RF Power Amplifier Mode Switching for Intermodulation Control
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Solution Overview
Problem
Existing radio-frequency circuits that simultaneously transmit multiple radio-frequency signals with different frequencies suffer from intermodulation distortion due to signal leakage between power amplifiers, leading to degraded signal quality.
Innovation Solution
A radio-frequency circuit that switches from an envelope tracking mode to an average power tracking mode for at least one power amplifier when its output power exceeds a threshold, reducing intermodulation distortion without decreasing output power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple power amplifiers are used to simultaneously transmit multiple radio-frequency signals, then transmission capability is improved, but intermodulation distortion increases due to signal leakage between amplifiers
Solution Approach 1:
The patent changes the operating parameters of power amplifiers by switching between envelope tracking mode and average power tracking mode based on output power levels. When output power exceeds a threshold, the system switches to average power tracking mode, which operates amplifiers at a fixed back-off power level, thereby reducing intermodulation distortion while maintaining high transmission capability
Solution Approach 2:
The system dynamically adjusts the operating mode of power amplifiers based on real-time output power conditions. By monitoring output power levels and switching between envelope tracking and average power tracking modes, the system adapts to varying transmission requirements while controlling intermodulation distortion
2Object-generated harmful factors
If output power of power amplifiers is reduced to minimize intermodulation distortion, then signal quality is improved, but transmission power decreases
Solution Approach 1:
The system dynamically switches between envelope tracking mode (for low power operation) and average power tracking mode (for high power operation with distortion control). This dynamic mode switching allows the system to maintain high output power when needed while controlling intermodulation distortion through appropriate mode selection
Solution Approach 2:
The patent changes the operating parameters by switching amplifiers between different amplification modes based on output power thresholds. When output power is high, average power tracking mode is used to control distortion; when output power is low, envelope tracking mode is used to maximize efficiency
Data Source
AI summary
A radio-frequency circuit includes a first power amplifier that amplifies a first transmission signal and outputs the first transmission signal amplified; and a second power amplifier that amplifies a second transmission signal different in frequency from the first transmission signal, and outputs the second transmission signal amplified. At least one of the first power amplifier or the second power amplifier switches from ET mode to APT mode, when (1) both the first power amplifier and the second power amplifier are outputting amplified transmission signals and (2) output power of at least one of the first power amplifier or the second power amplifier is greater than a first threshold power.