Ladder Filter Resonator Layout for Power Durability and Attenuation
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Solution Overview
Problem
Ladder-type filters with divided series resonators improve power durability but increase filter size, making it challenging to maintain attenuation characteristics while limiting filter size.
Innovation Solution
A filter design incorporating parallel and series resonators with specific antiresonant frequency differences across sections, distributing electric power and increasing the number of attenuation poles without dividing all series resonators, thereby enhancing power durability and attenuation characteristics without increasing filter size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If series resonators are divided into multiple sections to improve power durability, then power durability is improved, but filter size increases
Solution Approach 1:
The series resonators are divided into multiple sections (first section with first and second resonators, second section with third and fourth resonators) to distribute electric power and improve power durability. This segmentation allows the filter to handle higher power loads without increasing the overall filter size, as the division is optimized to maintain compact dimensions while achieving the reliability improvement.
Solution Approach 2:
Different sections of the filter are assigned different antiresonant frequency characteristics. The first section has a first difference in antiresonant frequency between its resonators, while the second section has a second difference, with the third difference between resonators in different sections being smaller. This local differentiation optimizes power distribution and attenuation characteristics in specific regions without requiring uniform increases in filter size throughout.
2Reliability
If series resonators are divided into multiple sections to improve power durability, then power durability is improved, but attenuation characteristic is degraded
Solution Approach 1:
The filter implements different antiresonant frequency differences in different sections: the first difference in the first section and the second difference in the second section are both larger than the third difference between sections. This local optimization ensures that each section contributes appropriately to both power durability and attenuation characteristics, preventing degradation of the attenuation performance while achieving improved power handling.
Solution Approach 2:
The invention optimizes the antiresonant frequency parameters of the series resonators in different sections. By carefully controlling the differences in antiresonant frequencies (first difference, second difference, and third difference), the filter achieves improved power durability while maintaining or enhancing attenuation characteristics through parameter optimization rather than structural expansion.
3Object-generated harmful factors
If additional series resonators are added to improve attenuation characteristics, then attenuation characteristics are improved, but filter size increases
Solution Approach 1:
The filter achieves improved attenuation characteristics by optimizing the local antiresonant frequency differences within existing sections rather than adding more resonators. The first difference and second difference in respective sections are configured to provide enhanced attenuation, while the third difference between sections is kept smaller to maintain compact dimensions. This approach improves attenuation without increasing filter size.
Solution Approach 2:
The invention improves attenuation characteristics through parameter optimization of the existing series resonators. By adjusting the antiresonant frequency differences (first difference, second difference, and third difference) within the current filter structure, enhanced attenuation is achieved without the need to add additional resonators, thereby avoiding an increase in filter 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
The design improves power durability and attenuation characteristics while maintaining a compact filter size by strategically distributing antiresonant frequencies and increasing the number of attenuation poles, thus securing desired performance without the need for additional series resonators.
Implementation Method 1
Ladder-type filters using acoustic wave resonators have been used in mobile communication terminals
Implementation Method 2
Ladder-type filters using acoustic wave resonators have been used in mobile communication terminals
Data Source
AI summary
A filter includes: parallel resonators connected in parallel between input and output terminals; series resonators connected in series between the input and output terminals; nodes at which the parallel resonators connect to a series pathway between the input and output terminals; first and second resonators included in the series resonators and connected in series in a first section of sections each being the series pathway between adjacent nodes of the nodes, the input terminal, and the output terminal, a difference in antiresonant frequency between the first and second resonators being a first difference; and third and fourth resonators included in the series resonators and connected in series in a second section of the sections, a difference in antiresonant frequency between the third and fourth resonators being a second difference, a third difference in antiresonant frequency between the first and third resonators being less than the first and second differences.