Time domain modeling in the thickness mode of a piezoelectric transducer and its electrical circuit including time-varying components

Abstract

Existing models for piezoelectric transducers are generally frequency domain-based. A limitation of these models is that they do not consider the fact that some components of the exciting or receiving electrical circuit can be time-dependent. This can happen when transducers are excited by capacitance discharge via a switch or when the circuit integrates active components such that diodes. In particular, in the case of capacitance discharge excitation, it is well known that the switch output impedance varies according to time. Indeed, its value is high when the switch is off and low when the switch is on. A temporal-based method is presented for the analysis of piezoelectric transducers in the thickness mode and their excitation circuit. A baclung material and a matching layer are also considered. This model takes into account time-varying components by means of a step-by-step calculation process. The method has been successfully tested by comparison with measurements of transducer responses using an electrical circuit based on capacitance discharge via a transistor switch.

Damping, amplitude, aging tests of stacked transducers for shock wave generation

“…With the help of the simulation method previously presented [12], the current going through the back transducer and the displacement of its faces was computed for each temporal step. Reflections of the generated wave within the back transducer, the front one, and the matching layer were calculated, as well as the voltage induced between the electrodes of the front transducer.…”

“…A model in the time domain was developed, based on a method that was previously presented for single-layer transducers [12]. This simulation method consists of two parts: in the first, only the back transducer is activated; in the second, only the front transducer is excited.…”