Coupled Bulk-Mode MEMS Resonator Array for High-Frequency Q Retention
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Solution Overview
Problem
High-quality microelectromechanical resonators face challenges in achieving higher frequencies due to scaled-down dimensions, which result in reduced driving and sensing capacitances, impacting signal strength and the 'Q' factor.
Innovation Solution
A MEMS array structure comprising multiple bulk mode resonators mechanically coupled through resonator coupling sections, with anchor coupling sections and stress/strain relief mechanisms to enhance oscillation and reduce energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the dimensions of resonators are scaled smaller to achieve higher frequencies, then the operating frequency is improved, but the driving and sensing capacitances are reduced, impacting signal strength and Q factor
Solution Approach 1:
Multiple resonators are merged into a coupled resonator system where they share common anchor points. This merging allows the resonators to collectively provide sufficient capacitance for strong driving and sensing signals while maintaining their individual high-frequency oscillation capabilities, thus resolving the contradiction between high frequency operation and adequate signal strength
Solution Approach 2:
The resonator system is segmented into multiple independently oscillating resonators that are coupled through shared anchors. Each resonator can be optimized for high frequency operation with minimal mass, while the collective system provides the necessary capacitance, separating the requirements of high frequency from high signal strength
2Strength
If resonators are mechanically coupled to the substrate, then structural support is provided, but energy is lost to the substrate and stress is communicated between resonators
Solution Approach 1:
The common anchor points serve as intermediaries between the resonators and the substrate. These anchors provide the necessary structural support while being designed to minimize energy transfer to the substrate and isolate stress between resonators, thus mediating between the need for structural support and the need to minimize energy loss
Solution Approach 2:
The harmful function of the substrate (energy dissipation and stress communication) is extracted from the useful function (structural support). By carefully designing the anchor mechanisms, the substrate's supportive role is maintained while its harmful energy-sinking and stress-transmitting properties are eliminated
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 solution improves signal strength and maintains a high 'Q' factor by minimizing energy loss and stress communication between resonators and the substrate, enabling efficient operation at higher frequencies.
Implementation Method 1
at least one resonator coupling section including a first resonator coupling section disposed between the first bulk mode resonator and the second bulk mode resonator to mechanically couple the first bulk mode resonator and the second bulk mode resonator
Implementation Method 2
the first anchor coupling section includes a spring
Implementation Method 3
the first anchor coupling section includes at least one stress/strain relief mechanism
Implementation Method 4
the plurality of bulk mode resonators have a first state of oscillation in which the first bulk mode resonator is contracted, at least in part, in at least one of a first direction and a second direction, and expanded, at least in part, in at least one of a third direction and a fourth direction
Data Source
AI summary
A MEMS array structure including a plurality of bulk mode resonators may include at least one resonator coupling section disposed between the plurality of bulk mode resonators. The plurality of resonators may oscillate by expansion and/or contraction in at least one direction/dimension. The MEMS array structure may include a plurality of sense electrodes and drive electrodes spaced apart from the plurality of bulk mode resonators by a gap. The MEMS array structure may further include at least one anchor coupling section disposed between the at least one resonator coupling section and a substrate anchor.