Low-frequency metamaterial absorber with small-size unit cell based on corrugated surface

In this paper, we report the design, analysis, and simulation of the low-frequency perfect metamaterial absorber (MMA) based on corrugated surface, which has very small unit-cell size. The proposed MMA consist of a regular square-array and a metallic background plane, separated by a corrugated surface with periodic square-pillar-array. Through the optimized design, the ratios between lattice constant and resonance wavelength for nearly-perfect and high absorption MMA are close to 1/15 and 1/21, respectively. To explain the absorption mechanism of suggested structures, the surface current and electromagnetic field distributions are given. Moreover, the absorption peaks remain high with large angles of incidence for both transverse electric and transverse magnetic polarizations, which provide more efficient absorptions for oblique incident electromagnetic wave.