Impact of BAW Gyroscope’s Proof Mass Perforation Shape on Matching Frequency of Its Drive and Sense Modes

For the balk acoustic wave (BAW) gyroscopes it is desired to maximize the matching frequency of the drive and the sense modes, since this improves the quality factor of the device. In this paper, the effect of perforation shape formed during the fabrication release steps of a BAW gyroscope upon its sense / drive mode matching frequency is examined.The Gyroscope is assumed to be a closed loop built employing SOI technology. In particular, we have considered the effects of two categories of perforation shapes. If the proof mass holes are cone-shaped with interior obtuse angle, mismatch frequency between modes becomes smaller but if cones are made with interior acute angle, mismatch frequency increases.