Feedback Spur Attenuation Filtering for Receiver Sensitivity
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Solution Overview
Problem
Conventional communication systems face challenges in effectively attenuating spurious responses, which degrade receiver sensitivity and transmitter emission masks, due to the large silicon area occupied by high-Q passive filters.
Innovation Solution
A filtering device with a feedback loop comprising a subtractor, multipliers, and a filter that subtracts feedback signals from input signals to attenuate undesired frequency components, allowing for efficient spur attenuation while minimizing the impact on desired signals, thereby improving system sensitivity and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-Q passive filters are used to attenuate spurious responses, then spur attenuation performance is improved, but silicon area occupied increases
Solution Approach 1:
The patent implements a feedback-based spur attenuation device that captures the output signal, processes it through a filter to extract spurious components, and feeds back an attenuated version to cancel the spurs. This feedback mechanism achieves effective spur attenuation without requiring large high-Q passive filters, thereby resolving the contradiction between attenuation performance and silicon area consumption
Solution Approach 2:
The patent introduces an intermediary processing path that captures the output signal, filters it to identify spurious components, and generates a correction signal. This intermediary mechanism enables spur attenuation through signal processing rather than direct passive filtering, reducing the silicon area while maintaining attenuation effectiveness
2Object-generated harmful factors
If conventional filtering methods are used, then spurious responses are attenuated, but receiver sensitivity degrades due to large filter area
Solution Approach 1:
The feedback mechanism captures spurious responses at the output, processes them through a filter, and feeds back an attenuated version to cancel the spurs before they degrade receiver sensitivity. This approach attenuates harmful spurious responses while preserving receiver sensitivity by using active signal processing instead of large passive filters
Solution Approach 2:
The patent extracts spurious responses from the output signal through filtering, separates them from the desired signal, and attenuates them independently. This extraction approach allows selective attenuation of harmful factors without affecting the desired signal, thereby maintaining receiver sensitivity while reducing spurious responses
3Object-generated harmful factors
If high-Q passive filters are used, then emission mask compliance is improved, but transmitter complexity increases
Solution Approach 1:
The feedback-based approach captures spurious responses, processes them through a filter, and feeds back attenuated versions for cancellation. This method achieves emission mask compliance through active signal processing, replacing complex high-Q passive filters with a more manageable feedback loop structure that reduces overall transmitter complexity
Solution Approach 2:
The patent replaces mechanical/passive filtering structures (high-Q passive filters) with an active electronic feedback system. This substitution achieves the same emission mask compliance through electronic signal processing, reducing the physical complexity and size of the transmitter while maintaining regulatory compliance
Data Source
AI summary
Exemplary embodiments of the invention disclose signal filtering. In an exemplary embodiment, a filter device may comprise a subtractor operably coupled between an input and an output and configured to receive an input signal comprising a desired component and at least one undesired frequency component. The filter device may further include a feedback loop configured to receive at least one of the input signal and an output signal from the subtractor and convey a feedback signal comprising at least one undesired component to the subtractor. Each undesired component of the feedback signal corresponds to an associated undesired component of the input signal. Furthermore, the subtractor subtracts the feedback signal from the input signal and convey the output signal.