Wireless Receiver Bypass Filtering for High Linearity
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Solution Overview
Problem
Receiver non-linearity results in signal distortion due to current leakage by transistors and charge injection, necessitating a high linearity wireless receiver design.
Innovation Solution
A wireless receiver architecture incorporating an out-band signal bypass filter, a mixer, and a baseband circuit, where the out-band signal bypass filter provides a bypass path to suppress out-band signals, improving linearity by preventing their conveyance to the baseband circuit, and utilizing LC tanks or N-path filters to differentiate between in-band and out-band signals for appropriate processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If out-band signals are allowed to pass through to the baseband circuit, then the receiver can process all incoming signals, but signal distortion occurs due to non-linearity
Solution Approach 1:
The patent extracts and removes out-band signals from the signal path before they can reach the baseband circuit. The bypass filter is configured to detect out-band signals and divert them through a separate path that prevents them from entering the non-linear baseband processing stage, thereby eliminating the source of distortion while preserving in-band signal processing.
Solution Approach 2:
The bypass filter acts as an intermediary component between the RF input and the baseband circuit. It mediates the signal flow by selectively routing out-band signals away from the baseband processor while allowing in-band signals to pass through to normal processing, thus protecting the baseband circuit from harmful out-band signals.
2Reliability
If a traditional filter is used to block out-band signals, then linearity improves, but in-band signal processing may be affected
Solution Approach 1:
The patent segments the signal processing path into multiple routes: a main path for in-band signals leading to the baseband circuit, and a bypass path for out-band signals. The bypass filter is segmented into multiple poles (first pole, second pole, etc.) that can be independently configured to handle different out-band frequency ranges, allowing precise filtering without affecting in-band processing.
Solution Approach 2:
The bypass filter employs dynamic switching mechanisms that can activate or deactivate different filter poles based on the detected signal characteristics. This dynamic configuration allows the filter to adapt its response to different operating conditions, blocking out-band signals when needed while maintaining full in-band signal processing capability when out-band interference is absent.
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 effectively suppresses out-band signals, significantly enhancing the linearity of the wireless receiver and preventing signal distortion, thereby improving the overall performance.
Implementation Method 1
utilizing LC tanks or N-path filters to differentiate between in-band and out-band signals for appropriate processing
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A wireless receiver with high linearity, having an out-band signal bypass filter, a mixer, and a baseband circuit. The out-band signal bypass filter has a first terminal and a second terminal respectively receiving a positive differential signal and a negative differential signal from a former-stage circuit, and the out-band signal bypass filter provides an out-band signal bypass path from the first terminal to the second terminal. The mixer receives a filtered signal from the out-band signal bypass filter. The baseband circuit is coupled to the mixer for generation of an in-phase signal and a quadrature phase signal.