Multilevel RF Amplifier Supply Modulation for Linearity Control
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Solution Overview
Problem
Achieving high efficiency and high linearity in radio-frequency (RF) amplifier systems, particularly RF power amplifier systems, is a longstanding challenge due to the difficulties in managing drain voltage transitions and reducing unwanted spectral components.
Innovation Solution
A system that modulates power supply signals to RF amplifiers using multi-level power supplies, modulators, and delay circuits to shape spectral components and improve linearity, while reducing noise and unwanted output components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If discrete transitions among operating states are used to improve efficiency, then efficiency is improved, but unwanted spectral components and noise are generated
Solution Approach 1:
The patent divides the single power supply system into multiple discrete power supply levels (e.g., first power supply, second power supply, third power supply). By segmenting the power supply into multiple levels and selectively switching between them, the system achieves efficient operation at different power levels while reducing unwanted spectral components through controlled transitions between segments.
Solution Approach 2:
The patent dynamically switches between different power supply levels based on operating conditions. The system transitions between discrete power supply states (e.g., first power supply level, second power supply level) to adapt to changing RF signal requirements, maintaining efficiency while managing spectral emissions through dynamic power level adjustment.
2Use of energy by moving object
If discrete transitions among operating states are used to improve efficiency, then efficiency is improved, but linearity deteriorates
Solution Approach 1:
The patent segments the power supply into multiple discrete levels with specific voltage values. By carefully selecting and controlling transitions between these segmented power levels, the system maintains linear RF signal amplification while achieving high efficiency operation, resolving the trade-off between efficiency and linearity.
Solution Approach 2:
The patent changes the power supply voltage parameter dynamically by switching between discrete levels (e.g., first power supply voltage, second power supply voltage). This parameter change approach allows the system to optimize both efficiency and linearity by selecting appropriate power supply levels based on operating conditions and signal requirements.
3Use of energy by moving object
If drain voltage is dynamically selected from multiple sources to improve efficiency, then efficiency is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple power supply sources into a unified multilevel power supply system. By combining the first power supply, second power supply, and third power supply into a single integrated system with selective switching capability, the patent reduces device complexity compared to having completely separate power supply circuits while maintaining the efficiency benefits of multiple voltage levels.
Data Source
AI summary
Described is a system for modulating power to one or more radio frequency (RF) amplifiers to suppress undesired output signal components, improve linearity and reduce noise. The described systems and techniques enable shaping of spectral components introduced via an amplifier bias voltage owing to transitions among bias discrete states. The systems and techniques facilitate operation of multilevel, RF amplifiers under a wider range of operating conditions. In embodiments, the system includes modulators coupled to a supply terminal port of each of the one or more amplifiers to modulate the voltage levels supplied to the one or more amplifiers. The outputs of the modulators may be combined to provide a combined signal coupled to the amplifiers. A delay circuit delays switching of at least one of the power modulators relative to other modulator, by a variable time delay. This results in suppression of undesired output signal components of the amplifier output.