Integrated Photonic Systems Simulation Development

Currently available thin, broad-band microwave absorbers do not perform well for near-grazing incidence of arbitrarily polarized waves. This limits their use for improving antenna isolation on airborne systems, such as towed decoys. Fortunately, for antenna isolation problems, the angles of incidence are known. A new absorber is proposed that uses this fact to full advantage. It is proposed that a very thin layer of metallization, containing a pattern of small resistively loaded elements, be added to an existing thin iron-loaded rubber type of absorber. The orientation and loading of the elements provide the additional degree of freedom needed for better absorption of arbitrarily polarized waves at near-grazing incidence. The advantages of adding this layer are twofold. First, since the absorption takes place in a very thin layer instead of over a volume, it is inherently lightweight. And second, the orientation of the elements provide directionality that can be optimized to capitalize on the fact that, for isolation problems, the incidence angles are known. The type of absorber proposed is sufficiently pliable to be easily cut and wrapped to cover the surface of cylinders and cones that form large portions of the outside surface on towed decoys.