Reconfigurable Filter Q-Factor Control Across Frequency Bands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional filters in wireless communications have fixed Q-factors, making them inflexible and costly, and existing methods for improving Q-factor, such as using an Audion receiver, are prone to oscillation and require frequent retuning.
Innovation Solution
A method and apparatus that stabilize active feedback in filters to provide a variable feedback, allowing for reconfiguration of center frequency and bandwidth based on input signal channel bandwidth, thereby adjusting the Q-factor across multiple frequency bands without altering hardware, using isolation amplifiers and encapsulating resonant circuits to avoid oscillation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional filters with fixed Q-factor are used, then manufacturing is simple and reliable, but adaptability to different frequency bands is poor and costs increase
Solution Approach 1:
The patent implements dynamic reconfiguration of filter characteristics by allowing the Q-factor and center frequency to be adjusted electronically based on the operating frequency band. This enables a single filter structure to adapt to multiple frequency bands (e.g., EUTRA, LTE-U, NR) without requiring separate fixed filters for each band, thereby resolving the contradiction between adaptability and complexity.
2Productivity
If Q-factor enhancement techniques are applied, then signal processing efficiency improves, but oscillation risk increases
Solution Approach 1:
The patent employs feedback mechanisms to monitor and control the Q-factor enhancement process. By using feedback loops, the system can dynamically adjust the enhancement level to maintain optimal signal processing efficiency while preventing oscillation conditions, thus resolving the contradiction between productivity and reliability.
3Adaptability or versatility
If parallel filter banks are implemented for each frequency band, then frequency band coverage is complete, but device complexity and manufacturing costs increase significantly
Solution Approach 1:
The patent creates a universal filter structure that can operate across multiple frequency bands by implementing electronic reconfiguration capabilities. Instead of requiring separate parallel filter banks for each band, a single multi-functional filter can be programmed to handle different bands (EUTRA, LTE-U, NR), significantly reducing device complexity while maintaining complete frequency band coverage.
4Adaptability or versatility
If fixed Q-factor filters are used, then manufacturing precision is maintained, but flexibility for reconfiguration is lost
Solution Approach 1:
The patent replaces mechanical tuning methods with electronic control mechanisms for Q-factor adjustment. This substitution allows for precise digital control of filter characteristics while maintaining manufacturing precision through standardized production processes. The electronic reconfiguration capability enables flexibility without compromising the precision achieved through controlled manufacturing.
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
Enables flexible and reconfigurable filters that can operate across various frequency bands, reducing manufacturing costs and avoiding oscillation, while achieving higher Q-factors for improved signal processing efficiency.
Implementation Method 1
A part of the amplified RF signal is positively fed back to a resonator in equal phase
Implementation Method 2
the resonant circuit or filter responds to frequencies close to a natural frequency much more strongly than to other frequencies
Implementation Method 3
using isolation amplifiers and encapsulating resonant circuits to avoid oscillation
Data Source
AI summary
The present invention provides a method and an apparatus for controlling a Q-factor for a filter. The method comprises stabilizing an active feedback to provide a variable feedback in a filter, varying the active feedback based on an input signal to the filter, and producing a desired Q-factor for the filter at a first frequency band, in response to the variable feedback. The method further comprises reconfiguring a center frequency and a bandwidth of the filter based on a channel bandwidth of the input signal to the filter to adjust the Q-factor for the filter in response to a second frequency band different than the first frequency band. By reconfiguring a center frequency and a bandwidth of a filter, the Q-factor for the filter, such as a flexible or reconfigurable filter, may be controlled across a multiplicity of frequency band signals. Using software, for example, a common signal path may be provided for the multiplicity of frequency band signals within a frequency agile radio of a base station by tuning the radio based on a variable feedback through realization of a negative parallel resistance. Thus, tuneability of the Q-factor may provide frequency agile radios that include flexible or reconfigurable filters in a base station to serve different frequency bands without changing hardware. In this way, significant savings associated with frequency agility may be obtained.