Design, calculation, and measurement of a single resonant mode metamaterial absorber and its tunable performance

A tunable metamaterial absorber with single resonance mode characteristics (amplitude of 0.728, the resonance position of 4.21 THz) is simulated, calculated, and measured in the 3.0–6.0 THz band. By optimizing the structural parameters (the diameter of the hole array or the thickness of the dielectric layer), this absorption peak is enhanced and moved to the high frequency region. Based on the phase transition characteristics of the strontium titanate (STO) layer, the absorption can also be enhanced by increasing the temperature and moved to the high frequency region. New bright-bright coupling effect is excited on the surface of the STO layer. The reflection loss and absorption amplitude of the metamaterial sample for electromagnetic waves are also enhanced. When the incident angle of the electromagnetic wave is between 0°-60°, the absorption amplitude of the metamaterial sample is higher than 0.633. Therefore, the metamaterial sample exhibits temperature tunability and wide-angle absorption characteristics.