Performance characterization of a new temperature-robust gain-bandwidth improved MEMS gyroscope operated in air

Abstract

This paper reports a new MEMS vibratory rate gyroscope designed with increased robustness to fabrication imperfections and variations in environmental conditions. The proposed architecture utilizes a single degree-of-freedom (DOF) drive-mode and a fully coupled 2-DOF sense-mode. The drive-mode operational frequency and the sense-mode bandwidth can be set independently, relaxing the tradeoff between the gain, die size, and detection capacitance inherent to the previously reported robust gyroscopes with dynamic vibration absorber (DVA) architecture of the 2-DOF sense-mode. Prototypes with 2.5 kHz operational frequency were extensively characterized in air and demonstrated sense-mode 3 dB bandwidth of 250 Hz. The uncompensated temperature coefficients of bias and scale factor were 313 ( ° /h)/ ° C and 351 ppm ° C, respectively. Using off-chip detection electronics, the rate sensitivity was 28 μ V/( ° /s), ARW – 0.09 ( ° /s)/ Hz , bias instability – 0.08 ( ° /s), and ARRW – 0.03 ( ° /s) Hz . Detailed time domain, Allan variance, and probability density function analysis revealed that both ARW and ARRW are of Gaussian type and Coriolis-uncorrelated, showing stable in-operational noise performance of the reported gyroscope.