Luc Knockaert

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An important issue in high-frequency signal integrity prediction is the modeling of the skin effect of thick conductors. A new differential surface admittance concept is put forward allowing to replace the conductor by equivalent electric surface currents and to replace the material of the conductor by the material of the background medium the conductor is(More)
The increasing use of expensive computer simulations in engineering places a serious computational burden on associated optimization problems. Surrogate-based optimization becomes standard practice in analyzing such expensive black-box problems. This article discusses several approaches that use surrogate models for optimization and highlights one(More)
A reduced order modeling method based on a system description in terms of orthonormal Laguerre functions, together with a Krylov subspace decomposition technique is presented. The link with Padé approximation, the block Arnoldi process and singular value decomposition (SVD) leads to a simple and stable implementation of the algorithm. Novel features of the(More)
Adapted finite-difference time-domain (FDTD) update equations exist for a number of objects that are smaller than the grid step, such as wires and thin slots. In this contribution we provide a technique that automatically generates new FDTD update equations for small objects. Our presentation will be focussed on 2-D-FDTD. We start from the FDTD equations in(More)
We propose to find the propagation constants of modes in layered media by means of signal identification methods. To this effect we employ Cauchy’s theorem, conformal mapping and Fast Fourier Transform (FFT) techniques to generate relevant Hankel moments, afterwards to be processed with selected signal identification algorithms. The method, terminated by a(More)
We propose a novel parametric macromodeling method for systems described by admittance and impedance representations, which depend on multiple design variables such as geometrical layout or substrate features. It is able to build accurate multivariate macromodels that are stable and passive over the entire design space. Poles and residues are parameterized(More)
We present a novel technique to perform variability analysis of multiport systems. The versatility of the proposed technique makes it suitable for the analysis of different types of modern electrical systems (e.g., interconnections, filters, connectors). The proposed method, based on the calculation of a set of univariate macromodels and on the use of the(More)