Bandwidth of some artificially soft surfaces

It has been demonstrated that polarization-independent soft surfaces in electromagnetism can be realized artificially in several ways, e.g., by using corrugations, strip loaded dielectric slab, or lossy or anisotropic material coating. The frequency response of various artificially soft surfaces is investigated by both moment method computations and experiments. It is shown that the bandwidth of a corrugated surface can be increased significantly by cavity loading or strip loading. The tilted corrugations have a smaller bandwidth than the conventional corrugations. The dual depth corrugated surfaces must be designed with widely separated bands, and soft surfaces realized by dielectric loading has a smaller bandwidth than when realized by corrugations.