The characteristic basis function method (CBFM) based on the mixed discretization (MD) is firstly proposed to analyze the electromagnetic scattering from electrically large inhomogeneous objects. The discontinuous Galerkin volume integral equation (DGVIE) method which employs nonconformal discretization permits to independently discretize the various component regions of the inhomogeneous object depending on its local shape or dielectric permittivity. Moreover, by the means of the CBFM, the low-level basis functions employed in the DGVIE method are converted into high-level basis functions, dramatically reducing the number of basis functions for modeling. In addition, the conformal discretization which is superior in dealing with homogenous regions is mixed with the nonconformal discretization to further cut down the number of the basis functions. Numerical results show that the CBFM based on mixed discretization (MD-CBFM) generates much less unknowns in contrast to several conventional methods. Several composite inhomogeneous examples are given to demonstrate the accuracy and efficiency of the proposed method.

首次提出基于混合离散（MD）的特征基函数法（CBFM）来分析电大非均匀物体的电磁散射。采用非共形离散化的不连续 Galerkin 体积积分方程 (DGVIE) 方法允许根据其局部形状或介电常数独立地离散非均匀物体的各个组成区域。此外，通过 CBFM，将 DGVIE 方法中使用的低级基函数转换为高级基函数，大大减少了建模的基函数数量。此外，将在同质区域处理方面具有优势的保形离散化与非保形离散化相结合，进一步减少了基函数的数量。数值结果表明，与几种传统方法相比，基于混合离散化 (MD-CBFM) 的 CBFM 生成的未知数要少得多。给出了几个复合非齐次例子来证明所提出方法的准确性和效率。