FEMATS: a general-purpose scattering code using the finite element method

The focus of the article is the code FEMATS, developed at the Radiation Laboratory of the University of Michigan. FEMATS is a general-purpose code for computing the radar cross-section (RCS) of arbitrary three dimensional targets with material inhomogeneities. It employs state-of-the-art techniques in finite element modeling of open structures, the latest sparse matrix solutions and graphical user interface for pre- and post-processing of the geometry and data files. Although the code has been primarily used for finding the echo-area of targets, FEMATS can be easily extended to solve open domain problems related to antennas, microwave circuits and cellular phones. The power of FEMATS comes from two features inherent in the technique: (i) the ability to model complicated geometries in three dimensions having arbitrary material fillings without code modification; (ii) the O(N) memory requirement of the method due to the employed local mesh termination techniques conformal to the target. This feature essentially implies that the technique scales favorably with problem size and thus very large problems can be tackled with minimal usage of computer memory and time.