Envelope-Tracked Doherty Power Amplifier for Back-Off Efficiency
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Solution Overview
Problem
Existing power amplifiers in base stations face efficiency losses when amplifying signals with high peak-to-average ratios, particularly when using the power back-off method, which results in increased energy consumption and limited improvement in power amplification efficiency.
Innovation Solution
A power amplifier configuration that includes an envelope modulator connected to both the main and auxiliary power amplifiers, using the envelope voltage as operating voltage for both, allowing for simultaneous adjustment and improving symmetry, thereby leveraging the efficiency advantage of Doherty amplifiers under power back-off and combining it with envelope tracking technology to enhance power amplification efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power back-off method is used to amplify signals with high peak-to-average ratio, then linearity of the power amplifier is improved, but power amplification efficiency decreases dramatically and energy consumption increases
Solution Approach 1:
The patent implements dynamic voltage adjustment by using an envelope modulator to track the envelope signal and dynamically adjust the operating voltage of the power amplifier. This allows the amplifier to operate in optimal regions for different signal conditions, maintaining linearity during high peak-to-average ratio signals while improving power amplification efficiency through adaptive voltage control rather than static power back-off
Solution Approach 2:
The patent changes the operating parameter (voltage) of the power amplifier dynamically based on the envelope signal characteristics. By adjusting the voltage parameter in real-time through the envelope modulator, the system achieves both good linearity and improved power amplification efficiency, resolving the contradiction between maintaining signal quality and reducing energy loss
2Loss of energy
If an envelope tracking amplifier and Doherty amplifier are combined, then power amplification efficiency is improved under back-off, but loss of power amplification efficiency is easily caused and improvement is limited
Solution Approach 1:
The envelope modulator serves multiple functions: it tracks the envelope signal, generates the appropriate voltage, and simultaneously controls both the main and auxiliary power amplifiers. This multi-functional design ensures stable and consistent efficiency improvement across different operating conditions without the reliability issues seen in previous combined amplifier designs
Data Source
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AI summary
Embodiments of the present invention provide a power amplifier, a radio remote unit RRU, and a base station. The power amplifier includes: an envelope controller, a main power amplifier, and an auxiliary power amplifier. The main power amplifier and the auxiliary power amplifier both use an envelope voltage output by the envelope modulator as operating voltages, and because the operating voltages of the main power amplifier and the auxiliary power amplifier may be adjusted simultaneously, symmetry of the power amplifier is improved, and there is a low probability that an efficiency loss occurs, thereby enhancing efficiency of the power amplifier.