IDT Electrode Layout for Reducing Transverse Mode Spurious
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Solution Overview
Problem
Existing acoustic wave devices with piezoelectric layers and interdigital transducers (IDT) electrodes face challenges in reducing transverse mode spurious, which affects the efficiency of acoustic wave conversion and signal processing.
Innovation Solution
The acoustic wave device incorporates a unique IDT electrode configuration with busbars, electrode fingers, bar electrodes, and connection portions arranged in a specific pattern to disperse reflection positions of transverse mode spurious, reducing their reinforcement and enhancing signal conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional IDT electrode configuration is used, then the device structure is simple, but transverse mode spurious are reinforced and signal processing efficiency deteriorates
Solution Approach 1:
The IDT electrode is segmented into multiple functional components: busbars, electrode fingers, bar electrodes, and connection portions. This segmentation allows each component to serve a specific function in dispersing transverse mode spurious while maintaining overall device performance. The bar electrodes are divided into multiple segments arranged in a specific pattern to achieve spurious dispersion without excessive complexity.
Solution Approach 2:
Different regions of the IDT electrode are assigned different structural qualities. The connection portions are disposed in a discontinuous manner at specific locations to create local variations in the electrode structure. This local quality differentiation enables targeted dispersion of transverse mode spurious at critical reflection positions while maintaining simple structures in other regions.
2Object-generated harmful factors
If connection portions are disposed in a continuous manner, then the manufacturing process is simpler, but transverse mode spurious are reinforced due to concentrated reflection positions
Solution Approach 1:
The connection portions are arranged in an asymmetric, discontinuous pattern rather than a continuous symmetric arrangement. This asymmetric disposition creates varied reflection positions for transverse mode spurious, preventing their reinforcement. The discontinuous arrangement with specific spacing between connection portions effectively scatters spurious energy while remaining manufacturable using standard photolithography techniques.
3Object-generated harmful factors
If bar electrodes are added to the IDT electrode structure, then transverse mode spurious are dispersed, but the device complexity increases
Solution Approach 1:
The bar electrodes are merged with the existing busbar and electrode finger structure to form an integrated IDT electrode system. The bar electrodes extend from the busbars and connect to electrode fingers, combining multiple functions into a unified structure. This merging approach disperses transverse mode spurious while avoiding the need for completely separate additional components, thus limiting the increase in device complexity.
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 effectively disperses and reduces transverse mode spurious, improving the acoustic wave device's performance by minimizing spurious components and enhancing signal processing capabilities.
Implementation Method 1
an acoustic wave device includes a piezoelectric body and an IDT electrode... capable of at least one out of converting acoustic waves to electrical signals and converting electrical signals to acoustic waves
Data Source
AI summary
An IDT electrode includes: a first busbar, a second busbar facing the first busbar, multiple first electrode fingers electrically connected to the first busbar, multiple second electrode fingers electrically connected to the second busbar and arranged in an alternating manner with the multiple first electrode fingers in an acoustic wave propagation direction, multiple bar electrodes interposed between the first busbar and the multiple first electrode fingers, and extending parallel to the first busbar and parallel to each other, multiple connection portions including a connection portion that is interposed between the first busbar and a corresponding one of the bar electrodes adjacent to the first busbar and that connects the first busbar to the corresponding bar electrode, and a connection portion that connects adjacent bar electrodes to each other. Some of the connection portions are disposed in a discontinuous manner with respect to an extension direction of the multiple electrode fingers.