A symmetric surface micromachined gyroscope with decoupled oscillation modes

Alper, Said Emre
Akın, Tayfun
This paper reports a new symmetric gyroscope structure that allows not only matched resonant frequencies for the drive and sense vibration modes for better resolution, but also decoupled drive and sense oscillation modes for preventing unstable operation due to mechanical coupling. The symmetry and decoupling features are achieved at the same time with a new suspension beam design. The gyroscope structure is designed using a standard three-layer polysilicon surface micromachining process (MUMPs) and simulated using the MEMCAD software. Measured results show that the drive and sense mode resonant frequencies are 28,535Hz and 30,306Hz, respectively, which are in agreement with the finite element simulations. The small mismatch can be reduced further by applying different DC bias voltages to the drive and sense electrodes, improving the performance. The performance of the fabricated sensor is limited due to large parasitic capacitance between the proof mass and the substrate, nevertheless, measurements and calculations show that the sensor can sense angular rates as small as 0.37 deg/sec even in atmospheric pressure. A capacitive readout circuit for the sensor was also developed in a 0.8mm CMOS process, and the fabricated circuit detects capacitance changes smaller than 0.1fF with a sensitivity of 45mV/fF.


A high performance automatic mode-matched MEMS gyroscope with an improved thermal stability of the scale factor
Sonmezoglu, S.; Alper, S.E.; Akın, Tayfun (2013-06-20)
This paper presents a high performance, automatic mode-matched, single-mass, and fully-decoupled MEMS gyroscope with improved scale factor stability. The mode-matching system automatically achieves and maintains the matching between the drive and sense mode resonance frequencies with the help of dedicated frequency tuning electrodes (FTEs). This method isolates the drive and sense mode frequency response dynamics by keeping the proof mass voltage (V PM ) constant, improving the scale factor stability up to ...
A high-performance silicon-on-insulator MEMS gyroscope operating at atmospheric pressure
Alper, Said Emre; Azgın, Kıvanç; Akın, Tayfun (Elsevier BV, 2007-03-30)
This paper presents a new, high-performance silicon-on-insulator (SOI) MEMS gyroscope with decoupled oscillation modes. The gyroscope structure allows it to achieve matched-resonance-frequencies, large drive-mode oscillation amplitude, high sense-mode quality factor, and low mechanical cross-talk. The gyroscope is fabricated through the commercially available SOIMUMPS process of MEMSCAP Inc. The fabricated gyroscope has minimum capacitive sense gaps of 2.6 mu m and a structural silicon thickness of 25 mu m,...
A single-crystal silicon symmetrical and decoupled MEMS gyroscope on an insulating substrate
Alper, Said Emre; Akın, Tayfun (2005-08-01)
This paper presents a single-crystal silicon symmetrical and decoupled (SYMDEC) gyroscope implemented using the dissolved wafer microelectromechanical systems (MEMS) process on an insulating substrate. The symmetric structure allows matched resonant frequencies for the drive and sense vibration modes for high-rate sensitivity and low temperature-dependent drift, while the decoupled drive and sense modes prevents unstable operation due to mechanical coupling, achieving low bias-drift. The 12-15-mu m-thick si...
An Automatically Mode-Matched MEMS Gyroscope With Wide and Tunable Bandwidth
Sonmezoglu, Soner; Alper, Said Emre; Akın, Tayfun (Institute of Electrical and Electronics Engineers (IEEE), 2014-04-01)
This paper presents the architecture and experimental verification of the automatic mode-matching system that uses the phase relationship between the residual quadrature and drive signals in a gyroscope to achieve and maintain matched resonance mode frequencies. The system also allows adjusting the system bandwidth with the aid of the proportional-integral controller parameters of the sense-mode force-feedback controller, independently from the mechanical sensor bandwidth. This paper experimentally examines...
An Optimized Analog Drive-Mode Controller for Vibratory MEMS Gyroscopes
Eminoglu, Burak; Alper, Said Emre; Akın, Tayfun (2011-09-07)
This paper presents an optimized analytical design procedure for the drive mode analog controllers used in vibratory MEMS gyroscopes. The behaviour of the controller during start-up is analyzed in detail including the effect of the limited voltage swing of the controller circuitry. As a result, an optimum design procedure is developed for controller design, which is also experimentally verified in a practical implementation demonstrating a settling time of only 50msec without any overshoot, for a gyroscope ...
Citation Formats
S. E. Alper and T. Akın, “A symmetric surface micromachined gyroscope with decoupled oscillation modes,” 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34854.