Multigrid ADI method for two-dimensional electromagnetic simulations

We propose a multigrid alternating-direction implicit (ADI) method for solving two-dimensional Maxwell's equations. This method is based on interpreting the ADI method as an iterative solver for the Crank-Nicolson (CN) scheme. By introducing a special procedure to solve the residual equation within the ADI framework, multigrid methods are incorporated into the iterative ADI method. The accuracy and efficiency of the proposed method are further demonstrated by numerical examples.