Equivalent network analysis of piezoelectrically-graded broadband ultrasound transducers

Performance of ultrasound transducers composed of a piezoelectric plate having a graded parameter is studied theoretically by using an equivalent network model formerly presented by the authors. Transfer functions and impulse responses are calculated for a linearly and an exponentially graded piezoceramic transducer model which has a water load on one side and a matched backing on the other side. The theoretical examinations made for the plates with some typical distributions of the piezoelectric constant e₃₃ clearly show the effectiveness of the functionally-graded plates. Some results are also presented for the case that the transducers are excited by a one-cycle sinusoidal electric pulse