Scattering analysis of arbitrary shaped cylinders in a focused beam system

Large sandwich and metal space frame radomes are assembled from many panels connected together with seams or metal beams. These seams/beams introduce scattering effects that degrade the overall electromagnetic performance of the antenna enclosed in the radome. The corner stone for the evaluation of the scattering effect of all the seams/beams is the knowledge of the scattering characteristics from individual seam/beam, which can be approximated from the scattering characteristics of an infinite cylinder with the cross section as the seam/beam in the radome. The scattering characteristics of an arbitrarily shaped cylinder is characterized by its forward scattering value (IFR) and its scattering pattern. The paper describes a new combined experimental and numerical procedure to determine the scattering characteristics, IFR and scattering pattern of arbitrarily shaped cylinders using a focused beam system. The unique features of the focused beam system avoid measurement errors due to specular and diffuse reflections from adjacent objects in contrast to the existing errors present in an open measurement system.