Lamb Wave Resonator Cavity Layout for Spurious Wave Suppression
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Solution Overview
Problem
Existing acoustic wave devices using Lamb waves suffer from performance degradation due to spurious waves, which are not adequately addressed in existing technologies.
Innovation Solution
The device incorporates a support substrate with interconnected or unconnected cavities beneath resonators, each with IDT electrodes, to suppress spurious waves by allowing resonators in the same frequency band to share a cavity and those in different frequency bands to be separated, with partition walls for heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resonators using Lamb waves are employed to enhance frequency characteristics, then high-frequency performance is improved, but spurious waves are generated causing device performance degradation
Solution Approach 1:
The patent converts the harmful spurious waves into beneficial effects by designing cavities that utilize the spurious wave energy for heat dissipation. The cavities are strategically positioned to trap and dissipate spurious waves generated by the Lamb wave resonators, transforming the harmful acoustic energy into thermal energy that can be efficiently removed from the device.
Solution Approach 2:
The patent introduces cavities as intermediary structures between the piezoelectric substrate and the support substrate. These cavities act as mediators that intercept and manage spurious waves before they can cause performance degradation, while also providing thermal pathways for heat removal from the resonator region.
2Productivity
If multiple resonators are disposed in the same resonator region, then device integration is improved, but spurious wave interference increases
Solution Approach 1:
The patent merges the functionality of multiple resonators by allowing them to share common cavity structures for spurious wave management. Multiple resonators can be disposed in the same resonator region while their associated cavities work together to collectively suppress spurious waves, reducing the overall interference compared to isolated resonator-cavity pairs.
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
Effectively suppresses spurious waves in Lamb waves, enhancing device performance by attenuating unwanted acoustic waves and improving heat dissipation.
Implementation Method 1
a piezoelectric substrate supported by the support substrate and defining a first resonator region on the support substrate; and a first resonator and a second resonator, which are disposed in the first resonator region of the piezoelectric substrate, each including a plurality of interdigital transducer (IDT) electrodes
Implementation Method 2
The support substrate includes a first cavity formed beneath the first resonator and a second cavity formed beneath the second resonator, wherein the first and second cavities are interconnected within the support substrate
Data Source
AI summary
An acoustic wave device for suppressing spurious waves in Lamb waves, and a filter including the same, are provided. The acoustic wave device comprises a support substrate; a piezoelectric substrate supported by the support substrate and defining a first resonator region; and a first resonator and a second resonator disposed in the first resonator region, each comprising a plurality of interdigital transducer (IDT) electrodes and electrically connected to each other. The support substrate includes a first cavity formed beneath the first resonator and a second cavity formed beneath the second resonator, wherein the first cavity and the second cavity are interconnected within the support substrate.