Electrothermal actuation of vanadium dioxide for tunable capacitors and microwave filters with integrated microheaters

• We propose for the first time microwave tunable capacitors based on VO2.
• We exploit the VO2 tunable capacitors for microwave tunable filters.
• We study the integration of microheaters for local VO2 electrothermal actuation.
• We highlight the advantages of the proposed devices over RF MEMS.

We report the fabrication, modeling and characterization of novel microwave tunable capacitors based on the metal-insulator transition (MIT) of Vanadium Dioxide (VO2) as a future replacement solution for microelectromechanical capacitive switches. We present the advantages of VO2-based capacitors over alternative technologies for microwave reconfigurable electronics in terms of ease of integration, design and performance at high frequency. We show the potential of the proposed devices for RF reconfigurable electronics by fabricating a tunable bandstop filter (22.5–19.8 GHz) with insertion loss <2 dB up to 40 GHz. We propose an alternative method for actuation of the VO2 active regions by employing integrated microheaters and we study their effect on the filter performance by electrothermal and electromagnetic simulations.