This paper reports on a new type of high-frequency mode-matched gyroscope with significantly reduced dependencies on environmental stimuli such as temperature,vibration,and shock.A novel stress-isolation system is use...This paper reports on a new type of high-frequency mode-matched gyroscope with significantly reduced dependencies on environmental stimuli such as temperature,vibration,and shock.A novel stress-isolation system is used to effectively decouple an axis-symmetric bulk-acoustic wave(BAW)vibratory gyro from its substrate,minimizing the effect that external sources of error have on the offset and scale factor of the device.Substrate-decoupled(SD)BAW gyros with a resonance frequency of 4.3 MHz and Q values near 60000 were implemented using the high aspect ratio poly and single-crystal silicon(HARPSS)process to achieve ultra-narrow capacitive gaps.Wafer-level packaged sensors were interfaced with a customized application-specific integrated circuit(ASIC)to achieve low variations in the offset across temperature(±26°s^(−1) from−40 to 85℃),supreme random-vibration immunity(0.012°s^(−1) gRMS−1)and excellent shock rejection.With a scale factor of 800μV(°s^(−1))^(−1),the SD-BAW gyro system attains a large full-scale range(±1250°s^(−1))with a non-linearity of less than 0.07%.A measured angle-random walk(ARW)of 0.39°/√h and a bias instability of 10.5°h^(−1) are dominated by the thermal and flicker noise of the integrated circuit(IC),respectively.Additional measurements using external electronics show bias-instability values as low as 3.5°h−1,which are limited by feed-through signals coupled from the drive loop to the sense channel,which can be further reduced through proper re-routing of the gyroscope pin-out configuration.展开更多
文摘This paper reports on a new type of high-frequency mode-matched gyroscope with significantly reduced dependencies on environmental stimuli such as temperature,vibration,and shock.A novel stress-isolation system is used to effectively decouple an axis-symmetric bulk-acoustic wave(BAW)vibratory gyro from its substrate,minimizing the effect that external sources of error have on the offset and scale factor of the device.Substrate-decoupled(SD)BAW gyros with a resonance frequency of 4.3 MHz and Q values near 60000 were implemented using the high aspect ratio poly and single-crystal silicon(HARPSS)process to achieve ultra-narrow capacitive gaps.Wafer-level packaged sensors were interfaced with a customized application-specific integrated circuit(ASIC)to achieve low variations in the offset across temperature(±26°s^(−1) from−40 to 85℃),supreme random-vibration immunity(0.012°s^(−1) gRMS−1)and excellent shock rejection.With a scale factor of 800μV(°s^(−1))^(−1),the SD-BAW gyro system attains a large full-scale range(±1250°s^(−1))with a non-linearity of less than 0.07%.A measured angle-random walk(ARW)of 0.39°/√h and a bias instability of 10.5°h^(−1) are dominated by the thermal and flicker noise of the integrated circuit(IC),respectively.Additional measurements using external electronics show bias-instability values as low as 3.5°h−1,which are limited by feed-through signals coupled from the drive loop to the sense channel,which can be further reduced through proper re-routing of the gyroscope pin-out configuration.
