Quantitative study on the nonlinear piezoelectric effect of KNbO₃ single crystal for super highly efficient SAW elastic convolver

This paper describes quantitative studies on the nonlinear piezoelectric effect of KNbO₃ single crystal for a highly efficient SAW elastic convolver. First, it is demonstrated that the simple measurement of the nonlinear piezoelectric constant of e₃₅₅ is very effective in the quantitative estimation of the efficiency of elastic convolver. Next, the third-order piezoelectric constants, e₃₅₅ and e₃₄₄ in the rotated Y-cut KNbO₃ substrates are measured by using the velocity variation under applied electric field. Using the measured third-order piezoelectric constants, the quantitative estimations of the convolution efficiency are discussed.