Operating characteristics analysis of a dual-excited full-wavelength piezoceramic ultrasonic transducer

A dual-excited full-wavelength piezoceramic ultrasonic transducer as a cascade of two half-wavelength sandwich piezoceramic transducers is studied. The relevant parameters' expressions of the figure of merit N for the transducer are derived, and the effects of the structure and material parameters of the transducer on its characteristics are further analyzed by numerical calculation. The results show that when the two piezoceramic stacks are respectively located at the displacement nodes of their own half-wavelength transducers, or the two piezoceramic stacks have the same number of pieces in the case of a certain number of piezoceramic pieces, the figure of merit of the transducer can reach a maximum. With increasing of the number of piezoceramic pieces in a fairly large range, the figure of merit of the transducer slightly decreases, but the force factor of the transducer increases rapidly. The metal materials of the transducer have little effect on its figure of merit. Thus it can be seen that the dual-excited full-wavelength transducer can effectively increase the volumes of the piezoceramic stacks in the case of that the transducer's comprehensive performance has only a little bit of degradation, so it's power capacity and load capability can be dramatically improved, which means the transducer is more suitable for high power and heavy load applications.