共查询到19条相似文献,搜索用时 328 毫秒
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提出了一种基于矩量法(MoM)结合多层快速多极子(MLFMA)和自适应交叉近似(ACA)算法计算目标电磁特性的算法,该算法实现了对电大尺寸复合目标散射计算的加速和内存的降低。对于目标自作用的近场区域,多层快速多极子加速矩量法中的矩阵矢量乘运算,降低了计算的存储和复杂度;对于远场区域,根据阻抗矩阵的低秩特性,采用ACA对其压缩,加速矩阵的填充。矩阵填充按照树形结构划分的单元块间的相互作用依次进行存储,对每一块与块之间的求解采用ACA算法,对矩阵做压缩处理。提出的基于ACA的混合算法能够对2个目标耦合作用的阻抗矩阵进行压缩,缩短矩阵的填充时间并降低内存需求,同时也能够减少迭代求解过程中矩阵向量的计算时间,从而极大缩短电磁散射计算的总时间。数值仿真实验表明该算法比传统方法计算更高效,且计算精确度保持一致。 相似文献
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多层快速卡特森展开算法(Multilevel Accelerated Cartesian Expansion Algorithm,MLACEA)可用于加速电小尺寸结构积分方程矩量法,且矩阵与矢量乘积运算计算复杂度为O(N)量级;MLACEA和多层快速多级子算法(Multilevel Fast MultipoleAlgorithm,MLFMA)均基于八叉树分组结构,便于实现它们的混合快速算法MLA-CEA-MLFMA.该混合算法可大幅度降低模拟合精细结构的电大尺寸目标宽带电磁散射问题的计算复杂度.还详细阐述了求解电场积分方程的MLACEA算法及其与MLFMA算法的混合快速算法MLACEA-MLFMA算法;并通过计算实例对比分析了MLFMA算法与MLACEA-MLFMA混合算法的计算效率. 相似文献
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介绍了用于分析电磁散射问题的快速多极算法(FMA)和多层快速多极算法(MLFMA)的基本思想与基本步骤。通过计算实例表明,快速多极算法在计算速度和存贮要求方面比矩量法有明显优势,适合于在现有计算机条件下求解电大尺寸目标的散射问题。 相似文献
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论文提出了一种叠层矩量法分析多尺度目标电磁特性。论文采用矩量法直接计算强相互作用区域,多层矩阵压缩方法(MLMCM)和多层快速多极子方法(MLFMA)分别用于加速计算低频和高频作用区域。论文通过使用多分辨ILU(MR-ILU)预条件加速迭代求解矩量法离散多尺度目标产生的病态矩阵方程。通过分析实际多尺度目标电磁特性证明论文方法的有效性。 相似文献
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利用多层快速多极子方法(MLFMA)分析三维导体介质复合结构的电磁辐射与散射特性.根据等效原理,介质表面构造Poggio-Miller-Chang-Harrington-Wu(PMCHW)方程,导体表面建立电场积分方程(EFIE).分析了含介质目标MLFMA算法中远区组矩阵矢量相乘运算以及有耗媒质空间中格林函数的平面波展开.利用该方法研究了涂敷目标电磁散射特性以及天线罩对直线阵天线辐射特性的影响.MLFMA的应用降低了计算量和存储量,实现了对电大尺寸目标快速、准确的求解. 相似文献
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随着物体电尺寸不断变大,传统矩量法计算物体电磁散射和辐射会使计算量和存储量迅速的增加,最终导致无法计算出结果,而自适应积分法解决了矩量法计算量和存储量的问题,使得存储量变小,并利用快速傅里叶变换(FFT)加速了矩阵向量乘积,更加适用于求解电大尺寸的目标。 相似文献
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利用积分方程法计算三维目标单站RCS时,需要逐个角度地进行矩阵方程的求解。为了提高计算效率,本文采用自适应交叉近似算法(ACA)对多角度照射时生成的激励矩阵进行低秩压缩,减少了矩阵方程的求解次数;进一步基于单站角度上的分组方式提出了双层ACA算法,该算法对内存占用极小,提高了算法的并行性,而且更有效地实现了激励矩阵的降秩;最后结合多层快速多极子算法(MLFMA)实现电大尺寸目标的快速求解。数值计算结果表明,该算法能大幅减少大宽角条件下的单站RCS计算时间,具有较高的计算精度和计算效率。 相似文献
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Sheng X.Q. Jin J.-M. Song J. Chew W.C. Lu C.-C. 《Antennas and Propagation, IEEE Transactions on》1998,46(11):1718-1726
We present an accurate method of moments (MoM) solution of the combined field integral equation (CFIE) using the multilevel fast multipole algorithm (MLFMA) for scattering by large, three-dimensional (3-D), arbitrarily shaped, homogeneous objects. We first investigate several different MoM formulations of the CFIE and propose a new formulation, which is both accurate and free of interior resonances. We then employ the MLFMA to significantly reduce the memory requirement and computational complexity of the MoM solution. Numerical results are presented to demonstrate the accuracy and capability of the proposed method. The method can be extended in a straightforward manner to scatterers composed of different homogeneous dielectric and conducting objects 相似文献
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Donepudi K.C. Jian-Ming Jin Velamparambil S. Song J. Weng Cho Chew 《Antennas and Propagation, IEEE Transactions on》2001,49(7):1069-1078
A higher order multilevel fast multipole algorithm (MLFMA) is presented for solving integral equations of electromagnetic wave scattering by three-dimensional (3-D) conducting objects. This method employs higher order parametric elements to provide accurate modeling of the scatterer's geometry and higher order interpolatory vector basis functions for an accurate representation of the electric current density on the scatterer's surface. This higher order scheme leads to a significant reduction in the mesh density, thus the number of unknowns, without compromising the accuracy of geometry modeling. It is applied to the electric field integral equation (EFIE), the magnetic field integral equation (MFIE), and the combined field integral equation (CFIE), using Galerkin's testing approach. The resultant numerical system of equations is then solved using the MLFMA. Appropriate preconditioning techniques are employed to speedup the MLFMA solution. The proposed method is further implemented on distributed-memory parallel computers to harness the maximum power from presently available machines. Numerical examples are given to demonstrate the accuracy and efficiency of the method as well as the convergence of the higher order scheme 相似文献
