Analysis and experimental verification of dual frequency ultrasonic transducer with contour and thickness vibration modes

The contour mode is introduced with normal thickness mode to generate dual frequency ultrasonic waves in a single element transducer. The proposed dual frequency transducers are analyzed and designed by finite element analysis. Based on the results of simulation analysis, the four transducers prototypes are fabricated and tested. For dual frequency transducer with optimized matching layer, the pulse echo characteristics of low frequency part are similar with the comparison characteristics of 1–3 composites transducer. The dual frequency transducer still simultaneously owns effective high frequency part. The results demonstrate that the proposed contour vibration mode can work with thickness vibration mode to realize dual frequency with a high performance.