Electromagnetic wave scattering by highly elongated and geometrically composite objects of large size parameters: the generalized multipole technique.

The potency and versatility of a numerical procedure based on the generalized multipole technique (GMT) are demonstrated in the context of full-vector electromagnetic interactions for general incidence on arbitrarily shaped, geometrically composite, highly elongated, axisymmetric perfectly conducting or dielectric objects of large size parameters and arbitrary constitutive parameters. Representative computations that verify the accuracy of the technique are given for a large category of problems that have not been considered previously by the use of the GMT, to our knowledge. These problems involve spheroids of axial ratios as high as 20 and with the largest dimension of the dielectric object along the symmetry axis equal to 75 wavelengths; sphere-cone-sphere geometries; peanut-shaped scatterers; and finite-length cylinders with hemispherical, spherical, and flat end caps. Whenever possible, the extended boundary-condition method has been used in the process of examining the applicability of the suggested solution, with excellent agreement being achieved in all cases considered. It is believed that the numerical-scattering results presented here represent the largest detailed three-dimensional precise modeling ever verified as far as expansion functions that fulfill Maxwell's equations throughout the relevant domain of interest are concerned.