Bi-layer PZT/polymer composite 1D 2.5 MHz phased array

Increasing the signal-to-noise ratio and the bandwidth is one major goal of medical ultrasound researchers. It was proposed, in recent publications, to use multi-layered PZT/polymer composite hybrid ultrasound arrays. In our evaluation three phased array prototypes were compared, all utilizing the same matching layers and backing: a conventional single-layer PZT array, a bi-layer PZT/PZT array and a bi-layer PZT/composite array. The bi-layer PZT/PZT array pulse-echo measurements show an improvement in the sensitivity of 8-10 dB relative to the conventional single-layer prototype. The bi-layer PZT/composite array increases the bandwidth by 10- 12%. The sensitivity advantage given by the bi-layer variants decreases when tuning the transducers with series inductors between system and cable