Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 247-259). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 247-259). Also available on the Internet.

Thesis (M.S.)--Tennessee Technological University, 2009. / Title from title page screen (viewed on Feb. 9, 2010). Bibliography: leaves 102-108.

Not available / text

published_or_final_version / abstract / toc / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

With the increasing market demand for wideband multifunctional electronic systems, real-time broadband measurement systems with few picoseconds switching rates are essential. Furthermore, stable millimeter wave sources are required to drive these wideband electronic systems. Nonlinear transmission lines (NLTLs) are high impedance transmission lines periodically loaded with reverse biased diode serving as varactors. Extremely high bandwidths are achievable because of the possibility to fabricate these structures monolithically, which is why pulses with ultra short transitions can be generated using NLTLs. Also, efficient wideband frequency conversion is made possible by NLTL technology. / In this thesis, a comprehensive study of NLTLs and their applications is presented. Sharpening of the edges of electrical pulses, voltage dependent true time delay, and harmonic generation in NLTLs are investigated through analytical studies as well as circuit simulations and experimental measurements. Designing the best possible mixers, frequency doublers, and edge sharpeners and optimizing them are not the objects of this thesis. The main objective is to study an alternative design approach by using NLTLs. To this end, analytical solution for the magnitude of the third harmonic along a nonlinear transmission line is derived for the first time. Also, for the first time the lowpass nature of the NLTL is combined with the solutions for the magnitudes of harmonics in order to improve the validity range of the predicted harmonics. An NLTL harmonic generator is fabricated and measurement results are reported. / Inspired by the distributed nature of nonlinear transmission lines, a novel filtering method is introduced for the suppression of the unwanted signals in different NLTL applications. The filtering method is applied to a nonlinear transmission line frequency multiplier in order to filter the third harmonic. The distributed filtering is also used to suppress the image signal in an NLTL mixer. The proposed filtering method is general and can be applied to other periodic structure as well (such as distributed amplifiers and distributed mixers). For implementing the filtering, compact complementary split ring resonators are proposed and designed for an NLTL frequency doubler.

No description available.

No description available.

Ultra wideband (UWB) systems have the potential for high data rate applications such as high-definition video streaming, high speed data transfer, etc. Recently, WiMedia based UWB evaluation systems and commercial products are available from industry. In order to understand the true performance of the WiMedia UWB system, it is important to study its characteristics from mathematical models and practical measurement tests. One of the key objectives of this thesis is to determine the important parameters in the path loss model based on the measurement results from the intended environments. Our focus is on residential environments including office buildings and houses, where intensive measurements are performed from various layers of a network (e.g. physical layer, packet level and application level). The results show that the WiMedia UWB system is fully capable of handling different high rate applications in residential networks. Another goal of this thesis is to propose a medium access control (MAC) protocol design tailored to high rate residential UWB wireless networks. The proposed multiband distributed MAC design utilizes the unique capabilities of UWB technology and the environment characteristics. We elaborate the design details and build a discrete event simulation program for performance evaluation purpose. By evaluating from both theoretical analysis and simulation, we show that the proposed MAC design has substantial advantage over single channel MAC in a high rate residential UWB wireless network. / Graduate