SAW Filter Substrate Thickness for 2140 MHz Attenuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional surface acoustic wave filters exhibit unsatisfactory filtering characteristics, particularly poor attenuation at 2140 MHz and its neighborhood, which affects their performance in portable telephone units.
Innovation Solution
The thickness of the piezoelectric substrate is reduced to not thicker than 0.2 mm, which improves the attenuation characteristic by reducing capacitance coupling and enhancing the filtering performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the piezoelectric substrate thickness is reduced to not thicker than 0.2 mm, then the attenuation characteristic at 2140 MHz is improved, but the manufacturing precision requirement increases
Solution Approach 1:
The invention changes the physical parameter of piezoelectric substrate thickness to not thicker than 0.2 mm, which fundamentally alters the capacitance coupling characteristics and improves attenuation at 2140 MHz. This parameter change directly resolves the technical contradiction by optimizing the filtering characteristic while establishing a new manufacturing specification.
2Reliability
If the piezoelectric substrate thickness is reduced, then the capacitance coupling is reduced and attenuation at 2140 MHz is improved, but the structural stability may be compromised
Solution Approach 1:
By changing the substrate thickness parameter to not thicker than 0.2 mm, the invention optimizes the capacitance coupling effect to achieve better attenuation characteristics while maintaining structural integrity through precise parameter control.
3Ease of manufacture
If a conventional piezoelectric substrate thickness is used, then the manufacturing is easier, but the filtering characteristic remains unsatisfactory with poor attenuation at 2140 MHz
Solution Approach 1:
The invention changes the substrate thickness parameter to not thicker than 0.2 mm, which improves filtering characteristics and attenuation at 2140 MHz. This parameter optimization balances manufacturing feasibility with performance requirements.
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 thickness optimization results in improved attenuation characteristics, with attenuation amounts below -50 dB in the critical frequency range, enhancing the overall filtering capability of the surface acoustic wave filters and duplexers.
Implementation Method 1
surface acoustic wave filter
Implementation Method 2
piezoelectric substrate 5 provided on the upper surfaces of resonators 3a ̃3e
Data Source
AI summary
A surface acoustic wave filter which includes a first terminal at the input side, a second terminal at the output side, a plurality of resonators electrically connected between the first and the second terminals, and a piezoelectric substrate provided on the upper surfaces of first and second terminals and the plurality of resonators. The piezoelectric substrate is made to have a thickness that is not thicker than 0.2 mm. The filtering characteristic of surface acoustic wave filter can be improved by taking advantage of the above structure.