FinBAR Resonator Array for Continuous UHF SHF Filtering
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Solution Overview
Problem
Current Bulk Acoustic Resonator (BAR) filters can only operate at a specific single frequency, making them unsuitable for multi-frequency wireless systems, and they lack continuous frequency tuning capability within the same manufactured resonator batch.
Innovation Solution
The development of Fin Bulk Acoustic Resonator (FinBAR) devices and arrays, featuring a fin structure on a substrate with a piezoelectric layer and electrodes, allowing for high-quality factor and electromechanical coupling, enabling continuous filtering across Ultra-High-Frequency (UHF) and Super-High-Frequency (SHF) bands by varying fin dimensions and using a single deposition of piezoelectric material for multiple frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single BAR filter is used, then it can operate at a specific single frequency, but it cannot be used for multi-frequency wireless systems requiring several RF filters working simultaneously at different frequencies
Solution Approach 1:
The BAR filter is designed with multiple resonant modes that enable a single device to operate at multiple frequencies simultaneously. By engineering the resonator structure to support both fundamental and overtone modes, the filter achieves multi-frequency functionality without requiring separate filter devices for each frequency band.
Solution Approach 2:
The filter incorporates tuning mechanisms that allow dynamic adjustment of resonant frequencies. Through variable capacitors or mechanical tuning elements, the filter can adapt its frequency response to support different operating frequencies, enabling it to function across UHF and SHF bands as system requirements change.
2Adaptability or versatility
If conventional BAR filters are used, then manufacturing is simplified, but continuous frequency tuning capability is lacking in the same manufactured resonator batch
Solution Approach 1:
The invention introduces post-manufacturing tuning mechanisms that allow frequency adjustment without changing the fundamental resonator structure. By incorporating variable capacitive elements or mechanical adjustment features, the same batch of resonators can be tuned to different frequencies, providing continuous frequency tuning capability while maintaining manufacturing efficiency.
3Volume of moving object
If FBAR devices with thin piezoelectric films are used, then size is reduced and fabrication efficiency is improved, but frequency tuning range is limited
Solution Approach 1:
The thin-film FBAR structure incorporates dynamic tuning elements such as variable capacitors or mechanically adjustable components that enable frequency tuning despite the fixed thin piezoelectric layer. This allows the compact device to achieve broad frequency coverage across UHF and SHF bands without increasing physical size.
Solution Approach 2:
The invention utilizes higher-order resonant modes (overtone modes) in addition to the fundamental mode to extend the frequency range. By exciting and controlling multiple resonant modes within the same thin-film structure, the device achieves broad frequency coverage while maintaining its compact form factor.
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
FinBAR devices and arrays provide high-quality factor and electromechanical coupling, enabling continuous filtering across UHF and SHF bands, allowing for simultaneous operation at multiple frequencies and improved frequency selectivity, surpassing the limitations of conventional BAR filters.
Implementation Method 1
a piezoelectric material sandwiched between two electrodes
Implementation Method 2
FBAR devices using piezoelectric films with thicknesses ranging from several micrometers down to tenth of micrometers resonate in the frequency range of roughly 100 MHz to 10 GHz
Data Source
AI summary
A Fin Bulk Acoustic Resonator (FinBAR) includes a fin integrally fabricated on a substrate of a glass or a semiconductor, an inner electrode deposited on the fin, a piezoelectric layer disposed on the inner electrode, an outer electrode deposited on the piezoelectric layer, a first electrode and a second electrode formed on the top surface of the substrate and connected to the inner and outer electrodes respectfully. The fin is characterized with a larger height than its width. A FinBAR array including a number of the FinBARs with different fin widths sequentially located on one chip is capable of continuously filtering frequencies in UHF and SHF bands.