Digital Predistortion Circuit for Multi-Voltage Power Amplifiers
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Solution Overview
Problem
Existing power amplifiers experience nonlinear distortion when operated with multiple discrete voltages, which current digital predistortion methods fail to adequately address.
Innovation Solution
A power amplification system and digital predistortion circuit that utilize a filter circuit connected in a switchable manner, employing different mathematical-expression models with distinct parameter sets to generate distortions in input signals based on the connection state of the filter circuit, thereby reducing nonlinear distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If multiple discrete voltages are supplied to the power amplifier, then power-added efficiency is improved, but nonlinear distortion increases
Solution Approach 1:
The patent applies dynamics by making the DPD circuit adaptable to different filter connection states. The circuit dynamically switches between different mathematical models and parameter sets based on whether the filter is connected or disconnected, allowing optimal predistortion compensation for each operating condition while maintaining high efficiency with multiple discrete voltages
Solution Approach 2:
The patent changes parameters by using different parameter sets for the mathematical models depending on the filter connection state. When the filter is disconnected, a first parameter set is used; when connected, a second parameter set is used. This parameter adaptation enables effective nonlinear distortion reduction across different power supply voltage conditions
2Object-generated harmful factors
If digital predistortion is applied, then nonlinear distortion is reduced, but device complexity increases
Solution Approach 1:
The patent segments the DPD approach by creating distinct mathematical models and parameter sets for different filter connection states. This segmentation allows the system to use simplified, optimized models for each specific condition rather than requiring a single complex model to handle all scenarios, thereby reducing overall circuit complexity while maintaining effective distortion reduction
Data Source
AI summary
A power amplification system includes: a first power amplifier; an output switch circuit configured to output a power supply to the first power amplifier; a filter circuit that is to connect to a first path in a switchable manner, the first path providing the power supply from the output switch circuit to the first power amplifier; and a digital predistortion circuit configured to generate distortions in a first input signal of the first power amplifier. When the filter circuit is not connected to the first path, the digital predistortion circuit generates the distortions by using a first mathematical-expression model with the first parameter set. When the filter circuit is connected to the first path, the digital predistortion circuit generates the distortions by using a second mathematical-expression model with the second parameter set. The first and second parameter sets are at least partially different from each other.