This work examines and implements two different techniques for the estimation of the capacitance and impedance of microstrip-like open structures. Both theories, one developed by Yamashita and Mittra and the other by Itoh and Hebert are based on variational methods. The results for the capacitance and impedance of a microstrip-like structure are calculated numerically and compared with measurements taken using a sample. The results presented in this thesis indicate that the first method produces results with large error and it can be used for microstrip structures with only one strip. The second method produces very accurate results for the microstrip structure under consideration and is the one recommended. / Master of Science

The field of superconductivity has recently begun to grow in an exponential fashion. This thesis has briefly described a history of superconductivity discoveries, provided the brief literature review about the superconductors. The superconductor material realization and characterization are provided. The delay line design method is presented and various printed delay lines are constructed. The experimental results are presented and discussed. / Master of Science

Cheng Sin-hang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 90-92). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Theory of Oscillator Design --- p.4 / Chapter 2.1 --- Open-loop approach --- p.4 / Chapter 2.2 --- One-port approach --- p.6 / Chapter 2.3 --- Two-port approach --- p.9 / Chapter 2.4 --- Voltage controlled oscillator (VCO) design --- p.10 / Chapter 2.4.1 --- Active device selection and biasing --- p.11 / Chapter 2.4.2 --- Feedback circuit design --- p.15 / Chapter 2.4.3 --- Frequency tuning circuit --- p.20 / Chapter Chapter 3 --- Noise in Oscillators --- p.23 / Chapter 3.1 --- Origin of phase noise --- p.23 / Chapter 3.2 --- Impact of phase noise in communication system --- p.28 / Chapter 3.3 --- Phase noise consideration in VCO design --- p.30 / Chapter Chapter 4 --- Low Temperature Co-Fired Ceramic --- p.31 / Chapter 4.1 --- LTCC process --- p.31 / Chapter 4.1.1 --- LTCC fabrication process --- p.32 / Chapter 4.1.2 --- LTCC materials --- p.34 / Chapter 4.1.3 --- Advantages of LTCC technology --- p.35 / Chapter 4.2 --- Passive components realization in LTCC --- p.37 / Chapter 4.2.1 --- Capacitor --- p.37 / Chapter 4.2.2 --- Inductor --- p.42 / Chapter Chapter 5 --- High-Q LTCC Resonator Design --- p.47 / Chapter 5.1 --- Definition of Q-factor --- p.47 / Chapter 5.2 --- Stripline --- p.50 / Chapter 5.3 --- Power losses --- p.52 / Chapter 5.4 --- Laminated stripline resonator design --- p.53 / Chapter 5.4.1 --- λ/4 resonator structure --- p.57 / Chapter 5.4.2 --- Meander-line resonator structure --- p.60 / Chapter 5.4.3 --- Bi-metal-layer resonator structure --- p.63 / Chapter Chapter 6 --- LTCC Voltage Controlled Oscillator Design --- p.67 / Chapter 6.1 --- Circuit design --- p.67 / Chapter 6.2 --- Output filter --- p.68 / Chapter 6.3 --- Embedded capacitor --- p.71 / Chapter 6.4 --- VCO layout and simulation --- p.72 / Chapter Chapter 7 --- Experimental Setup and Results --- p.77 / Chapter 7.1 --- Measured Result: LTCC resonators --- p.77 / Chapter 7.1.1 --- Experimental results --- p.79 / Chapter 7.2 --- Measured results: LTCC voltage controlled oscillators --- p.83 / Chapter Chapter 8 --- Conclusion and Future Work --- p.88 / Reference List --- p.90 / Appendix A: TRL calibration method --- p.93 / Appendix B: Q measurement --- p.103 / Appendix C: Q-factor extraction program listing --- p.109 / Chapter 1. --- Function used to calculate Q from s-parameter --- p.109 / Chapter 2. --- Function used to calculate Q from z-parameter --- p.111

