Current progress in the development of and modeling with the electric field integral equation surface patch code

The triangular surface patch code [1], based on the electric field Integral Equation, allows one the flexibility to model scattering and radiation from perfectly conducting surfaces of a very general shape. The essential features of the technique are: triangulation of the scattering surface, assignment of a piecewise linear basis function to each edge connected to a pair of triangles, and use of an approximate Galerkin technique to remove difficulties associated with an otherwise highly singular kernel. A new code based on these techniques is under development. Not only is this code more efficient than the original code, but it also has new capabilities. This code is able to model intersecting surfaces, multiple bodies, symmetry/ground planes, surface impedance loading, and surface voltage sources. Furthermore, the capability to compute near as well as far fields has been added to the code. An automated mesh generator based on canonical structures simplifies generation of input data. Finally, the code has been validated for the case of a thin, perfectly conducting, spherical shell with a circular hole [2]. A continuation of the effort in [3] allows for the attachment of arbitrarily shaped wires to the surface. These wires may be excited by plane waves or voltage sources and may have lumped impedance loads. Numerical examples illustrate new capabilities and limitations of the code. The capability to treat fins allows the modeling of aircraft to be carried out in a much more efficient manner than previously [4]. Figure 1 illustrates a crude model of an aircraft generated by the mesh generator. Other applications are coupling through near resonant apertures and properties of antennas mounted on conducting surfaces.