Fast calculation of wide-band RCS for three-dimensional PEC objects based on preconditioned AWE technique

The asymptotic waveform evaluation (AWE) technique combined with the method of moments (MOM) is often applied to accelerate the calculation of the wide-band radar cross section (RCS) of the target. However, the technique is still quite time-consuming for solving the inverse of impedance matrix when the objects are electrically large. In this paper, Krylov subspace iterative methods are applied to solve the matrix equation derived from electric field integral equation instead of matrix inverse. The dual threshold incomplete LU factorization preconditioner is adopted to improve the convergence behavior of the Krylov subspace iterative methods. The numerical computation shows that the results in this paper are in good agreement with the results obtained by the method of moments at each frequency, and the computational efficiency is improved greatly.