An electric surface patch formulation for scattering and radiation by surfaces with arbitrary shape

As an extension of the authors´ (see Abd-Alhameed and Excell, IEE Conf. on Computation in Electromagnetics, Nottingham, p.382-5, 1994) earlier work on the modelling of the complete current distribution on the surface of a helical wire the surface patch formulation used was extended to enable it to treat surfaces of arbitrary shape. The surfaces are represented by triangular and rectangular surface patches. Considered as orthogonal pairs of surface dipoles whose self and mutual impedances can be evaluated by using the method of moments. The formulation is valid for both open and closed surfaces and attachment (or close proximity) of a thin wire or a stripline to the surface is included. A numerical procedure was devised which incorporated all of the facilities necessary to model an arbitrary antenna structure