Abstract: In micromachined gyros, input angular rate signals are measured indirectly from displacements by Coriolis forces or torques, and one hundredth or even one thousandth of Augstrom must be resolved resulting in micro or nano Volt electrical outputs. So the resolution of the gyro is very easily affected by error sources, which may even cause operation failure in some cases. These error sources are mainly caused by imperfections during manufacturing and special design, such as subtle imbalances in the mechanical sense element, comb drive oscillations. Some error sources special for micromachined comb drive tuning fork gyro, microstructure Brownian noise, electronic noise, mechanical coupling effects and electromechanical crosstalk, etc. are presented qualitatively in this paper. Some solutions are also discussed. The knowledge of aforementioned error sources is the basis of microstructure fabrication and circuit design.

Key words: micromachined comb-drive tuning-for k gyroscope, Brownia n noise, electronic noise, mechanicalcoupling effects, elect romechanical crosst alk