The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 09, 1987
Filed:
Aug. 14, 1986
Hitoshi Suzuki, Yokohama, JP;
Yasuo Ebata, Yokohama, JP;
Sadao Matsumura, Tokyo, JP;
Jisaburo Ushizawa, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A surface acoustic wave device has been developed, such as a surface acoustic wave filter in which a plurality of electroacoustic interdigital electrodes are formed, as thin films made principally of aluminum, on the surface of a Li.sub.2 B.sub.4 O.sub.7 single crystal substrate and a surface acoustic wave resonator, in which a plurality of electroacoustic interdigital electrodes and grating reflectors for reflecting the surface acoustic wave are formed, as thin films made principally of aluminum, on the surface of a Li.sub.2 B.sub.4 O.sub.7 single crystal substrate. Here, a cut angle, at which the substrate is cut from the Li.sub.2 B.sub.4 O.sub.7 single crystal, and the propagation direction of the surface acoustic wave are so set that, when the Eulerian angle representation is (90.degree..+-..lambda., 90.degree..+-..mu., 90.degree..+-..theta.), .lambda.=38.degree. to 52.degree., .mu.=0.degree. to 5.degree. and .theta.=0.degree. to 10.degree., whereby the TCD of the surface acoustic wave device is below .+-.5 ppm/.degree.C. and coupling coefficient K.sup.2 is about 1.0%, and the propagation speed suffers almost no angular dependence.