The radial composite piezoelectric ceramic transducer

The radial composite piezoelectric ceramic transducer is presented and analyzed. The transducer consists of two metal thin circular rings and a thickness polarized piezoelectric thin ring which is sandwiched between the two metal rings in the radial direction. The radial vibrations of a metal thin ring and a piezoelectric ceramic thin ring are analyzed. Their electro-mechanical equivalent circuits are obtained. Based on the electro-mechanical equivalent circuits and the radial boundary conditions, the composite electro-mechanical equivalent circuit of a radial composite piezoelectric transducer is obtained and the resonance and the anti-resonance frequency equations are derived. The relationship between the resonance frequency, the anti-resonance frequency, and the effective electro-mechanical coupling coefficient and the geometrical dimensions of the radial composite transducer is analyzed. It is illustrated that the resonance frequencies and the anti-resonance frequencies from the frequency equations are in a good agreement with experimental results.