Gap width influence between the electrodes of a piezoelectric resonator with a lateral electric field on its characteristics

The gap width influence between the resonator electrodes with a lateral electric field on its characteristics was experimentally investigated. The resonator represented a plate made of ceramics PZT-19 with shear dimensions of ~ 20×18 mm2. One side of the plate was covered with a film of aluminum with a gap in the center, the width of which was changed wide range. The thickness of the plate was 3.07, 2.38 and 1.9 mm. The frequency dependences of the real and imaginary parts of the electric impedance and admittance were measured, which showed the presence of three resonances in the ranges 63-73 kHz, 75-83 kHz and 91-113 kHz. It is shown that an increase in the gap width leads to an increase in the frequency of parallel and series resonances and to an increase in the maximum value of the real part of the electrical impedance. At the same time, the maximum value of the real part of the electrical admittance decreases for the first and third resonances, and increases for the second one. It was also established that with an increase in the width of the gap, the electromechanical coupling coefficient increases, reaches the maximum and then decreases for the first and third resonances. For the second resonance, the electromechanical coupling coefficient is monotonously increasing with an increase in the gap width.