Fast computation of wide-band radar cross section using asymptotic waveform evaluation technique

The asymptotic waveform evaluation (AWE) technique was applied to the method of moments to calculate the radar cross section (RCS) of an arbitrarily shaped two-dimensional perfect electric conductor over a wide frequency band. The method of moments and the singular value decomposition technique were used to solve the electric field integral equation, and the surface electric current density for a single frequency was obtained. In the AWE technique, the surface current on the perfect electric conductor is expanded in a rational function via the Pade approximation. Using the function, the electric current distribution can be obtained at any frequency within the given frequency range, which is used to compute the scattered fields and the wide-band RCS. The employment of the singular value decomposition technique eliminates the interior resonance problem which suffered from the electric field integral equation. The numerical results are in good agreement with the results obtained by the method of moments at each frequency. The computational efficiency is improved by more than an order of magnitude.