An extrapolation method based on current for rapid frequency and angle sweeps in far-field calculation in an integral equation algorithm

An extrapolation method based on the solution of induce current is introduced to rapidly perform angle and frequency sweep in the far-field calculation using the sparsely sampled solutions. This method is based on the observation of the characteristics of the current distribution as a function of incident angles and frequency. It is easy to be implemented for in core processing, and needs a small extra memory. In addition, the extrapolation applies to both angle and frequency sweeps. Numerical examples for conducting and material scatterers show that the far-field scattering results generated by the extrapolation method agree to that provided by the direct solution, but the extrapolation method uses about the same amount of memory, and much less CPU time than that of the brute-force approach.