Naval Device Applications of Relaxor Piezoelectric Single Crystals

"We propose a directional, broadband, highly efficient underwater acoustic transducer using a baffled cylinder made out from piezoelectric single crystals. The prospective application areas will be for an underwater acoustic modem communication andAutonomous Underwater Vehicles (AUV), in which high efficiency of the transducer system is required due to the limited energy availability (battery) and the size of the transducer needs to be sufficiently small to fit the relatively small housing spaceand delivery system. In a multi-user communication network, a directional transducer may be desired in order to focus the acoustic beam in a particular direction in order to reduce the interference of communication signals and to increase thesignal-to-noise ratio.The significance of this project will be the reduction of transducer dimension and broadening of operational frequency range by exploiting the low sound speed and high coupling coefficient of piezoelectric single crystals. The transducer must be small andbroadband but highly efficient as it will be delivered with a A-size sonobuoy and will have limited battery energy. Utilization of piezoelectric single crystals will realize this smaller dimension, broaden the bandwidth and prolong the lifetime of thedevice in comparison with conventional piezoelectric materials e.g. PZT-4, PZT-5A or PZT-8. The Navy will gain a very broadband, leight weight directional source that is highly efficient