Terahertz Broadband Adjustable Absorber Based on VO2 Multiple Ring Structure

A broadband adjustable absorber operating in the terahertz (THz) range is presented based on a vanadium dioxide (VO2) multiple ring structure with certain gap design. The dynamic absorption regulation of realized by utilizing phase-change characteristics VO2, which easily affected external temperature. simulation results show that when temperature reaches 350 K, conductivity VO2 can reach 2 × 105 S/m, and obtain an efficiency over 90% from 3.01 THz to 7.27 THz. At this time, bandwidth 4.26 82.9% relative bandwidth. When 300 changes 200 less than 4%, indicating strong ability. Further, through analyzing optimal impedance matching electric field distribution under different conductivities, mechanism be obtained. Finally, paper shows spectrum cannot influenced small angle incidences both polarization modes. Therefore, ultra-wideband expected have applications fields detecting, modulating, switching.