A lateral-axis micromachined tuning fork gyroscope with novel driving and sensing combs

A decoupled lateral-axis TFG (tuning fork gyroscope) with novel driving and sensing combs is presented. The EFBD (electrostatic force balanced comb driver) adopted in the TFG can efficiently suppress the mechanical coupling in a simple manner. The structure of the gyroscope is also optimized to suppress the coupling further. Moreover, torsional sensing combs are adopted to detect the out-of-plane movement, so it can work at atmospheric pressure. The TFG was fabricated and tested at atmosphere. The measured CFDTS (coupling from driving mode to sensing mode) and CFSTD (coupling from sensing mode to driving mode) are -45 dB and -51 dB respectively. The sensitivity is 2.9 mV/deg/s while the nonlinearity is 0.9% with the full scale of 800deg/s. The noise floor is 0.035deg/s/Hz^1/2.