Receiver Front-End Attenuation for Overload Without Sensitivity Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems, particularly those operating under IEEE 802.11 and 802.16 standards, face challenges in blocking unwanted signals while maintaining sensitivity to desired signals, leading to potential overload and distortion.
Innovation Solution
A receiver with a variable attenuator controlled by a detection and comparison scheme, positioned after preselector filters and low noise amplifiers, to selectively block unwanted signals while preserving the sensitivity to desired signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the receiver blocks unwanted signals to prevent overload, then the protection of downstream components is improved, but the sensitivity to desired signals deteriorates
Solution Approach 1:
The patent applies dynamics by implementing a variable attenuator that can dynamically adjust its attenuation level based on real-time signal conditions. The attenuator transitions from a static component to a dynamic one that responds to detector feedback, allowing the system to adapt between blocking unwanted signals and preserving desired signals as conditions change.
Solution Approach 2:
The patent implements feedback through a detection and comparison scheme where the detector monitors signal strength and provides feedback to the controller. The controller compares detected signal levels against threshold values and adjusts the variable attenuator accordingly, creating a closed-loop control system that resolves the contradiction between blocking and preserving signals.
2Reliability
If a fixed attenuator is used to block strong signals, then the overload protection is improved, but the receiver sensitivity to weak desired signals deteriorates
Solution Approach 1:
The patent replaces the fixed attenuator with a variable attenuator that can dynamically change its attenuation characteristic. This allows the system to have high attenuation when strong unwanted signals are present and low attenuation when weak desired signals need to be preserved, resolving the contradiction inherent in fixed attenuation approaches.
Solution Approach 2:
The patent changes the attenuation parameter from a fixed value to a variable value that can be adjusted based on signal conditions. The variable attenuator modifies its attenuation parameter in response to controller commands, enabling the system to optimize between overload protection and signal sensitivity by changing the attenuation parameter as needed.
3Reliability
If the variable attenuator is positioned before the preselector filters, then the overload protection for filters is improved, but the complexity of the system increases due to potential oscillation issues
Solution Approach 1:
The patent applies preliminary action by positioning the variable attenuator after the preselector filters and low noise amplifiers, allowing these components to first process the signal without immediate attenuation. This sequencing prevents oscillation issues while still providing overload protection, as the attenuator acts on already-processed signals rather than causing instability in the filtering stage.
Data Source
AI summary
An embodiment is a receiver for a communications system that may substantially block unwanted signals in a frequency range to protect the receiver from overload. Simultaneously, the receiver of an embodiment substantially passes a desired signal so that its information may be processed by the, for example, communications system of which the receiver is part.