Index of content:
Volume 121, Issue 6, June 2007
- TRANSDUCTION 
121(2007); http://dx.doi.org/10.1121/1.2722053View Description Hide Description
Hollow piezoelectric cylindrical shell transducers may be made directional for underwater acoustic applications by the use of suitable acoustical baffles and the operational bandwidth may be extended by using multiple resonant modes. A theoretical and experimental investigation was performed for circumferentially baffled piezoelectric cylindrical shell transducers operating in the zero and one modes of extensional vibration. The frequency responses and directivity patterns were analyzed under various conditions of energizing separate halves of electrodes. It was found that the broadest frequency response with nearly constant beamwidth can be obtained when the two halves of the piezoelectric ring are electromechanically excited out-of-phase. The experimental results obtained with a proof-of-concept transducer were in good agreement with the theoretical predictions.