Outphasing RF Amplifier Paths for Linear Constant-Envelope Transmission
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Solution Overview
Problem
Linear power amplifiers used for radio frequency transmission are inefficient and costly, leading to suboptimal signal amplification with potential nonlinear distortions.
Innovation Solution
The apparatus decomposes input signals into multiple constant-envelope components, applies discrete phase control and amplification in outphasing paths using non-linear amplifiers, and combines the outputs for efficient transmission, allowing for linear amplification with cheaper and more energy-efficient components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If linear power amplifiers are used for radio frequency transmission, then signal amplification is linear and non-linear distortions are avoided, but energy efficiency deteriorates and cost increases
Solution Approach 1:
The input signal is decomposed into multiple constant-envelope signal components through signal decomposition circuitry. Each component is then processed by a separate non-linear power amplifier, allowing the system to achieve linear amplification of the composite signal while using efficient non-linear amplifiers, thus resolving the contradiction between signal quality and power efficiency
Solution Approach 2:
Constant-envelope signal components serve as intermediaries between the original signal and the non-linear amplifiers. These components have constant amplitude envelopes that are suitable for efficient non-linear amplification, while their phase variations carry the original signal information, enabling linear amplification效果 through the intermediary representation
2Reliability
If linear power amplifiers are used for radio frequency transmission, then signal amplification is linear, but device cost increases
Solution Approach 1:
The signal is segmented into multiple constant-envelope components that can be amplified by cheaper non-linear power amplifiers. The segmentation allows the use of cost-effective non-linear amplifier technology while maintaining linear amplification performance through the combination of multiple amplified components
Solution Approach 2:
The invention replaces expensive linear power amplifiers with multiple cheaper non-linear power amplifiers. While individual non-linear amplifiers are less efficient, their lower cost and the ability to use multiple units in parallel provides a cost-effective solution that achieves the desired linear amplification performance
3Use of energy by moving object
If non-linear amplifiers are used for signal amplification, then power efficiency improves, but non-linear distortions are created in the amplified signal
Solution Approach 1:
The original signal is segmented into multiple constant-envelope components, each of which can be efficiently amplified by non-linear power amplifiers without creating significant distortion. The segmented structure allows each component to remain within the efficient operating range of non-linear amplifiers while preserving the overall signal integrity through proper reconstruction
Solution Approach 2:
The invention changes the parameter representation of the signal from amplitude-modulated form to phase-modulated constant-envelope form. This parameter transformation allows the signal to be processed by non-linear amplifiers in a way that maintains signal quality, as non-linear amplifiers handle constant-envelope signals more efficiently with reduced distortion
Data Source
AI summary
An apparatus is provided that includes circuitry for decomposing an input signal to multiple substantially constant-envelope components and an outphasing path for each substantially constant-envelope component. The apparatus also includes a modulator for discrete phase control in each outphasing path, an amplifier in each outphasing path and a combiner for combining output signals from the outphasing paths. A system and method are also provided.