Convergence of low-frequency EFIE-based systems with weighted right-hand-side effect

published_or_final_versio

Finite element implementation of the generalized-lorenz gauged A-phi formulation for low-frequency circuit modeling

The A-Φ formulation with generalized Lorenz gauge is free of catastrophic breakdown at low frequencies. In the formulation, A and Φ are completely separated and Maxwell's equations are reduced into two independent equations pertinent to A and Φ, respectively. This, however, leads to more complicated equations in contrast to the traditional A-Φ formulation, which makes the numerical representation of the physical quantities challenging, especially for A. By virtue of the differential forms theory and Whitney elements, both A and Φ are appropriately represented. The condition of the resultant matrix system is wellcontrolled as frequency becomes low, even approaches to 0. The generalized-Lorenz gauged A-Φ formulation is applied to model low-frequency circuits at μm lengthscale.postprin

Implementation of a simplified form of CMP-EFIE for low-frequency capacitive problems

Session: Well-Conditioned Integral Equation Formulations: paper 106.8In this paper, a simplified form of electric field integral equation with Calder´on multiplicative preconditioner (CMP-EFIE) is presented for solving capacitive problems in the low-frequency regime. The decomposed three-term CMP-EFIE, though very stable, cannot capture the current accurately for a capacitor at low frequencies. By omitting the part of the hypersingular preconditioned term, the electric currents solved from the remaining two terms are of the right frequency order for a capacitor. Hence, the resultant two-term formulation can guarantee the accuracy of results for capacitive problems, and also makes the iterative system more stable at low frequencies. Both theoretical analysis and numerical results are provided to verify the practicality of the proposed method.published_or_final_versio

Enhanced A-EFIE with Calderon multiplicative preconditioner

Session: Well-Conditioned Integral Equation Formulations: paper 106.9In this work, a Calderón multiplicative preconditioner (CMP) is proposed for the augmented electric field integral equation (A-EFIE) to improve the convergence. To avoid the imbalance between the vector potential and the scalar potential in the traditional EFIE, A-EFIE considers both the charge and the current as unknowns. After implementing the appropriate frequency scaling and the enforcement of charge neutrality, its formulation is also stable in the low-frequency regime and applicable for large-scale and complex problems. Instead of using other preconditioners, Calderón preconditioning converts the first kind integral equations into the second kind, thus improving the spectrum of the original A-EFIE system. The numerical results show that the resultant system with the combined methods is more stable at low frequencies and converges faster in the calculation of far-field scattering fields.published_or_final_versio

Recent development of surface integral equation solvers for multiscale interconnects and circuits

This paper presents a brief review and recent development of surface integral equation solvers for multiscale interconnects and circuits modeling. As the future production processes down to 5 nm and the operating frequency increases, both multi-scale and large-scale natures should be taken into account in the electromagnetic simulations. Fast, efficient, stable, and broadband integral equation based solvers become indispensable when millions or ten s of millions of unknowns might be involved in the simulation of the integrated circuit. Recent progress and our latest researches in the development of broadband fast electromagnetic solvers will be demonstrated.published_or_final_versio

A vector potential integral equation method for electromagnetic scattering

In this paper, we implement a vector potential integral equation method for electromagnetic scattering problems. The proposed equations are formulated by imposing both the tangential and normal components along the surface of a scatterer. They can be solved by a subspace projection method such as the Galerkin's or moment methods by considering the induced surface currents and the normal component n. A as unknowns. Numerical results validate the effectiveness, stability and accuracy of the proposed formulation.postprin

Calderon preconditioner for the electric field integral equation with layered medium Green's function

published_or_final_versio

Integral sliding mode control with integral switching gain for magnetic levitation apparatus

Author name used in this publication: Norbert C. CheungRefereed conference paper2008-2009 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Calderon Multiplicative Preconditioned EFIE With Perturbation Method

In this paper, we address the low-frequency breakdown and inaccuracy problems in the Calderón multiplicative preconditioned electric field integral equation (CMP-EFIE) operator, and propose the perturbation method as a remedy for three-dimensional perfect electric conductor (PEC) scatterers. The electric currents at different frequency orders as a power series can be obtained accurately in a recursive manner by solving the same matrix system with updated right hand side vectors. This method does not either require a search for the loops in the loop-tree/-star based method or include charge as additional unknown in the augmented EFIE method. Numerical examples show the far-field pattern can be accurately computed at extremely low frequencies by the proposed perturbation method. © 1963-2012 IEEE.published_or_final_versio

Design and simulation of a testing fixture for planar magnetic levitation system control using switched reluctance actuator

Author name used in this publication: Norbert C. CheungRefereed conference paper2008-2009 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe