Discrete-Component-Free Metasurface Absorber with Broadband Switching via VO2-Driven Pattern-Level Sheet Resistance Control

초록

This article presents a broadband, frequency-reconfigurable metasurface absorber that eliminates the need for discrete components and overcomes the limitations of conventional multilayer designs. Traditional absorbers employ discrete resistors for broadband performance and diodes for tunability. In contrast, our resistive-pattern-switchable metasurface (RPSM) integrates both functions into a single-layer, screen-printable structure by employing a thermally tunable, large-area vanadium dioxide (VO2) film. This work demonstrates, for the first time, broadband frequency reconfiguration using large-area VO2 switching, achieved without pixel-level addressability or lithographic complexity. The key innovation is pattern-level modulation of sheet resistance via the VO2 phase transition, enabling dynamic switching between two distinct absorption bands. The fabricated RPSM exhibits over 90% absorption in the 9.86–12.4 GHz band (metallic VO2) and the 13.2–17 GHz band (insulating VO2), with a subwavelength thickness of only 0.05λ0. A built-in resistive heater enables reversible thermal switching, and the concept is experimentally validated, establishing a pathway toward low-cost, scalable, and reconfigurable metasurfaces.

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