A Dual-Band Metamaterial Absorber With Wide-Angle and Polarization Stability

A compact dual-band metamaterial (MM) absorber with wide-angle and polarization insensitivity is presented in this paper. The lower frequency absorption is realized through a circular ring resonator, and the upper frequency absorption is obtained by using a hybrid resonator consisting of a split-ring and a cross-dipole. The surface current distributions are also investigated to illustrate the mechanism of the absorber. The overall size of the unit cell is 10×10×0.8 mm
³
(0.17λ1×0.17λ1×0.014λ1, λ1 is the wavelength of the free-space at the lower frequency). The simulated results indicate that, under normal incidence, the absorber provides two distinct absorption at 5.4 GHz and 7.0 GHz, with the peaks of 95.3/95.2%, and full width at half maximum (FWHM) of 200/240 MHz (5.3-5.5/6.98-7.22 GHz), respectively.