A surface acoustic wave device using a longitudinally polarized guided wave comprises a composite substrate comprising a piezoelectric layer formed over a base substrate, wherein the crystalline orientation of the piezoelectric layer with respect to the base substrate is such that, the phase velocity of the longitudinally polarized wave is below the critical phase velocity of the base substrate at which wave guiding within the piezoelectric layer vanishes. A method of fabrication of such surface acoustic wave device is also disclosed.

A surface acoustic wave device using a longitudinally polarized guided wave comprises a composite substrate comprising a piezoelectric layer formed over a base substrate, wherein the crystalline orientation of the piezoelectric layer with respect to the base substrate is such that, the phase velocity of the longitudinally polarized wave is below the critical phase velocity of the base substrate at which wave guiding within the piezoelectric layer vanishes. A method of fabrication of such surface acoustic wave device is also disclosed.