MEMS Sensor Control Using Differential Resonant Phase Detection
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Solution Overview
Problem
Conventional MEMS sensor circuits are complex and expensive due to the use of electronic circuits for controlling transduction elements and processing signals, and they are often sensitive to temperature and humidity variations.
Innovation Solution
A MEMS sensor control circuit that employs a differential resonant detection method using a feedback loop and phase detection to measure accelerations, reducing complexity and cost by eliminating the need for high-precision synchronization and digital signal processing, while being less sensitive to temperature variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electronic circuits are used to control transduction elements and process signals in conventional MEMS sensors, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces electronic circuit-based signal processing with a purely mechanical differential resonant detection system. The transduction elements are driven at their resonant frequency, and acceleration is measured through mechanical phase detection of the resonant response, eliminating the need for complex electronic circuits while maintaining measurement precision.
Solution Approach 2:
The patent utilizes mechanical resonance of transduction elements as the core detection mechanism. By driving the transduction elements at their resonant frequency and measuring the phase difference in their mechanical vibrations, the system achieves precise acceleration measurement without requiring complex electronic processing circuits.
2Measurement precision
If conventional electronic circuits are used in MEMS sensors, then signal processing capability is improved, but sensitivity to temperature and humidity variations increases
Solution Approach 1:
The patent replaces electronic signal processing with mechanical resonance-based detection. The transduction elements are driven at their resonant frequency, and the measurement is based on mechanical phase differences, which are inherently less sensitive to temperature and humidity variations compared to electronic circuits.
Solution Approach 2:
The patent changes the operating parameter from electronic signal processing to mechanical resonant frequency operation. By measuring acceleration through the phase difference of mechanical vibrations at resonance, the system achieves reduced sensitivity to environmental factors while maintaining measurement capability.
3Measurement precision
If high-precision synchronization and digital signal processing are used, then measurement accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent eliminates electronic signal processing and digital processing by using purely mechanical resonance and phase detection. The differential resonant detection method measures acceleration directly through mechanical phase differences, removing the need for high-precision synchronization circuits and digital signal processing while maintaining measurement accuracy.
Solution Approach 2:
The patent uses mechanical vibration phase detection as the core measurement mechanism. By measuring the phase difference between vibrations of two transduction elements driven at their resonant frequency, the system achieves accurate acceleration measurement without requiring complex electronic synchronization or digital processing.
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 proposed control circuit achieves improved dynamic range and reduced sensitivity to environmental factors, offering enhanced accuracy and cost-effectiveness in MEMS sensor operations.
Implementation Method 1
A first resonant element and a second resonant element of an accelerometer are driven at their resonant frequency
Implementation Method 2
A phase detector measures a phase shift between vibrations of the resonant elements
Data Source
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AI summary
The present description relates to a method for controlling a micro-electromechanical sensor, comprising the following steps: exciting, by the same first signal (FSL), a first resonant element (206L) and at least one second resonant element (206R); and evaluating a phase shift (Δϕ) between the first signal and a second signal (FSR) representing vibrations of the second resonant element.