2D mixed finite element/analytical model of the mechanical coupling in ultrasonic array

The crosstalk between the elements of an acoustical array is a major cause of limitation of performance, when the pitch is around or below the wavelength. An accurate modelization of the mechanical part of the crosstalk can be obtained by finite element models. An original bidimensional mixed finite element/analytical analysis has been developed for infinite periodic arrays. The finite element method is used to analyze only one elementary transducer. Then, by expanding the electrical exitation of the array into harmonic exitations, the cross coupling is computed analytically for any combination of coupling layers including solid or fluid media. Both theoretical explanations and preliminary validations with previous analytical or numerical models are presented