Investigation of longitudinal leaky surface acoustic wave on lithium niobate and quartz

The high frequency SAW transducers have shown great vitality in mobile phone and satellite communications and so on. One of the important ways to raise the working frequency and keeping the size of strips unchanged is to utilize the SAW devices based on high velocity acoustic wave modes. Therefore, the investigation of quasi-longitudinal acoustic surface leaky waves (QLASLWs) is of great significant because of its potential applications. Both theoretical and experimental results on LiNbO₃ and quartz are shown in this paper, for example, on LiNbO₃ in the range of Euler angles (0°, β, 90°), the theoretical velocities are between 6000 m/s and 7000 m/s, nearly about twice that of normal surface waves, but the piezoelectric coupling coefficients varies between about 0.14% to 0.5%, much less than that of surface waves. The experimental results, for example, on LiNbO ₃ at Euler angle (0°, 38°, 90°), shows well agreement with the theoretical results. The theoretical results on quartz in the range of Euler angle (0°, 124°, γ) are also shown in this paper