Electrical coupling in microgyro is an important phenomenon which can affect its performance and reliability. The objective of this study was to characterize the influence of leakage voltages on microgyro performance. The study was performed with a vibrating microgyro, which is based on electrostatic actuation and optical sensing, and fabricated by bulk micromachining of SOI wafers. Two parameters were measured in this study: (1) amplitude ratio between leakage voltage measured on the sense pads and actuation voltage applied to the actuation pads and (2) phase shift of those voltages. It is found that the net electrostatic force exerted on the sense masses of the microgyro is quite small due to symmetry of the leakage voltages. Hence, the corresponding displacement is negligible small. Frequency dependency of the leakage voltages and resulting electrical coupling is considered as one of the mechanisms for bias short term instability and estimated to be less than 1°/hr.

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