An unconditionally stable 3-D ADI-MRTD method free of the CFL stability condition

In this paper, an alternating direction implicit (ADI) technique is applied to the recently developed multiresolution time-domain (MRTD) method, resul ting in an unconditionally stable ADI-MRTD scheme free of the Courant-Fried ich-Lecy (CFL) stability condition. The unconditional stability is theoreti cally proved, and preliminary numerical results are presented to validate t he scheme. Because the scheme is now free of the stability condition, its t ime step is determined only by modeling accuracy. The price for having the unconditional stability is, however, that the required computation memory b ecomes almost twice of that for the original MRTD.