Patent ID: 6429570
Filing Date: 2002-08-06
Classification: H03H

Abstract:
A surface acoustic wave device comprising a substrate and an inter-digital electrode having a finger on a surface of said substrate, wherein:the substrate is formed by cutting out of a single crystal represented by a chemical formula, La&agr;Ta&bgr;Ga&ggr;O&dgr;(2.9&lE;&agr;&lE;3.1, 0.48&lE;&bgr;&lE;0.52, 5.4&lE;&ggr;5.6 and 13.8&lE;&dgr;14.2); a cut angle of the substrate cut out of the single crystal and a direction of propagation of surface acoustic waves on die substrate represented in terms of Euler's angles (&phgr;, &thgr;, &psgr;), &phgr;, &thgr; and &psgr; are found in one of a first area represented by âˆ’5 degrees &lE;&phgr;&lE;5 degrees, 135 degrees &lE;&thgr;&lE;150 degrees and 20 degrees a ratio obtained by dividing a thickness h of the finger of the inter-digital electrode by a wavelength &lgr; of the surface acoustic wave, such that the ratio h/&lgr; exceeds 0.5% and is equal to or smaller than 4%.