任意形体金属目标电磁散射计算中奇异积分处理的新方法

针对用S.M.Rao提出的模型对任意形体金属目标散射计算遇到的奇异积分的难题,提出了一种新的解析计算方法.用该方法将全局坐标下的积分转换为局部坐标求积,通过坐标的平移和旋转,将问题由三维直角坐标系转换到二维极坐标系,解析计算出中间结果后,再通过坐标反变换得到原问题中的结果.用该方法对方形金属平板、弯折金属板和金属球分别进行了计算,计算结果与已有文献吻合.结果表明该方法具有较好的计算精度和较快的计算速度.

A New Method to Solve the Singular Integral in the Computation of Electromagnetic Scattering by Surfaces of Arbitrary Shape

The difficulty of singular integral is met with in the computation of electromagnetic scattering by surfaces of arbitrary shape using the model presented by S.M.Rao. In this paper an analytical algorithm with high precision and speed is proposed. The question is first transformed from the global three dimensional rectangular coordinate system to a local two dimensional polar coordinate system by shifting and rotating the coordinates. As a result, the singular point is eliminated, so the intermediate result of singular integral can be analytically worked out. Then the value of the singular integral of the original question is obtained by the transformation of coordinates inversely. To prove the validity of this method, the distribution of current density on surfaces of conducting square flat plate, bent plate and sphere are computed. The results are in good agreement compared with those from related references.