ON THE INFLUENCE OF THE PARAMETERS OF THE ELECTRIC EXCITATION PULSE OF A PIEZOELECTRIC PLATE OF A NORMAL PROBE ON THE CHARACTERISTICS OF THE FREQUENCY SPECTRUM AND PULSE OF THE RECORDED ECHO SIGNAL

Abstract

On the basis of computer modeling of the electro acoustic channel of a normal probe for a reflector in the form of a bottom surface, the influence of some typical forms and corresponding frequency spectra of the electric pulse of excitation of the piezoelectric plate on the characteristics of the frequency spectrum and pulse of the recorded echo signal is considered. Calculations of signals using an exciting pulse in the form of a voltage jump (step), in the form of half a sine wave and a rectangular shape have shown the feasibility of using rectangular pulses with a duration equal to half of the oscillation period at the nominal frequency of the probe. The maximum of the pulse envelope of the recorded bottom echo for the excitation pulse of a rectangular shape piezoelectric plate is approximately twice as high as the maximum of the envelope when the piezoelectric plate is excited by a pulse in the form of a jump and a quarter more than the maximum when excited by a semi sinusoidal pulse for the nominal frequencies of the probes 2.5 and 5.0 MHz.