Efficient Algorithm for Wideband Scattering Problems Using CMBFM with WACA

An interpolation method for the reduced matrix in the wideband characteristic mode basis function method (WCMBFM) with the wideband adaptive cross approximation (WACA) algorithm is proposed to efficiently compute the wideband electromagnetic scattering problems. In this method, the characteristic mode basis functions (CMBFs) and the selected dominant basis functions of the far-field block pairs obtained by the ACA decomposition are extracted at the highest frequency within the band of interest. Then, the approximate compression of the reduced matrix at other required frequencies within the band of interest can be efficiently generated by the polynomial interpolation. Compared with the conventional interpolation method for the reduced matrix, the proposed method reduces the dimension of the matrix to be interpolated, which makes the construction of the reduced matrix more efficient. The numerical result of the frequency selective surface (FSS) is investigated to show the advantages of the proposed method.