Power Amplifier DPD Architecture for Drive-Stage Linearity
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Solution Overview
Problem
Current power amplifiers in communication systems face inefficiencies and increased power consumption due to nonlinear distortions, particularly in the drive stage, which complicates the use of high-efficiency power amplifiers like Class C, D, E, and F amplifiers and limits the effectiveness of digital pre-distortion technologies when applied to both drive and final power amplifiers.
Innovation Solution
The implementation of a high-efficiency power amplifier design that includes multiple DPD correction modules and multi-path control modules to pre-distort and correct nonlinear characteristics of drive and amplified signals, improving the efficiency of the drive amplifier and overall power amplifier performance by using feedback loops and adaptive correction methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If power back-off method is used to reduce distortion, then linearity is improved, but power amplifier efficiency deteriorates
Solution Approach 1:
The patent applies pre-distortion technology to the drive signal before it enters the power amplifier. A pre-distorter circuit modifies the drive signal in advance to compensate for the nonlinear characteristics of the power amplifier, allowing the amplifier to operate at higher efficiency without excessive distortion in the final output signal.
Solution Approach 2:
The patent implements feedback mechanisms where the output signal is monitored and used to adjust the drive signal. This feedback loop enables the system to maintain linearity while operating the power amplifier at higher efficiency points by dynamically compensating for nonlinear distortions.
2Loss of energy
If high-efficiency power amplifiers with strong nonlinearity are used, then power amplifier efficiency is improved, but distortion of amplitude and phase increases
Solution Approach 1:
The patent applies pre-distortion to the drive signal before amplification. The pre-distorter introduces opposite nonlinear characteristics to the drive signal, which compensates for the strong nonlinearity of high-efficiency power amplifiers (Class C, D, E, or F), reducing the overall distortion in the final output while maintaining high efficiency.
Solution Approach 2:
The patent converts the harmful strong nonlinearity of high-efficiency power amplifiers into a beneficial characteristic by applying pre-distortion. The nonlinear pre-distorter deliberately introduces distortion that is the opposite of the amplifier's nonlinear distortion, so that when combined, they cancel out and produce a linear output signal.
3Manufacturing precision
If DPD correction is applied to both drive and final power amplifiers, then linearity is improved, but device complexity increases
Solution Approach 1:
The patent segments the power amplifier system into distinct functional blocks: a pre-distorter for the drive signal, a drive amplifier, and a final power amplifier. This segmentation allows DPD correction to be applied selectively and efficiently at different stages, improving linearity while managing complexity through modular design.
Solution Approach 2:
The patent applies different levels of correction to different parts of the system. The pre-distorter applies nonlinear correction to the drive signal, while the feedback mechanism applies linear correction to the final output. This local quality approach optimizes linearity where most needed while minimizing unnecessary complexity.
Data Source
AI summary
A high-efficiency power amplifier is provided, including a drive amplifier and a final power amplifier, and further including a first digital pre-distortion (DPD) correction module and a second DPD correction module. The first DPD correction module is configured to pre-distort nonlinear characteristics of drive signals output by the drive amplifier, and the second DPD correction module is connected to the first DPD correction module in series, and is configured to pre-distort nonlinear characteristics of amplified signals output by the final power amplifier. Another high-efficiency power amplifier is also provided, including a drive amplifier and a final power amplifier, and further including a second multi-path control module, a fourth DPD correction module, and a second gating module. The overall efficiency of the high-efficiency power amplifier is increased by improving the working efficiency of the drive amplifier. Further, higher overall efficiency is also achieved for a power amplifier with a higher gain.