Polarisation‐insensitive and wide‐angle multi‐layer metamaterial absorber with variable bandwidths

Three different metamaterial absorbers based on ultra‐thin multi‐layer structures, with different bandwidth characteristics, are presented. The proposed structure is composed of three vertically stacked metal‐dielectric layers backed by a metal ground. All the metallic patches are of crossed dipole shape and have different geometrical dimensions, which can be manipulated to design triple‐band, 3 dB and 10 dB absorbers separately. The designed structures are polarisation‐insensitive as well as wide‐angle absorptive for both TE and TM polarisations. The 10 dB broadband structure, exhibiting an absorption bandwidth of 7.5% at 10 GHz, has been fabricated and the absorption performance has been verified with the simulated response. The proposed absorber has the advantages of ultra‐thin thickness ( λ 0 /50 corresponding to the centre frequency), compact size, simpler design, tunable absorption bandwidth and experimental validation, which makes it a promising candidate for many potential applications.