Analysis of Periodic Arrays Using Characteristic Mode Basis Function Method Combined with Sampling Techniques

To address the issues of low efficiency of the traditional method of moments (MoM) in analyzing the scattering properties of periodic electromagnetic arrays, the characteristic mode basis function method based on block theory is proposed in this paper. Firstly, the target is divided into multiple identical unit cells, and the characteristic modes are extracted from the self-impedance matrix established on the single unit cell. Secondly the characteristic modes are sorted, and the appropriate thresholds are selected to partition the characteristic modes series. Thirdly, the entire eigenvectors corresponding to in-band characteristic modes, and the eigenvectors corresponding to out-of-band characteristic modes obtained by uniformly sampled are selected to form the basis functions collectively. Finally, the constructed basis functions are utilized to reduce the dimension of the original impedance matrix. Numerical results demonstrate that compared to the traditional MoM, the proposed method exhibits higher computational efficiency.