In this paper, we present further improvements in the subdomain multilevel approach (SMA), one of the techniques used for fast full-wave analysis of large printed antennas and circuits. The time for filling the method of moments (MoM) matrix is improved in two ways: by taking advantage of translational or rotational symmetries and by using the equivalent moments. The first way obviates the recomputation of the subdomains that represent translated or rotated replicas of an already computed subdomain. The second one speeds up the computation of the interaction between two different subdomains. To show the advantages of the implemented improvements in simulating a printed structure with repetitive subdomains, an 8×8 corporate-fed array of patches is chosen.