A multiband metamaterial absorber for GHz and THz simultaneously

• This paper presents a concept to design the cross-band metamaterial absorbers, and a cross-band metamaterial absorber (CMMA) is designed by this concept. Such a superposition design concept novel and efficacious to design a CMMA. • The proposed CMMA achieves three absorption peaks in GHz-band and two absorption peaks in THz-band, and four bands of them have the absorptivity above 90%. Also, it is insensitive to the polarized incident wave, and works well under large incident angles in both TE and TM modes. • The proposed CMMA’s thickness is ultra-thin, it is 337 μ m , which is only 0.124 of the wavelength at the minimum resonance frequency. • The change rules and absorption characteristics of individual unit cell are consistent with that of the superposed unit cell, which means this concept can be used to design a cross-band metamaterial absorber through design each individual absorber. • The characteristic of simultaneous absorption to GHz and THz waves render the CMMA widely used in multi-band electromagnetic stealth and electronic countermeasures. Nowadays, more and more metamaterial absorbers (MMAs) are explored not only in the microwave band but also in terahertz band, but few studies concentrate on metamaterial absorbers which can work in cross-band, that to say, absorb gigahertz (GHz) and terahertz (THz) electromagnetic (EM) waves simultaneously. This paper proposed a design concept of MMA which can realize the absorption in GHz-band and THz-band simultaneously, and designed a cross-band metamaterial absorber (CMMA). The proposed CMMA can achieve three absorption peaks in GHz-band and two absorption peaks in THz-band. The characteristic of simultaneous absorption to GHz and THz waves render the CMMA widely used in multi-band electromagnetic stealth and electronic countermeasures, and the superposition design concept provides a novel idea for designing cross-band absorber.