High performance, high frequency ultrasound transducers incorporating PbTiO3

An improved method to design high frequency single element transducers for ultrasonic imaging applications was developed. In the method, the center frequency of the transducer is determined by electrical tuning. The electrical tuning also plays an important role in other performance parameters such as bandwidth and sensitivity. Several PbTiO₃ ceramic transducers with aperture sizes equal to or larger than 3 mm were fabricated based on the new design approach. These devices were tested for -6dB bandwidth and sensitivity using the pulse/echo response from a flat quartz target. They displayed center frequencies between 30-100 MHz, bandwidths in the range of 25% to 100%, and insertion losses from 20 dB to 35 dB. The improved performance of this approach was demonstrated by imaging an excised eye with an ultrasound backscatter microscope