Multilevel LINC Transmitter with Dynamic Out-Phasing Control

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Solution Overview

Problem

Conventional LINC transmitters face a trade-off between power efficiency and linearity due to fixed out-phasing angles, which are not dynamically adjusted according to the input signal envelope, limiting their ability to achieve high power efficiency and linearity.

Innovation Solution

A multilevel LINC transmitter with a multilevel scaler that dynamically adapts the scale factor based on the input signal, allowing adjustable out-phasing angles and enhancing power efficiency and linearity by optimizing the Wilkinson power combiner efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional LINC transmitter uses a fixed scale factor, then the device complexity is reduced, but the power efficiency and linearity deteriorate due to fixed out-phasing angles that cannot adapt to varying input signal envelopes

Engineering Contradiction:
Improveadaptability to input signal envelopeVSAvoidcomplexity of signal component separator
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by replacing the fixed scale factor with a dynamic multilevel scaler that adapts the scale factor based on the input signal envelope. The scaler selects from multiple predefined scale factors (r0, r1, r2, ..., rn) depending on the current envelope level, enabling the out-phasing angle to dynamically adjust to match the input signal characteristics, thereby resolving the contradiction between adaptability and complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of the scale factor from a fixed constant to a variable that can take multiple discrete values. The multilevel scaler modifies the scale factor parameter based on the detected input signal envelope, allowing the system to optimize power efficiency and linearity by selecting appropriate scale factors for different operating conditions without requiring continuous adjustment mechanisms.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the out-phasing angle is fixed, then the manufacturing precision is simplified, but the power efficiency deteriorates because the Wilkinson power combiner cannot operate at optimal efficiency across varying signal conditions

Engineering Contradiction:
Improvepower efficiency of power amplifiersVSAvoidprecision of out-phasing angle
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent makes the out-phasing angle dynamic by linking it to a variable scale factor selected based on the input signal envelope. This allows the Wilkinson power combiner to operate with optimized out-phasing angles for different signal conditions, maximizing power efficiency across varying operating points rather than being constrained to a single fixed angle.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the out-phasing angle parameter from a fixed manufacturing specification to a dynamically adjustable parameter. By selecting from multiple predefined scale factors, the system can optimize the out-phasing angle for different input envelope levels, improving power efficiency without requiring complex continuous adjustment mechanisms that would compromise manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a single scale factor is used, then the device complexity is minimized, but the linearity deteriorates due to inability to maintain constant phase across varying supply voltages and signal conditions

Engineering Contradiction:
Improvelinearity of power amplifiersVSAvoidcomplexity of scaling mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by implementing a multilevel scaler that adjusts the scale factor in response to varying input signal envelopes and supply voltage conditions. This dynamic adjustment maintains the constant phase relationship required for linear operation across different operating conditions, preventing the linearity deterioration that would occur with a fixed scale factor.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the scale factor parameter from a single fixed value to a multi-level variable parameter. The system selects from multiple predefined scale factors based on the input envelope and voltage conditions, enabling the maintenance of constant phase and linear operation across varying conditions without requiring complex continuous control mechanisms.

Inventive Principle:
Principle #35Parameter changes

4Use of energy by moving object

If the scale factor is dynamically adjusted, then the power efficiency is improved, but the device complexity increases due to the need for multilevel scaling and envelope detection

Engineering Contradiction:
Improvepower efficiency of transmitterVSAvoidcomplexity of multilevel scaler
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent implements dynamics through a multilevel scaler that dynamically adjusts the scale factor based on envelope detection. This dynamic adjustment improves power efficiency by optimizing the out-phasing angle for different signal conditions. The complexity is managed by using discrete predefined scale factors rather than continuous adjustment, and by integrating the envelope detection function within the existing signal component separator architecture.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies universality by making the signal component separator perform multiple functions: it separates the input signal into constant envelope components while simultaneously detecting the envelope and controlling the multilevel scaler. This multi-functionality reduces overall device complexity by eliminating separate envelope detection and scaling control circuits.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP1881597B1Multilevel LINC transmitter
Publication Date: 2011.10.19 MEDIATEK INC
  • EP1881597B1 patent drawingFigure 1
  • EP1881597B1 patent drawingFigure 2A
  • EP1881597B1 patent drawingFigure 2B

AI summary

The invention relates to a multilevel LINC transmitter. The multilevel LINC transmitter comprises a multilevel signal component separator, a phase modulator block, and an RF block. The multilevel signal component separator comprises a multilevel scaler and converts a base band signal to constant envelope signals. The phase modulator block is coupled to the multilevel signal component separator. The RF block comprises a plurality of power amplifiers coupled to the phase modulator block and the multilevel scaler and a power combiner coupled to the power amplifiers.