SPICE Modeling Nonlinearity Effects on Ultrasonic Waves

Abstract

Nonlinearity is one of the phenomena that affect the ultrasonic wave during its propagation in a given medium. In the time domain the nonlinearity is seen as a variation of the phase velocity which leads to a distortion of the waveform. This corresponds in the frequency domain to energy transfer from the fundamental frequency to the harmonic and among the harmonic themselves. Our purpose in this paper is to introduce a SPICE implementation of the computational model of the nonlinear ultrasound propagation. We first study the plane wave distortion based on the Burgers’ equation. Our SPICE model allowed studying the temporal profile of the ultrasonic wave during its propagation. The simulation results are compared to the analytical solution of the Burgers’ equation showing the validity of the model. An experimental device based on ultrasonic transmission mode is used to carry out measurements and the comparison with the simulation results shows a good agreement.