Laminated Acoustic Wave Structure for Fractional Bandwidth Tuning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional acoustic wave devices face difficulties in adjusting their fractional bandwidth to suit various communication bands, limiting their effectiveness as filters.
Innovation Solution
The acoustic wave device incorporates a multilayer structure with alternately laminated rotated Y-cut lithium tantalate and lithium niobate layers, allowing for easy adjustment of the fractional bandwidth by varying the number of these layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single piezoelectric layer is used, then the device structure is simple, but the fractional bandwidth cannot be sufficiently broadened and cannot be adjusted to values suitable for filter devices
Solution Approach 1:
The piezoelectric layer is segmented into multiple thin films (lithium tantalate and lithium niobate layers) with different piezoelectric coefficients. By dividing the single layer into alternating layers of different materials, the device achieves adjustable fractional bandwidth while maintaining a manageable structure. The number of layers can be varied to control the bandwidth characteristic.
Solution Approach 2:
The invention uses composite piezoelectric materials consisting of alternating lithium tantalate and lithium niobate layers. These composite structures combine the advantages of different piezoelectric materials to achieve customizable fractional bandwidth. The composite nature allows tuning of acoustic wave properties by adjusting layer composition and thickness.
2Adaptability or versatility
If alternating lithium tantalate and lithium niobate layers are used, then the fractional bandwidth can be adjusted, but the manufacturing process becomes more complex
Solution Approach 1:
The piezoelectric layer is segmented into multiple thin films (lithium tantalate and lithium niobate layers) with different piezoelectric coefficients. By dividing the single layer into alternating layers of different materials, the device achieves adjustable fractional bandwidth while maintaining a manageable structure. The number of layers can be varied to control the bandwidth characteristic.
Solution Approach 2:
The invention adjusts the fractional bandwidth by changing parameters such as the number of alternating layers, layer thickness, and material composition ratio. These parameter changes allow continuous tuning of the bandwidth characteristic without fundamentally changing the device architecture, facilitating manufacturing flexibility.
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
This configuration enables flexible adjustment of the fractional bandwidth over a wide range, reducing unwanted Rayleigh mode waves and improving frequency-temperature characteristics, making the device more suitable for high-frequency filtering applications.
Implementation Method 1
The piezoelectric layer includes at least one rotated Y-cut lithium tantalate layer and at least one rotated Y-cut lithium niobate layer alternately laminated
Data Source
AI summary
An acoustic wave device includes a support substrate, a piezoelectric layer directly on or indirectly above the support substrate, and an IDT electrode on the piezoelectric layer. The piezoelectric layer includes at least one rotated Y-cut lithium tantalate layer and at least one rotated Y-cut lithium niobate layer alternately laminated. A total number of the lithium tantalate layers and the lithium niobate layers is three or more.