Design of Electronic Gyroscope

Abstract

This thesis present a micro electromechanical system-inter digital transducer (MEMS-IDT) surface acoustic wave (SAW) gyroscope with an 80MHz central frequency on a 128° YX lithium-Nobelium tri-oxide(LiNbO3) wafer. The developed MEMS-IDT gyroscope is composed of a two-port SAW resonator, a dual delay line oscillator, and metallic dots. The SAW resonator provides a stable standing wave, and the vibrating metallic dot at an anti node of the standing wave induces the second SAW in the normal direction of its vibrating axis. The dual delay line oscillator detects the Carioles effect (gyro phenomena) by comparing the resonant frequencies between two oscillators through the interference effect. The coupling of k-wave MATLAB added tool box modeling was used to extract the optimal design parameters prior to simulation. In the electrical testing by the network analyzer, the simulated SAW resonator and delay lines showed low insertion loss and similar operation frequencies between a resonator and delay lines. When the device was rotated, the resonant frequency differences between two oscillators linearly varied owing to the Carioles force. The obtained sensitivity was approximately 119 1000 in the angular rate range of 0- . Satisfactory linearity and superior directivity were also observed in the test.