Kinseki Limited

Nikko Kyodo Co., Ltd.

Nikko Kyondo Co., Ltd.

Takahiro Sato

Hidenori Abe

Yukio Ohkubo

Surface acoustic wave device with an electrode insulating film and

A surface acoustic wave device comprises a piezoelectric substrate of lithium tetraborate single crystal, and a metal film formed on the surface of the piezoelectric substrate for exciting, receiving, reflecting and/or propagating surface acoustic waves, the metal film being so formed that a cut angle of the surface of the piezoelectric substrate and propagation direction of the surface acoustic wave are an Eulerian angle representation of (0.degree.-45.degree., 30.degree.-90.degree., 40.degree.-90.degree.) and directions equivalent thereto, the surface acoustic wave having higher propagation velocity than Rayleigh waves and leaky waves, and a characteristic of radiating part of energy of the surface acoustic wave into the piezoelectric surface while propagating.

Surface acoustic wave device

A surface acoustic wave device comprises lithium tetraborate single crystal substrate to make use of surface acoustic waves with higher propagation velocities and smaller propagation losses, whereby frequencies to be signal-processed can be as high as above 1 GHz. The surface acoustic wave device comprises a metal film formed on a surface of a lithium tetraborate single crystal substrate, the metal film being for exciting, receiving, reflecting and/or propagating surface acoustic waves, the metal film being so formed that a cut angle of the substrate, and a propagation direction of the surface acoustic waves are in an Eulerian angle representation of (39.degree.-51.degree., 66.degree.-114.degree., -20.degree.-20.degree.) and directions equivalent thereto. In this propagation direction few Rayleigh waves exit, and only surface acoustic waves of high propagation velocity are generated. Propagation losses can be eliminated.

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Toda, Japan

Takahiro Sato