Vector Combining RF Amplification for Linear Complex Envelopes

Solution Overview

Problem

Traditional power amplifiers face a tradeoff between linearity and efficiency, with linear amplifiers being inefficient and non-linear amplifiers producing spectrally distorted output signals, especially in wireless communication systems, and existing outphasing techniques suffer from insertion loss and limited bandwidth, making them unsuitable for complex signal amplification.

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 recombined to minimize non-linear distortion while maximizing efficiency, allowing for efficient amplification of complex signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional linear power amplifiers are used to maintain signal linearity, then output signal quality is improved, but power efficiency deteriorates

Engineering Contradiction:

Improvesignal linearityVSAvoidpower efficiency

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the amplification process into multiple parallel amplifier branches, each handling a portion of the input signal spectrum. This allows each branch to operate more efficiently while maintaining overall signal linearity through coherent combination of the amplified components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary signal processing stage that decomposes the input signal into multiple frequency components before amplification, and another intermediary stage that recombines the amplified components. This mediates between the conflicting requirements of linearity and efficiency by enabling efficient amplification of individual components while preserving overall signal integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 distortion increases

Engineering Contradiction:

Improvepower efficiencyVSAvoidsignal linearity

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent segments the amplification process into multiple parallel amplifier branches, each handling a portion of the input signal spectrum. This allows each branch to operate more efficiently while maintaining overall signal linearity through coherent combination of the amplified components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary signal processing stage that decomposes the input signal into multiple frequency components before amplification, and another intermediary stage that recombines the amplified components. This mediates between the conflicting requirements of linearity and efficiency by enabling efficient amplification of individual components while preserving overall signal integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If existing outphasing techniques are used for signal amplification, then power efficiency is improved, but bandwidth and insertion loss characteristics deteriorate

Engineering Contradiction:

Improvepower efficiencyVSAvoidbandwidth

Core Design Contradiction:

Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent segments the amplification process into multiple parallel amplifier branches, each handling a portion of the input signal spectrum. This allows each branch to operate more efficiently while maintaining overall signal linearity through coherent combination of the amplified components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from traditional time-domain outphasing techniques to a frequency-domain approach by decomposing the signal into multiple frequency components for parallel amplification. This dimensional change in the processing domain enables simultaneous achievement of high efficiency and wide bandwidth by independently optimizing each frequency component.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS8059749B2Systems and methods of RF power transmission, modulation, and amplification, including embodiments for compensating for waveform distortion

Publication Date: 2011.11.15 PARKERVISION INC

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.