Thesis (M.S.E.C.E.)--University of Delaware, 2007. / Principal faculty advisor: Keith W. Goossen, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 67-72). Also available in electronic version.

D.Ing. / In the field of power electronics, the relentless demand for higher efficiencies, lower costs and ever-decreasing volume and profile have driven the development of many innovative technologies. Planarization and hybridization have become a substantial part of present system integration methodology. With the subsequent size reduction, the effects of layout and component parasitics are becoming vital issues in the development of innovative structures. The component ‘parasitics’ can be considered dimensional effects of the component structure that are not considered during the design process. The concept of electromagnetic integration is aimed at the utilization and modification of these dimensional effects. This leads to an integrated structure that fulfills multiple electromagnetic functions with the potential for improved power density, efficiency and reliability. In this dissertation, a family of electromagnetically integrated passives is presented. The related electromagnetic modeling and design approach of these complex electromagnetic structures is presented through a case study of L-L-C-T structures. The development of a sufficiently accurate, yet simplified electromagnetic model for design purposes is presented for the case study. With the electromagnetic model as basis, a comprehensive electromagnetic loss model is created. The electromagnetic design and loss models are combined into a design evaluation program. The graphical output of this design evaluation program allows for rapid selection of improved designs based on external cost criteria. This led to numerous insights into the relationships between the design variables. Through modification of the program, some fundamental limits of the integration approach are addressed. A case study design for a 1MHz, 500W dc-dc converter was considered to evaluate the design program. To assess the accuracy of the electromagnetic modeling, three L-L-C-T prototypes are constructed and experimentally tested. The construction process presented improved power density by 80% over previous processes. The electromagnetic component parameters for three prototypes were within 10% of the required design values, while the electromagnetic loss model estimations were within measurement error. The design evaluation program was enlisted in the design of two of these prototypes. This resulted in a 100% further improvement in power density (480W/in3 or 29.3W/cm3) compared to the original prototype without a loss in efficiency.

No description available.

Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 26, 2007) Includes bibliographical references.

Thesis (M.E.E.)--University of Delaware, 2006. / Principal faculty advisor: James Kolodzey, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

Nanotechnology is providing a new set of tools to the engineering community to design nanoscale components with unprecedented functionalities. The integration of several nano-components into a single entity will enable the development of advanced nanomachines. Nanonetworks, i.e., networks of nanomachines, will enable a plethora of applications in the biomedical, environmental, industrial and military fields. To date, it is still not clear how nanomachines will communicate. The miniaturization of a classical antenna to meet the size requirements of nanomachines would impose the use of very high radiation frequencies. The available transmission bandwidth increases with the antenna resonant frequency, but so does the propagation loss. Due to the expectedly very limited power of nanomachines, the feasibility of nanonetworks would be compromised if this approach were followed. Therefore, a new wireless technology is needed to enable this paradigm. The objective of this thesis is to establish the foundations of graphene-enabled electromagnetic communication in nanonetworks. First, novel graphene-based plasmonic nano-antennas are proposed, modeled and analyzed. The obtained results point to the Terahertz Band (0.1-10 THz) as the frequency range of operation of novel nano-antennas. For this, the second contribution in this thesis is the development of a novel channel model for Terahertz Band communication. In addition, the channel capacity of the Terahertz Band is numerically investigated to highlight the potential of this still-unregulated frequency band. Third, a novel modulation based on the transmission of femtosecond-long pulses is proposed and its performance is analyzed.% in terms of achievable information rates. Fourth, the use of low-weight codes to prevent channel errors in nanonetworks is proposed and investigated. Fifth, a novel symbol detection scheme at the receiver is developed to support the proposed modulation scheme. Sixth, a new energy model for self-powered nanomachines with piezoelectric nano-generators is developed. Moreover, a new Medium Access Control protocol tailored to the Terahertz Band is developed. Finally, a one-to-one nano-link is emulated to validate the proposed solutions.

There is strong interest in the use of small low-cost highly sensitive magnetic field sensors for applications (such as small memory and biomedical devices) requiring weak field measurements. Among weak-field sensors, the magneto-impedance (MI) sensor has demonstrated an absolute resolution on the order of 10-11 T. The MI effect is a sensitive realignment of a periodic magnetization in response to an external magnetic field within small ferromagnetic structures. However, design of MI sensors has relied primarily on trial and error experimental methods along with decoupled models that separate the micromagnetic and classical electromagnetic equations describing the MI effect. To offer a basis for more cost-effective designs, this thesis research presentation begins with a general formulation describing MI sensors, which relaxes assumptions commonly made leading to decoupling. The coupled set of nonlinear equations is solved numerically using an efficient meshless method in a point collocation formulation. For the problem considered, the chosen method is shown to offer advantages over alternative methods including the finite element method. In the case of time, projection methods are used to stabilize the time discretization algorithm while quasi-Newton methods (nonlinear solver) are shown to be more computationally efficient, as well. Specifically, solutions for two MI sensor element geometries are presented, which were validated against published experimental data. While the examples illustrated here are for MI sensors, the approach presented can also be extended to other weak-field sensors like fluxgate and Hall effect sensors.

Thesis (Ph.D.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references (ℓ. 131-144)

Thesis (Ph. D.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 16, 2007) Includes bibliographical references (p. 134-136).