Adaptive Power Amplifier Linearization for Sideband Distortion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power amplification systems in wireless communication networks face efficiency limitations due to high intermodulation distortion, which increases power consumption and costs, while also failing to meet regulatory requirements for signal quality and BER.
Innovation Solution
A system comprising a linearizer, power amplifier, coupler, upconverter, downconverter, and analog feedback block that uses current predistortion to cancel high and low sideband amplifier distortions, allowing for efficient power amplification while reducing noise and improving linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If power amplification is increased to improve output power, then system gain and link capacity are improved, but intermodulation distortion increases and efficiency decreases
Solution Approach 1:
The patent applies predistortion technique where distortion compensating circuits pre-compensate the signal by introducing opposite distortion before amplification. This preliminary action counteracts the intermodulation distortion that will be generated by the power amplifier, allowing high output power to be achieved without exceeding distortion limits.
Solution Approach 2:
The patent converts the harmful intermodulation distortion into a beneficial effect by using distortion compensating circuits that generate opposite distortion signals. These compensating circuits transform the potential harm (distortion) into a benefit (distortion cancellation), improving overall system performance while maintaining high power output.
2Power
If power amplification is increased to improve output power, then link capacity is improved, but power consumption increases
Solution Approach 1:
By applying predistortion before amplification, the system can operate the power amplifier at higher efficiency points without generating excessive distortion. This preliminary compensation allows the amplifier to work in a more efficient region, reducing power consumption for the same effective output power.
Solution Approach 2:
The patent changes the signal parameters by introducing predistortion signals that modify the amplitude and phase characteristics before amplification. This parameter modification enables the power amplifier to operate at optimal efficiency points, improving the ratio of output power to power consumption.
3Reliability
If distortion compensation is applied to reduce intermodulation distortion, then signal quality is improved, but device complexity increases
Solution Approach 1:
The patent segments the distortion compensation into separate frequency bands using bandpass filters for low-frequency and high-frequency components. This segmentation allows independent optimization of each band's compensation, improving signal quality while managing circuit complexity through modular architecture.
Solution Approach 2:
The patent applies different distortion compensation characteristics to different frequency bands (low-frequency and high-frequency sidebands). Each band receives tailored compensation parameters optimized for its specific characteristics, improving overall signal quality while avoiding the need for a single complex all-encompassing compensation circuit.
4Manufacturing precision
If separate compensation for low-frequency and high-frequency distortion is applied, then manufacturing precision of distortion cancellation is improved, but device complexity increases
Solution Approach 1:
The patent divides the distortion compensation task into separate low-frequency and high-frequency paths, each with dedicated gain adjusters and phase adjusters. This segmentation enables precise independent control of each frequency band's compensation parameters, achieving high distortion cancellation precision while maintaining manageable circuit complexity through modular design.
Solution Approach 2:
The patent implements local optimization by applying specific gain and phase adjustments tailored to each frequency band's distortion characteristics. This local quality approach ensures that each compensation circuit is optimized for its specific frequency range, improving overall cancellation precision without requiring a single overly complex universal circuit.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An exemplary system comprises a linearizer, a power amplifier, and a feedback block. The linearizer may be configured to use a predistortion control signal to add predistortion to a receive signal to generate a predistorted signal. The power amplifier may be configured to amplify power of the predistorted signal to generate a first amplified signal. The power amplifier may also add high side and low side amplifier distortion to the predistorted signal. The high side and low side amplifier distortion may cancel at least a portion of the predistortion. The feedback block may be configured to capture a feedback signal based on a previous amplified signal from the power amplifier, to determine high side and low side distortion of the captured feedback signal, and to generate the predistortion control signal based on the determined high side and low side distortion.