Equivalent circuit for VO₂ phase change material film in reconfigurable frequency selective surfaces

We developed equivalent circuits of phase change materials based on vanadium dioxide (VO₂) thin films. These circuits are used to model VO₂ thin films for reconfigurable frequency selective surfaces (FSSs). This is important as it provides a way for designing complex structures. A reconfigurable FSS filter using VO₂ ON/OFF switches is designed demonstrating −60 dB isolation between the states. This filter is used to provide the transmission and reflection responses of the FSS in the frequency range of 0.1–0.6 THz. The comparison between equivalent circuit and full-wave simulation shows excellent agreement.