Review of multi-scale electromagnetic modeling

This paper reviews various methods to solve multiscale problems ranging from low-frequency methods to very high-frequency methods. ©2010 IEEE.published_or_final_versionThe 2010 International Conference on Electromagnetics in Advanced Applications (ICEAA), Sydney, N.S.W., 20-24 September 2010. In Proceedings of ICEAA'10, 2010, p. 641-64

A frequency-domain formulation of the Fréchet derivative to exploit the inherent parallelism of the distorted Born iterative method

With its consideration for nonlinear scattering phenomena, the distorted Born iterative method (DBIM) is known to provide images superior to those of linear tomographic methods. However, the complexity involved with the production of superior images has prevented DBIM from overtaking simpler imaging schemes in commercial applications. The iterative process and need to solve the forward-scattering problem multiple times make DBIM a slow algorithm compared to diffraction tomography. Fortunately, as computer prices continue to decline, it is becoming easier to assemble large, distributed computer clusters from low-cost personal computer systems. These are well-suited to DBIM inversions, and offer great promise in accelerating the method. Traditional frequency-domain DBIM formulations produce an image by inverting the Fréchet derivative. If the derivative is treated as a matrix, it is costly to construct and awkward to invert on distributed computer systems. This paper presents an interpretation of the Fŕchet derivative that is ideal for parallel-computing applications. As a bonus, this formulation reduces the storage requirements of DBIM implementations, making it possible to invert larger problems on a fixed system. © 2006 Taylor & Francis.link_to_subscribed_fulltex

A comparison of the computational efficiency of three inverse scattering methods

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On preconditioning and the eigensystems of electromagnetic radiation problems

A formulation of the Method of Moments (MoM) impedance matrix is presented that facilitates discussion of the behavior of its eigenvalues and eigenvectors. This provides insight into the difficulties of producing iterative solutions to electromagnetic radiation problems, which typically involve nonuniform meshes. Based on this analysis, a localized self-box inclusion (SBI) preconditioner is developed to overcome the aforementioned issues. Numerical results are shown using a parallel multilevel fast multipole algorithm (MLFMA) library, coupled with an implementation of the SBI preconditioner. Using these parallel libraries allows the solution of very large problems, due to both excessive size and poor conditioning. A model of an XM antenna, mounted atop an automobile above a very large ground plane, establishes the effectiveness of these methods for more than 3.5 million unknowns. © 2008 IEEE.link_to_subscribed_fulltex

Improving the effectiveness of the distorted born iterative method with a parallel, multi-frequency approach

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Parallelization of the reduced-coupling technique for a method-of-moments-based field solver used for product-level wide data-bus analysis

A parallel LU decomposition algorithm is presented to take advantage of the sparse impedance matrix produced by the reduced-coupling method. This algorithm allows rapid simulation of very large chip and packaging problems. A representative example is shown for a wide, on-chip data-bus that required one million surface unknowns and the computational power of a 1024-node IBM BlueGene cluster with distributed memory. © 2007 IEEE.link_to_subscribed_fulltex

Parallelization of the reduced-coupling technique for a method-of-moments-based field solver used for product-level wide data-bus analysis

A parallel LU decomposition algorithm is presented to take advantage of the sparse impedance matrix produced by the reduced-coupling method. This algorithm allows rapid simulation of very large chip and packaging problems. A representative example is shown for a wide, on-chip data-bus that required one million surface unknowns and the computational power of a 1024-node IBM BlueGene cluster with distributed memory. © 2007 IEEE.link_to_subscribed_fulltex

Computational electromagnetics: Casimir force, multiscale calculations, coordinate stretching

This presentation summarizes some recent advances and applications of computational electromagnetics for complex structures in Casimir force calculation, and multiscale simulation in circuits and antennas. It discusses the concept of coordinate stretching and its relationship to transformation optics. ©2009 IEEE.link_to_subscribed_fulltex

Recent trends in computational electromagnetics

An overview of computational electromagnetics and its recent trends are given. Fast integral equation solvers, and its recent progress in handling multi-scale complex structures will be illustrated. Some numerical examples will be shown.link_to_subscribed_fulltex