Design of multispectral tunable metamaterial absorber based on phase transition of VO<sub>2</sub>

Abstract

Recently, metamaterial absorber has attracted considerable attention because of a broad range potential application to electromagnetic stealth, electromagnetic detectors, and electromagnetic communication. And to solve the problem which traditional metamaterial absorbers can only operate at a fixed frequency or within a limited frequency range, the tunable metamaterial absorbers attract more and more attention. But the previous metamaterial absorber can only achieve adjustable absorption in a single frequency band, which has not met people’s increasingly higher requirements for practical applications. To solve this problem, a multispectral tunable metamaterial absorber was designed by combining VO2 and metamaterial absorbers using the phase transition characteristics. In this paper, the absorption rate curve in the terahertz band and infrared band had been simulated by CST Microwave Studio software. And the simulation results showed that the metamaterial exhibited meta-absorption in the terahertz band when the temperature was set to high temperature (80°C) and the VO2 behaved as a metal phase in this temperature. However, the simulation results showed that the metamaterial exhibited meta-absorption in the infrared band when the temperature was set to low temperature (40°C) and the VO2 behaved as an insulator phase. Furthermore, the absorptive properties of the metamaterial absorber had been simulated under different lengths of VO2-cross when the VO2 behaved as a metal phase and under different lengths of metal-cross when the VO2 behaved as an insulator phase. Finally, the mechanism of electromagnetic absorption and multispectral tunable were discussion by simulating and analyzing the surface current distribution and electric field of the metamaterial absorber. The results showed that the metamaterial absorber can realize meta-absorption in the terahertz band or infrared band by changing the temperature which have potential application values in the fields of multispectral stealth, multispectral detection and multispectral communication.