promising results. To correctly model the interaction between electromagnetic waves and skin, the proper knowledge of the complex permittivity of healthy skin is critically important. To this end, the common used measurement methods for in vivo skin complex permittivity are reviewed and analyzed ...


Efficient Estimation And Mitigation For Radio-Frequency Interference, Qiaolei Huang Jan 2019

Efficient Estimation And Mitigation For Radio-Frequency Interference, Qiaolei Huang

Doctoral Dissertations

"With rapid innovations in Internet of Things (IoT) and wireless technology, more and more consumer electronic devices around the world are now connected to the internet. In a small form factor electronic device, there are plenty of potential noise sources such as System On Chip (SoC), high speed traces, flexible cables and power converters, etc. Those noise sources can possibly introduce radio frequency interference (RFI) issues. In this dissertation, a transfer function based calculation method is proposed to estimate radio frequency interference (RFI) problems. The derived equations can clearly decompose the RFI problem into two parts: the noise source and ...


Design And Prototyping Of A Real-Time Millimeter Wave Imaging System, Zahra Manzoor Jan 2019

Design And Prototyping Of A Real-Time Millimeter Wave Imaging System, Zahra Manzoor

Doctoral Dissertations

"The goal of this work is to design, prototype and test an innovative millimeter wave imaging system that operates in the frequency range of 33-35 GHz and is capable of producing rapid images of various diverse scenes. In particular, the imaging system includes two main sections, one is related to the hardware design of the system, and the other focuses on the development of a novel comprehensive image reconstruction algorithm. The hardware design includes custom transmitter and receiver sub-systems, and a sparse switched array which was optimized for 320 mm x 220 mm aperture plane, and also included an improved ...


Characterization And Modeling Of Esd Events And Near-Field Scanning Calibration Structures, Shubhankar Kashinath Marathe Jan 2019

Characterization And Modeling Of Esd Events And Near-Field Scanning Calibration Structures, Shubhankar Kashinath Marathe

Doctoral Dissertations

"This research is divided into three papers that cover, two major topics. The first topic, system-level electrostatic discharge (ESD), is discussed over the course of two papers. The second topic, a calibration structure for near-field scanning probe calibration application, is discussed in the last paper. In the first paper, software-assisted detection methods are proposed for secondary ESD discharges. The measured waveforms are analyzed with respect to waveform parameters, such as the vertical threshold of the rising edge, the derivative of the current waveform, and total charge delivered. These parameters enable automatic detection of secondary ESD while monitoring the discharge waveform ...


Modeling Strategies For Estimating And Suppressing Electromagnetic Interference And Improving Power Integrity, Tamar Makharashvili Jan 2019

Modeling Strategies For Estimating And Suppressing Electromagnetic Interference And Improving Power Integrity, Tamar Makharashvili

Doctoral Dissertations

"Decoupling capacitors are used to suppress high-frequency noise in power distribution networks. The inductance associated with a mounted decoupling capacitor can vary by 26% depending on characteristics of the printed circuit board. Here, simple and accurate inductance models of 2- and 8-terminal capacitors including connections to the power and return plane are developed. Circuit models of the capacitors and layout are created using the partial equivalent element circuit method which provide options for circuit-level simulations as well as analytic estimation of inductance. The circuit solution matches results from the full-wave simulation model within 9% for the 8-terminal capacitor and within ...


Smart Control Architecture For Microgrid Application, Vikram Roy Chowdhury Jan 2019

Smart Control Architecture For Microgrid Application, Vikram Roy Chowdhury

Doctoral Dissertations

"This research proposes non-linear control architectures dedicated towards improving transient response, reliability and computational burden for grid connected inverters applicable for ac micro-grids. Also this work proposes an optimization procedure applied to a small microgrid to reduce the billing cost for power incorporating battery degradation mechanism.

Three works are discussed in this research that discusses methodologies to improve the operation of a three phase grid connected inverters. The first work discusses a globally stable estimation architecture for estimating the plant parameters for a grid connected inverter during its operation. Then a Lyapunov based control architecture is utilized and online parameter ...


Deep Neural Network Learning-Based Classifier Design For Big-Data Analytics, Krishnan Raghavan Jan 2019

Deep Neural Network Learning-Based Classifier Design For Big-Data Analytics, Krishnan Raghavan

Doctoral Dissertations

"In this digital age, big-data sets are commonly found in the field of healthcare, manufacturing and others where sustainable analysis is necessary to create useful information. Big-data sets are often characterized by high-dimensionality and massive sample size. High dimensionality refers to the presence of unwanted dimensions in the data where challenges such as noise, spurious correlation and incidental endogeneity are observed. Massive sample size, on the other hand, introduces the problem of heterogeneity because complex and unstructured data types must analyzed. To mitigate the impact of these challenges while considering the application of classification, a two step analysis approach is ...


Ferrite Characterization Techniques & Particle Simulations For Semiconductor Devices, Nicholas Erickson Jan 2019

Ferrite Characterization Techniques & Particle Simulations For Semiconductor Devices, Nicholas Erickson

Doctoral Dissertations

"This dissertation is divided into three papers, covering two major topics. The first topic, techniques for ferrite characterization, is discussed over the course of two papers. The second topic, particle simulations for semiconductor devices, is discussed in the last paper. In the first paper, the method for extracting permeability from ferrite materials is discussed for the Keysight 16454A permeability extraction fixture, where the ferrite material to be characterized is assumed to be homogeneous. Then the method is updated to account for layered materials. The updated method is verified through full-wave simulations. In the second paper, a planar printed circuit board ...


Hardware Architectures For Compact Microwave And Millimeter Wave Cameras, Matthew Jared Horst Jan 2019

Hardware Architectures For Compact Microwave And Millimeter Wave Cameras, Matthew Jared Horst

Doctoral Dissertations

"Millimeter wave SAR imaging has shown promise as an inspection tool for human skin for characterizing burns and skin cancers. However, the current state-of-the-art in microwave camera technology is not yet suited for developing a millimeter wave camera for human skin inspection. Consequently, the objective of this dissertation has been to build the necessary foundation of research to achieve such a millimeter wave camera. First, frequency uncertainty in signals generated by a practical microwave source, which is prone to drift in output frequency, was studied to determine its effect on SAR-generated images. A direct relationship was found between the level ...


2x-Thru, 1x-Reflection, And Thru-Line De-Embedding: Theory, Sensitivity Analysis, And Error Corrections, Bichen Chen Jan 2019

2x-Thru, 1x-Reflection, And Thru-Line De-Embedding: Theory, Sensitivity Analysis, And Error Corrections, Bichen Chen

Doctoral Dissertations

"Due to the simplicity of design and measurement, as well as the accuracy of results, the 2X-Thru de-embedding (2XTD), 1X-Reflection de-embedding (1XRD), and Thru-Line de-embedding (TLD) have been replaced the traditional de-embedding algorithms, such as TRL and SOLT. In this dissertation, theory of 2n-port 2XTD, 1XRD, and TLD are completely derived first. The self-error reduction schemes is introduced to mitigate the de-embedding errors due to non-ideal manufacturing effects of non-zero mode conversion terms, as well as the asymmetric, and manufacturing variations. The validations are performed on both theory and self-error reduction through simulation and measurements cases. The 2X-Thru ...