SAW Resonator Electrode Overlap Structure for Spurious Mode Suppression
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Solution Overview
Problem
Traditional surface acoustic wave (SAW) resonators/filters suffer from clutter in spurious modes, which affects their performance. There is a need to improve the clutter suppression capability of these devices.
Innovation Solution
A surface acoustic wave resonator device is designed with a conductive structure that includes a body structure and a sawtooth structure. This conductive structure overlaps with the end portions of the interdigital electrodes and is configured to enhance clutter suppression by increasing the overlapping area with the interdigital electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional surface acoustic wave resonator design is used, then the device structure is simple, but clutter in spurious modes occurs which degrades performance
Solution Approach 1:
The conductive structure is segmented into multiple functional parts: a body structure for basic grounding, and multiple sawtooth structures (first and second) for targeted clutter suppression. Each segment serves a specific purpose in suppressing spurious modes while maintaining overall device functionality.
Solution Approach 2:
Sawtooth structures are strategically positioned at specific locations where clutter suppression is most needed - particularly at the ends of interdigital electrodes and in regions with strong spurious mode activity. This localized approach enhances clutter suppression capability without requiring complex structures throughout the entire device.
2Reliability
If the overlapping area between conductive structure and interdigital electrodes is increased, then clutter suppression is enhanced, but device area increases
Solution Approach 1:
The sawtooth structures extend in the thickness direction (vertical dimension) rather than only in the planar direction. This allows the conductive structure to achieve greater overlapping area with interdigital electrodes by utilizing the third dimension, thereby enhancing clutter suppression without proportionally increasing the device footprint.
Solution Approach 2:
The sawtooth structures are nested within or adjacent to the body structure, with the first and second sawtooth structures positioned at different locations and orientations. This nested arrangement maximizes the overlapping area with interdigital electrodes while minimizing the overall space occupied by the conductive structure.
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 proposed design effectively suppresses clutter in the resonator device, improving its performance by reducing energy loss and enhancing the filtering capabilities.
Implementation Method 1
a piezoelectric substrate; an interdigital transducer, disposed on a side of the piezoelectric substrate and including a plurality of interdigital electrodes
Implementation Method 2
surface acoustic wave resonator device... Clutters in spurious modes are present in traditional surface acoustic wave resonators/filters
Data Source
AI summary
A surface acoustic wave resonator device and manufacturing method therefor and filter, the surface acoustic wave resonator device includes: an interdigital transducer, disposed on a piezoelectric substrate and including first and second interdigital electrode lead-out parts, and first and second interdigital electrodes located in the body region and respectively connected to the first and second interdigital electrode lead-out parts; and a conductive structure, disposed on a side of the interdigital transducer away from the piezoelectric substrate, and at least includes a body structure and a first sawtooth structure, the body structure continuously extends across the interdigital electrodes in the second direction, the first sawtooth structure is located at a side of the body structure, and at least a portion of the body structure and the first sawtooth structure overlap with end portions of the interdigital electrodes close to a periphery region in the third direction.