Terahertz metamaterial absorber based on asymmetric dual “U” structure

In the study, a terahertz metamaterial absorber with an asymmetric dual U-shaped structure on top of a polyimide dielectric spacer is proposed. The calculated simulation results indicated that the structure provides an absorption peaks over 90% at the peak frequency. By adjusting the length of one of the two-parallel U-shaped metal strip, the structure can provide a wide tuning range in 0.95 THz. Geometrical parameter analysis has been carried out to justify the similarity of the results of adjusting each metal strip. Furthermore, the tuning range can reach 2.06 THz by equivalently adjusting the length of the two sides, and the absorption rate of each peak frequency point is higher than 90%. The study of this dual asymmetric U-shaped structure will have applications in filtering, detection and terahertz tunability.