Electrical model for a nonlinear piezoelectric transducer

For a slightly nonlinear piezoelectric transducer with L coupling, a relation between acoustic wave function and its electrical and mechanical environment has been established. An electrical model that takes into account any type of nonlinearity has been proposed. Due to harmonic generation, each frequency ω_R must be treated separately: nonlinear terms appear in the constitutive equations, different for each harmonic frequency, which can be evaluated as a perturbation from nonlinear coefficients and the most important wave functions. These terms disturb the transductor behavior in three different ways: through the differential wave equation, in mechanical and in electrical boundary conditions