A numerical investigation of power loss in a thickness-mode piezoelectric transducer

Abstract

Power loss reduction in piezoelectric transducers has been attracting the attention of diverse researchers and the ultrasonic technology manufactures for years. In this context, fundamentally two frequencies have been profusely investigated to excite these transducers, namely the resonance and antiresonance ones. However, more recently other operation points have been examined. This article presents a numerical investigation of power loss in a thickness-extensional mode piezoelectric transducer, excited at its fundamental resonance, and designed with the data compatible with a very-high mechanical quality factor (Q m) piezoceramic. Additionally, harmonic electric excitations of the device and a constant velocity of its front face were supposed, when it was acoustically coupled to air or water loads, i.e. in real loading conditions for numerous applications. In this investigation it was found an optimal operation point where a remarkable power loss reduction may be obtained regarding excitations at the resonance or antiresonance frequencies. Finally, it was discovered that power loss frequency spectrum depends on the external acoustic load for this type of transducers. In simulations, a linear piezoelectrics was assumed.