Fast simulations of electromagnetic scattering from 1-D rough surface through adaptively modified characteristic basis function method

In this paper, the Adaptively Modified Characteristic Basis Function Method (AMCBFM) is proposed to fast simulate the electromagnetic scattering from one-dimensional rough surface. Firstly, the Primary Characteristic Basis Functions (PCBFs) arising from the self-interaction within the self-block are generated, and the coefficients of the basis function and the first current of each block are obtained. Secondly, the Secondary Characteristic Basis Functions (SCBFs) which account for the mutual coupling effects from the other distinct domains are obtained by using the inter-impedances. The higher SCBFs can be also derived through the same way. Finally, a new precision method is applied to control the current error, which is used to determine the order of the higher order SCBFs. By Comparing numerical simulations through the AMCBFM and the traditional Characteristic Basis Function Method (CBFM), the AMCBFM can guarantee the accuracy and void higher iteration, and the convergence performance is better than the CBFM in the lower order SCBFs. Moreover, by comparing numerical results of the AMCBFM and the method of moments (MoM), the AMCBFM can effectively reduce the size of the impedance matrix, and significantly reduce computing time.