Design of vanadium dioxide based ultra-wideband tunable terahertz metamaterial absorber

Abstract In this paper, an ultra-wideband (UWB) terahertz Metamaterial Perfect Absorber (MPA) based on the phase change feature of vanadium dioxide (VO2) is proposed. The proposed absorber consists of two square loops of vanadium dioxide (VO2), silicon dioxide (SiO2) as the dielectric substrate and a layer of gold (Au) acting as the ground. Phase transition material VO2 changes the conductivity (conductivity is changed from 200 to 2×105 S/m, concerning temperature 300 K to 341 K) by several orders of magnitude at temperatures above 340 K by shifting from an insulating to a metallic state. The absorption of this suggested absorber can be adjusted from 4% to 100% within the conductivity range of 200 to 2×105 S/m, which corresponds to temperatures between 300 K and 341 K. In the 2.2 - 6.8 THz range, with a bandwidth of up to 4.6 THz, more than 80% absorption is observed. The absorber design we proposed is polarization insensitive, simple and easily integrable. There are numerous uses for the suggested absorber in communication-related futuristic devices.