Fast and accurate modelling of large plane array antenna

This paper presents a new way of modelling very large planar array antennas included in tridimensional structure. The aim is to match a rigorous method to a Floquet mode expansion. The first method is in fact a multi domain one (a domain decomposition method) based on electrical field integral equation -EFIE- and partial differential equation -FEM-. It describes electromagnetic behaviour of a single radiating element of the array. The description requires the use of generalised scattering matrices. Fields in radiation space are expressed by an Floquet modes combination with usual hypothesis. The array´s environment is finally taken into account by asymptotic methods (PO and PTD) or rigorous method (EFIE). The accuracy and efficiency of our technique is illustrated by RCS diagram of a patch antenna placed in a canonical metallic box.