Two-Stage Power Amplifier Control for PAPR-Driven Gain Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power amplifier modules face challenges in achieving both linearity and efficiency, particularly due to variations in gain caused by switching between multiple amplification paths, which also increase the module size and result in switching losses.
Innovation Solution
A power amplifier module with a first amplifier circuit and a second amplifier circuit, where the second control signal increases the power-supply voltage for the second amplifier as the peak-to-average power ratio of the RF signal increases, and the first control signal compensates for variations in the second gain caused by changes in power-supply voltage, allowing for flexible gain control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple amplification paths are switched to adapt to different PAPR signals, then linearity and efficiency are improved, but gain variations occur and module size increases
Solution Approach 1:
The patent implements dynamic gain control by adjusting the power supply voltage to the second amplifier circuit based on the detected PAPR of the RF signal. When PAPR is high, the voltage is increased to improve linearity; when PAPR is low, the voltage is reduced to improve efficiency. This dynamic adjustment eliminates the need for multiple fixed amplification paths while adapting to different signal conditions.
Solution Approach 2:
The patent changes the power supply voltage parameter of the second amplifier circuit according to the PAPR of the input signal. By varying this electrical parameter dynamically, the amplifier can operate in different modes (high linearity or high efficiency) without requiring multiple physical amplification paths, thus reducing module size while maintaining performance.
2Reliability
If multiple amplification paths are used to handle different PAPR signals, then linearity and efficiency are improved, but switching losses occur
Solution Approach 1:
The patent uses a single continuous amplification path with dynamic power supply voltage control instead of switching between multiple amplification paths. The amplifier continuously processes the signal while the power supply voltage is adjusted smoothly based on PAPR detection, eliminating the discontinuities and energy losses associated with switching operations.
3Reliability
If the power-supply voltage for the second amplifier is increased to improve linearity, then gain increases, but gain variation occurs
Solution Approach 1:
The patent employs a feedback mechanism where the control unit detects the PAPR of the RF signal and adjusts the power supply voltage to the second amplifier circuit accordingly. This closed-loop control ensures that the gain variation caused by voltage changes is compensated, maintaining overall gain stability while achieving the desired linearity improvement when high PAPR signals are detected.
Data Source
AI summary
A power amplifier module includes a first amplifier circuit that amplifies a radio frequency signal with a first gain corresponding to a first control signal to generate a first amplified signal; a second amplifier circuit that amplifies the first amplified signal with a second gain corresponding to a second control signal to generate a second amplified signal; and a control unit that generates the first control signal and the second control signal. The second control signal is a control signal for increasing a power-supply voltage for the second amplifier circuit as a peak-to-average power ratio of the radio frequency signal increases. The first control signal is a control signal for controlling the first gain of the first amplifier circuit so that a variation in the second gain involved in a variation in the power-supply voltage for the second amplifier circuit is compensated for.