The ultrasonic transducer is an electroacoustic device.Its performance is determined mainly by the properties of its sensitive element

namely piezoelectric ceramics.A 140 kHz Tonpilz piezoelectric ceramic ultrasonic transducer is investigated.Derived from the piezoelectric constitutive equation

the equivalent circuit model and finite element model are constructed respectively.The difference between above two models is described.A comparison shows that the method of FEA has a good accuracy

and its analysis error can be controlled within 5 %.So FEA is suitable for such type piezoelectric transducer.Some transducer prototypes are made according to the design result.The corresponding test shows a good performance.