A Novel Reconfigurable CMOS Compatible Ka Band Bandstop Structure Using Split-Ring Resonators and Vanadium Dioxide (VO 2 ) 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 (VO 2 ) phase change (PC) thermally triggered transition. The work focuses on the VO 2 thin film conductivity levels challenges on silicon dioxide (SiO 2 )/ silicon (Si) substrates caused by the limited conductivity in the metallic state of the VO 2 films versus their non-zero conductivity in the insulating state. We characterize first various samples of VO 2 thin films deposited on SiO 2 /Si substrates and present different fabricated filters responses with several VO 2 switches dimensions. The filters show higher bandstop rejection levels than previously reported VO 2 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 VO 2 reconfigurable SRR bandstop structures for the Ka band.