A miniature class V flextensional cymbal transducer with directional beam patterns: the double-driver

The "double-driver" cymbal, a directional class V flextensional transducer, is described in this paper. Its basic structure is a bilaminar piezoelectr ic disk with metal caps as mechanical transformers and amplifiers. The dire ctivity was accomplished by exciting the double-driver in a combined flexur al and bending mode causing the sound pressure to add in one direction and cancel in the opposite direction. The cardioid beam pattern predicted by fi nite element modeling agreed well with the experimental measurements. A 3 x 3 double-driver array was constructed to demonstrate that under optimal co nditions the array can provide a directional beam pattern with a front-to-b ack ratio of more than 20 dB. (C) 2001 Elsevier Science B.V. All rights res erved.