Analysis of electromagnetic scattering, guided systems in (closed problems) and in free space (open problems), is a subject that has traditionally attracted a huge interest in literature and that even today, due to its diverse and multiple applications, remains the subject of further investigations by the international scientific community. Thus many structures implemented passive microwave guide, such as band pass filters for communications, filters banda removed for microwave heating applications, transducers ortomodales or drawer of polarization phenomena in their operation based dispersion generated in the inside these devices, while the behavior of a large number of radiating elements in free space, which include antennas or reflector systems multireflectores is due to the electromagnetic scattering preoducen such structures in these cases. In turn, the determination of the radar cross-section (RCS) targets, the analysis of structures such as semi-horn antennas, and even the study of models of programming environments for application in mobile communications, are problems of dispersal. because all these applications require an accurate characterization, while effective, difererentes of electromagnetic scattering problems arising in each case be used for this method is the more appropriate.