Predistortion Linearizer Bias Circuit for Gain and Phase Shape Control
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Solution Overview
Problem
Conventional predistortion linearizers using self-biasing non-linear mechanisms fail to control the shape of gain and phase expansions, leading to imperfect linearization of power amplifiers across their entire range.
Innovation Solution
A predistortion linearization device with a modified self-biasing mechanism using two diodes, where the first and second channels receive adjustable fractions of the input signal to generate direct currents and voltages, allowing for the combination of opposing direct voltages and currents to control the shape of gain and phase expansions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional predistortion linearizer with self-biasing non-linear mechanism is used, then the device complexity is reduced, but the manufacturing precision of gain and phase expansion shape control deteriorates
Solution Approach 1:
The linearizer is divided into multiple independent channels (first channel, second channel, third channel) with distinct functions. The first channel generates a first direct current, the second channel generates a second direct current, and the third channel performs gain and phase expansions. This segmentation allows each channel to be optimized independently, achieving precise shape control without excessive overall complexity.
Solution Approach 2:
Multiple self-biasing currents are combined in the third channel to control the shape of gain and phase expansions. The first direct current from the first channel and the second direct current from the second channel are merged to jointly control the expansion characteristics, achieving precise shape control through combined action of multiple simpler components.
2Adaptability or versatility
If the amplitude of gain and phase expansions is adjusted to match the power amplifier, then the adaptability to the amplifier is improved, but the linearization precision deteriorates due to shape mismatch
Solution Approach 1:
The linearizer dynamically adjusts both the amplitude and shape of gain and phase expansions through multiple controllable channels. By independently controlling the amplitude of each channel's direct current and combining them in the third channel, the system can adapt to different power amplifiers while maintaining precise linearization across the entire power range.
Solution Approach 2:
The invention changes multiple parameters simultaneously - the amplitude of direct currents from different channels and their combination ratios - to control both the shape and amplitude of gain/phase expansions. This multi-parameter control allows the linearizer to match different amplifiers while maintaining precise linearization, resolving the contradiction between adaptability and precision.
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
This approach enables precise control over the shape of gain and phase expansions, significantly enhancing the linearization of power amplifiers across their entire range, improving the accuracy of signal transmission.
Implementation Method 1
a first channel connected to the first output in order to be supplied by the first fraction of the input signal, and arranged to generate a first direct current from a first self-biasing of a first diode as a function of the first fraction of the input signal
Implementation Method 2
responsible for carrying out gain and phase expansions at a port forming an output (of the second channel and of the linearization device) from a second self-biasing of at least one second diode as a function of the second fraction of the input signal
Implementation Method 3
a bias circuit connected to, and supplying with direct voltages, the first and second channels, and responsible for combining, in an opposing manner, the direct voltages and currents originating from the first and second self-biasings of the first and second channels so as to control the shape of the gain and phase expansions
Data Source
AI summary
A predistortion linearization device (D) produces gain and phase expansions making it possible to compensate for the gain compression and phase variation of a power amplifier. This device (D) also allows the conventional adjustment of amplitude, the adjustment of the form of the gain and phase expansions as a function of a microwave input signal (Se).