Multi-Window Integrating Notch Filter for High-Selectivity RF Rejection
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Solution Overview
Problem
N-path filters in radio frequency applications face limitations in clock generation, selectivity, and electrical consumption due to frequency limitations and the need for non-overlapping clocks, leading to increased complexity and mismatching, which degrades performance and requires additional components like separators and combiners, resulting in higher power consumption and reduced selectivity.
Innovation Solution
An electronic notch filter that integrates the input signal over multiple time windows with a duration reciprocal to the cutoff frequency, allowing for high selectivity and reduced electrical consumption by eliminating the need for additional components like separators and combiners, and enabling better flow rates through clock control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If N-path filters are used to improve selectivity and rejection, then filtering performance is improved, but device complexity increases due to the need for separators and combiners
Solution Approach 1:
The patent combines the bandpass filtering and bandstop filtering functions into a single integrated filter architecture. The input signal is routed through a unified structure where the same signal path performs both filtering operations simultaneously, eliminating the need for separate separators and combiners that would be required in traditional multi-filter configurations.
2Measurement precision
If N-path filters are used to achieve high rejection, then filtering performance is improved, but electrical consumption increases
Solution Approach 1:
The patent merges multiple filtering operations into a single integrated structure that processes the signal through shared components. By combining bandpass and bandstop filtering in one architecture, the same hardware resources are utilized for multiple filtering functions, reducing the total power consumption compared to implementing separate filters for each function.
3Measurement precision
If the number of switches N is increased to reduce switch resistance, then out-of-band rejection is improved, but electrical consumption increases and maximum frequency of use is reduced
Solution Approach 1:
The patent combines multiple filtering functions into a single integrated structure that processes the signal through shared components. By merging bandpass and bandstop filtering operations, the system achieves improved out-of-band rejection through the combined effect of both filter types working together, rather than relying solely on increasing the number of switches in a single filter path.
4Measurement precision
If N-path filters are used to improve selectivity, then filtering performance is improved, but the maximum frequency of use is reduced
Solution Approach 1:
The patent integrates bandpass and bandstop filtering functions into a single unified filter architecture. This merged structure allows the system to achieve high selectivity through the combined filtering action while operating at higher frequencies than traditional N-path filters, as the integrated design reduces the clock frequency limitations associated with multiple separate filter stages.
Data Source
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AI summary
This electronic band-stop filter (10) is capable of receiving an input signal (Xe) and delivering a filtered signal (E) having, at a cutoff frequency (Fc), an amplitude attenuated compared to that of the input signal (Xe). It comprises a module (12) for integrating the input signal over several successive time windows, each time window beginning at a respective initial time instant and having a duration substantially equal to the inverse of the cutoff frequency (Fc), the initial time instants of at least two distinct windows being separated by a time offset of a value greater than or equal to a predefined reference duration, each integration of the input signal (Xe) during a respective time window resulting in a respective intermediate signal (Si); and a module (16) for summing the intermediate signals (Si) from the integration module (12); the filtered signal (E) being a function of the sum of said intermediate signals (Si).