Receiver Chain Peak Detection for AGC Saturation Control
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Solution Overview
Problem
Existing communication device receivers face signal saturation issues due to high gain amplification of both data-bearing and interference components, leading to distortion and potential loss of data, especially in stages prior to filter stages.
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 signal extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high gain amplification is applied to improve reception of weaker signals, then signal sensitivity 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 filters interference for data extraction, and a control path that preserves interference components for AGC measurements. This segmentation allows the AGC to base gain control on total signal strength (data + interference) rather than filtered signal strength alone, preventing saturation while maintaining sensitivity.
Solution Approach 2:
The system implements automatic gain control (AGC) with feedback from the control path that measures both data-bearing and interference components. The AGC circuit continuously monitors the control path signal and adjusts the gain of amplifier stages to maintain optimal signal levels, preventing saturation while preserving weak signal detection capability.
2Measurement precision
If filter stages are used to remove interference, then data extraction is improved, but interference components are lost for AGC determinations
Solution Approach 1:
The receiver is segmented into two parallel paths: the main path applies filtering to extract data from the signal while removing interference, and the control path preserves both data and interference components for AGC measurements. This allows each path to fulfill its specific function without compromising the other.
Solution Approach 2:
The control path acts as an intermediary that preserves the complete signal spectrum including interference components, providing this information to the AGC circuit. This intermediary path enables the AGC to make informed gain decisions based on total signal strength without requiring the main filtered path to carry interference information.
3Device complexity
If a single feedback path is used for AGC control, then device complexity is reduced, but accurate gain control in presence of interference is compromised
Solution Approach 1:
The feedback system is segmented into two distinct paths: a main feedback path from the filtered signal path for data validation, and a control feedback path from the unfiltered path for accurate AGC measurements. This segmentation enables the AGC to accurately measure total signal strength including interference while keeping the device complexity manageable through modular path design.
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.