One-Port Quality Factor Measurement of High-Q Mems Gyroscope Utilizing Negative Impedance Converter

We propose a novel Q-factor measurement method utilizing a negative impedance converter (NIC) in the MEMS gyros for the first time. It can be regarded as a variant of the commonly used closed-loop counterpart but with only one mandatory port. It facilitates a more reliable Q-factor measurement of the sense resonator in an open-loop MEMS gyro, where the force electrode is unavailable. Its build-up time can be shortened to 0.16s with a Q-factor of 15.4k by increasing the value of negative impedance. Alternatively, the build-up time can also be improved by adding noise excitation during its drive phase. This approach also applies to the drive resonator, and two pairs of drive and detection caps can both be utilized to provide 2x extra gain factor.