Stacked SAW-BAW Filter Structure for Compact RF Signal Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing acoustic wave filters face challenges in achieving desirable filter performance while reducing size and cost, particularly in radio frequency electronic systems.
Innovation Solution
The proposed solution involves a stacked arrangement of surface acoustic wave (SAW) devices and bulk acoustic wave (BAW) resonators, supported by a temperature compensation layer, which allows for a compact hybrid acoustic wave filter component.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acoustic wave filters are designed to achieve desirable filter performance, then filtering effectiveness is improved, but device size increases
Solution Approach 1:
The patent transitions from planar arrangement to three-dimensional stacked configuration, placing BAW resonators vertically above SAW devices. This vertical stacking enables multiple filtering functions to coexist in the same footprint area, improving filter performance while maintaining compact device size.
Solution Approach 2:
The stacked device structure integrates multiple acoustic wave resonator types (SAW and BAW) into a single hybrid filter component. The BAW resonators and SAW devices work together to provide enhanced filtering capabilities across different frequency ranges, achieving desirable filter performance in a unified compact structure.
2Reliability
If acoustic wave filters are designed to achieve desirable filter performance, then filtering effectiveness is improved, but manufacturing cost increases
Solution Approach 1:
The patent combines BAW resonators and SAW devices into a single integrated stacked structure that functions as one hybrid filter component. This merging eliminates the need for separate filter assemblies, reducing overall manufacturing complexity and cost while maintaining enhanced filtering performance.
Solution Approach 2:
The hybrid stacked filter provides multiple filtering functions within a single device, replacing what would traditionally require multiple separate filters. This multi-functionality reduces the total component count and assembly requirements, thereby lowering manufacturing costs while achieving desirable filter performance.
3Volume of moving object
If acoustic wave filters are designed to reduce size, then device compactness is improved, but filter performance deteriorates
Solution Approach 1:
The patent utilizes vertical stacking to arrange BAW resonators above SAW devices in the third dimension. This approach concentrates filtering functionality in a compact footprint while maintaining adequate separation between resonator types, ensuring both device compactness and effective filter performance are achieved simultaneously.
Solution Approach 2:
The stacked configuration nests BAW resonators within the vertical space above the SAW devices, effectively utilizing the three-dimensional space. This nesting arrangement allows multiple resonator types to coexist in a compact volume without interfering with each other's acoustic fields, preserving filter performance while reducing overall device size.
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 reduces the overall size of the filter while maintaining effective radio frequency signal filtering, offering improved design flexibility and cost-effectiveness.
Implementation Method 1
A surface acoustic wave resonator can include an interdigital transductor electrode on a piezoelectric substrate. The surface acoustic wave resonator can generate a surface acoustic wave on a surface of the piezoelectric layer
Implementation Method 2
An acoustic wave filter can include a plurality of resonators arranged to filter a radio frequency signal. Example acoustic wave filters include surface acoustic wave (SAW) filters and bulk acoustic wave (BAW) filters.
Implementation Method 3
The surface acoustic wave resonator can include an interdigital transductor electrode on a piezoelectric substrate
Data Source
AI summary
A stacked acoustic wave device structure can include at least one surface acoustic wave device that supports a bulk acoustic wave resonator. The surface acoustic wave device includes a first piezoelectric layer with an interdigital transducer electrode on the first piezoelectric layer that generate a surface acoustic wave. In addition, a layer is located above the surface acoustic wave device along which the surface wave propagates. The bulk acoustic wave resonator is supported by the layer, the bulk acoustic wave resonator including an air cavity in contact with the layer, and the bulk acoustic wave resonator further includes a second piezoelectric layer above the air cavity and electrodes on opposing sides of the second piezoelectric layer.