Patent ID: 7375454

Claim:
A surface acoustic wave excitation device comprising a non-piezoelectric member made of a glass, a piezoelectric member, interdigital transducers constituting a pair of the finger electrodes interposed between the non-piezoelectric member and the piezoelectric member, and pre-pressurizing means for applying pressure onto the piezoelectric member against the non-piezoelectric member by way of the interdigital transducers, wherein the length of the piezoelectric member in the perpendicular direction to the finger electrodes of the interdigital transducers is set to integer times of the ½ wavelength of the wave propagating on the piezoelectric member to cause standing waves of an acoustic wave on the piezoelectric member when alternating voltage is applied to the interdigital transducers, thereby exciting the surface acoustic wave on the non-piezoelectric member.