Catálogo de publicaciones - libros

One of the major goals in designing of the integrated EMI filters is to improve their highfrequency characteristics. To achieve this, special technologies need to be developed, including the mechanisms for suppression of the equivalent parallel capacitance (EPC) and of the equivalent series inductance (ESL), in spite of increasing the high-frequency losses. In this light, the main goal of the paper is to develop and analyse the effectiveness of several EPCreducing technologies. The study is performed using the numerical analysis software Maxwell Q2D Extractor that is able to give at the end of the numerical analysis process the values of the lumped per-unit-length capacitance or inductance of the geometrical structure proposed. There are calculated the EPC of the four single winding structures and of the coupled windings.

The buffered block forward backward method is described and applied to the problem of scattering from dielectric cylinders. Numerical results suggest that the method converges in the case of scattering from bodies closed at infinity while it produces divergent results in the case of scattering from closed bodies.

The electrodynamic simulation of 3D high-voltage technical devices can be performed under the electro-quasistatic assumption. In order to avoid large spatial discretization domains, a Finite-Element-Method (FEM) is coupled to a Boundary-Element-Method (BEM) which implicitly asserts the electrophysical asymptotic attenuation condition. A symmetric FEM-BEM coupled formulation in time domain is presented. Numerical results are shown for the simulation of a three dimensional high-voltage application.

The paper analyzes the influence of the computational errors on the accuracy of magnetic material modelling with scalar Preisach model. The numerical tests on magnetic recording media allow the correct choosing of numerical algorithms for model parameter identification.

We first show the idea behind a space-mapping iteration technique for the effi- cient solution of optimization problems. Then we show how space-mapping optimization can be understood in the framework of defect correction. We observe a difference between the solution of the optimization problem and the computed space-mapping solutions. We repair this discrepancy by exploiting the correspondence with defect correction iteration and we construct the manifold-mapping algorithm, which is as efficient as the space-mapping algorithm but converges to the accurate solution.

Resistive, capacitive and inductive parasitic coupling effects are very important in integrated circuit technology development and must be taken into account in the global circuit analysis and design. These values are seldom possible to be computed analytically because often we deal with complex multi-route layout geometries. Optimizing the placement of the routes inside the integrated design, in accordance with imposed constraints, one may lead to the decrease of the coupling effects.

This work concerns the multiobjective optimization of an monolithic ESBT_ device aimed to get a characterization of the best design. The optimization will select the epitaxial specifications (thickness, doping concentration) which minimize the energy dissipation, maximize the current flow and keep a breakdown voltage of 1000V. Since these goals are in conflict with each other the best solution must be characterized with respect to all trade-offs. The search was carried out with an extension of the DIRECT algorithm to the multiobjective case.

This papers deals with the optimal design of semiconductor devices, based on the adjoint method and the Energy Transport model. A partially decoupled adjoint system is obtained by considering the electrostatic potential as the new design variable and by interpreting the Poisson equation as a state equation for the doping profile. This leads to an efficient iterative optimization algorithm based on a variant of the Gummel iteration.

In this paper we present a hierarchy of extended hydrodynamical models for electron transport in Silicon, which differ from each other for the number of scalar and vector moments of the electron distribution function used as state variables. The closure of the moment equations is achieved by means of the Maximum Entropy Principle. The main scattering mechanisms between electrons and phonons are taken into account. An application to the case of bulk Silicon is presented.

A typical problem in engineering is to find a numerical solution to a partial differential equation (or a coupled set thereof), given a number of boundary conditions, and the usual approach of solving the problem starts by discretizing the domain into elementary volumes. In this paper, we focus on mesh generation suitable for the solution of field problems in arbitrary VLSI structures. We assume that the problem cannot be easily reduced to a lower dimensionality by exploiting symmetry or regularity, so that the problem-domain is intrinsically threedimensional. Also, we assume that the selected numerical technique (e.g., the finite element method) requires a three-dimensional discretization (as opposed to a surface-discretization). Surveys on mesh generation are given in [2] and [5]. The mesh generator described in this paper is based on techniques from the Delaunay-based mesh generation literature. The main benefit of these techniques is that the quality of the resulting meshes can be , and, equally important, that the meshes are still small enough to be . An additional advantage is that computation of the mesh is efficient in practice. In general, mesh computation is much faster than solving the subsequent numerical problems. An example mesh generated by our implementation is shown in Figure 1.