Novel ultrathin penta-band metamaterial absorber

This paper presents a novel resonant metamaterial absorber exhibiting five resonant peaks with absorptivity more than 90% in the range from S band to Ku band for radar cross-section reduction and other FCC-airborne applications. The structure is designed on a low cost FR-4 substrate with 1 mm thickness which is equivalent to lambda/17.75 where lambda is the wavelength corresponding to maximum resonant frequency of absorption, showing its ultrathin nature. The fourfold symmetry of the design results in polarization insensitivity and provides an angular stability up to 60 degrees of incident angle. The multiband characteristics are obtained by combining three different geometries in a single structure. Performance of the absorber is studied in terms of absorptivity, material parameters, normalized impedance, polarization insensitivity and oblique incidence. Finally, the design is fabricated on a 200 x 200 mm(2) FR-4 substrate and measurements are performed. (C) 2020 Elsevier GmbH. All rights reserved.