Interface development and modification of CBS3DS radar cross section analysis tool

CBS3DS is a radar cross section (RCS) analysis tool used to compute the backscattering RCS of a cavity backed aperture or slot in an infinite ground plane. The programs implement the hybrid finite element method and method of moments techniques and can analyze arbitrarily shaped three-dimensional cavities or slots filled with inhomogeneous, lossy materials. CBS3DS requires two data files defining the geometry of the problem and the electrical characteristics of the medium. This paper presents the development of an interface between the FEMAP finite element modeler and the modified CBS3DS programs. Fmpp5.m is a MATLAB m-file developed to overcome the limitations of FEMAP for this purpose and produce the required data files for CBS3DS. Fmpp5.m produces tetrahedral meshing from the hexahedral meshing provided by FEMAP and assigns electrical characteristics to the elements within the cavity or slot. Fmpp5.m writes the geometry input data file for CBS3DS which includes the coordinates of the nodes, the identification of nodes forming each tetrahedral volume element and triangular surface element, and the segregation of triangular elements into groups belonging to perfect electric conductor (PEC) surfaces or apertures