PSpice circuital modelling of ultrasonic imaging transceivers including frequency-dependent acoustic losses and signal distortions in electronic stages.

A new global circuital model is proposed taking into account some piezoelectric and electronic non-ideal aspects of the broadband ultrasonic transceivers used in NDT and imaging applications. A quadratic approach, alternative to previous linear Spice implementations, is proposed for the frequency dependence of the mechanical losses into the piezoelectric sections. Non-ideal frequency-dependent electrical effects influencing excitation circuitry performance, and attenuations in the propagation medium varying with frequency, are also considered. Results calculated, by using PSpice implementations, from conventional and the new modelling approaches show how the quadratic option to calculate losses clearly reduces the rippled and sharpened waveforms typically originated in many echo-signals simulations, and which are not observed in real measured responses. Experimental waveforms for driving spikes and for echo-signals, in very good agreement with responses simulated from the new modelling here proposed, are also shown.