A broadband hybrid magnetostrictive/piezoelectric transducer array

Most existing sonar transducer technologies that are capable of producing broadband, high power acoustic signals required for future Navy needs, are only conceptual in design, or very early into their development stage. A high power broadband 16 element array of Hybrid Magnetostrictive Piezoelectric Tonpilz Transducer (MPT) projectors is currently being developed at Naval Undersea Warfare Center (NUWC), Newport, R.I. for these applications. The Hybrid Transducer combines the high strain magnetostrictive material, Terfenol-D, with that of Lead Zieconate Titanate piezoelectric ceramic, to create a double resonant, high power broadband device. This design provides a 1 kHz increase in bandwidth below the low end of the frequency band of a conventional piezoelectric Tonpilz transducers of the same size and weight. The theory of operation, fabrication technique and test results will be discussed for a single element and then compared with a conventional Tonpilz sonar transducer of same size and weight. Modeling and measurement data for the 16-element array will also be discussed.