Reconfigurable SAW Reflectors for Frequency-Agile Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surface acoustic wave (SAW) devices in telecommunications lack frequency agility, requiring different geometrical parameters for each frequency band, leading to increased volume and cost, and are unable to change operating frequency without degrading other performance metrics.
Innovation Solution
A SAW device with modified electrical boundary conditions, utilizing a switching circuit to dynamically reconfigure electrode connections between ground and floating states, allowing frequency agility without altering geometrical parameters, and enabling control over stop bands and resonance conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If different SAW components are used for each frequency band, then filtering performance for each band is improved, but device volume and cost increase
Solution Approach 1:
The patent implements a single SAW device that can operate across multiple frequency bands by dynamically reconfiguring the electrical connections of reflector electrodes between ground and floating states. This allows one device to perform the filtering function for multiple bands that would traditionally require separate dedicated components, thereby reducing overall device volume while maintaining filtering performance.
Solution Approach 2:
The patent introduces dynamic reconfigurability to the SAW device through switching circuits that can change the electrical boundary conditions of reflector electrodes in real-time. This dynamic capability enables the device to adapt its frequency response and operate at different nominal frequencies, eliminating the need for multiple static components for different bands.
2Reliability
If different SAW components are used for each frequency band, then filtering performance for each band is improved, but device cost increases
Solution Approach 1:
The patent implements a single SAW device that can operate across multiple frequency bands by dynamically reconfiguring the electrical connections of reflector electrodes between ground and floating states. This allows one device to perform the filtering function for multiple bands that would traditionally require separate dedicated components, thereby reducing overall device volume while maintaining filtering performance.
Solution Approach 2:
The patent combines multiple filtering functions into a single integrated SAW device structure. By merging the capabilities of what would traditionally be separate band-specific components into one reconfigurable device, the patent reduces component count, simplifies manufacturing, and lowers overall system cost while maintaining the required filtering performance across bands.
3Adaptability or versatility
If operating frequency is changed in conventional SAW devices, then frequency adaptability is improved, but other performance metrics are degraded
Solution Approach 1:
The patent introduces dynamic reconfigurability to the SAW device through switching circuits that can change the electrical boundary conditions of reflector electrodes in real-time. This dynamic capability enables the device to adapt its frequency response and operate at different nominal frequencies, eliminating the need for multiple static components for different bands.
Solution Approach 2:
The patent changes the electrical parameters (connection states) of the reflector electrodes rather than altering the physical geometry of the device. By switching electrodes between ground and floating states, the device modifies its electrical boundary conditions to achieve frequency tuning while preserving the structural integrity and performance characteristics designed into the original geometry.
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 solution provides frequency-agile SAW devices that maintain performance integrity across different nominal frequencies, reducing bulk and cost by allowing flexible frequency adjustment and enabling the production of filters and oscillators with specific specifications.
Implementation Method 1
The operation of these devices is based on the conversion of electrical energy into at least one elastic wave via a transducer typically comprising two interdigital electrode combs deposited on the surface of a material that may or may not be piezoelectric
Implementation Method 2
The acoustic reflectors are Bragg mirrors disposed on either side of this transduction zone. They are formed by periodic arrays of electrodes R1 and R2 deposited on the surface of the same substrate Mat, and ensure a strong reflection coefficient for the surface acoustic waves within a certain range of frequencies, called stop band
Implementation Method 3
A SAW device with modified electrical boundary conditions, utilizing a switching circuit to dynamically reconfigure electrode connections between ground and floating states, allowing frequency agility without altering geometrical parameters
Data Source
AI summary
A surface acoustic wave device includes at least one transducer; two acoustic reflectors disposed on either side of the at least one transducer so as to form a cavity, each acoustic reflector comprising an array of electrodes in the form of lines parallel with each other, each array comprising a subset of electrodes connected to a reference potential denoted mass defining a first connection type, and a subset of electrodes that are not connected to any potential, i.e. that have a floating connection defining a second connection type; at least one switching circuit configured to modify the distribution of the connections of at least one part of the electrodes of each array between the different connection types.