CORDIC-based implementation architectures for the second-harmonic excitation of a micro-gyroscope

This paper presents a novel drive strategy for the drive mode of a micro-gyroscope using second-harmonic excitation, which drives the resonator with a pair of orthogonal signals at half the resonant frequency and senses the vibration signal at the full resonant frequency, thus realizing the frequency isolation between the actual mechanical response and electrical crosstalk signal. This approach is mainly implemented using the coordinate rotation digital computer (CORDIC) algorithm and is applied to drive a slot-structure micro-gyroscope. The behavior of the second-harmonic resonance is compared with that of the normal resonance. Test results show that the non-ideal electrical antiresonance peak caused by electrical crosstalk is removed and the resonant peak height is increased by approximately 9dB over a 600Hz span using the second-harmonic excitation.