A hybrid numerical-composite UTD ray analysis of the radiation by large locally convex conformal arrays on large platforms

A new efficient hybrid numerical-composite UTD ray solution is presented to describe the radiation from an aperture formed by a large phased array antenna mounted conformally on a locally convex, but otherwise relatively arbitrary large platform. The aperture distribution is first obtained from a numerical solution for the array fields, which takes into account only the local array portion of the platform geometry, via the finite element-boundary integral (FE-BI) or the finite element method (FEM) based approaches. The electromagnetic (EM) equivalence theorem can be used to obtain the equivalent sources over the array aperture; the latter equivalent sources then radiate the array fields via a new composite uniform geometrical theory of diffraction (UTD) for arrays. This composite UTD describes the fields radiated by the entire array in terms of just a few rays arising from a point in the interior of the array aperture, and from specific points on the edges and corners of the array aperture boundary. These rays once launched from the array aperture then interact with the rest of the platform via the conventional UTD. Such an approach is far more efficient than solving the whole large complex array and its even larger platform simultaneously in some numerical fashion. Furthermore, it provides a physical insight into the array radiation mechanisms.