Temperature Tunable Seven Band Terahertz Metamaterial Absorber Using Slotted Flower-Shaped Resonator on an InSb Substrate

Development of metamaterial absorbers that can operate in the terahertz spectrum has become the latest research interest of the electromagnetic fraternity. Temperature tunable absorbers are a special type of absorbers whose absorption spectra shift with the temperature. Initially, single-band and dual-band temperature tunable absorbers were designed and with progressive research in this field more sophisticated designs with multi-band absorption spectra are being developed. In this paper a seven-band temperature tunable terahertz metamaterial absorber is proposed, whose unit cell consists of a slotted flower-shaped resonator (S-FSR) on InSb dielectric substrate. The peak absorption's offered by the structure at 210 K are 99.12% at 0.895 THz, 97.63% at 1.042 THz, 96.97% at 1.268 THz, 99.7% at 1.401 THz, 89.37% at 1.551 THz, 97.57% at 1.646 THz, and 94.89% at 1.831 THz. Its temperature sensitivity is found to be 12.6 GHz/K, 10.9 GHz/K, 9.2 GHz/K, 8.2 GHz/K, 7.7 GHz/K, 7.2 GHz/K, and 6.5 GHz/K respectively. The novel design has several applications in the design of terahertz temperature sensors.