The development of novel surface acoustic wave MEMS-IDT gyroscope based on standing wave mode

The objective of this paper is to present a novel surface acoustic wave (SAW) gyroscope with an 80 MHz central frequency on a 128deg YX LiNbO₃ piezoelectric substrate. The developed gyroscope is composed of a two-port SAW resonator, metallic dots (as a driving part) and a dual delay line oscillator (as a sensing part). The coupling of mode (COM) modeling was used to extract the optimal design parameters prior to fabrication. Unlike other MEMS gyroscopes, this gyroscope has a planar configuration with no suspended resonating mechanical structures, thereby resulting in robustness and good shock resistance. In the electrical testing by the network analyzer, the fabricated SAW resonator and delay lines showed low insertion loss and similar operation frequency between resonator and oscillators. When the device was rotated, the resonant frequency differences between two oscillators were linearly varied due to the Coriolis effect. In the angular rate test of the fabricated SAW gyroscope, A 119 Hzdeg^-1s^-1 sensitivity was obtained. Good linearity and superior directivity were also observed.