Novel gyroscopic mounting for crystal oscillator (payload) applied in high dynamic host vehicle (platform) to improve its output stability

Abstract

When crystal oscillator applied in high dynamic host vehicle, dynamic loads impact its short and medium-term stability. In order to suppression and/or reduction these impacts, gyroscopic mounting is proposed to install oscillator on it. One of the main parameters which affect dynamic loads impacts on oscillator output is crystal g-sensitivity vector. Therefore, at first, statistical study has been accomplished on this parameter for SC-cut crystals which used in high dynamic oscillators. This study reveals that the angle between this vector and crystal surface (φ) nearly follows Rayleigh distribution with 1σ=19°. Thus, this vector tends to be close to crystal surface not perpendicular to it. Furthermore the analysis results of using gyro-mounting shows the acceptable results for quartz crystals with |φ|<;2σ=38° (85%). To prove gyro efficiency, its effect on each dynamic load is analyzed separately. The results of related analyses reveal that gyro shows its best for attitude change of host vehicle, such that it totally suppresses relevant disturbances. In the case of steady state load, sinusoidal and random vibrations, gyro best effects appear for |φ|<;30° and β angles which are not too close to 90°. Totally when high dynamic crystal oscillator is installed on gyro-mounting, the probability of observing instability on its output is reduced.