A wide angle polarization insensitive multi-band metamaterial absorber for L, C, S and X band applications

This paper investigates polarization insensitive multiple band Metamaterial Absorber (MA). The proposed MA is a splitted circular ring acting as outer structure and inner structure is a type of four fan blade. The metallic resonating structure is mounted over a dielectric substrate (FR-4), which is covered by complete ground plane. The structure yields thirteen independent high absorption peaks (>80%) over the range of interest. The absorption peaks are at 1.50, 2.92, 3.88, 4.84, 5.50, 7.09, 7.65, 8.54, 8.81, 9.26, 9.90, 11.69 and 12.02 GHz with absorptivity of 88.58, 98.27, 80.62, 88.76, 91.32, 81.74, 81.21, 88.47, 81.95, 96.16, 98.67, 98.58 and 96.26% respectively. The metamaterial behaviour of the structure is proven by plotting real & imaginary part of permittivity (ε) & permeability (μ) and normalized impedance (Z). Further, to explain absorption mechanism, the current distribution is plotted at the front and back side of the structure for an independent frequency belongs to L, C, S and X band spectrum. The polarization insensitive behaviour of the structure is studied under different angles for normal and oblique incidence. The structure proposed is compared with the previously reported multi band absorbers and it is found that proposed absorbers have more numbers of absorption peaks and cover frequency spectrum such as L, C S and X band simultaneously. The proposed multi band absorber finds practical applications in the field of IoT, Bio Medical sensing applications, Energy harvesting, Radar cross section reduction, Military applications, back lobe reductions in case of antenna, satellite communication, WI-FI devise and many more.