Passive components like resistors, capacitors and inductors are used in every electronic system. These are the very basic components which affect the system performance at higher frequencies and it is necessary to understand and model the behavior of these components in a very accurate manner. This work focuses on utilizing Printed Circuit Board (PCB) test boards, or fixtures, made of FR4 for characterizing Surface Mount Device (SMD) components. Agilent's Advanced Design System (ADS) microwave circuit simulation software was used for designing the microstrip transmission lines as well as for generating the layout for manufacturing of the PCB. SMD resistors, capacitors and inductors were soldered into the fixture and then measured using the Vector Network Analyzer (VNA). The calibration kit was developed in ADS. The measured data were calibrated using the TRL (Thru-Reflect-Line) calibration algorithm. A calibration kit consisting of through, three transmission lines of various lengths, open and short was designed and manufactured. Calibration procedures were performed using Cascade Microtech's WinCal XE software. Based on our experience, TRL calibration did not perform to its full potential due to errors in the value of the characteristic impedance of microstrip transmission line. This impedance is ideally assumed to be 50 Ohm, but our lines had characteristic impedance of around 49 Ohm. Simple models for the resistors and capacitors were developed by our collaborators at the University of Zagreb and we developed the model for the inductors. We used ADS for simulations and comparison with the measured data. Extensive optimization of these models was done so as to fit the measured and modeled data. As the frequency goes above 4 GHz models and measurements don't match due to the limitations of the PCB material, the increasing effects of the parasitics and calibration artifacts. This work shows how and when we can use inexpensive FR4 PCB for the characterization of the passive SMD components in the low GHz frequency range. It also examines the range of operating frequency of SMD components, verifies the parameters extracted from the simple model and tests the TRL calibration algorithm.

A model is presented which incorporates the advantages of a mixed mode simulation to characterize transmission line behavior in multiple coupled Transmission line systems. The model is intended for use by digital circuit designers who wish to be able to obtain accurate transmission line behavior for complex digital systems for which continuous time simulation tools such as SPICE would time prohibitive. The model uses a transverse electromagnetic wave approximation to obtain solutions to the basic transmission line equations. A modal analysis technique is used to solve for the attenuation and propagation constants for the transmission lines. Modal analysis done in the frequency domain after a Fast Fourier Transform of the time-domain input signals. Boundary conditions are obtained from the Thevinized transmission line input equivalent circuit and the transmission line output load impedance. The model uses a unique solution queue system that allows n-line coupled transmission lines to be solved without resorting to large order matrix methods or the need to diagonals larger matrices using linear transformations. This solution queue system is based on the method of solution superposition. As a result, the CPU time required for the model is primarily a function of the number of transitions and not the number of lines modeled. Incorporation of the model into event driven circuit simulators such as Network C is discussed. It will be shown that the solution queue methods used in this model make it ideally suited for incorporation into a event-driven simulation network. The model presented in this thesis can be scaled to incorporate direct electromagnetic coupling between first, second, or third lines adjacent to the line transitioning. It is shown that modeling strictly adjacent line coupling is adequate for typical digital technologies. It is shown that the model accurately reproduces the transmission line behavior of systems modeled by previous authors. Example transitions on a 8-line system are reviewed. Finally, future model improvements are discussed.

Thesis (Ph. D.)--Ohio State University, 2007. / Full text release at OhioLINK's ETD Center delayed at author's request

Orientadores: Hugo Enrique Hernandez Figueroa, Gilberto Medeiros Ribeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e da Computação / Made available in DSpace on 2018-08-05T03:16:18Z (GMT). No. of bitstreams: 1 Sousa_AntonioCarlosTorrezande_M.pdf: 2536341 bytes, checksum: 2f6ebfc74e6b1e0305c7887d30758ce9 (MD5) Previous issue date: 2005 / Resumo: O objetivo deste trabalho é construir uma instrumentação que permita a realização de ressonância de spin eletrônico (ESR) em amostras com baixo número de spins, como, por exemplo, pontos quânticos (QDs) auto-formados de InAs. Para isto, este trabalho se propõe em usar cavidades de microfita (MRs). Apesar do seu baixo fator de qualidade, MRs apresentam um alto fator de preenchimento, parâmetro diretamente relacionado com a sensibilidade. Assim, ao analisar como cada dimensão da cavidade influencia na sensibilidade e tendo em mente os outros requisitos da ESR a serem satisfeitos, a geometria final de uma cavidade em GaAs pode ser determinada. Fora a cavidade, todas as transições presentes no sistema foram avaliadas. Por fim, diversos sistemas de detecção foram testados e comprovaram a funcionalidade do sistema montado, completando a análise de todos os elementos de um espectrômetro de ESR / Abstract: The goal of this work is to build an electron-spin resonance (ESR) spectrometer with enhanced sensitivity in order to allow the measurement of samples with a small number of spins such as InAs self-assembled quantum dots (QDs). Here, it is proposed the use of microstrip resonators (MRs) to achieve this goal. Despite of its low quality factor, MRs have a very large filling factor, which boosts the signal-to-noise ratio (SNR) of the system. This way, the final geometry of a MR built on GaAs substrate was determined after fulfilling the requirements from the sensitivity as well as from the ESR. Besides that, all the transitions present in the system were assessed. By the end, some detection systems were tested and proved the working of the system built, completing the analysis of all the elements of a spectrometer / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica