Design trade-offs of micromachined gyroscope concept allowing interchangeable operation in both robust and precision modes

This paper presents design trade-offs for a z-axis gyroscope allowing interchangeable operation in either precision or robust modes. This is enabled through a complete 2-DOF sense mode which allows the specification of the peak spacing and degree of coupling independent of frequency. Simulated sense mode frequency responses for various coupling amounts indicate that weakly coupled systems are desirable due to the larger precision mode gain increase (over 20 dB) for atmospheric pressure operation. Experimentally measured sense mode frequency responses for strong and weak coupling confirm the simulation results in air while also revealing that strong coupling is desirable at vacuum due to the increased precision mode gain improvement of over 40 dB while leaving the robust mode relatively unaffected.