Field decomposition technique for thin cylindrical conducting scatterers

The scattering of a plane wave from infinite or finite length conducting cylinders has been extensively treated both analytically, by Felsen and Marcuvitz (1973) for example, and with large scale numerical methods such as the Numerical Electromagnetics Code. No simple closed form engineering solution has been established to reliably estimate practical cylindrical scatterers. We demonstrate that engineering solutions for the near, intermediate and far scattered fields can be derived by both heuristic and analytical methods for thin conducting cylinders that are generally one quarter of the free space wavelength or longer in electrical length. The technique described arises from the approximate decomposition of the scattered fields into those of a cylinder of infinite length together with an amplitude scaling function derived from the current and charge on the finite cylinder. This technique is applicable to a wide range of cylindrical scatterers with defined terminations and with the above stated dimensional constraint, including scattering from power lines, wire fences and pipes together with the implications for surface and subsurface communication and radar systems. The paper commences with the formulation of the field decomposition (FD) technique leading to the scattered near and far fields. Application of this technique to configurations of connected thin conducting cylinders immersed in a lossy medium and subject to oblique multiple frequency illumination are also considered