Vanadium dioxide thin films integrated with printed circuit board enables low-cost, reconfigurable millimeter-wave...

Millimeter-wave switches are essential for reconfigurable and adaptive communication systems, yet current solutions often face trade-offs between performance, scalability, and cost. Here we present a scalable, high performance and cost-effective approach to develop reconfigurable millimeter-wave substrate integrated waveguide (SIW) devices by integrating vanadium dioxide (VO₂) thin films with printed circuit board (PCB) technologies. The integration technique involves depositing VO₂ films on thin, flexible polymer substrates, which are then transferred and affixed to PCB circuits. The VO₂ is thermally activated and selectively doped to reduce power consumption depending on applications. Using experimental prototypes, we demonstrate several reconfigurable devices operating in the millimeter-wave band, including series and parallel switches and a reconfigurable hybrid coupler that transforms into dual through-line SIWs. Electromagnetic simulations and measurements validate the approach, revealing low insertion loss, good isolation, and broadband operation. This method simplifies fabrication and supports large-area integration, offering a practical route to scalable, low-cost, reconfigurable millimeter-wave components.