Efficient implementation of the spectral domain method including pre-calculated corner basis functions (microstrip circuits)

A general implementation of the spectral domain method, formulated for planar microstrip circuits of arbitrary metallization pattern, is presented. The inclusion of a priori knowledge about the edge and corner singularities in the set of basis functions results in a large decrease in the order of the problem to be solved. Libraries of basis functions allow the rapid rigorous analysis of realistically complex circuits. Calculated S-parameters are given for three microstrip lowpass filters and compared to results from both measurements and other techniques.