Effect of the interruption of the propagation path on the response of surface acoustic wave transducers

This paper presents the effect of an arbitrary interruption of the propagation path in Surface Acoustic Wave (SAW) microdevices on the intensity of the scattered surface waves. Using finite element modeling, simulations have been carried out to validate a new equivalent circuit based on the conventional Mason and Smith model. In addition, experimental results obtained with 30, 50 and 100 μm diameter microholes are reported. The comparison of theory, simulation and experiment proves that it is possible to fabricate an interruption like deep microcavities or microholes in the propagation path which results in an acceptable signal magnitude attenuation, but without shift in the operating frequency.