“…When passing through the elements of the system, this beam is transformed into reflected/transmitted beams which characteristics are determined by means of the ABCD laws. Since then, an important number of gaussian-beam based techniques have been developed in the context of quasi-optical systems [2], but also to treat other problems as radomes [3], or indoor propagation [4]. In most cases, modeling approaches based on gaussian beams are constituted by two key components: the expansion and the tracking.…”