Sparse Approximate Inverse Preconditioned Iterative Algorithm with Block Toeplitz Matrix for Fast Analysis of Microstrip Circuits

In this paper, several preconditioning technique such as symmetric successive overrelaxation (SSOR), block diagonal matrix, sparse approximate inverse and wavelet based sparse approximate inverse are applied to conjugate gradient (CG) method for solving the dense matrix equations from the mixed potential integral equation (MPIE). Our numerical calculations show that the PCG-FFT algorithms with these preconditioners can converge much faster than the conventional one to the MPIE for the analysis of microwave circuits. Some typical microstrip discontinuities are analyzed and the good results demonstrate the validity of these proposed algorithms.