Combining Lissajous Frequency Modulation With 250 nm Piezoresistive Sensing in MEMS Gyroscope: Theoretical Advantages and Practical Challenges

The introduction of miniaturized piezoresistive sensing into Lissajous frequency modulated gyroscopes has an interesting potential to reduce noise. This letter presents the first design of such a system from both the electro-mechanical and electronics point of view and tests the system in operation. An angle random walk of 3 mdps/√hz is demonstrated, together with a full-scale range that exceeds 2000 dps for a 46 Hz split, thus corresponding to about 20 Hz system bandwidth. Experimental results also show the importance of tracking the mode-split in operation, as this largely correlates with the zero-rate output drift, leading to a stability improvement by almost a factor of 20, down to 1 °/hr.