Multi-level characteristic basis function method for analysis of scattering from objects embedded in multi-layered media

The multi-level characteristic basis function method is adapted to analyze the problem of scattering from objects embedded in layered media. Inhomogeneous plane waves incident upon the layered media are used to construct multiple levels of characteristic basis functions (CBFs). The use of the CBFs helps reduce the size of the impedance matrix of the associated method of moment significantly, enabling us to employ direct solver as opposed to iterative solvers. The process of generating the reduced matrix is shown to be naturally parallel, and the reduced matrix to be well conditioned, which obviates the need of pre-conditioning. Numerical results are included to demonstrate the accuracy and efficiency of the present approach when used for the analysis of scattering from objects embedded in multi-layered media.