Doughnut Resonator Spurious Mode Attenuation for High Q
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Solution Overview
Problem
MEMS resonators with doughnut-shaped vibrators and single anchor parts often generate spurious modes, leading to a reduction in the Q factor of the main vibration mode used for gyro operations.
Innovation Solution
Incorporating an attenuation mechanism with lower electrodes and controllers that selectively suppress the vibration of spurious modes by controlling capacitance differences, thereby reducing energy transfer from the main mode to the spurious mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a doughnut-shaped vibrator with a single anchor part is used, then the device complexity is reduced and ease of manufacture is improved, but spurious modes are generated and the Q factor of the main mode deteriorates
Solution Approach 1:
An attenuation mechanism is introduced as an intermediary component between the vibrator and the anchor part. This mechanism selectively attenuates spurious modes through controlled mechanical coupling, allowing the simple doughnut-shaped vibrator structure to maintain high Q factor by suppressing unwanted vibrations without complicating the basic design
Solution Approach 2:
The attenuation mechanism changes the mechanical parameters of the system by providing selective coupling strength to different vibration modes. By adjusting the coupling parameters, spurious modes are attenuated while the main mode operates with high Q factor, resolving the contradiction between structural simplicity and vibration quality
2Device complexity
If a doughnut-shaped vibrator with a single anchor part is used, then the device structure is simplified, but spurious modes are generated and energy loss increases
Solution Approach 1:
The attenuation mechanism serves as a mediator that selectively couples to spurious modes and converts their energy to heat or other non-useful forms. This allows the simplified doughnut-shaped vibrator to maintain energy in the main mode by directing spurious mode energy away, reducing overall energy loss without adding complex structures
Solution Approach 2:
The attenuation mechanism converts the harmful spurious mode vibrations into beneficial selective damping. By intentionally introducing controlled energy dissipation pathways for spurious modes only, the system transforms what would be harmful energy loss into a protective mechanism that preserves main mode energy, maintaining low overall energy loss despite the simplified structure
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively maintains a high Q factor for the main vibration mode by minimizing the impact of spurious modes, enhancing the resonator's operational efficiency and accuracy.
Implementation Method 1
an attenuation mechanism which selectively attenuates vibration of a spurious mode mechanically that is coupled to a first mode when the vibrator vibrates in the first mode
Implementation Method 2
A vibrator having an opening at the center thereof (doughnut shaped vibrator) can be hold on a substrate by using a single anchor part and spring portions
Data Source
AI summary
According to one embodiment, a resonator is disclosed. The resonator includes a vibrator and an attenuation mechanism. The attenuation mechanism selectively attenuates vibration of a spurious mode that is mechanically coupled to a first mode when the vibrator vibrates in the first mode.