Ultra-broadband and polarization-insensitive metamaterial absorber based on frequency selective surface

In this letter, we report the fabrication, and measurement of an ultra-broadband polarization insensitive metamaterial absorber (MA), consisting of three layers. The EW and flaky carbonyl iron powders were used to produce two kinds of silicone rubber matrix magnetic composites for the top and the bottom layer, respectively. The middle layer is frequency selective surface (FSS) in the form of single square loop. The results show that the proposed 2.0 mm thick RAM can provide a 10 -dB reflectivity over the frequency range of 5.35-18 GHz and exhibit polarization-insensitive properties over the whole range of 2-18 GHz. Experimental results were in good agreement with simulated ones.