Gerhard Paoli

Electromagnetic field computation of simple structures on printed circuit boards by the finite-element method

The aim of this paper is to study some problems arising in simulating structures on printed circuit boards. Hexahedral edge finite elements of second order using different potential formulations have been employed. Some simplifications are proposed to reduce the computational effort. The input impedance of a micro strip on a test board is computed and compared with measurement data. Some numerical issues are investigated. A semi-analytical method to compute the losses in the microstrip and in the board is presented and results are shown

Extraction of circuit parameters from PCB by FDTD and SIBC

Purpose – The purpose of this paper is to study the extraction of scattering parameters (SPs) from simple structures on a printed circuit board (PCB) by the finite difference time domain (FDTD) method with the aid of a surface impedance boundary condition (SIBC).Design/methodology/approach – The incorporation of SIBC into the FDTD method is described for the general case. The excitation of a field problem by a field pattern and the transition from the field solution to a circuit representation by SPs is discussed.Findings – SPs obtained by FDTD with SIBC are validated with semi‐analytic solutions and compared with results obtained by different numerical methods. Results of a microstrip with a discontinuity considering losses are presented demonstrating the capability of the present method.Originality/value – The comparison of numerical results obtained by different methods demonstrates the capability of the present method to extract SPs from PCBs very efficiently.

On the convergence of the transfinite‐element method

Purpose – The convergence of the transfinite‐element (TFE) method for high frequency methods is analyzed in this paper. Two different potential formulations will be compared in the frequency and time domain.Design/methodology/approach – The A*‐and A,v‐formulation for time domain and frequency domain transfinite elements are described. The convergence properties of the methods are investigated and demonstrated on a simple test problem.Findings – It is shown that the convergence of the frequency domain method depends also on the discretization of areas where the field values do not change very much. A numerical example shows that for the calculation of the whole frequency range, the time domain approach is much more faster than the frequency domain method.Research limitations/implications – Further, work should also cover additional formulations like, e.g. the T,Φ‐formulation.Practical implications – Pros and cons of different formulations and methods for solving high frequency problems for printed circuit ...