Joule-Heated Vanadium Dioxide Switch Design for Reconfigurable Millimeter-Wave Antenna Arrays

A joule-heated vanadium dioxide millimeter-wave switch operating from 50 GHz to 110 GHz is designed and fabricated using a combination of chemical vapor deposition, annealing, and sputtering processes. The phase change material is transitioned from the monoclinic to tetragonal state by direct joule-heating of the switch element, which requires a significantly lower voltage for the transition compared to the less efficient and more commonly used separate heater method. Using the biasing method presented, this approach offers the ability to switch in and out different transmission lines using two series switch elements for applications in reconfigurable antenna array feed networks operating at millimeter-wave frequencies as demonstrated through simulation. The fabricated design provides less than 4 dB insertion loss across the entire frequency range whilst also achieving better than 10 dB isolation below 90 GHz.