Macro basis functions for accurate and fast solution of scattering from elements comprising of junctions of wires and strips

In this paper we introduce a set of macro basis functions for efficient representation of the currents induced on elements comprising of junctions of wires or strips. The use of these functions leads to a relatively small and well-conditioned matrix, only a 3×3 size for a cross-shaped element, for instance. Furthermore, an important advantage of using these basis functions is that the fields they generate can be expressed in close forms, circumventing the need to use the Green´s function and to handle the singularity problem associated with these functions. We show that by taking advantage of these two features we can solve the scattering problem, either from a single element or from an array of the same, in an accurate and numerically efficient manner. The results are presented and compared well with those generated by a commercially available EM simulation software package. Our proposed method is accurate and fast. The computational time is reduced by orders of magnitude.