Balanced Error-Correction Amplifier for Wideband Low Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing amplifier technologies face challenges in achieving very high levels of DC and AC precision with very low nonlinear, harmonic, and intermodulation distortion across a wide range of frequencies, as previous error correction techniques are either complex, costly, or limited in their frequency range and stability.
Innovation Solution
The development of an amplifier device using a balanced negative feedback error correction mechanism with active error feedback loops that decouples the error correction process from the main signal path, allowing for significant error reduction across a wider frequency band without interfering with the useful signal, thus preserving dynamic stability and response characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional negative feedback techniques are used for error correction, then distortion is reduced to some extent, but the frequency range is limited and stability margins are compromised
Solution Approach 1:
The patent divides the error correction function into multiple independent nested loops, each operating at different frequency ranges. The first loop handles low-frequency errors while the second loop handles high-frequency errors, allowing the system to achieve low distortion across the entire frequency spectrum without compromising stability in any single band.
Solution Approach 2:
The patent implements nested feedback loops where a second error correction loop is placed inside the first loop structure. The outer loop corrects low-frequency distortion while the inner loop corrects high-frequency distortion, creating a hierarchical error correction system that extends the effective frequency range while maintaining stability margins through proper loop design.
2Adaptability or versatility
If nested differentiating feedback loops are inserted to increase high-frequency gain, then frequency response is improved, but additional gain blocks interfere with amplifier response and introduce further errors
Solution Approach 1:
The patent uses feedback loops that sense the output error and feed it back through differentiating networks to generate correction signals. The feedback mechanism automatically adjusts the correction amount based on the actual error measured, preventing the introduction of additional errors while maintaining improved frequency response across the audio band.
Solution Approach 2:
The patent changes the parameters of the feedback loops by introducing different time constants and gain values in different frequency ranges. The differentiating feedback networks use RC circuits with specific time constants to boost high-frequency gain without affecting low-frequency operation, thereby improving overall frequency response without introducing significant errors.
3Measurement precision
If active error feedback loops are added to reduce distortion, then error correction is improved, but dynamic stability margins are reduced and time-frequency response is compromised
Solution Approach 1:
The patent segments the error feedback into multiple loops with different stability characteristics. The outer loop is designed with higher stability margins for low-frequency operation, while the inner loop can operate with lower stability margins for high-frequency correction. This segmentation allows each loop to be optimized for its specific frequency range without compromising overall system stability.
Solution Approach 2:
The patent makes the feedback system dynamic by using frequency-dependent gain and phase characteristics in the differentiating networks. The loops automatically adjust their correction strength based on frequency, providing strong correction where needed while maintaining stability margins through proper compensation networks that adapt the loop characteristics across the frequency spectrum.
4Measurement precision
If multiple correction loops are used to achieve very low distortion, then distortion performance is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges the error correction function with the existing amplifier stages by using the amplifier output and input nodes directly in the feedback loops. The correction loops share components with the main signal path where possible, and the nested structure allows two loops to be implemented with relatively modest additional components compared to using multiple independent correction circuits.
Data Source
AI summary
A very low distortion amplifier using one or more error correction loops based on a balanced error negative feedback scheme intrinsically and easily reiterable. Such loops are applied to a generic amplifier block A1 in order to reduce its error in a wide frequency band, without substantially interfering, in the correction process, with the main path of the useful signal Vi, to amplify, whereby the corrected amplifier preserves the same response, in time and frequency, the same dynamic behavior and the same stability margins in amplitude and phase, of the not corrected amplifier A1. This result is obtained by means of a balance and reference block A2, capable to decouple the error correction loop from the main path of the useful signal Vi, in a very wide frequency band.