Fast analysis of narrow-band transient electromagnetic scattering using the ACA enhanced envelope-tracking marching-on-in-time solver.

In this paper, an efficient adaptive cross approximation (ACA) algorithm enhanced envelope-tracking marching-on-in-time (ET-MOT) solver is proposed to analyze the narrow-band transient electromagnetic scattering from three-dimensional perfect electrically conducting (PEC) objects. In the ET-MOT method, the time step size is inversely proportional to the bandwidth of the incident signal. However, the size of spatial discretization is still inversely proportional to the maximum frequency component of the incident wave. Therefore, the transmission distance of electromagnetic wave in one-time step is usually much larger than the size of spatial discretization. This results in the immediate interaction matrix Z0 being a dense matrix or even a full rank matrix for narrow-band problems. The ACA algorithm is used to accelerate the matrix-vector multiplication during the iteration solution at each time marching step. A series of numerical examples show the accuracy and efficiency of the proposed method. [ABSTRACT FROM AUTHOR]