Research on Frequency Characteristics of Spherical-Cymbal Transducers

A new type of cymbal-type transducer, called spherical-cymbal, has been developed to increase the frequency performances of traditional cymbal transducers. Spherical-cymbal transducer consists of a piezoelectric ceramic disk (poled in the thickness direction) sandwiched between two spherical metal end-caps, each end-cap containing a shallow spherical inner cavity. A analytical model was developed to evaluate the resonance frequencies of spherical-cymbal transducers, and finite element analysis (FEA) is also used to calculate the resonance frequencies of spherical-cymbal transducers. The results show that the analytical model is reasonable when the cavity is shallow, it can be used to calculate the resonance frequencies of spherical-cymbal transducers. Under the same dimensions, the first resonance frequency of spherical-cymbal transducers is lower about 4.8~8.4% than that of traditional cymbal transducers. The first resonance frequency of spherical-cymbal transducers can be easily tailored simply by changing the end-cap material or varying the end-cap dimensions. This capability gives spherical-cymbal transducers wider applications.