Surface Acoustic Wave Resonator Groove Layout for Compact Reflection
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Solution Overview
Problem
The increasing number of communication bands in 5G and beyond requires a significant increase in the number of filters in communication devices, leading to larger sizes and higher costs, while existing surface acoustic wave filters are limited by their size and complexity.
Innovation Solution
A surface acoustic wave resonator design that includes a piezoelectric material layer with a first region and two second regions, an interdigital transducer, and a reflective electrode structure, where a groove is formed in the piezoelectric material layer at the side of the remaining reflective electrode structure away from the interdigital transducer, reducing the size of the resonator while maintaining reflection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional reflective electrode structure is used in surface acoustic wave resonators, then the reflection effect is sufficient, but the device size becomes large
Solution Approach 1:
The reflective electrode structure is divided into two separate reflective electrodes positioned at opposite ends of the interdigital transducer. This segmentation allows each electrode to be optimized for specific reflection functions while reducing the overall space required compared to a single large reflective electrode structure, directly addressing the contradiction between maintaining reflection effectiveness and reducing device size.
Solution Approach 2:
The patent introduces a depth dimension by forming grooves in the substrate beneath the reflective electrodes. This vertical dimensionality change enhances the reflection effect through acoustic impedance mismatch at the groove interfaces, allowing for compact horizontal dimensions while maintaining sufficient reflection performance.
2Adaptability or versatility
If the number of filters is increased to support more communication bands, then communication compatibility improves, but the device size and complexity increase
Solution Approach 1:
The surface acoustic wave resonator design with segmented reflective electrodes and substrate grooves creates a compact, high-performance filtering element that can be integrated into multi-band filter systems. The reduced size of individual resonators enables multiple filters to be packed into a smaller overall device volume, allowing support for multiple communication bands without proportionally increasing device size.
3Volume of moving object
If the reflective electrode structure is reduced in size for miniaturization, then the device becomes more compact, but the reflection effect deteriorates
Solution Approach 1:
The patent compensates for reduced horizontal electrode dimensions by introducing vertical dimensionality through grooves etched into the substrate. These grooves create acoustic impedance mismatches that enhance reflection without requiring large horizontal electrode areas, thus maintaining reflection effectiveness while achieving miniaturization.
Solution Approach 2:
The substrate grooves act as intermediary structures that mediate between the compact reflective electrodes and the acoustic wave field. The grooves enhance the reflection capability of the small electrodes by creating additional acoustic impedance boundaries, effectively amplifying the reflection effect of the miniaturized electrode 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 design achieves miniaturization of the surface acoustic wave resonator, allowing for smaller filter sizes and more compact communication devices, while maintaining the same reflection effect and suppressing noise generation.
Implementation Method 1
a piezoelectric material layer, comprising a first region and two second regions arranged in a first direction
Implementation Method 2
an interdigital transducer, located at a side of the piezoelectric material layer
Implementation Method 3
a reflective electrode structure, arranged in the same layer as the interdigital transducer... the groove is located in the second regions and at a side of the reflective electrode structure away from the interdigital transducer
Data Source
AI summary
A surface acoustic wave resonator, a filter and a communication device are provided. The surface acoustic wave resonator includes a piezoelectric material layer, an interdigital transducer and a reflective electrode structure; the piezoelectric material layer includes a first region and two second regions arranged in a first direction; the interdigital transducer is located at a side of the piezoelectric material layer; the reflective electrode structure is arranged in the same layer as the interdigital transducer; the first region is located between two second regions, the interdigital transducer is located in the first region, the reflective electrode structure is located in the second region, and the surface acoustic wave resonator further includes a groove located in the piezoelectric material layer, the groove is located in the second region, and is located at a side of the reflective electrode structure away from the interdigital transducer in the first direction.