PRINCIPLE OF PIEZOELECTRIC FREQUENCY-TUNABLE TRANSDUCER

Eecently, in our papers^1,2 the effect of electric load on the characteristics of piezoelectric vibration system has been obtained. The resonant frequency of such a system changes continually with the changing of the electric load. In accordance with this effect, we made piezoelectric frequency-tunable transducers. In this paper, the principle of this freqency-tunable piezoelectric transducer is described.
We theoretically analyse the piezoelectric frequency-tuning of the sandwich transducers and experimentally investigate a sandwich transducer of length-vibration bar with field parallel to length. The theoretical and experimental results show that such frequency-tuning is available at one and half octaves.