An ultrawide bandwidth high frequency phased-array ultrasound transducer fabricated using the PMN-0.3PT single crystal

Abstract

High frequency (≥20 MHz) phased-array ultrasound transducers exhibit many benefits in biomedical applications. However, high performance array transducers, with high resolution and high sensitivity, are hard to fabricate due to the limitation of their rigorous dimensions. In this study, to achieve a high -6 dB bandwidth, a 20-MHz 64-elements phased-array transducer based on a PMN-0.3PT single crystal as an active layer has been fabricated using a photolithography method. High piezoelectric properties of PMN-0.3PT, such as high electromechanical coupling coefficients and high piezoelectric constants, lead the transducer to exhibit a -6 dB bandwidth of ∼90% and an insertion loss of 29 dB in the pulse-echo measurement. The results show a great enhancement on the performance when comparing with those reported 20-MHz array transducers based on piezoelectric single crystal and ceramic materials.