Simulation of generation of bulk acoustic waves by interdigital transducers

Interdigital transducers (IDTs) in a substrate will generate bulk acoustic waves (BAWs) along with the surface acoustic waves. Whereas the effect of BAW generation by IDTs may be employed to fabricate BAW transducers working at high frequency, the relationships of BAW generation by IDTs are discussed in this article. The resistance densities of BAW generation by IDTs are employed to describe the efficiency of BAW generation for given crystal orientations. The results of simulation show that for some crystal orientations there are the most efficient BAW generations. The generation directions of pure BAW modes are illustrated. Moreover, the possibility of fabricating HF BAW transducers by IDTs is discussed.