Radiation condition in modal methods: Numerical implementation by means of complex coordinates transformations

In this paper show how to implement effectively the method of moments in the general framework of modal methods. It also used to generalized stretched coordinates in order to enhance spatial resolution on one hand and to introduce a radiation condition on the other hand. The modal methods and mode matching techniques are well established methods to solve waveguide and scattering problems. Such methods lead to an eigenvalue problem that is transformed into a numerical matrix eigenvalue problem by the method of moments.