Systematic study of double-layered ultra-thin stacked patch absorbers

We present a sensitivity study of a double-layered metamaterial absorber with two stacked patches. Two parameters of the topology are systematically tuned: the thickness of the top layer, and the size of the top patch. When parameters are tuned properly, a single-resonance-like behaviour with two resonators can be seen. Absorptions of more than 99 % can be achieved, despite the simplicity of the structure.