共查询到18条相似文献,搜索用时 218 毫秒
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《中国无线电电子学文摘》2007,(1)
O441 2007011036合元极技术再认识——一种电大复杂目标散射混合计算技术的考察/盛新庆,彭朕(北京理工大学电子工程系)//电子学报.―2006,34(1).―93~98.合元极技术,即混合有限元、边界元、快速多极子技术,是计算电磁学中近年来日益受到关注的一种精确、高效、通用的技术。该文首先将该技术推广应用于既带涂层又带腔的复杂电大目标电磁散射的计算;接着对合元极技术各种算法的计算精度、迭代收敛速度进行了理论和数值实验的分析研究;然后,从通用性和高效性的角度,对作者采用的不对称合元极技术和近来来其他作者提出的对称合元极技术做了分析比较。最后,该文计算了几种复杂目标的散射截面以证实该项技术的高效、通用。图9表4参18 相似文献
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本文将一种多层不完全LU分解预处理方法应用于合元极技术(即混合有限元、边界元、快速多极子技术).理论和数值实验表明,此种预处理方法能大大减少合元极技术的内存需求,同时兼有极高的计算效率.本文首先给出此种预处理方法的构造方式和实施步骤,接着对此种预处理方法在合元极技术中的数值性能进行了理论和数值实验的分析研究;最后,本文计算了几种电大尺寸复杂目标的散射,以展示应用了此种预处理方法的合元极技术的计算能力. 相似文献
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本文将有理函数逼近技术(Rational Function Approximation Technique,RFAT)应用到合元极技术中以快速求解三维复杂目标的宽频带和宽角度散射特性.有理函数逼近技术是计算数学中的一种重要的函数逼近方法.近年来颇受关注的渐进波形估计技术(Asymptotic Waveform Evaluation,AWE)和基于模型的参数估计技术(Model-Based Parameter Estimation,MBPE)均属于有理函数逼近的范畴.本文将AWE和MBPE两种有理函数逼近技术应用到合元极技术中,并从理论分析和数值性能的角度研究和比较了两种方法的优劣.典型数值实验表明,有理函数逼近技术结合合元极技术能够极大的加速三维复杂目标宽频带和宽角度散射特性的求解. 相似文献
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区域分解算法(domain decomposition method,DDM)是实现大规模电磁散射问题求解的有效途径,其易于并行,与非共形技术结合后,可进一步降低实际应用中目标建模与网格划分的难度,近年来在计算电磁领域引起广泛关注.本文介绍了电磁计算领域有限元法(finite element method,FEM)和积分方程法区域分解技术的研究进展,以及它们在合元极技术中的应用.最后,对区域分解合元极技术当前仍然存在的挑战和未来发展方向进行了讨论. 相似文献
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针对电大深腔目标散射问题的高阶合元极算法的瓶颈[1],提出并实现了一种并行方案。通过计算各种复杂电大深腔散射问题,其中包括带有发动机且涂层的飞机进气道模型,含有不均匀段结构的腔体,以及口径电尺度为15λ×15λ、深度达100λ的电大深腔,充分展示了并行高阶合元极算法的计算能力。数值实验证实了此并行方案具有较高的并行效率。 相似文献
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参数扰动正交匹配追踪是一种有效的偏离网格目标时延估计技术.但是,该方法在每次迭代时只搜索一个目标,计算量大.本文提出一类低计算量的偏离网格目标时延估计技术——参数扰动带排除贪婪重构算法.该算法在贪婪重构方法中引入带排除技术,用于检测多个与目标最邻近的离散网格,利用参数扰动技术来估计目标与最邻近离散网格之间的时延偏差.本文以正交压缩采样雷达为例,采用回溯自适应正交匹配追踪方法,研究参数扰动带排除贪婪重构算法性能.仿真实验表明,与已有的相关方法相比,该算法在不影响估计精度的情况下可减少一倍以上的计算时间. 相似文献
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实现了计算电大均匀介质体散射问题的高效混合并行混合场积分方程(Electric and Magnetic Current Combined-Field Integral Equation, JMCFIE)求解, 在单纯消息传递接口(Message Passing Interface, MPI)并行基础上采用共享存储并行编程(Open Multi-Processing, OpenMP)进一步提升性能.该混合MPI与OpenMP的并行多层快速多极子技术通过灵活的进程和线程策略, 提升了负载平衡和可扩展性.数值实验展示了此混合MPI与OpenMP的并行多层快速多极子技术的计算能力, 计算了不同尺寸的电大目标体(包含一个半径120 m、1.1亿未知数目的介质球). 相似文献
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《Antennas and Propagation, IEEE Transactions on》2009,57(2):467-474
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An IE-ODDM-MLFMA Scheme With DILU Preconditioner for Analysis of Electromagnetic Scattering From Large Complex Objects 总被引:1,自引:0,他引:1
Wei-Dong Li Wei Hong Hou-Xing Zhou 《Antennas and Propagation, IEEE Transactions on》2008,56(5):1368-1380
For electrically large complex electromagnetic (EM) scattering problems, huge memory is often required for most EM solvers, which is too difficult to be handled by a personal computer (PC) even a workstation. Although the multilevel fast multipole algorithm (MLFMA) effectively deals with electrically large problems to some extent, it is still time and memory consuming for very large objects. In order to further reduce the CPU time and the memory requirement, a hybrid algorithm, based on the overlapped domain decomposition method for integral equations (IE-ODDM), MLFMA and block-diagonal, incomplete lower and upper triangular matrices (DILU) preconditioner, is proposed for the analysis of electrically large problems. The dominant memory requirement for plane wave expansions in the three processes of aggregation, translation and disaggregation in the MLFMA is drastically reduced by the first two techniques. The iterative procedure for each overlapped subdomain solved by the MLFMA is effectively sped up by the DILU preconditioner. After integrating these techniques, the proposed hybrid algorithm is more efficient in computing time and memory requirement compared to the conventional MLFMA and is more suitable for analyzing very large EM scattering problems. Enough accurate solution can be obtained within quite a few outer iterations, where an outer iteration means a complete sweep for all the subdomains. Some numerical examples are presented to demonstrate its validity and efficiency. 相似文献
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采用矩量法(MoM)计算电大尺寸的复合目标的电磁散射。为了能够高效快速地计算电大尺寸三维复合目标的电磁散射,提出一种新的混合方法,将自适应交叉近似(ACA)算法和多层快速多级子(MLFMA)算法相结合,共同加速矩量法的计算。其中,MLFMA用于加速目标与自身的作用,ACA用于加速目标与其他目标的相互作用。提出的混合算法在计算复合目标电磁散射时,可降低运算存储,缩短阻抗矩阵填充时间,并且能够加快矩阵矢量乘,且不影响计算精确度。数值算例表明,所提快速算法能够在保证电磁散射计算精确度前提下,比传统方法更高效。 相似文献
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《Antennas and Propagation, IEEE Transactions on》2008,56(7):2031-2042
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Vande Ginste D. Michielssen E. Olyslager F. De Zutter D. 《Antennas and Propagation, IEEE Transactions on》2006,54(5):1538-1548
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 PML-MLFMA is developed to efficiently evaluate matrix-vector multiplications arising in the iterative solution of the scattering problem. The computational complexity of the new algorithm scales down to O(N) for electrically large structures. The theory is validated by means of several illustrative, numerical examples. 相似文献
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Method-of-moments (MoM) solutions of surface integral equations are especially well suited for scattering computations involving metallic objects. Improved modeling flexibility for dielectric (possibly lossy) and mixed dielectric/metallic bodies is obtained by combining a surface-integral-equation formulation, involving electric and magnetic equivalent surface-current densities, with a volumetric finite-element (FE) model of the dielectric regions. This results in the well-known hybrid FEBI (finite-element-boundary-integral) technique. For many years, hybrid FEBI techniques, as well as stand-alone Bl (surface-integral equation, often just termed MoM) techniques, were restricted to relatively small (with respect to a wavelength) geometries. However, with the development of powerful multilevel fast multipole methods/algorithms (MLFMM/MLFMA), it has become possible to compute a larger variety of practical scattering and radiation problems with the hybrid FEBI-MLFMM technique. In this contribution, we give a short review of our hybrid FEBI-MLFMM approach, with a focus on mixed dielectric/metallic geometries and multiple Bl domains. We then present a variety of scattering results for metallic and mixed dielectric/metallic objects, together with comparisons with measured RCS (radar cross section) data. Broadband computations are used to derive high-resolution range (HRR) profiles of several configurations. 相似文献