Zheliaskova T. Diagnostic and therapeutic ultrasound piezoelectric transducers

The thesis is devoted to solving the actual problem synthesis of broadband ultrasonic piezoelectric transducers with the following parameters and characteristics that allow they use in medical diagnosis and therapy. Acoustic and electric parameters of piezoelectric transducer that operates on a radiation-receiving had been investigated in this work, and obtained the equations for calculating its transfer functions. Method of independent global search had been proposed for optimizing the parameters of a piezoelectric transducer that provide maximum bandwidth. The possibility of expanding the bandwidth of medical diagnostic piezoelectric transducer had been investigated, by way excitation by electrical pulses of a special form. Experimental model of broadband therapeutic transmitter had been designed and had been investigated frequency characteristics its electric and acoustic parameters.