Perfect and broad absorption by the active control of electric resonance in metamaterial

Abstract

Anti-oscillating plasmas have been the key to perfect absorption induced by magnetic resonance. This is an achievement in recent research on metamaterials (MMs), especially in GHz and the lower-frequency regions of electromagnetic waves. Here, a comprehensive view of perfect absorption is introduced by means of both magnetic resonance and electric resonance in meta molecules. A conventional metal-dielectric-metal MM absorber is proposed to obtain dual-band perfect absorption. It is clarified that the mechanism of dual-band absorption is due to fundamental (at 7.2 GHz) and third-order (at 18.7 GHz) magnetic resonances. Finally, we develop triple-band absorption by integrating resistors in to the MM absorber. The electric resonance, under the presence of resistors, matches the impedance of the MM absorber with the air at 13 GHz and gives rise to the new absorption band, with absorption higher than 90%.