Trapped-energy vibratory gyroscopes using rotated Y-cut LiNbO3

In a rotated Y-cut plate of class (3m) crystal such as LiNbO3 and LiTaO3, two orthogonal thickness-shear vibrations can be excited independently, by electric fields perpendicular and parallel to the plate surface. Using the trapped-energy thickness-shear vibrations, vibratory gyroscopes of easy support with no need of trimming are expected to be realized. In this paper, a trapped-energy vibratory gyroscope using a rotated 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 each other, and the energy of the thickness-shear vibrations is trapped around the electrodes. The basic characteristics of a vibratory gyroscope using a 163 degrees rotated Y-cut LiNbO3 plate, about 2 mm thick, is presented.