Experimental Investigation of the Modification of the Backscattering Cross Sections of Metallic Objects

摘要

An experimental investigation on the backscattering cross sections of the metallic objects of various shapes is presented. The metallic scatterers are assumed to be illuminated by a plane electromagnetic wave at normal incidence. The modification of the backscattered fields of these targets is accomplished by employing the impedance loading method or the compensation method. The impedance loading method is to add some impedances on the object surface and the compensation method consists of attaching some impedance loaded wires to the target object. The backscattering cross section of a sphere is modified by the addition of two vertical cylinders loaded with appropriate impedances. Both theory and experiment yield results which are in good agreement. The backscattering cross sections of loops, either circular or rectangular, are modified by loading the loop with a pair of impedances positioned symmetrically on opposite sides of the loop. The backscattering of a plate is modified by placing an impedance loaded loop in front of the plate. Similarly, the scattered field of a thick cylinder is modified by placing a thin loaded cylinder adjacent to it. In all these schemes, a coaxial line (or cavity) has been used as the loading impedance in the experiment. (Author)