Sparse approximate inverse preconditioned CG-FFT algorithm with block Toeplitz matrix for fast analysis of microstrip circuits

In this paper, the multifrontal method is employed to precondition the conjugate gradient (CG) algorithm with the block Toeplitz matrix based fast Fourier transform (FFT) technique for dense matrix equations from the mixed potential integral equation (MPIE) to enhance the computational efficiency of the CG-FFT algorithm. Our numerical calculations show that the preconditioned CG-FFT algorithm with this Sparse Approximate Inverse preconditioner can converge hundreds of times faster than the conventional one for the analysis of microstrip. Some typical microstrip discontinuities are analyzed and the good results demonstrate the validity of the proposed algorithm. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35.