MEMS Resonator With Intermediary Base Structure For Frequency Stability
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Solution Overview
Problem
Existing resonance devices using MEMS technology experience frequency shift and phase noise due to vibration damping, which distorts the resonant waveform and affects resonance characteristics, especially at large amplitudes.
Innovation Solution
A resonator design with multiple vibrating arms undergoing out-of-plane bending in different phases, featuring a specific base and connecting structure that minimizes torsional moments and vibration leakage, including a holding portion and holding arms to reduce frequency shift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If vibrating arms undergo large amplitude vibrations in opposite phases, then vibration energy is sufficient for operation, but resonant frequency shifts and phase noise increase due to torsional moments and vibration damping
Solution Approach 1:
A base portion is introduced as an intermediary component between the vibrating arms and the support structure. This base portion absorbs and isolates the torsional moments generated by opposite-phase vibrations, preventing them from being transmitted to the support structure. The base portion acts as a mediator that decouples the vibration source from the damping structure, thereby maintaining resonant frequency stability while allowing large amplitude vibrations to occur.
Solution Approach 2:
The support structure is segmented into distinct components: the base portion that receives vibrations from the vibrating arms, and the support structure proper that provides mechanical support. This segmentation allows the base portion to be optimized for vibration isolation while the support structure is optimized for structural stability, resolving the contradiction between vibration energy and frequency stability.
2Device complexity
If a simple base structure is used to connect vibrating arms to support, then device complexity is reduced, but vibration damping causes resonant waveform distortion and frequency shift
Solution Approach 1:
The base portion serves as an intermediary element that is strategically positioned between the vibrating arms and the support structure. It provides a controlled interface that manages vibration transmission, allowing the overall structure to remain relatively simple while achieving the desired vibration isolation effect. The base portion's geometry can be optimized without significantly increasing overall device complexity.
Solution Approach 2:
The base portion's physical parameters (such as its dimensions, material properties, and geometric configuration) are optimized to provide appropriate vibration damping characteristics. By carefully selecting these parameters, the base portion can reduce vibration transmission to acceptable levels while maintaining structural simplicity and avoiding excessive complexity in the overall design.
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
The design effectively suppresses resonant frequency shift and enhances vibration characteristics by dispersing rotational moments and reducing vibration leakage, thereby improving the resonance device's performance.
Implementation Method 1
a plurality of vibrating arms each of which has a fixed end and an open end and among which at least two vibrating arms undergo out-of-plane bending in different phases
Implementation Method 2
a torsional moment about a center axis extending in parallel to a Y axis is generated on each of the vibrating arms
Implementation Method 3
some extent of the vibration is damped in the base. The present inventors have found that this damping of the vibration distorts a resonant waveform and shifts a resonant frequency
Data Source
AI summary
The resonator includes a vibrating portion that has three or more vibrating arms each having a fixed end and an open end and at least two vibrating arms undergoing out-of-plane bending in different phases. Moreover, the resonator includes a first base portion having a first front end connected to the fixed ends and a first rear end facing the first front end, a second base portion having a second front end facing the first rear end and a second rear end facing the second front end, and a connecting portion connected between a vicinity of a center of the first rear end and a vicinity of a center of the second front end, a holding portion that is provided in at least a part of a periphery of the vibrating portion, and a holding arm that is provided between the vibrating portion and the holding portion.