Dual-Frequency Piezoelectric Micromachined Ultrasonic Transducers for Fundamental and Harmonic Imaging

A piezoelectric micromachined ultrasonic transducer (PMUT) with single oval vibrating diaphragm and dual frequency bands is developed for fundamental and harmonic imaging. The feature of dual-frequency bands of single PMUT element is verified by ultrasonic imaging experiments. The dual-frequency PMUT doubles the fractional bandwidth and halves the device dimensions compared to state of the art, which will enable ultrasonic imaging with combined advantages of high resolution via harmonic imaging and large depth via fundamental imaging. Therefore, it holds great promise for next-generation intravascular ultrasound (IVUS).