Microwave Power Limiting Devices Based on the Semiconductor–Metal Transition in Vanadium–Dioxide Thin Films

We present a novel concept of microwave (MW) power-limiting devices based on reversible semiconductor-to-metal transition (SMT) of vanadium-dioxide thin films integrated on coplanar waveguides. We designed, simulated, and fabricated devices, which can be reversibly driven from a low-loss (<; 0.7 dB) transmission state into an attenuating state (> 20 dB) as the VO₂ material is changing from semiconductor to the metal state when the incident MW power exceeds a threshold value. These devices are broadband and present a tunable threshold power value. They could be easily integrated as protection circuits from excess power in a large variety of MW components.