SAW Resonator Sensor Matching Network for Compact Acceleration Monitoring
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Solution Overview
Problem
Existing surface acoustic wave sensors occupy a large volume and require a bigger piezoelectric substrate to monitor multiple acceleration values, leading to increased manufacturing costs and reduced miniaturization suitability, along with high insertion loss and lower flexibility due to dual-direction energy loss in surface acoustic wave delay line structures.
Innovation Solution
A surface acoustic wave resonator type vibration sensor with a matching network comprising capacitors and inductors connected in series or parallel, an acceleration detection circuit with branch circuits connected in parallel to the matching network, and an elastic switch component in each branch circuit, allowing for efficient acceleration monitoring without increasing the substrate area and minimizing energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple reflection gratings are set on the piezoelectric substrate to monitor multiple acceleration values, then the monitoring capability is improved, but the substrate area and manufacturing cost increase
Solution Approach 1:
The patent implements multi-functionality by enabling a single reflection grating to monitor multiple acceleration values through the acceleration detection circuit with branch circuits. The circuit is designed to connect different numbers of branch circuits in parallel under different acceleration conditions, allowing one grating to perform what previously required multiple gratings.
Solution Approach 2:
The patent introduces an acceleration detection circuit as an intermediary between the reflection grating and the matching network. This circuit includes branch circuits with elastic switch components that act as mediators to change the electrical connection state based on acceleration conditions, enabling multiple acceleration values to be monitored through a single grating.
2Loss of energy
If the distance between reflection grating and interdigital transducer is increased, then the energy reflection is improved, but the insertion loss increases and wireless enquiry distance decreases
Solution Approach 1:
The patent changes the electrical parameters in the matching network through the acceleration detection circuit. By connecting different numbers of branch circuits in parallel under different acceleration conditions, the electrical characteristics are adjusted to optimize energy transfer and reflection, compensating for the effects of grating-transducer distance.
3Adaptability or versatility
If surface acoustic wave delay line structure is used, then the RFID functionality is achieved, but dual-direction energy loss occurs leading to high insertion loss
Solution Approach 1:
The patent replaces the mechanical delay line structure with a resonator-type structure combined with an electrical acceleration detection circuit. This substitution eliminates the dual-direction energy loss inherent in delay line structures while maintaining RFID functionality through the interdigital transducer and matching network.
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 results in a compact circuit structure with reduced space occupation, cost savings, and improved flexibility by allowing multiple acceleration values to be monitored without increasing the sensor's volume, while maintaining efficient energy transfer and reflection.
Implementation Method 1
the interdigital transducer is used to conduct the sound-electronic interconversion
Implementation Method 2
The elastic component connects to the measurement reflection grating and constitute a normal open circuit. When the sensed vibration acceleration exceeds a pre-set threshold, the measurement reflection grating and the elastic component and the matching network constitute a close circuit together
Data Source
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AI summary
The present invention discloses a surface acoustic wave resonator type vibration sensor and vibration detection system, said surface acoustic wave resonator type vibration sensor comprising a first antenna, a matching network, a reflection grating, and an interdigital transducer, with at least said reflection grating and said interdigital transducer assembled on a piezoelectric substrate, characterized in that said matching network comprising an optimal matching network which is composed of at least one capacitor and at least one inductor, said optimal matching network also connecting an acceleration detection circuit in parallel, said acceleration detection circuit comprising multiple branch circuits connected in parallel, different number of branch circuits being connected to said optimal matching network under different acceleration conditions. With the setup of the acceleration detection circuit in the matching network, the surface acoustic wave resonator type vibration sensor of present invention has a simple circuit structure, occupies a small space, does not require extra area on piezoelectric substrate, and is beneficial to costs saving.