Scattering analysis of arbitrarily shaped cylinders in a focused beam system-oblique incidence case

The scattering from an arbitrarily shaped cylinder for the general oblique incident case is characterised by its induced field ratio (IFR) and its co-polarised and cross-polarised scattering patterns. The paper describes how a unique focused-beam measurement system is used to determine experimentally the scattering characteristics of an arbitrarily shaped cylinder for an obliquely incident plane wave. The fields of the transmitting and receiving antennas of the focused-beam measurement system are approximated by equivalent fundamental Gaussian beams. An analytical algorithm, based on computation of the coupling between the transmit and receive Gaussian beams of the focused-beam measurement system and the scattered field of the cylinder, is used to determine the IFR and the co-polarised and cross-polarised scattering patterns of the cylinder. The experimental results obtained by this method for typical dielectric and metal cylinders agree well with the theoretical scattering characteristics computed numerically by the method of moments (MOM) and the finite element method (FEM).