A VO2-based 30 GHz variable attenuator

This paper presents a millimeter-wave variable attenuator using vanadium dioxide (VO
₂
)-based variable resistors. The thin-films VO
₂
are integrated monolithically with a 0-dB coupler to realize the variable attenuator. A 30 GHz variable attenuator is designed, fabricated, and tested to verify the concept. It exhibits a continuous attenuation tuning range of 13 dB, and a return loss of 15 dB over a bandwidth of 5 GHz. The proposed VO
₂
based variable attenuators have a great potential to be used in a wide range of millimeter-wave applications.