Modelagem de uma via de acesso metálica utilizando o método iterativo baseado no conceito de ondas.

Abstract

This work presents a new electromagnetic modeling of a via-hole using a Wave Concept Iterative Procedure (WCIP). From the analysis of the field equations in a viahole described in cylindrical and rectangular coordinates, it is shown that a via-hole can be represented as a structure with rectangular geometry. As the via-hole is disposed orthogonally to the interface, the transverse field is lightly perturbed. Therefore, there will be specific TM modes associated with the insertion of the via-hole influencing the incident and reflected waves. These modes, called in this work “vias modes” are represented by a function defined from the tangential fields that propagates through the via-hole. The formulation of the WCIP is presented considering the influence of one via’s mode, the fundamental TM mode. Then, this formulation is expanded to the case where several vias modes are considered. The validity of the model presented is verified, first, from the analytical calculation of the admittance seen by the source from a circuit composed of a localized source and a short-circuited microstrip line analyzed from a one-dimensional structure. Afterwards, the performance of the proposed model was verified from the simulation results obtained using the WCIP. The circuit used as reference for the simulations performed is composed by a planar source, a microstrip line and a via-hole. The advantage of the modeling presented herein allows the simulation of planar circuits with a layer using a 3D formulation with the WCIP.