N-Way Doherty Distributed Amplifier With Power Tracking at Back-Off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional N-way Doherty amplifiers face efficiency and gain degradation at high output back-off power, especially with high peak-to-average power ratio (PAPR) signals, and struggle to optimize gain and output power due to device matching circuit and delay mismatch issues.
Innovation Solution
The implementation of a dual-feed distributed amplifying method with hybrid couplers and transmission lines replaces the power splitter and combiner, along with adaptive bias supply techniques like envelope tracking and average power tracking, to enhance gain and efficiency performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional N-way Doherty amplifier uses power splitter and combiner, then device matching is simplified, but gain is reduced due to splitter loss
Solution Approach 1:
The patent removes the power splitter and combiner components from the conventional N-way Doherty amplifier architecture. Instead, it uses N separate amplifiers with individual power supplies that directly drive the load, eliminating the signal loss associated with splitter and combiner components while maintaining device matching simplicity through independent amplifier design.
Solution Approach 2:
The patent divides the amplifier system into N independent amplifier units, each with its own power supply and control circuitry. This segmentation allows each amplifier to operate independently with optimized matching circuits, avoiding the cumulative loss of traditional splitter-combiner architectures while maintaining overall system coordination through the control unit.
2Use of energy by moving object
If asymmetric Doherty amplifier uses different power device sizes, then efficiency at various back-off powers is improved, but gain and output power optimization becomes difficult due to device matching circuits and delay mismatch
Solution Approach 1:
The patent implements a control unit that receives feedback signals from each amplifier and adjusts the power supply voltages dynamically. This feedback mechanism allows the system to optimize gain and output power automatically, compensating for the complexity of different device sizes and delay mismatches while maintaining high efficiency across various back-off power levels.
Solution Approach 2:
The patent uses dynamically adjustable power supply voltages for each amplifier, controlled by the control unit based on real-time operating conditions. This dynamic adjustment allows the asymmetric Doherty amplifier to adapt to different back-off power levels and optimize performance despite the complexity of different device sizes and timing delays.
3Use of energy by moving object
If conventional N-way Doherty amplifier is used, then efficiency at high output back-off power is improved, but gain and efficiency deteriorate for higher peak-to-average power ratio signals
Solution Approach 1:
The control unit monitors the operating status of each amplifier and adjusts power supply voltages in real-time based on feedback signals. This feedback control enables the system to maintain stable gain and efficiency even when processing high PAPR signals, preventing the performance deterioration seen in conventional N-way Doherty amplifiers.
Solution Approach 2:
The patent dynamically changes the power supply voltage parameters for each amplifier based on the input signal characteristics and operating conditions. By adjusting these parameters in real-time, the system maintains optimal efficiency at high back-off power while preserving gain and linearity for high PAPR signals that would otherwise cause performance deterioration.
Data Source
AI summary
A power amplifier using N-way Doherty structure with adaptive bias supply power tracking for extending the efficiency region over the high peak-to-average power ratio of the multiplexing modulated signals such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. In an embodiment, the present invention uses a dual-feed distributed structure to an N-way Doherty amplifier to improve the isolation between at least one main amplifier and at least one peaking amplifier and, and also to improve both gain and efficiency performance at high output back-off power. Hybrid couplers can be used at either or both of the input and output. In at least some implementations, circuit space is also conserved due to the integration of amplification, power splitting and combining.