TRAPPED-ENERGY VIBRATORY GYROSCOPES USING ROTATED Y-CUT LINBO3

In a rotated Y-cut plate of class (3m) crystal such as LiNbO3 and LiTa O3, two orthogonal thickness-shear vibrations can be excited independe ntly, by electric fields perpendicular and parallel to the plate surfa ce. Using the trapped-energy thickness-shear vibrations, vibratory gyr oscopes of easy support with no need of trimming are expected to be re alized. In this paper, a trapped-energy vibratory gyroscope using a ro tated Y-cut of LiNbO3 is proposed. It is shown experimentally that by choosing appropriate electrode dimensions the resonance frequencies of the two orthogonal thickness-shear vibrations almost coincide with ea ch other, and the energy of the thickness-shear vibrations is trapped around the electrodes. The basic characteristics of a vibratory gyrosc ope using a 163 degrees rotated Y-cut LiNbO3 plate, about 2 mm thick, is presented.