Fast analysis of electrically large electromagnetic scattering/radiation problems using the adaptive cross approximation with FFT

This paper presents a multilevel method for solving electromagnetic scattering/radiation problems. The original domain is decomposed using the octree technique. At the octree levels, the adaptive cross approximation (ACA) is employed to calculate the dominant sources and responses, and the long-distance interactions are computed using the fast Fourier transform (FFT). The algorithm leads to a great reduction in memory requirement and computing time. Numerical examples demonstrate that the proposed method has a good accuracy and a high computational efficiency.