The magnetic field integral equation based method of moments (MoM) with the Kirchhoff approximation can predict the interior scattering from cavities with impedance boundary condition (IBC) walls. However, if the IBC wall is a small part of the whole wall and is modified multiple times, the conventional MoM may be time-consuming due to the repeated and expensive lower–upper (LU) decompositions of impedance matrices. In this Letter, the Sherman–Morrison–Woodbury (SMW) formula is used to mitigate the problem. The authors only require to perform the LU decomposition of the cavity without IBC walls, and to efficiently obtain the solutions of the cavity with different IBC walls by reusing the LU decomposition and the SMW formula.

中文翻译：

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具有部分 IBC 壁的空腔内部散射的有效计算

基于磁场积分方程的矩量法 (MoM) 和 Kirchhoff 近似可以预测来自具有阻抗边界条件 (IBC) 壁的腔的内部散射。然而，如果 IBC 壁是整个壁的一小部分并且被多次修改，由于阻抗矩阵的重复和昂贵的下-上 (LU) 分解，传统的 MoM 可能会很耗时。在这封信中，谢尔曼-莫里森-伍德伯里 (SMW) 公式用于缓解这个问题。作者只需要对没有IBC壁的空腔进行LU分解，通过重用LU分解和SMW公式，高效得到不同IBC壁的空腔的解。