MODE OF EXCITATION FOR ROD-SHAPED HYDROACOUSTIC TRANSDUCER Russian patent published in 2013 - IPC H04R1/44 

FIELD: electrical engineering.

SUBSTANCE: mode of excitation for rod-shaped hydroacoustic transducer containing piezoelectric rod divided electrically into two parts with rear and front straps consists in that to the part of piezoelectric rod contacting with the rear strap exciting voltage U_t is supplied. Amplitude of this voltage is decreased at first with frequency growth and then, when it reaches its maximum value at frequency F₂ corresponding to the first even harmonic of the piezoelectric rod at in-phase excitation, amplitude is decreased symmetrically. At that phase of voltage U_t in relation to voltage U_F supplied to the other part of the piezoelectric rod is changed sequentially with growth of frequency from ±π at frequency F₀=0 up to ±π at frequency 2F₂; at that values of specific impedance z_F and thickness l_F of the front strap are selected under the following conditions: and I_F≈0.251·c_F/c, where z_k and z_c are specific impedance of piezoelectric rod material and liquid medium into which emission is carried out; 1 is a length of the piezoelectric rod; c_F and c are rates of sound in materials of the front strap and piezoelectric rod.

EFFECT: increase of passband of the rod-shaped hydroacoustic transducer by means of electrically controlled excitation of two parts of the piezoelectric rod.

2 cl, 7 dwg