Doherty Power Amplifier Phase Control for Envelope Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-efficiency power amplifier technologies, such as Doherty ET power amplifiers, face inefficiencies due to poor phase alignment between main and auxiliary power amplifier links at different envelope voltages, leading to suboptimal performance and efficiency.
Innovation Solution
A power amplifier control method and apparatus that generates phase modulation control signals to optimize the phase difference between the main and auxiliary power amplifier links in a Doherty power amplifier circuit, ensuring optimal phase alignment at varying envelope voltages by using envelope signals to adjust the phase difference to specific values corresponding to current envelope voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If Doherty ET power amplifier technology is used to achieve high efficiency, then back-off efficiency is improved, but phase alignment between main and auxiliary power amplifier links deteriorates at different envelope voltages
Solution Approach 1:
The patent applies dynamics by making the phase shift amount adjustable based on envelope voltage levels. The phase shift between main and auxiliary power amplifier links is dynamically changed according to the current envelope voltage, transitioning from a fixed phase shift to a variable one that adapts to different operating conditions, thereby resolving the phase alignment deterioration while maintaining high back-off efficiency
Solution Approach 2:
The patent changes the phase shift parameter from a fixed value to a variable value that depends on envelope voltage. By adjusting the phase shift amount according to different envelope voltage levels, the system optimizes both efficiency and phase alignment precision under varying operating conditions
2Power
If envelope voltage is increased to improve power amplifier output, then saturation power is improved, but phase difference between main and auxiliary links increases causing performance degradation
Solution Approach 1:
The patent implements feedback by monitoring the envelope voltage level and using it to adjust the phase shift amount. This feedback mechanism ensures that as envelope voltage increases to improve saturation power, the phase shift is simultaneously adjusted to maintain optimal phase alignment, preventing performance degradation
Solution Approach 2:
The system dynamically adjusts the phase shift parameter in response to changing envelope voltage levels. This dynamic adaptation allows the power amplifier to maintain high saturation power while compensating for phase differences that would otherwise degrade performance
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 enhances the efficiency and performance of power amplifiers by optimizing phase differences at different envelope voltages, improving back-off efficiency and increasing saturation power, thus addressing the limitations of existing high-efficiency power amplifier technologies.
Implementation Method 1
a phase modulation circuit, configured to adjust a phase difference between the main power amplifier link and the auxiliary power amplifier link based on the envelope signal
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A power amplifier control method and apparatus, and a power amplifier control system are disclosed, and are applicable to a power amplifier system that includes an envelope control circuit and a Doherty power amplifier circuit. A phase modulation control signal may be generated according to an envelope signal that is output by a baseband unit (401); and phase modulation may be performed on a signal of a main power amplifier link and/or an auxiliary power amplifier link in the Doherty power amplifier circuit according to the phase modulation control signal, so that a phase difference between the signal of the main power amplifier link and the signal of the auxiliary power amplifier link after the phase modulation is a specified value corresponding to a current value of the envelope signal, where the specified value is an optimal phase value of the Doherty power amplifier circuit when the supply voltage of the Doherty power amplifier circuit is an envelope voltage corresponding to the current value of the envelope signal (402). Therefore, problems such as a relatively poor effect and poor performance that exist in an existing high-efficiency power amplifier technology are resolved.