Surface transverse waves on langasite

Surface transverse waves are numerically simulated in a periodic transducer on rotated Y-cuts of langasite crystal. The resonance and antiresonance frequencies of the transducer are evaluated as functions of the crystal cut, temperature and the thickness of the aluminum electrodes. For an optimal cut, we demonstrate a vanishing first-order temperature coefficient and find a coupling strength several times higher than that for Rayleigh waves in ST-cut quartz. The transverse waves in langasite differ from those in quartz in that the shear-wave velocity in langasite is lower than that in the aluminum electrodes, resulting in an essentially lower sensitivity of the resonance frequency to the thickness variations of the electrodes