High Quality Factor Mode Ordered Dual Foucault Pendulum Gyroscope

This paper presents the implementation of a coupling mechanism on dynamically-balanced Dual Foucault Pendulum (DFP) gyroscopes, ordering the anti-phase and in-phase modes of vibration. A wide frequency separation is achieved between the desired anti-phase and the spurious in-phase resonance. Mode ordering of dual mass tuning fork gyroscopes provides isolation of the anti-phase resonance, resulting in the reduction of energy losses through mode conversion and improves common-mode rejection. A mode ordered Dual Foucault Pendulum (DFP) gyroscope at an operational frequency of 15 kHz was fabricated using the wafer-level epitaxial silicon encapsulation process. The quality factor higher than 700,000 was achieved after vacuum sealing with an activated getter. The coupling mechanism was explained and initial rate characterization of the device was reported.