Space spectral domain approach (SSDA) is a full-wave analysis method that combines the advantages of the spectral domain analysis (SDA) with that of the one dimensional method of lines (MOL). This approach is very e-cient to solve 3D MIC/MMIC circuits with higher convergence, higher accuracy and minimized computation time. However, arbitrary shaped structures involving non-homogenous metallization distribution in the resonator patch could hardly be solved using this method. In this paper, the analysis of the space spectral domain approach (SSDA) is developed using non-equidistant MOL discretization as well as modifled current basis functions to reduce the computation time window and to sense also accurately the flne metallization details of arbitrary shaped resonators. The modifled SSDA approach is applied to solve ten arbitrary shaped resonators with a reduction of computation time less than 10%. Design curves are also presented for these shapes and good agreement is achieved between numerical and experimental results.