In this paper local multilevel fast multipole algorithm (LMLFMA) based on a novel improved electric field integral equation (IEFIE) is developed to achieve fast and efficient solution of electromagnetic scattering fro...
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In this paper local multilevel fast multipole algorithm (LMLFMA) based on a novel improved electric field integral equation (IEFIE) is developed to achieve fast and efficient solution of electromagnetic scattering from 3D conducting structures. A well-conditioned matrix is constructed in the IEFIE by adding the principle value term of magnetic field integral equation (MFIE) operator into traditional EFIE operator. Only several update steps for the current vector are required to attain a reasonable solution. To further speed up the computation of matrix-vector multiplications in the iteration, LMLFMA is applied. The present method attains much faster convergence of iteration than traditional EFIE and less computational complexity of matrix-vector multiplications than MLFMA, and it still keeps good accuracy. Numerical results show the validity and efficiency of the present method.
To further expedite solution of electromagnetic scattering from conducting structures with slots, a novel improved electric field integral equation (IEFIE) is developed to reduce the iteration time in multilevelfast ...
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To further expedite solution of electromagnetic scattering from conducting structures with slots, a novel improved electric field integral equation (IEFIE) is developed to reduce the iteration time in multilevel fast multipole algorithm (MLFMA). By adding the principal value term of magnetic field integral equation (MFIE) operator on the both sides of the EFIE operator, a well-conditioned improved EFIE operator is constructed. To achieve a reasonable accuracy, only several update steps for the unknown current is required. Numerical results demonstrate the validity of the present method.
In this letter, we consider the solution of large electromagnetics problems of composite structures with coexisting open and closed conductors. By modifying the construction of the combined-field integral equation (CF...
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In this letter, we consider the solution of large electromagnetics problems of composite structures with coexisting open and closed conductors. By modifying the construction of the combined-field integral equation (CFIE), we demonstrate a significant improvement in the iterative solution of these problems compared to the conventional electric-field formulation.
We present an efficient technique to reduce the interpolation and anterpolation (transpose interpolation) errors in the aggregation and disaggregation processes of the multilevel fast multipole algorithm (MLFMA), whic...
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We present an efficient technique to reduce the interpolation and anterpolation (transpose interpolation) errors in the aggregation and disaggregation processes of the multilevel fast multipole algorithm (MLFMA), which is based on the sampling of the radiated and incoming fields over all possible solid angles, i.e., all directions on the sphere. The fields sampled on the sphere are subject to various operations, such as interpolation, aggregation, translation, disaggregation, anterpolation, and integration. We identify the areas on the sphere, where the highest levels of interpolation errors are encountered. The error is reduced by employing additional samples on such parts of the sphere. Since the interpolation error is propagated and amplified by every level of aggregation, this technique is particulary useful for large problems. The additional costs in the memory and processing time are negligible, and the technique can easily be adapted into the existing implementations of MLFMA.
The solenoidal basis functions proposed by Carvalho and Mendes, which are defined on tetrahedrons, are applied into multilevelfast multiple algorithm to analyze the electromagnetic scattering problem of the three-dim...
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ISBN:
(纸本)9780780395930
The solenoidal basis functions proposed by Carvalho and Mendes, which are defined on tetrahedrons, are applied into multilevelfast multiple algorithm to analyze the electromagnetic scattering problem of the three-dimensional homogeneous or inhomogeneous dielectric objects. Necessary formulations for implementation are given in detail. Three popular Krylov subspace iterative methods, that is, conjugate gradient method (CG), bi-conjugate gradient method (BiCG), and general minimize residual (GMRES), are introduced to solve the resultant linear equations. We also introduce a novel iterative method-loose general minimize residual (LGMRES), which gives a little modification to GMRES, but promotes the convergence rate obviously. The results display that the LGMRES has a best performance, while CG is inefficient in the calculations for large electric-size using solenoidal basis functions method of moment.
In practical applications, frequency-selective surfaces (FSSs) are finite, and sometimes even curved. In this paper, we present a hybrid volume-surface integral-equation approach to analyze the transmission and reflec...