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Jiade Yuan Zhenyi Niu Zhuo Li Changqing Gu 《Journal of Infrared, Millimeter and Terahertz Waves》2010,31(6):744-752
The equivalent dipole-moment method (EDM) is extended and applied in the analysis of electromagnetic (EM) scattering by arbitrarily
shaped perfect electric conductor (PEC) targets coated with electric anisotropic media in this paper. The scattering targets
are discretized into tetrahedral volume elements in the material region and into triangle patches on the conducting surface,
where the volume-surface integral equation (VSIE) is set up. Then the method of moments (MoM) is employed to solve the VSIE.
In the impedance matrix, the near field interaction elements are computed by the conventional MoM while the far field interaction
elements are modeled by the EDM. The proposed approach is sufficiently versatile in handling arbitrarily shaped objects coated
with general electric anisotropic media and is easily constructed through a simple procedure. Numerical results are given
to demonstrate the accuracy and efficiency of this method. 相似文献
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Wei-Bin Ewe Er-Ping Li Hong-Son Chu Le-Wei Li 《Antennas and Propagation, IEEE Transactions on》2007,55(7):2073-2079
A fast solution to the electromagnetic scattering by large-scale three-dimensional magnetodielectric objects with arbitrary permittivity and permeability is presented. The scattering problem is characterized by using coupled field volume integral equation (CF-VIE). By considering the total electric and magnetic fields, i.e., the sum of incident fields and the radiated fields by equivalent electric and magnetic volume currents, the CF-VIE can be established in the volume of the scatterers. The resultant CF-VIE is discretized and solved by using the method of moments (MoM). For large-scale scattering problems, the adaptive integral method (AIM) is then applied in the MoM in order to reduce the memory requirement and accelerate the matrix-vector multiplication in the iterative solver. The conventional AIM has been modified to cope with the two sets of equivalent volume currents. 相似文献
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Xin-Qing Sheng Jian-Ming Jin Jiming Song Cai-Cheng Lu Weng Cho Chew 《Antennas and Propagation, IEEE Transactions on》1998,46(3):303-311
This paper studies, in detail, a variety of formulations for the hybrid finite-element and boundary-integral (FE-BI) method for three-dimensional (3-D) electromagnetic scattering by inhomogeneous objects. It is shown that the efficiency and accuracy of the FE-BI method depends highly on the formulation and discretization of the boundary-integral equation (BIE) used. A simple analysis of the matrix condition number identifies the efficiency of the different FE-BI formulations and an analysis of weighting functions shows that the traditional FE-BI formulations cannot produce accurate solutions. A new formulation is then proposed and numerical results show that the resulting solution has a good efficiency and accuracy and is completely immune to the problem of interior resonance. Finally, the multilevel fast multipole algorithm (MLFMA) is employed to significantly reduce the memory requirement and computational complexity of the proposed FE-BI method 相似文献