共查询到20条相似文献,搜索用时 46 毫秒
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本文研究了一种可以高效求解任意非常规目标电磁散射的修正电场积分方程方法.借助磁场积分方程主值项的提取,加入到传统电场积分方程中,将传统的一次迭代求解过程转变成逐渐逼近真解的内外两层迭代.其外层迭代不断刷新电流,最终得到精确解.加入磁场主值项的修正电场积分方程显著降低了条件数,同时保留了原电场积分方程普适性强,可用于处理任意非常规目标的优点.对于每一外层迭代步中电流的求解,本文采用了加速矩阵矢量相乘的多层快速非均匀平面波算法,形成高效的内层迭代求解.数值结果表明,该方法在保证精度的同时,可以显著降低问题的求解时间. 相似文献
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三维散射与辐射问题通常采用电场积分方程(EFIE)结合矩量法(MoM)求解,而基函数是决定矩量法精度和效率的重要因素。本文针对采用三角形网格剖分会引起未知元过多而采用四边形网格剖分会因为网格质量变差而影响计算精度的问题,提出一种基于三角形与四边形混合网格的混合基函数,应用于散射体RCS和天线阻抗特性计算。结果表明,相比于三角形剖分,混合基函数能够在减少未知元个数的同时获得较高的精度;另外也解决了基于单纯四边形网格的基函数在网格质量较差的情况下不能准确模拟表面电荷的问题。 相似文献
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三维集成电路通过高密度金属互连线实现芯片在三维空间上互连,其电路参数的快速提取是保证信号完整性良好设计的关键技术之一.文中基于体积分混合势积分方程(mixed potential integral equation,MPIE)方法,结合多层平面介质格林函数与预纠正快速傅里叶变换(pre-corrected fast fourier transformation,pFFT)方法,通过对互连线内趋肤电流准确建模,实现对互连线结构S参数的快速准确提取.通过对典型互连线结构的仿真表明,本文求解器得到的结果与商业软件HFSS结果在网格剖分考虑趋肤效应时,其精度相当,计算效率可提高50%以上.所以本文方法在三维集成电路互连线参数快速提取方面具有一定的应用前景. 相似文献
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采用电磁场理论方法研究近场光学成像问题,通过将LippmanrrSehwinger积分方程(LISE)离散化,应用复共轭梯度法与快速傅里叶变换(CCGM-FFT)相结合的方法进行数值求解。数值模拟结果表明,近场光学成像表现为一种复杂的电磁场干涉现象,电磁场干涉的程度与样品的尺寸大小及样品间的间距有关,同时对采用P波和S波入射时所得出的样品形貌图像特点给予合理的解释,数值模拟的结果对实验分析具有参考价值。并且,与传统的矩量法(MOM)求解LSIE相比较,采用CCA3M-FFT有效地节约了计算机的内存和CPU的运算时间。 相似文献
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该文采用Coifman区间尺度函数作为矩量法中的展开函数和权函数,求解电磁场积分方程,利用Coifman尺度函数的消失矩特性,减少计算矩阵元素的双重积分次数,同时对两个具有不同积分核的方程,提出了不同的消失矩近似方法。 相似文献
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针对任意形状金属-介质混合目标的电磁散射问题,使用矩量法将体-面结合的积分方程(VSIE)转换成线性方程组,并利用预修正快速傅立叶变换(P-FFT)方法来进行快速求解.为减少直接计算和预修正的近区未知量个数,采用一种改进的模板拓扑.数值计算结果表明,基于VSIE的P-FFT方法可以高效准确地求解金属-介质混合目标的电磁散射问题,改进的模板拓扑可以显著减少近区未知量个数,从而减少算法的存储需求和计算时间. 相似文献
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An iterative method for solving scattering problems 总被引:2,自引:0,他引:2
An iterative method is developed for computing the current induced by plane wave excitation on conducting bodies of arbitrary shape. In this method, the scattering body is divided into lit- and shadow-side regions separated by the geometric optics boundary. The induced current at any point on the surface of the scatterer is expressed as the sum of an approximate optics current and a correction current. Both of these currents are computed by iteration for the lit and shadow regions separately. The general theory is presented and applied to the problems of scattering from a two-dimensional cylinder of circular and square cross sections. The results are compared with the method of moments and good agreement is obtained. This method does not give erroneous results at internal resonances of the scatterer, does not suffer from computer storage problems and can be extended to nonperfect conductors as well as to three-dimensional bodies. 相似文献
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The authors discuss a neural network model for solving electromagnetic problems which can be represented as combinational optimisation problems, with cost functions as the network energy. Solutions correspond to the minimum of energy. An example is given to illustrate the method 相似文献
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The topology-finite-element method has been proposed for solving electromagnetic field problems. This method is characterised by a higher degree of simplicity and standardisation in comparison with the finite-element method. On the other hand, the mathematical model derived by this method is proved to be simple and of evident geometric and physical significance as well, thus creating favourable conditions for making optimal designs in engineering science. 相似文献
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A 3-dimensional numerical method of determining the vector fields within a closed lossless electromagnetic system is described. The method is used to find the dominant-mode resonant frequencies for two cases of a rectangular cavity partially loaded with dielectric. 相似文献
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The development of a novel approach to solve electromagnetic problems in three dimensions is presented. The method described as the 'multigrid TLM method' uses different grid sizes to model space thus allowing the modelling of small features using a fine mesh of grid points, whereas the rest of space is modelled using a coarse mesh. The advantage of this method is that it offers simultaneously very high space resolution and modest computer storage and run-time requirements. The basis of the method is described briefly, together with typical results and conclusions.<> 相似文献
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提出一种分段积分共形时域有限差分算法(PI-CFDTD),用于计算电磁散射问题。首先采用邻近网格电场场量插值表示变形网格中沿线电场场量,再以分段积分代替传统电场沿线积分求解,减小了阶梯误差,提高了电场环路积分的计算精度。推导出两种不同类型变形网格的电场环路积分公式,并对PI-CFDTD算法的稳定性进行研究,归纳得到应用原则。以金属方形平板和金属圆形平板作为算例进行验证,通过与传统时域有限差分法(FDTD)、传统共形时域有限差分法(CFDTD)以及矩量法(MoM)进行比较,表明PI-CFDTD计算精度更高。 相似文献
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The method of steepest descent is applied to the solution of electrostatic problems. The relation between this method and the Rayleigh-Ritz, Galerkin's, and the method of least squares is outlined. Also, explicit error formulas are given for the rate of convergence for this method. It is shown that this method is also suitable for solving singular operator equations. In that case this method monotonically converges to the solution with minimum norm. Finally, it is shown that the technique yields as a by-product the smallest eigenvalue of the operator in the finite dimensional space in which the problem is solved. Numerical results are presented only for the electrostatic case to illustrate the validity of this procedure which show excellent agreement with other available data. 相似文献
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It is shown that there exists a class of vector transforms and vector series expansions that are independent of their scalar counterparts. They can be used to simplify the solutions of a class of vector electromagnetic scattering problems. The applications are shown of vector Fourier, Hankel, and Mathieu transforms and series expansions to the formal solutions of scattering by rectangular, circular and elliptical disks and open-ended waveguides. The problems solved are canonical problems, however, more complex problems for applications in microwaves, microstrip integrated circuits, geophysical probing, etc. can be solved in a similar fashion. 相似文献