Guided acoustic wave method for characterization of medical ultrasound transducers

A guided acoustic wave technique for nondestructive evaluation (NDE) of the medical ultrasound transducers is presented. A revised reflection coefficient measurement technique is used to obtain the dispersion curves of the Lamb waves by finding the local minimum of the broad band reflection spectrum. A set of specimens with controlled interface conditions between the matching layer and the piezoelectric layer are tested. The results of experiment show there is strong relation between the position of the turning point in the lowest order mode dispersion curve and bond quality of transducers.