Piezoelectric Resonator Electrode Offset for Vibration Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional piezoelectric resonators with width-expansion vibration mode fail to achieve optimal resonator characteristics due to inner vibration regions being influenced by adjacent regions, causing end portions on center lines to not act as true node points, leading to insufficient performance.
Innovation Solution
A resonator design featuring a rectangular vibrating plate with four vibration regions arranged in a row, where the center lines of electrode films and support portions are displaced from the center lines of the vibration regions, allowing for improved phase opposition and enhanced contour vibration, thereby optimizing resonator characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If support portions are connected to end portions on center lines of inner vibration regions, then the structure is simple and easy to manufacture, but the resonator characteristics are insufficient because the end portions do not serve as true node points
Solution Approach 1:
The patent applies asymmetry by displacing the support portions from the center lines of the inner vibration regions. Specifically, the support portions are positioned at asymmetric locations relative to the vibration regions, allowing them to connect to true node points that are offset from the geometric centers. This asymmetric positioning ensures that the support portions connect to points of minimum displacement, thereby improving resonator characteristics while maintaining manufacturing feasibility.
2Device complexity
If vibration regions are disposed on opposite sides of inner vibration regions, then the structure is symmetric and easy to manufacture, but the inner vibration regions are influenced by displacement of adjacent regions causing insufficient resonator characteristics
Solution Approach 1:
The patent introduces asymmetry into the symmetric structure by displacing the support portions from the center lines of the inner vibration regions. This asymmetric modification allows the support portions to connect to true node points that are offset from the geometric centers, thereby reducing the influence of adjacent vibration regions on the inner vibration regions and improving resonator characteristics without significantly increasing device complexity.
Solution Approach 2:
The patent applies local quality by making the support portions have different positioning characteristics relative to different vibration regions. Specifically, the support portions are positioned to connect to node points of the inner vibration regions, which are located at specific offset positions from the center lines. This localized adjustment optimizes the connection points for each vibration region, thereby improving overall resonator characteristics.
3Device complexity
If center lines of electrode films coincide with center lines of vibration regions, then the electrode structure is simple, but the phase opposition between adjacent vibration regions is not optimized leading to vibration loss
Solution Approach 1:
The patent applies asymmetry by displacing the center lines of the electrode films from the center lines of the vibration regions. The electrode films are positioned at asymmetric locations that correspond to the true node points of the vibration regions. This asymmetric positioning optimizes the phase opposition between adjacent vibration regions, ensuring that maximum voltage differences are applied across regions that need to vibrate in opposite phases, thereby reducing vibration loss.
Solution Approach 2:
The patent applies local quality by making the electrode films have different positioning characteristics relative to different vibration regions. Specifically, the electrode films are positioned to align with the node points of their corresponding vibration regions, which are located at specific offset positions from the geometric centers. This localized optimization ensures that each electrode film applies electric fields at the most effective locations for generating phase opposition, thereby minimizing vibration loss.
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 displacement of electrode film and support portion center lines within the resonator improves vibration efficiency and minimizes vibration loss, resulting in enhanced resonator characteristics compared to conventional designs.
Implementation Method 1
A piezoelectric resonator that vibrates in a so-called width-expansion vibration mode
Data Source
AI summary
A resonator includes a support frame, a rectangular vibrating plate that performs contour vibration in a predetermined direction, and two pairs of support arms. The vibrating plate includes four vibration regions arranged in a row in the lengthwise direction and electrodes disposed in the vibration regions. Each of the vibration regions vibrate with a phase opposite to phases with which the adjacent vibration regions vibrate upon excitation. A center line of a pair of the electrodes in the lengthwise direction is offset from a center line, in the lengthwise direction, of a corresponding vibration region that includes the electrode disposed thereon.