2001 Fiscal Year Final Research Report Summary
Fabrication of All-Oxide Ferroelectric/High-Temperature Superconductor/Ferromagnetic Heterostructures for Electorically and Magnetically Tunable Microwava Devices
| Project/Area Number |
12650685
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Composite materials/Physical properties
|
|---|
| Research Institution | Kinki University |
|---|
Principal Investigator |
HONTSU Shigeki Kinki University Professor, 生物理工学部, 教授 (40157102)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ISHII Junya Kinki University Professor, 生物理工学部, 教授 (80088351)
NISHIKAWA Hiroaki Kinki University Research Associate, 生物理工学部, 助手 (50309267)
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Keywords | superconducting filter / tunable device / perovskite oxide / mobile communication / surface resistance |
|---|
| Research Abstract |
This report mainly concerns with tunable microwave filter for mobile telecommunications. In order to realize large tuning and lowinsertion loss, we propose an electrically and magnetically tunable superconducting microwave filters with all-oxide superconductor/ferroelectric/ferromagnetic heterostructures.
We have fabricated YBa2Cu3O7y (YBCO), Ba0.05Sr0.95TiO3 (BSTO) and Pr0.85Ca0.15MnO3(PCMO) singlecrystal films and half-wavelength coplanar wave guide (CPW) resonator consisting of YBCO/BSTO/PCMO heterostructures. We have also investigated electric properties of the BSTO film and magnetic-electric properties of the PCMP film. Moreover, we have observed change of the resonant frequency of the tunable CPW resonator with the resonant frequency around 7 GHz under application of both electric and magnetic fields. The results show that the shift of the resonant frequency is about 7.5 MHz (tunability : about 0.1%) by an application of an electric field. On the other handk, the shift is about 20 MHz (tunability ; about 0.25%) by an application of a magnetic field. These values are available for use in the adjustable application. However, these values have a disadvantage for the filter of software-defined radio. Also, the keeping effect of the characteristic impedance under both applied electric and magnetic fields could not be observed because of its small tunability. Thus, we have proposed a mechanically tunable superconducting microwave filter based on this research technique. As a result, we have obtained the large tunability of 20%.
|
