Femke Olyslager

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In this paper, a new technique for preconditioning electric field integral equations (EFIEs) by leveraging Calderon identities is presented. In contrast to all previous Calderon preconditioners, the proposed preconditioner is purely multiplicative in nature, applicable to open and closed structures, straightforward to implement, and easily interfaced with(More)
Novel time domain integral equations for analyzing scattering from perfect electrically conducting objects are presented. They are free from DC and resonant instabilities plaguing standard electric field integral equation. The new equations are obtained using operator manipulations originating from the Calderon identities. Theoretical motivations leading to(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)
An efficient multilevel fast multipole algorithm (MLFMA) formalism to model radiation and scattering by/from large planar microwave structures is presented. The technique relies on an electric field integral equation (EFIE) formulation and a series expansion for the Green dyadic, based on the use of perfectly matched layers (PML). In this way, a new(More)
A Calderon multiplicative preconditioner (CMP) for the combined field integral equation (CFIE) is developed. Just like with previously proposed Calderon-preconditioned CFIEs, a localization procedure is employed to ensure that the equation is resonance-free. The iterative solution of the linear system of equations obtained via the CMP-based discretization(More)
A novel method, called the nondirective stable plane wave multilevel fast multipole algorithm (NSPWMLFMA), is presented to evaluate the low-frequency (LF) interactions that cannot be handled by the multilevel fast multipole algorithm (MLFMA). It is well known that the MLFMA cannot be used for LF interactions, since it suffers from numerical instability.(More)
The scattering of time-harmonic electromagnetic waves by perfect electrical conductors (PECs) can be modelled by several boundary integral equations, the magnetic and electric field integral equations (MFIE and EFIE) being the most prominent ones[1]. These equations can be discretized by expanding current distributions in terms of Rao-Wilton-Glisson (RWG)(More)
Time domain electric field integral equations often are used to analyze transient scattering from perfect electrically conducting objects. When discretized using marching-on-in-time recipes they give rise to linear systems of equations that can be solved for the induced currents for all time steps. Unfortunately, when the scatterer is approximated by(More)
In this paper, a new strategy for the parallelization of the multilevel fast multipole algorithm (MLFMA) on distributed memory computers is presented. By using an asynchronous implementation of the parallel MLFMA, an efficient parallelization scheme is obtained when multiple dielectric objects are involved in the simulation. Furthermore, a better spreading(More)
Magnetic field integral equation (MFIE) and Calderon preconditioned electric field integral equation (EFIE) operators applied to toroidal surfaces have nontrivial nullspaces in the static limit. The nature of these nullspaces is elucidated and a technique for generating a basis for them presented. In addition, the effects of these nullspaces on the(More)