Hut
Beiträge zur Algorithmik des Quasi-TEM-Spektralbereichs-Verfahrens und der Vollwellen-Vektor-Finite-Elemente-Methode für Multi-Layer-Strukturen
Abstract
dc:descriptionIn the submitted thesis two different numerical simulation methods for the computation of coupled parallel conductors have been investigated, with emphasis on the application to multilayered microwave integrated circuits (MMIC), and they have been implemented with own algorithmic improvements. For extra fast computations the Quasi-TEM-Spectral-Domain-Approach (SDA) has been accelerated and extended. For this, for the first time the sinus-transformation inherent in the method was substituted by the real-valued Hartley-transformation, and additionally the convergence of the spectral operator was exploited. For further acceleration, methods have been investigated and developed, that allow the correct computation of vertically stacked and partially overlapping conductors, though still using a single-dimensional, horizontal spectral transformation. The combination of horizontal conductor elements used for this purpose, together with a matched discretisation, gives way to approximating conductors of arbritrary contours, and even hollow conductors. For the adequate determination of inductive coupling effects, a method was used which is not based on the application of Neumann-integrals, but uses the same method as for computing the capacitive coupling effects, and which is suitable even for the simulation of magnetic inhomogeneous substances. A particular focal point was the construction of modes in multiconductor systems. Here, the determination of the characteristic eigenmodes using matrix methods not only was carried out for inhomogeneous geometries; for the first time a method for the determination of eigenmodes in the completely degenerated case of homogeneous materials has been developed, using only the capacitance and inductance matrices, but without requiring the conductor geometry; nevertheless delivering modes consistent to the slightly inhomogeneous case. The second part of the work is given by investigations of the Fullwave-Vector-Finite-Element-Method (VFEM), with special consideration of significant dielectric losses. Here, the direct discretisation of the Galerkin approach was choosen. The usage of vector valued edge elements for the shape function, eliminating nonphysical solutions, was significantly eased by using a special notation. Additionally the influence of the fundamental choise of using magnetic or electric fields for the computation onto the extraction of the desired multiconductor line parameters is shown. The consideration of heavy dielectric losses within the simulated geometries results into complex-valued symmetrical system matrices. This leads to severe convergence problems with those known numerical eigensolvers, which are basically applicable for systems with a large number of degrees of freedom. Therefore, another particular focal point of the work was the investigation of methods, suitable for solving the problems at hand. With the backward iteration a method was found which is capable of robust operation. Finally it was demonstrated that contrary to general opinion even with correct implementation of the method, in spite of using vector-valued edge elements nonphysical solutions are not completely eliminated, and their cause was identified.
Degree
thesis:*- Grantor dc:publisher
- Hut
- Year dc:date
- 2008
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Boysen, Philipp Alexander
- Contributors dc:contributor
-
- Jansen, Rolf H.
Subjects
dc:subject × 13Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger