Adaptive Bias Coupling Circuit for Power Amplifier Linearity
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Solution Overview
Problem
Conventional bias circuits, particularly adaptive bias circuits, introduce nonlinearity that degrades the linearity of power amplifiers, and existing technologies have not effectively addressed this issue.
Innovation Solution
The implementation of an adaptive coupling circuit that adjusts its impedance based on the power level of the input signal, which is used to modify the bias signal to reduce or eliminate nonlinearity introduced by the bias circuit, thereby optimizing the linearity of the power amplifier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an adaptive bias circuit is used to improve amplifier efficiency, then energy efficiency is improved, but linearity deteriorates due to introduced nonlinearity
Solution Approach 1:
An adaptive coupling circuit is introduced as an intermediary component between the adaptive bias circuit and the amplifier. This coupling circuit modifies the bias signal to compensate for nonlinearity introduced by the adaptive bias circuit, thereby preserving both the efficiency benefits and the linearity performance of the amplifier
2Device complexity
If a fixed coupling circuit is used to connect bias circuit to amplifier, then device complexity is reduced, but linearity performance deteriorates due to inability to compensate nonlinearity
Solution Approach 1:
The coupling circuit transitions from a fixed, static configuration to a dynamic adaptive configuration that automatically adjusts its characteristics based on the amplifier's operating conditions. This enables the coupling circuit to compensate for nonlinearity across different power levels while maintaining manageable complexity through automated adaptation
Data Source
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AI summary
Bias networks for amplifiers are disclosed. An example bias network includes an adaptive bias circuit, configured to generate a bias signal for an amplifier, and further includes a coupling circuit, configured to couple the adaptive bias circuit to the amplifier. The coupling circuit is made adaptive in that its' impedance depends on a power level of an input signal to be amplified by the amplifier. By configuring the coupling circuit to have a variable impedance that depends on the power level of the input signal, the coupling circuit may adapt to the input power level and, thereby, may modify the bias signal to reduce/optimize at least some of the nonlinearity that may be introduced to the bias signal by the adaptive bias circuit.