Multimode directional telesonar transducer

Directional transducers will improve the performance of undersea acoustic modems. Current designs provide only vertical directionality with omni-directionality in the horizontal plane. Horizontal directionality can yield a higher source level and higher received signal to noise through the increase in the DI or equivalently the narrower beam pattern of the device. Moreover, a horizontal steered directive beam allows selective and more secure communications between the nodes of the system, This paper reports the development of a prototype device that achieves desired directivity by the controlled combining of the three most fundamental extensional modes of vibrational of a piezoelectric cylinder