Analysis of quad-band polarization- and incident-angle independent low profile metamaterial absorber

Abstract In this paper, a quad-band polarization- and incident-angle independent low-profile metamaterial absorber is proposed. The design consists of three square rings one into another and one plus-shaped slot structure. The size of the unit cell is 11 × 11 mm2 and is printed on an FR-4 substrate having a thickness of 1 mm. It provides 99.2%, 97.6%, 99.3%, and 99.9% absorption at 3.55 GHz, 5.27 GHz, 7.57 GHz, and 11.57 GHz, respectively, thus covering the S, C, and X bands. The surface current distribution of the proposed absorber is also shown at the four resonating frequencies to get a better insight into the design. Moreover, the stability of the proposed design is also validated with different incident angles (for both TE and TM modes) and polarization angles. In addition, a prototype of the proposed absorber structure is also fabricated and then verified experimentally.