High-order accurate ADI-FDTD method with high-order spatial accuracy

A new concept of the exponential evolution operator (EEO) is introduced, from which the conventional ADI-FDTD method can be derived. And what´s more important, new high-order accurate unconditionally-stable ADI-FDTD method can be constructed from the EEO. In order to improve spatial accuracy, fourth-order accurate central finite difference scheme is used in the new method. The final analysis shows that its numerical dispersion error is greatly reduced in compared with that of the conventional one. In this paper, the principal characteristics and the disadvantages of genetic algorithm and BP algorithm are introduced.