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In practical applications, frequency-selective surfaces (FSSs) are finite, and sometimes even curved. In this paper, we present a hybrid volume-surface integral-equation approach to analyze the transmission and reflection characteristics of finite and curved FFS structures. The hybrid integral equations are established using the surface- and volume-equivalent principles. This approach has two advantages. One is the capability of modeling arbitrarily shaped FSS structures in detail, the other one allows its to easily apply the multilevelfast multiple algorithm to speed up the solution process. The scattering characteristics and frequency responses of several FSSs are analyzed. The simulation results show that for a finite-sized FSS, reducing the radius of curvature causes amplitude variation, frequency shift, and bandwidth change in the reflection and transmission responses. (c) 2005 Wiley Periodicals, Inc.
作者：
Ohnuki, SChew, WCNihon Univ
Coll Sci & Technol Dept Elect Engn Tokyo 1018308 Japan Univ Illinois
Dept Elect & Comp Engn Ctr Computat Electromagnet & Electromagnet Lab Urbana IL 61801 USA
In this paper, we focus on the truncation error of the multipole expansion for the fastmultipole method and the multilevel fast multipole algorithm. When the buffer size is large enough, the error can be controlled a...
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In this paper, we focus on the truncation error of the multipole expansion for the fastmultipole method and the multilevel fast multipole algorithm. When the buffer size is large enough, the error can be controlled and minimized by using the conventional selection rules. On the other hand, if the buffer size is small, the conventional selection rules no longer hold, and the new approach which we have recently proposed is needed. However, this method is still not sufficient to minimize the error for small buffer cases. We clarify this fact and show that the information about the placement of true worst-case interaction is needed. A novel algorithm to minimize the truncation error is proposed.
The solution of the electromagnetic scattering from target with electrically large aperture cavity is very important and challenging. The electric field integral equation(EFIE) with partial coupling principle presente...
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ISBN:
(纸本)078039433X
The solution of the electromagnetic scattering from target with electrically large aperture cavity is very important and challenging. The electric field integral equation(EFIE) with partial coupling principle presented in this paper to compute equivalent magnetic current on aperture surface is easy to understand and can expand the aperture electrical size greatly. Furthermore, a new usage of multilevel fast multipole algorithm(MLFMA) speeds up the computation.
Based on the addition theorem, the principle of a multilevel ray-propagation fastmultipolealgorithm (RPFMA) and fast far-field approximation (FAFFA) has been demonstrated for three-dimensional (3-D) electromagnetic ...
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Based on the addition theorem, the principle of a multilevel ray-propagation fastmultipolealgorithm (RPFMA) and fast far-field approximation (FAFFA) has been demonstrated for three-dimensional (3-D) electromagnetic scattering problems. From a rigorous mathematical derivation, the relation among RPFMA, FAFFA, and a conventional multilevel fast multipole algorithm (MLFMA) has been clearly stated. For very large-scale problems, the translation between groups in the conventional MLFMA is expensive because the translator is defined on an Ewald sphere with many sampling (k) over cap directions. When two groups are well separated, the translation can be simplified using RPFMA, where only a few sampling (k) over cap directions are required within a cone zone on the Ewald sphere. When two groups are in the far-field region, the translation can be further simplified by using FAFFA where only a single (k) over cap is involved in the translator along the ray-propagation direction. Combining RPFMA and FAFFA with MLFMA, three algorithms RPFMA-MLFMA, FAFFA-MLFMA, and RPFMA-FAFFA-MLFMA have been developed, which are more efficient than the conventional MLFMA in 3-D electromagnetic scattering and radiation for very large structures. Numerical results are given to verify the efficiency of the algorithms.
＜正＞As the fastest numerical solver for 3D electromagnetic scattering up to now,multilevel fast multipole algorithm（MLFMA） has the excellent *** computational complexity and the storage requirement is O（NlogN） a...
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ISBN:
(纸本)0780385624
＜正＞As the fastest numerical solver for 3D electromagnetic scattering up to now,multilevel fast multipole algorithm（MLFMA） has the excellent *** computational complexity and the storage requirement is O（NlogN） and O（N） respectively,for a N unknowns *** a given object,MLFMA has different property and accuracy when the discretization density and the grouping technique of MLFMA *** paper investigates the computational complexity,the storage requirement and the accuracy of MLFMA in case of conducting sphere scattering in *** is shown a good property including the complexity and accuracy can be achieved when a suitable discretization density and the grouping size are chosen.
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