Tunable HTS microwave filters using strontium titanate thin films

Effects of substrate on the dielectric and tunable properties of epitaxial SrTiO3 thin films

“…The frequency tuning can be achieved by integrating STO thin films into these YBCO devices and tuning the dielectric constant of the STO films by an electrical bias. 9,10 Because of chemical and structural compatibilities of YBCO to STO, STO/YBCO heterostructures are very attractive for tunable microwave devices. Consequently, it is desirable to understand the effects of various substrates on the dielectric and tunable properties of STO thin films.…”

Planar tunable HTS microwave filter with patterned ferroelectric thin film

“…Previous approaches for achieving ferroelectric thin film on only the selected region included the use of the flip-chip method, in which the ferroelectric thin films are grown on separate pieces of substrate and subsequently attached to the substrate with the patterned conductive circuit layer [5,6]. However this approach is usually very difficult to implement in practice as it requires the device design to have a very large displacement error tolerance for the placement position of the substrates or that the device to be assembled with very high precision.…”

Tunable Coplanar Waveguide Microwave Devices on MOCVD-SrTiO3Thin Films

“…mechanically tuned resonant structures, ferrite based components or semiconductor-based voltage controlled electronics [3]. SrTiO 3 (STO) FE thin films associated with high temperature superconducting (HTSC) materials make a good compromise to realize electronically tunable devices [4][5][6] combining controllable dielectric properties of FE films with low loss microwave conductivity in HTSC. STO, which exhibits a perovskite structure, is suitable for epitaxial growth of the HTSC YBa 2 Cu 3 O 7−x (YBCO) material and has been widely studied to realize phase shifters and tunable filters or capacitors.…”