The measurement of reflected second harmonics and nonlinearity parameter of media using a transducer with complex structure

The sound transmission and reflection of finite amplitude acoustic wave in layered media is calculated in this article. The measurement of nonlinear parameter using the second-harmonic reflective model is studied and a new kind of complex ultrasound transducer is designed and fabricated for this purpose. With this transducer and the finite amplitude insert-substitution method an experimental system to measure the nonlinear parameter using reflective model is developed. The nonlinear parameter B/A values of some liquids and biological tissues are obtained and the results coincide well with the B/A values presented in the literatures.