Large-signal impedance measurements of piezoelectric ultrasonic transducers

This paper reports the use of large-signal impedance measurements to study the behaviour of piezoelectric ultrasonic transducers (PUTs). The method requires only ordinary laboratory equipment including a signal generator, a digital oscilloscope together with a high frequency transformer. Equivalent circuit model parameters are extracted from the impedance measurement data of for investigating the device characteristics of the PUT. Such useful model parameter extraction is not possible from impedance measurements using even a sophistical LCR meter which is for small-signal impedance measurements. This low-cost and simple impedance measurement method is attractive for allowing even undergraduate students to perform research-related experiments.