Metamaterial dual polarised resistive Hilbert curve array radar absorber

A novel thin metamaterial wideband radar absorber, formed by two layers of resistive Hilbert curve arrays, is analysed numerically, revealing a reduction in monostatic radar cross section (RCS) of more than 10 dB from 8 to 18.8 GHz (81% fractional bandwidth) for E-x and 9.1-20.7 GHz (78% fractional bandwidth) for E-y polarisations, respectively. These bandwidths are significantly wider than those reported so far for space filling curve array-based absorbers. Furthermore, the structure has thickness of only 0.11 lambda to 0.24 lambda at lowest and highest frequencies, respectively. The lateral dimensions are only 0.13 lambda to 0.3 lambda per unit cell at lowest and highest frequencies, respectively, which is several times smaller than that of recently reported circuit analogue absorbers operating in the similar frequency band. The significance of smaller lateral dimensions is that the proposed structure can suppress diffraction effects.