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Zeitschriftenartikel:

A. Kulygin, Ch. Kirsch, P. Schwarz, U. Schmid, H. Seidel:
"Decoupled Surface Micromachined Gyroscope With Single-Point Suspension";
Journal Of Microelectromechanical Systems, 21 (2012), 1; S. 206 - 216.



Kurzfassung deutsch:
This paper focuses on the performance of a new micromechanical gyroscope for automotive and consumer applications.
Its most characteristic properties are a single-point mechanical suspension, seismic masses vibrating in antiphase tuning fork
motion, as well as the spatial separation of the drive oscillator and the sense oscillator for minimizing electromechanical crosstalk
between drivemode and sensemode. In detail, nonlinearities in the damping behavior of the drive unit were measured and analyzed
theoretically. They can be attributed to fringe field effects in the comb drive unit. New design rules were defined to overcome this
effect. Furthermore, an ambient pressure level of 1 mbar was found to yield optimum sensitivity of the sensor element for a
given excitation amplitude of the drive unit. Further reduction of pressure does not improve the results. The temperature-dependent
performance of the gyroscope was measured at an ambient pressure of 3 mbar. The temperature coefficient of frequency was
measured to be −45.3 ppm/K for the drive mode (bending) and −35.5 ppm/K for the sense mode (torsional). The temperature
coefficient of sensitivity was determined to be −858 ppm/K in the case of operating with constant drive amplitude. This value could
be reduced to 17.5 ppm/K over the full observed temperature range by adapting the drive amplitude as a linear function of temperature
in an optimal way. The resolution limit of the sensor element was found to be about 0.08◦/s/√Hz at application-relevant
ambient pressure levels ranging from 1 to 10 mbar.

Kurzfassung englisch:
This paper focuses on the performance of a new micromechanical gyroscope for automotive and consumer applications.
Its most characteristic properties are a single-point mechanical suspension, seismic masses vibrating in antiphase tuning fork
motion, as well as the spatial separation of the drive oscillator and the sense oscillator for minimizing electromechanical crosstalk
between drivemode and sensemode. In detail, nonlinearities in the damping behavior of the drive unit were measured and analyzed
theoretically. They can be attributed to fringe field effects in the comb drive unit. New design rules were defined to overcome this
effect. Furthermore, an ambient pressure level of 1 mbar was found to yield optimum sensitivity of the sensor element for a
given excitation amplitude of the drive unit. Further reduction of pressure does not improve the results. The temperature-dependent
performance of the gyroscope was measured at an ambient pressure of 3 mbar. The temperature coefficient of frequency was
measured to be −45.3 ppm/K for the drive mode (bending) and −35.5 ppm/K for the sense mode (torsional). The temperature
coefficient of sensitivity was determined to be −858 ppm/K in the case of operating with constant drive amplitude. This value could
be reduced to 17.5 ppm/K over the full observed temperature range by adapting the drive amplitude as a linear function of temperature
in an optimal way. The resolution limit of the sensor element was found to be about 0.08◦/s/√Hz at application-relevant
ambient pressure levels ranging from 1 to 10 mbar.


"Offizielle" elektronische Version der Publikation (entsprechend ihrem Digital Object Identifier - DOI)
http://dx.doi.org/10.1109/JMEMS.2011.2170816


Erstellt aus der Publikationsdatenbank der Technischen Universität Wien.