P039

Analysis of a Baffled Cylindrical Piezoelectric Transducer for Broadband Applications

A0096 Tetsuo Oishi Acoustic Research Laboratory, University of Massachusetts Dartmouth

A0097 Boris Aronov Acoustic Research Laboratory, University of Massachusetts Dartmouth

A0098 David A. Brown BTECH Acoustics

The demand of high data transfer rate and long propagation distances

is increasing in recent underwater acoustic applications such as data

transmission, underwater communications, active sonar and other

underwater research. Sources employed in these applications are

required to have design criteria such as high bandwidth, high power

output, high energy efficiency, and often directionality. Receivers

may be also required to have high bandwidth and directionality.

Further in some application, a reciprocal transducer may be needed for

both transmit and receive operation. Unidirectional beams are desired

to reduce the reverberation noise, to reduce the interference of

communication signals in a multi-user environment and to conserve

limited power.

We have recently developed cylindrical piezoelectric transducers with

a part of the surface baffled. The rigid or compliant baffle makes it

possible for the beam patterns to be directional and moreover to

increase the radiation. The broad bandwidth was achieved by

simultaneously exciting zeroth (breathing) and first (dipole) modes of

the radial vibration. A prototype of this type of transducer was

fabricated and experimental results including electrical impedance,

transmit voltage response and beam patterns were obtained. A

comparison with a recent broadband Tonpilz design is made.

[This work was supported in part by ECE Dept. UMass Dartmouth, BTECH

Acoustics and ONR 321 SS (J. Lindberg).]