Differential Amplifier Nonlinear Feedback for Third-Harmonic Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing amplifier designs face challenges in reducing third harmonic distortion and improving power consumption, robustness, and cost, particularly in achieving efficient linearization.
Innovation Solution
A differential amplifier design incorporating a feedback mechanism through non-linear elements affecting output stages, utilizing MOS transistors in the triode region to provide feedback from output signals, which reduces third-order nonlinearity and maintains low current and noise overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If non-linear feedback circuit with function generator is used to reduce third harmonic distortion, then linearity is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent extracts the essential non-linear feedback function and implements it directly within the amplifier circuit using simplified non-linear elements (such as diodes or transistors in specific configurations) rather than using a complex external function generator and computer control system. This extracts only the necessary feedback mechanism while removing unnecessary complexity.
Solution Approach 2:
The amplifier circuit is designed to automatically generate and apply the non-linear feedback signals through internal non-linear elements that self-regulate based on the output signal level, eliminating the need for external computers and function generators to calculate and deliver control signals.
2Manufacturing precision
If non-linear feedback circuit with function generator is used to reduce third harmonic distortion, then linearity is improved, but power consumption increases
Solution Approach 1:
The non-linear feedback elements are designed to operate passively or with minimal biasing, automatically generating feedback signals proportional to the output signal without requiring continuous power-intensive computation or active control, thereby reducing overall power consumption while maintaining linearity improvement.
Solution Approach 2:
The patent uses simple, low-power non-linear elements (such as diodes or lightly-biased transistors) that consume minimal power compared to the continuous operation of computers and function generators, providing an energy-efficient solution for distortion reduction.
3Manufacturing precision
If resistive source degeneration network is used to improve linearity, then third harmonic distortion is reduced, but device complexity and cost increase
Solution Approach 1:
The patent combines the linearity improvement function with the existing amplifier circuit structures by integrating non-linear feedback elements directly into the signal path, merging multiple functions (amplification and distortion reduction) into a unified circuit rather than adding separate degeneration networks.
Solution Approach 2:
The patent extracts the essential linearity improvement mechanism and implements it through minimal non-linear feedback elements rather than comprehensive resistive source degeneration networks, taking out only the necessary components to achieve the desired linearity enhancement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed solution effectively reduces third-order nonlinearity while maintaining low noise and minimal chip area overhead, enhancing amplifier performance and efficiency.
Implementation Method 1
A differential amplifier design incorporating a feedback mechanism through non-linear elements affecting output stages, utilizing MOS transistors in the triode region to provide feedback from output signals
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A differential amplifier comprises a first differential circuitry structure including a first part comprising at least one branch of transistors and a second part comprising at least one branch of transistors, and a second circuitry structure. The second circuitry structure has a first non-linear device and a second non-linear device. The non-linear devices each comprise a transistor having a control node connected to a differential output terminals of the differential amplifier. A common centre node of the non-linear devices is connected to a control node of one of the transistors of each branch of the first part having a differential output terminal. Amplifier applications, communication devices and network nodes are also disclosed.