Patent ID: 6404101
Filing Date: 2002-06-11
Classification: H03H

Abstract:
A surface acoustic wave device comprising:a piezoelectric substrate at which a surface acoustic wave having an anisotropy index &ggr; in the propagation direction of less than about âˆ’1 is excited; and at least one interdigital transducer disposed on the piezoelectric substrate and including first and second bus bar electrodes and a plurality of electrode fingers, the plurality of electrode fingers being connected to the first and second bus bar electrodes so as to define a pair of comb-shaped electrodes that are interdigitated with each other, the plurality of electrode fingers containing Al as a major component; wherein each of the electrode fingers has a film thickness of not less than about 0.04 &lgr;, where &lgr; is the wavelength of the surface acoustic wave, and at least a portion of the first and second bus bar electrodes has a thickness larger than that of each of the electrode fingers so that the energy of the surface acoustic wave is trapped substantially perpendicularly to the propagation direction of the surface acoustic wave.