Within complex sensor systems different physical effects and electronics for signal processing have to be considered in the design process. In this paper we describe an approach for system level simulation of sensor systems and its application to a gyro sensor system. The gyro sensor system consists of a polysilicon sensor element and an electronic circuit for excitation of the structure and evaluation of the sensor signal. The sensor element is fixed in the centre by flexible beams and is excited electrostatically via comb drives to perform resonant oscillations. Due to the law of conservation of angular momentum a gyration leads to an orthogonal oscillation which is evaluated as a capacitive sensor signal. For system level simulation of the sensor system we combined: Analytical models for the suspensions beams, Linear models of the rotor generated from an FEM description, Models of electrostatics. Simulation results of the static case and of the small signal response for lower eigenfrequencies show a good correspondence between the full and the reduced system. For transient simulation the sensor was stimulated with a trapeziodal gyration. The oscillating movement can be observed as a change in capacitance at the detection electrodes.
Journal: TechConnect Briefs
Volume: 3, Technical Proceedings of the 2005 NSTI Nanotechnology Conference and Trade Show, Volume 3
Published: May 8, 2005
Pages: 616 - 619
Industry sector: Sensors, MEMS, Electronics
Topic: MEMS & NEMS Devices, Modeling & Applications