Dual Layer Polarization Insensitive Dual Band Metamaterial Absorber with Enhanced Bandwidths

In this paper, a dual layer polarization-insensitive metamaterial absorber with enhanced bandwidths at two distinct frequency bands has been presented. The unit cell of the proposed structure consists of various circular loops whose dimensions are parametrically optimized to exhibit dual band absorption response with full width half maximum (FWHM) bandwidth of 800 MHz at both the frequency bands. The structure is also studied with polarization angle variation where bandwidth-enhanced absorption at both the frequencies has been observed. Also, the structure is studied with oblique incidence under both TE and TM polarizations. It is found that upto 60 degrees incident angles under TE polarization, the bandwidth enhanced absorption for both the bands holds good. The structure behaves as enhanced-bandwidth dual band absorber upto 45 degrees incident angles for TM polarization. The structure is fabricated and experimental results validate simulated responses.