Ultra-wideband Terahertz Absorber Based on E Shape Graphene Pattern

We present a tunable ultra-wideband (UWB) absorber based on a multilayer of "E" shaped graphene patterns. The numerically calculated results indicate that the absorption of the proposed design is above 95% in the range of 1.12 to 14.04 THz. By using the multiple layers of graphene, the relative bandwidth is 95% and reaches up to 170% of the central frequency. Furthermore, for transverse electric polarization mode at a resonating fre-quency of 1.68, 3.99, 7.51, 13.56, and 17.74 THz the absolute value exceeds 99.57, 99.37, 99.94, 99.86, and 99.09%, respectively. Also, owing to the structure's rota-tional symmetry, the absorber is insensitive to both trans-verse magnetic (TM) and transverse electric (TE) polar-ization. The absorption peaks and frequency band can be controlled effectively by altering the Fermi level of graphene without modifying the structure manually. Moreover, the absorber exhibits steady absorption over an incident angle of 0 & DEG; to 60 & DEG;, with just a minor decrease in bandwidth around 60 & DEG;.