Lateral Piezoelectric Layer Layout for BAW Harmonic Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Suppression of non-linearity and harmonic distortion in bulk acoustic wave (BAW) resonators, particularly in high power applications, is a challenge that affects radio frequency systems, leading to issues like harmonic emission and receiver de-sensing.
Innovation Solution
The implementation of a BAW device with multiple piezoelectric layers positioned laterally between electrodes, where the layers have different properties such as c-axis orientation and doping concentration, allowing for parallel connection and suppression of second harmonic distortion without additional parasitics, and enabling multiple resonant frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple piezoelectric layers with different properties are used to suppress second harmonic distortion, then non-linearity suppression is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple piezoelectric layers with different properties (different c-axis orientations or doping concentrations) within a single BAW resonator device. This merging approach allows the device to suppress second harmonic distortion through the interaction between layers while maintaining a unified structure, rather than using separate compensating devices.
Solution Approach 2:
The patent introduces local variations in piezoelectric layer properties (different c-axis orientations or doping concentrations) at specific positions within the device. These localized property differences enable second harmonic distortion suppression without requiring the entire device to be complex, as only specific layers need the varied properties.
2Reliability
If additional components are added to suppress harmonic distortion, then non-linearity suppression is improved, but area consumption increases
Solution Approach 1:
The patent merges the harmonic distortion suppression function into the existing BAW resonator structure by incorporating multiple piezoelectric layers with different properties. This eliminates the need for additional separate components, thereby suppressing harmonic distortion without increasing area consumption.
Solution Approach 2:
The BAW resonator device is designed to perform multiple functions: it provides the primary acoustic wave resonance function while simultaneously suppressing second harmonic distortion through the interaction of multiple piezoelectric layers. This multi-functionality eliminates the need for separate harmonic suppression components.
3Reliability
If multiple piezoelectric layers are used to achieve wide frequency range rejection, then filter performance is improved, but device complexity increases
Solution Approach 1:
The patent uses local variations in piezoelectric layer properties (different doping concentrations or c-axis orientations) to create multiple resonant frequencies within a single device. This localized differentiation enables wide frequency range rejection while maintaining a relatively simple unified structure.
Solution Approach 2:
The patent employs composite piezoelectric structures with layers having different properties (different materials, doping concentrations, or orientations). This composite approach enables the device to achieve wide frequency range rejection through the combined resonant characteristics of the different layers.
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 effectively suppresses second harmonic distortion and achieves wide frequency range rejection with fewer components, reducing area consumption and maintaining filter performance.
Implementation Method 1
In BAW resonators, acoustic waves propagate in a bulk of a piezoelectric layer
Implementation Method 2
acoustic waves propagate in a bulk of a piezoelectric layer
Implementation Method 3
The first acoustic wave resonator and the plurality of additional acoustic wave resonators are together configured to filter a radio frequency signal
Data Source
AI summary
Aspects of this disclosure relate to an acoustic wave device with a plurality of piezoelectric layers positioned laterally relative to each other between two electrodes. One of the piezoelectric layers has a different property than another of the piezoelectric layers. Examples of the different property include c-axis orientation, doping concentration, dopant material, and piezoelectric material. At least part of each of the piezoelectric layers can be in a main acoustically active region of the acoustic wave device.