Tunable Flower-Shaped Terahertz Absorber with Equivalent Circuit

In this work, a novel design of the adjustable terahertz absorbers consists of flower-shaped Split Ring Resonators (SRR) and a graphene thin surface on a SiO₂ substrate was introduced. The proposed absorber exhibited tunable broad-band dual-band absorption having an absorption exceeding of 94.12% and 98.63% across two frequency peaks spanning from 2.43 to 4.39 THz and 5.61 to 6.21THz. Furthermore, the equivalent circuit of proposed sensor was simulated by the ADS software. Due to the adjustability of the designed absorber, different voltages can be applied to the graphene surface to tune the absorption frequencies. Sensitivity, FOM and Q-factor of the proposed THz absorber were also investigated. This work also satisfied metamaterial condition of negative refractive index and the absorber demonstrated sensitivity of 2.44 in the refractive index between 1.33 to 1.46 that is essential for biomedical purposes.<br>