Application of IE-FFT with combined field integral equation to electrically large scattering problems

A fast integral equation method, termed IE-FFT, is applied with tire combined field integral equation (CFIE) for solving electromagnetic scattering problems of three-dimensional (3D) electrically large targets. For closed conducting surfaces, the employment of CFIE eliminates the interval resonance problem suffered by, both the electric field integral equation and the magnetic integral equation. Furthermore, it improves the efficiency of IE-FFT significantly by reducing the number of iterations for convergence. If is shown that the memory requirement and the computational complexity per iteration of the IE-FFT are O(N-1.5) and O(N-1.5 log N), respectively, for 3D perfectly electric conducting scattering problems. Some numerical examples are provided to demonstrate the accuracy and efficiency of the technique. (C) 2008 Wiley Periodicals, Inc.