分段积分共形算法在电磁散射问题中的应用

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。

A piecewise integration conformal method for electromagnetic scattering problems

A piecewise integration conformal finite difference time domain(PI-CFDTD)method is presented and applied for solving the electromagnetic scattering problems.The electric field component along the contour segment is expressed by the interpolation of the nearest ones.To compute electric-field contour-integral value more accurately,the piecewise-integration method is used instead of the common integration.Therefore,the staircasing errors can be reduced significantly.The electric-field contour-integral formula is derived for two kinds of deformed cells,respectively.Furthermore,the numerical stability is discussed.Finally,a metal square plate and a metal circular plate are simulated as examples.The results are compared with those of the conventional FDTD method CFDTD method and the MoM.It is found that the PI-CFDTD method is more accurate than the conventional CFDTD method.