Stock material or miscellaneous articles – Composite – Of inorganic material
Reexamination Certificate
1998-09-25
2001-02-27
Kiliman, Leszek (Department: 1773)
Stock material or miscellaneous articles
Composite
Of inorganic material
C428S690000, C428S690000, C428S900000, C252S06251C, C252S062560, C252S062570, C333S134000, C333S147000, C333S148000, C333S150000, C333S156000, C333S193000, C333S201000, C359S280000, C359S282000, C385S001000, C385S006000, C385S130000
Reexamination Certificate
active
06194091
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a magnetostatic wave device, and more particularly to a magnetostatic wave device comprising a magnetic garnet single crystal film.
2. Description of the Related Art
Single crystals of Y
3
Fe
5
O
12
(referred to YIG hereinafter), a kind of magnetic garnet single crystal film, has been an important substance as a material for use in magnetostatic wave devices. A remarkable property of YIG is that it has an extremely small ferromagnetic half-width (&Dgr;H), which is related to the fact that the difference between input signals and output signals can be made small when it is used for the magnetostatic wave device. An additional feature is that a YIG is characterized by a saturation phenomenon at a relatively small input signal level. The YIG single crystal films have been widely used for magnetostatic wave devices such as limiters and noise filters by taking advantage of this phenomenon. Various kind of single crystal films of magnetic garnet containing iron have been also used for the magnetostatic wave device in addition to the YIG single crystal film described above.
However, the feature of the YIG output signal being saturated at a relatively small input signal level is not revealed immediately after receiving the input signal. Instead, the input signal is directly output as an output signal. There is therefore a transient response phenomenon in that the output signal is saturated as a function of a time lapse which causes a problem in that the function as a magnetostatic wave device can not be fully displayed. Although increasing the insertion loss of the magnetostatic wave device is one solution for this problem, too large an insertion loss makes the output signal level too small.
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide a magnetostatic wave device with improved performance by shortening the time interval suffering the transient response phenomenon without increasing the insertion loss.
For attaining the foregoing object, the present invention provides a magnetostatic wave device which comprises a magnetic garnet single crystal film, and the magnetic garnet single crystal film is represented by the general formula of Y
3
Fe
5-x-y
In
x
M
y
O
12
(wherein M is at least one of Ga, Al and Sc, 0.01≦x≦0.45 and 0≦y≦1.2) and the Curie temperature of the magnetic garnet single crystal film is about 150° C. to 285° C.
According to the present invention, a magnetostatic wave device can be obtained in which the time interval suffering the transient response phenomenon is shortened less than 120 ns without increasing the insertion loss.
For the purpose of illustrating the invention, there is shown in the drawing a form presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
REFERENCES:
patent: 5801604 (1998-09-01), Fujino
patent: 5871856 (1999-02-01), Kumatoriya
patent: 5985472 (1999-11-01), Geho
patent: 6016088 (2000-01-01), Fijno
patent: 6052042 (2000-04-01), Kumotoriya
patent: 6114929 (2000-09-01), Kurata
patent: 55-143009A (1981-01-01), None
patent: 09208393 (1997-12-01), None
Patent Abstracts of Japan; vol. 005, No. 015 (E-043); Jan. 29, 1981 & JP 55 143009 A (Matsushita Electric Ind. Co., Ltd.), Nov. 8, 1980, Abstract.
Patent Abstracts of Japan; vol. 097, No. 012, Dec. 25, 1997 & JP 09 208393 A (Shin Etsu Chem Co., Ltd.), Aug. 12, 1997, Abstract.
Kiliman Leszek
Murata Manufacturing Co. Ltd.
Ostrolenk Faber Gerb & Soffen, LLP
LandOfFree
Magnetostatic wave device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetostatic wave device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetostatic wave device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2609442