The state of the art of the MMP (multiple multipole) codes is examined, and different possible combinations with other methods are described. The basic principles of the MMP codes and of the combination with the Floquet theory are considered, and an overview of the analytical basis path of resolution is given. A simple example involving a finite or infinite chain of perfectly conducting 2-D cylinders is presented. The comparison between the normal MMP code and the one with the Floquet processor shows that, on the one hand, the number of cylinders is strongly dependent on the frequency (low frequency needs more). On the other hand, it is necessary to take many Floquet modes to get an accurate field representation. >