一种新的频域模式格林函数自适应快速算法  

A novel efficient adaptive integration method for evaluating modal Green’s functions in frequency domain

作　　者：俞文明[1] 方大纲[1] 

机构地区：[1]南京理工大学,电子工程与光电技术学院,江苏南京210094

出　　处：《电波科学学报》2008年第4期601-605,共5页Chinese Journal of Radio Science

摘　　要：频域模式格林函数是频域旋转对称矩量法(FDBoRMoM)各Fourier模式分量特有的格林函数,它是个急速振荡积分,振荡频率随模式数和电尺寸的增大而增大。能否快速计算这个振荡积分是提高FDBoRMoM效率的瓶颈,特别是平面波倾斜照射时。基于振荡核的谱估计和模式缩减技术,我们提出了一种模式格林函数的单区间自适应积分方法。该方法能够根据场源点位置自动确定是否需要作数值积分;如果需要,它可以自适应选择整个积分区间作单次Gauss积分时合适的采样点数;在保持很高计算精度的前提下,它具有自适应、高效和稳定的优点。Modal Green＇s function （MGF） in frequency domain is the special Green＇s function for each Fourier component （or harmonic） of the method of moments for the bodies of revolution in frequency domain （FDBoRMoM）. It is an extremely fast oscillating integration, especially when the harmonic index and the electric size of the BoR become larger and larger and therefore it forms a bottle-neck to accelerate the FDBoRMoM. In this paper, a novel efficient adaptive integration method is proposed to evaluate the MGF＇s based on the spectrum estimation of the integration kernel and a technique to reduce the harmonics. It can automatically decide whether a numerical integration is really needed and select a proper number of sampling points for single Gauss quadrature on the whole range of integration according to coordinates of the field and source points. Compared with other typical methods, this method is smart, accurate, and rohust and can save much CPU time especially when the objects are electrically large. The validity of the method is verified by several numerical examples.

关 键 词：旋转对称体 模式格林函数 振荡积分 

分 类 号：TN011[电子电信—物理电子学]