Receiver Chain Peak Detection for AGC Saturation Prevention
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Solution Overview
Problem
Existing communication receiver devices face signal saturation and distortion issues due to high gain amplification of both data-bearing and interference components, leading to difficulty in extracting data from stronger signals and potential loss of data.
Innovation Solution
An integrated circuit with a receiver chain that includes a separate control path to preserve and measure interference components, allowing the automatic gain control (AGC) circuit to adjust gain based on both data-bearing and interference signal strengths, thereby preventing saturation and improving sensitivity to weaker signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high gain is applied to amplify weaker signals, then sensitivity to weaker signals is improved, but signal saturation and distortion occur in stronger signals
Solution Approach 1:
The receiver chain is divided into two separate paths: a main signal path that applies high gain for sensitivity and a control path that preserves interference components for AGC decisions. This segmentation allows each path to be optimized for its specific function without compromising the other.
Solution Approach 2:
A control path acts as an intermediary between the amplifier stages and the AGC circuit. This control path preserves interference components that would otherwise be filtered out, providing the AGC with accurate information about total signal strength including interference, enabling it to prevent saturation.
2Object-affected harmful factors
If filter stages are used to remove interference, then interference is reduced, but AGC feedback no longer measures interference components leading to saturation
Solution Approach 1:
The receiver is segmented into a main path with filtering for data extraction and a separate control path without filtering for AGC measurements. This allows the main path to achieve interference rejection while the control path maintains accurate measurement of total signal strength including interference components.
Solution Approach 2:
The control path creates a copy of the amplified signal before filtering is applied in the main path. This copy preserves the interference components needed for accurate AGC feedback, while the main path proceeds with filtering for data-bearing signal extraction.
3Reliability
If a separate control path is added to preserve interference for AGC, then saturation is prevented, but device complexity increases
Solution Approach 1:
The control path is merged with the existing receiver chain by tapping into the amplified signal after the amplifier stages but before the filter stages. This allows the control path to share amplification resources while adding minimal additional complexity for interference preservation and AGC feedback.
Data Source
AI summary
An integrated circuit device is provided. In some examples, the integrated circuit device includes an amplifier stage that receives an input signal and a control signal and provides an amplified signal in response. A main path is coupled to the amplifier stage that receives the amplified signal and provides a first feedback signal corresponding to a signal strength of a data-bearing portion of the input signal. A control path also receives the amplified signal and provides a second feedback signal corresponding to a signal strength of the data-bearing portion and an interference component. A gain control circuit is coupled to the main path and the control path that receives the first and second feedback signals and provides the control signal in response to the feedback signals. In some such examples, the control path and main path include separate mixer stages with different performance characteristics.