Ultrasonic transducers frequency response study with equivalent circuit and finite element method

Broadband ultrasonic transducers have many advantages, such as, short time response, high resolution in axis, wide band of launching and receiving waves. In this paper, the KLM equivalent circuit (KLM model) was used to obtain the frequency response function of an ultrasonic transducer. Based on the frequency response function, the relationship of the bandwidth and the acoustic impedance of backing or matching layer were analysed, and the optimum impedances of these two structures were obtained. Finally, finite element method (FEM) was used to get the frequency response of transducers. It is shown that the frequency responses obtained by the KLM model and FEM agree with each other well.