Fast RCS Computation Using Method of Moments along with Characteristic Modes and General Asymptotic Waveform Evaluation

The technique to integrate the characteristic modes (CM) with the general asymptotic waveform evaluation (GAWE) is proposed for computing the radar cross section (RCS) of an arbitrarily shaped perfect electric conductor (PEC). In the analysis, a few CMs with smaller eigenvalue are chosen to construct the subspace of the solution of a matrix equation. Hence, the solution of the equation can be obtained by combining the based-vectors of the subspace with a set of coefficients, which is determined by GAWE at a given frequency. In addition, the criterion of the spectral radius is found in order that the subspace can be adaptively constructed. The comparison of the two kinds of methods of asymptotic waveform evaluation (AWE) is also given. Finally, the RCS for different PEC objects are computed. The numerical results prove that the novel technique with CM and GAWE (CMGAWE) is effective in widening the extrapolation range.