A Novel Reconfigurable CMOS Compatible Ka Band Bandstop Structure Using Split-Ring Resonators and Vanadium Dioxide (VO2) Phase Change Switches

The article presents the design, fabrication and characterization of a novel complementary metal-oxide-semiconductor (CMOS) compatible reconfigurable Ka band bandstop structure using split ring resonators (SRR) while employing the Vanadium Dioxide (VO2) phase change (PC) thermally triggered transition. The work focuses on the VO2 thin film conductivity levels challenges on silicon dioxide (SiO2)/ silicon (Si) substrates caused by the limited conductivity in the metallic state of the VO2 films versus their non-zero conductivity in the insulating state. We characterize first various samples of VO2 thin films deposited on SiO2/Si substrates and present different fabricated filters responses with several VO2 switches dimensions. The filters show higher bandstop rejection levels than previously reported VO2 based CMOS compatible bandstop filters for the Ka band and displays a higher reconfigurable range from: 29.7 GHz–38.7 GHz. The filters while introducing a new compact tuning mechanism present the first VO2 reconfigurable SRR bandstop structures for the Ka band.