Study on the radial vibration of a new type of composite piezoelectric transducer

In this paper, a new type of composite piezoelectric ceramic transducers is studied. The transducer consists of a piezoelectric ceramic thin ring polarized in the thickness direction and a metal thin circular ring. The radial vibration of the transducer is analyzed and its radial electro-mechanical equivalent circuit is obtained. Based on the electro-mechanical equivalent circuit, the resonance and anti-resonance frequency equations are obtained. The relationship between the resonance frequency, the anti-resonance frequency, and the effective electro-mechanical coupling coefficient and the geometrical dimensions is analyzed. Some radial composite piezoelectric transducers are designed and manufactured. The resonance frequencies and anti-resonance frequencies are measured and the effective electro-mechanical coupling coefficient is calculated. It is illustrated that the measured radial resonance frequencies are in good agreement with the theoretical results from the resonance frequency equation. The finite element method is also used to find the resonance frequency and the radial displacement distribution. It is shown that the resonance and anti-resonance frequencies from the finite element method are also in good agreement with those from the analytical method in this paper.