A 200-kHz ultrasonic transducer coupled to the air with a radiating membrane

The development of a 200-kHz air ultrasonic transducer that consists of a piezoceramic disc and metal housing, the latter acting as a radiating membrane, is discussed. Theoretical analysis of the axially symmetric transducer structure is based upon the finite-element method. Calculations of the resonance frequencies, corresponding transducer deformations and input electrical admittance are performed using triangular ring elements with six degrees of freedom. Measured values on experimentally built transducers show good agreement with theory.