Power Amplifier Nulling Monitor for Distortion-Only Feedback
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Solution Overview
Problem
In wired communication networks, existing methods for echo cancellation in full duplex systems face challenges due to the need for high-performance analog-to-digital converters (ADCs) to distinguish between desired fundamental signals and distortion signals, leading to increased power consumption and reduced headroom.
Innovation Solution
A power amplifier circuit is designed to generate a distortion feedback signal from the intended output signal, using partial and full output monitoring approaches with virtual ground techniques, which allows for effective cancellation of distortion without affecting the fundamental output power, thereby reducing the requirements for ADC performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-performance ADCs are used to distinguish between fundamental signals and distortion signals, then measurement precision is improved, but power consumption increases and headroom decreases
Solution Approach 1:
The patent extracts the distortion signal from the fundamental signal by monitoring the amplifier output and separating the distortion component. This allows the ADC to process only the distortion signal at lower levels, reducing the required ADC performance specifications and thereby reducing power consumption and improving headroom while maintaining the ability to distinguish between fundamental and distortion components
Solution Approach 2:
The patent segments the signal processing by creating separate paths: one for the fundamental signal and one for the distortion signal. The distortion monitoring circuit separates distortion components from the main signal path, allowing independent processing and enabling the use of lower-performance ADCs for distortion measurement, thus reducing power consumption
2Reliability
If distortion feedback signal is generated from intended output signal, then echo cancellation effectiveness is improved, but device complexity increases
Solution Approach 1:
The patent introduces an intermediary distortion monitoring circuit that sits between the amplifier output and the feedback path. This intermediary circuit processes the output signal to extract distortion components and feeds them back separately, improving echo cancellation effectiveness while isolating the complexity from the main signal path
Solution Approach 2:
The patent applies partial action by monitoring only the distortion portion of the signal rather than processing the entire signal path. The distortion feedback network focuses specifically on extracting and feeding back distortion components, achieving effective echo cancellation with reduced circuit complexity compared to processing the full signal
Data Source
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AI summary
Techniques for monitoring a distortion signal of a power amplifier circuit, where the output of a distortion monitoring circuit includes little or no fundamental signal and closely represents the actual distortion of the amplifier circuit of a wired communications system. The power amplifier circuit can generate a distortion feedback signal that does not affect the power amplifier's output power capability, e.g., no inherent loss in the fundamental output of the amplifier. That is, using a distortion monitor circuit, the power amplifier circuit can resolve a distortion feedback signal from the intended output signal of the output power amplifier circuit.