Noise-based optimization and noise analysis for resonant MEMS structures
Publication Type:Journal Article
Source:12th Annual Meeting PCAMM 2007, Vancouver, BC, Canada (2007)
A design for high sensitivity of MEMS structures needs to take into account the noise shaping induced by damping phenomena at micro scale. The existing scientific literature analyzes the mechano-thermal noise in microstructures based on the assumption of a constant damping coefficient . This might be a correct assumption for low-frequencies, but fails to consider the more complex behavior of gas damping as the operating frequency increases, which is the case for resonators and resonating sensors. There are nevertheless detailed models of the combined elasto-damping action of the gas upon the movable plate in the case of squeeze-film damping, but without considering its impact on noise analysis . This work bridges these two aspects, and presents a noise analysis and optimization process based on simulated behavior of a MEMS resonating sensor. This methodology also optimizes the signal to noise ratio by exploiting the spectral noise shaping of the equivalent input noise source and tuning the mechanical suspensions to an optimal value.