Abstract: When the Asymptotic Waveform Evaluation（AWE） technique is used in calculating the wide-band Radar Cross Section（RCS） of the object, the computational efficiency is improved greatly. However, the calculation of matrix inversion is very time-consuming when the objects are electrically large. Krylov subspace iterative methods are used to solve the matrix equation obtained from electric field integral equation instead of matrix inversion. The dual threshold incomplete LU factorization preconditioner is adopted to improve the convergence behavior of the Krylov subspace iterative methods. The numerical computation shows that the results are in good agreement with the results obtained by the method of moments at each frequency, and the computational efficiency is improved greatly.

Key words: Radar Cross Section（RCS）, Asymptotic Waveform Evaluation（AWE）, incomplete LU preconditioning, method of moments

摘要： 应用渐近波形估计技术计算目标宽带雷达散射截面（RCS），可有效提高计算效率。然而当目标为电大尺寸时，阻抗矩阵求逆运算将十分耗时，甚至无法计算。提出使用Krylov子空间迭代法取代矩阵逆来求解大型矩阵方程，应用双门槛不完全LU分解预处理技术降低迭代求解所需的迭代次数。数值计算表明，该方法结果与矩量法逐点求解结果吻合良好，并且计算效率大大提高。

关键词: 雷达散射截面（RCS）, 渐近波形估计（AWE）, 不完全LU预处理, 矩量法