Method of making a microwave device having a polycrystalline ferrite substrate
US6060433A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 1999 |
| Grant date | May 9, 2000 |
| Priority date | — |
| Expiry date | Jan 26, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/742
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The invention provides a structure comprising a high temperature superconducting layer deposited on a ceramic polycrystalline ferrite plate suitable for making commercial microwave devices. In one embodiment, the high temperature superconductor is yttrium barium copper oxide (YBCO), the ferrite is yttrium iron garnet (YIG), and the microwave device is a phase shifter. The method of making this embodiment comprises, polishing the YIG plate, depositing biaxially oriented yttria-stabilized zirconia (YSZ) to form a crystalline template using an ion-beam-assisted-deposition technique, depositing a CeO.sub.2 lattice matching buffer layer using pulsed laser deposition, depositing YBCO using pulsed laser deposition, and annealing the YBCO in oxygen. Etching the YBCO to form a meanderline patterned waveguide results in a high figure-of-merit microwave phase shifter when the device is cooled with liquid nitrogen and an external magnetic field is applied. Different patterns can be etched in the YBCO in order to make other well known ferrite-based microwave devices. Other oxide compounds can be used for ferrite plate and the high temperature superconductor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.