Effects of Cavity on RCS of Cylinder Coated with Microwaves Absorbing Material

摘要

A cylinder with 2.5m of length and 0.15 m of diameter had its RCS (radar cross section) measurement performed. Subsequently, its RCS was reduced with microwave absorbing material. It was studied what the impact to the RCS of the target after transform the cylinder coated with material into a cylindrical cavity. The absorber material behavior was evaluated under the strain of a cylindrical curvature compared to the initial characterization data held in flat surface. Thus, was obtained about 20 dBsm (side) and 6 dBsm (bases) for the RCS of the cylinder. The material with 18 dB absorption capacity presented 14 dB in the case of cylindrical target, a result considered satisfactory, since this value was limited by the baseline scattering present in the "setup". It was observed that, even subject to the stresses of curvature, the material showed no plastic deformation or cracking. Finally, it was found that the reduced RCS (360°) of the cylindrical cavity was increased in relation to the reduced RCS of the cylinder.