Vector Combining RF Amplifiers for Linearity and Power Efficiency
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Solution Overview
Problem
Traditional power amplifiers face a tradeoff between linearity and power efficiency, with linear amplifiers being inefficient and non-linear amplifiers producing spectrally distorted output signals, especially in wireless communication systems with high peak-to-average power ratios, and existing outphasing techniques suffer from insertion loss and limited bandwidth.
Innovation Solution
The method of vector combining power amplification, where a time-varying complex envelope signal is decomposed into substantially constant envelope signals, amplified individually, and then re-combined to minimize non-linear distortion while maximizing power efficiency, allowing for efficient amplification of complex signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If linear power amplifiers are used to maintain signal linearity, then output signal quality is improved, but power efficiency deteriorates
Solution Approach 1:
The patent segments a single linear power amplifier into multiple non-linear power amplifiers operating in parallel. Each amplifier handles a portion of the signal spectrum or power range, allowing the system to achieve linear output through constructive combination while each individual amplifier operates inefficiently. This segmentation resolves the contradiction by distributing the linearity requirement across multiple components rather than demanding it from a single efficient amplifier.
Solution Approach 2:
The patent merges outputs from multiple non-linear power amplifiers to produce a combined linear signal. By carefully controlling the phase and amplitude of each amplifier's output and combining them constructively, the system achieves linear overall performance while maintaining high power efficiency through non-linear operation of individual amplifiers. This merging approach allows simultaneous achievement of both linearity and efficiency that are contradictory in single-amplifier systems.
2Use of energy by moving object
If non-linear power amplifiers are used to improve power efficiency, then power consumption is reduced, but output signal linearity deteriorates causing spectral distortion
Solution Approach 1:
The patent segments the signal processing function across multiple non-linear amplifiers, each operating in its efficient non-linear region. By dividing the overall signal into multiple components that can be handled by individual non-linear amplifiers, the system maintains high power efficiency while the collective output achieves linearity through coordinated combination of these segmented amplifier outputs.
Solution Approach 2:
The patent employs feedback mechanisms to monitor and adjust the outputs of non-linear power amplifiers. By measuring the combined output signal and adjusting the phase, amplitude, or operating parameters of individual amplifiers, the system compensates for non-linear distortions and maintains signal linearity while allowing each amplifier to operate efficiently in its non-linear region.
3Power
If traditional power combining techniques are used to combine amplifier outputs, then signal power is increased, but insertion loss and limited bandwidth occur
Solution Approach 1:
The patent replaces traditional mechanical power combining techniques (such as resistive or transformer-based combiners) with a phase-controlled signal addition approach. By using phase shifters and controlled signal routing to combine amplifier outputs constructively in the voltage domain before power dissipation occurs, the system achieves high output power with minimal insertion loss, substituting mechanical combining with a more efficient phase-controlled electrical combination method.
Data Source
AI summary
Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.