High-Q Electroacoustic Resonator Tip Geometry for Harmonic Suppression
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Solution Overview
Problem
Electroacoustic resonators in wireless communication devices generate harmonics that interfere with other signals, particularly due to nonlinearities at the electrode finger tips, which can degrade device performance.
Innovation Solution
The electroacoustic resonator is designed with modified electrode finger tips and gap reflectors to suppress harmonics, utilizing specific shapes and structures that reduce second-order nonlinearities without increasing device size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional electrode finger tips are used in electroacoustic resonators, then the device structure is simple, but harmonics are generated that interfere with other signals
Solution Approach 1:
The patent applies local quality by modifying only the electrode finger tip geometry (creating chamfered or beveled edges) while keeping the rest of the electrode structure conventional. This localized modification suppresses second-order nonlinearities and harmonic generation at the tip region without requiring changes to the overall device architecture, thus reducing harmful effects while minimizing added complexity.
Solution Approach 2:
The patent introduces asymmetry by creating non-symmetric electrode finger tip shapes (chamfered or beveled edges) instead of symmetric rectangular tips. This asymmetric geometry disrupts the symmetry of the electric field distribution at the tip, which suppresses even-order harmonics (particularly second-order) that are generated by symmetric tip configurations, thereby reducing harmonic interference.
2Reliability
If electrode finger tips are modified to suppress harmonics, then signal integrity is improved, but device area increases
Solution Approach 1:
The modification is confined to a small region at the electrode finger tips (chamfered or beveled edges) rather than extending across the entire electrode structure. This localized approach improves signal integrity by suppressing harmonics while adding minimal area, as the modified region represents only a small fraction of the total resonator footprint.
3Object-generated harmful factors
If conventional electrode structures are used, then manufacturing is simple, but second-order nonlinearities are significant
Solution Approach 1:
The patent reduces second-order nonlinearities by modifying only the local geometry of the electrode finger tips (chamfered or beveled edges) rather than changing the entire electrode structure. This localized modification can be integrated into existing fabrication processes with minimal additional steps, thus reducing harmful nonlinearities while maintaining relative ease of manufacture.
Solution Approach 2:
The asymmetric chamfered or beveled tip geometry is designed to suppress second-order nonlinearities through its non-symmetric field distribution. This asymmetric shape can be fabricated using standard photolithography and etching processes with appropriate mask design, balancing the reduction of nonlinearities with manufacturability constraints.
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 modified electrode finger tips and gap reflectors effectively suppress harmonics, improving device performance with minimal area increase and enhancing signal integrity in wireless communication systems.
Implementation Method 1
Using a piezoelectric material as a vibrating medium, acoustic resonators operate by transforming an electrical signal wave that is propagating along an electrical conductor into an acoustic wave that is propagating via the piezoelectric material.
Data Source
AI summary
Aspects include high q resonator devices and associated systems and methods. In one aspect, a device includes first and second busbars. The device includes a first electrode finger coupled to the first busbar and extending in a first direction towards the second busbar without touching the second busbar, where the first electrode finger comprises a finger tip having a first shape, a first stub electrode finger coupled to the second busbar and extending in a second direction opposite the first direction towards the finger tip of the first electrode finger, where the first stub electrode finger comprises a first end coupled to the second busbar and a second end, and where the second end comprises a stub tip having a second shape different than the first shape.