3D Capacitance Extraction With the Method of Moments

In this thesis, the Method of Moments has been applied to calculate capacitance between two arbitrary 3D metal conductors or a capacitance matrix for a 3D multi-conductor system. Capacitance extraction has found extensive use for systems involving sets of long par- allel transmission lines in multi-dielectric environment as well as integrated circuit package including three-dimensional conductors located on parallel planes. This paper starts by reviewing fundamental aspects of transient electro-magnetics followed by the governing dif- ferential and integral equations to motivate the application of numerical methods as Method of Moments(MoM), Finite Element Method(FEM), etc. Among these numerical tools, the surface-based integral-equation methodology - MoM is ideally suited to address the prob- lem. It leads to a well-conditioned system with reduced size, as compared to volumetric methods. In this dissertation, the MoM Surface Integral Equation (SIE)-based modeling approach is developed to realize electrostatic capacitance extraction for 3D geometry. MAT- LAB is employed to validate its e?ciency and e?ectiveness along with design of a friendly GUI. As a base example, a parallel-plate capacitor is considered. We evaluate the accu- racy of the method by comparison with FEM simulations as well as the corresponding quasi-analytical solution. We apply this method to the parallel-plate square capacitor and demonstrate how far could the undergraduate result 0C = A ? =d\u27 be from reality. For the completion of the solver, the same method is applied to the calculation of line capacitance for two- and multi-conductor 2D transmission lines

Capacitance extraction of three-dimensional interconnects using element-by-element finite element method (EBE-FEM) and preconditioned conjugate gradient (PCG) technique

10.1093/ietele/e90-c.1.179IEICE Transactions on ElectronicsE90-C1179-187IELE

Numerical simulation of the capacitance sensor behavior for multiphase core-flow monitoring

Orientador: Luiz Felipe Mendes de MouraDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecanicaResumo: Os sistemas de transporte de óleos pesados, que adicionam um líquido de menor viscosidade como água, geram uma mistura que pode escoar em diferentes padrões. Um deles é o escoamento anular ou core-flow, onde a água escoa na região perimetral anular e o óleo na região central, permitindo uma diminuição da potencia utilizada no transporte convencional. Quando são injetados óleo e água torna-se necessário monitorar o comportamento deste processo. Uma solução do problema consiste em utilizar uma sonda não-intrusiva, que utiliza a modificação do campo elétrico devida à diferença entre as permissividades do óleo e da água num capacitor de placas côncavas colocado na superfície externa da tubulação, de maneira que a distribuição das fases modifica a capacitância. Existem diferentes geometrias para os eletrodos, formas de colocar-los na tubulação, separação entre eletrodos, entre outros parâmetros que podem modificar o comportamento do sensor. Testar as diferentes configurações de forma experimental pode resultar árduo. Aproveitando a natureza do fenômeno e as leis físicas que o governam, é possível utilizar ferramentas computacionais e, mediante técnicas numéricas, obter soluções que ajudem a agilizar o processo de desenvolvimento. Pode-se testar um volume razoável de configurações e obter um mapa do comportamento do sistema, para que na etapa de testes sejam somente utilizados os parâmetros que deram as melhores respostas. As simulações dependem da escolha de diferentes parâmetros e devem fornecer respostas não ambíguas, que possam ser lidas com um sistema eletrônico. Neste trabalho são levadas em conta diferentes situações presentes em escoamentos do tipo core-flow que afetam a medida feita pela sonda, como a variação do diâmetro do fluido que escoa na região central (neste caso é o óleo), a excentricidade que pode apresentar esta região, a mudança de permissividades devida às emulsificações ocasionadas na injeção do óleo na tubulação cheia de água e o efeito volumétrico do capacitor.Abstract: The heavy oil transport systems, that add a liquid of lower viscosity as water, generate a mixture which can flow with different patterns. One of them is the core-flow, where water flow in the annular region and the oil in the core, allowing a reduction in the power used in the conventional transport. When oil and water are injected it becomes necessary monitoring the behavior of the process. One solution for this problem consists in use a non-intrusive probe, which uses a modification of the electric field due to the difference between the oil and the water permittivities, inside a capacitor of concave plates placed in the external surface of the pipe, thus the distribution of the phases modifies the capacitance. There are different geometries for the electrodes, ways for placing them in the pipe, separation between electrodes, among other parameters, which can modify the sensors behavior. Taking advantage of the nature of the phenomenon and the physical laws that govern it, is possible to use computational tools and, by numerical techniques, to get solutions that help expediting the development process. It can be tested a reasonable volume of configurations and getting a map of the behavior of the system, so that in the stage of testing only will be used the parameters which provided the best answers. The simulations depend on the choice between different parameters and should not provide ambiguous answers, which can be read with an electronic system. In this work are taking into account different situations in draining of the core-flow kind that affect the measurement made by the probe, such as the variation of the diameter of the fluid that flows in the central region (in this case oil), the eccentricity that can show this region, the changes i the permittivity due to the emulsion produced in the oil injection in to the tubing full of water and the volumetric effect of the capacitor.MestradoTermica e FluidosMestre em Engenharia Mecânic

Device and circuit-level models for carbon nanotube and graphene nanoribbon transistors

Metal-oxide semiconductor field-effect transistor (MOSFET) scaling throughout the years has enabled us to pack million of MOS transistors on a single chip to keep in pace with Moore’s Law. After forty years of advances in integrated circuit (IC) technology, the scaling of silicon (Si) MOSFET has entered the nanometer dimension with the introduction of 90 nm high volume manufacturing in 2004. The latest technological advancement has led to a low power, high-density and high-speed generation of processor. Nevertheless, the scaling of the Si MOSFET below 22 nm may soon meet its’ fundamental physical limitations. This threshold makes the possible use of novel devices and structures such as carbon nanotube field-effect transistors (CNTFETs) and graphene nanoribbon field-effect transistors (GNRFETs) for future nanoelectronics. The investigation explores the potential of these amazing carbon structures that exceed MOSFET capabilities in term of speed, scalability and power consumption. The research findings demonstrate the potential integration of carbon based technology into existing ICs. In particular, a simulation program with integrated circuit emphasis (SPICE) model for CNTFET and GNRFET in digital logic applications is presented. The device performance of these circuit models and their design layout are then compared to 45 nm and 90 nm MOSFET for benchmarking. It is revealed through the investigation that CNT and GNR channels can overcome the limitations imposed by Si channel length scaling and associated short channel effects while consuming smaller channel area at higher current density