High-Power, Low-Frequency, Textured PMN-PT Underwater Projector

There is an ongoing need to improve the design of low-frequency, high-power, broadband sonar transducers for use in A-sized sonobuoys. Desired improvements include lowering the frequency, increasing the power, increasing bandwidth, reducing size, reducing weight, and lowering cost. Most sonobuoy applications currently utilize flextensional or flexural transducers that use piezoelectric PZT type ceramics for transduction. Single crystal piezoelectric ceramics have been investigated as possible improvements to PZT. A major drawback, however, is that they are costly and are size restricted which limits low-frequency and high-power usage. Recently, textured PMN-PT ceramics have been developed. They have piezoelectric properties that approach those of single crystal ceramics, with the advantages that it can be fabricated in larger sizes with lower cost and can be driven at higher drive levels. Therefore, a transducer made with this material has the potential to produce more source level and can also can be designed to be more compact, lighter, have a broader bandwidth, and higher effective coupling than one using PZT. During Phase I of this SBIR Program, Massa will develop an A-sized transducer for sonobuoys using textured ceramics that will contain the desired improvements.