Multilayer piezoelectric transducer models combined with Field II

One-dimensional and three-dimensional axisymmetric transducer model have been compared to determine their feasibility to predict the volt-to-surface impulse response of a circular Pz27 piezoceramic disc. The ceramic is assumed mounted with silver electrodes, bounded at the outer circular boundary with a polymer ring, and submerged into water.

The transducer models are developed to account for any external electrical loading impedance in the driving circuit. The models are adapted to calculate the surface acceleration needed by the Field II software in predicting pressure pulses at any location in front of the transducer. Results show that both models predict the longitudinal resonances with consistency.

The one-dimensional model is found to exhibit approximately 2.9 dB peak overshoot at the lowest longitudinal resonance frequencies prediction. These values are decreasing for higher longitudinal modes. If the three-dimensional model is restricted in its radial movement at the circular boundary both models exhibit identical results.

The Field II predicted pressure pulses are found to have oscillating consistency with a 2.0 dB overshoot on the maximum amplitude using the one-dimensional compared to the three-dimensional model. This is with no electronic loading. With a 50 Ω loading an amplitude overshoot is found to be 1.5 dB.