Digital Upconversion for Multi-Band MOPA Path Calibration

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Solution Overview

Problem

Existing Multi-Order Power Amplifiers (MOPAs) face challenges in accurately controlling gain, phase, and delay of split input signals, especially for multi-band signals, due to frequency dependence and complexity, which limits efficiency and requires frequent calibration across multiple amplification paths.

Innovation Solution

A digital upconversion system that independently controls gain, phase, and delay for each frequency band of multi-band split signals in a Multi-Order Power Amplifier, using digital signal splitters, upconverters with calibration actuators, and digital-to-analog converters to optimize performance parameters like linearity and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If baseband signal splitting is used, then control flexibility is improved, but upconversion chain matching complexity increases

Engineering Contradiction:
Improvecontrol flexibilityVSAvoidupconversion chain matching complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces analog upconversion chain matching with digital signal processing. Digital upconverters and calibration actuators are used to independently control gain, phase, and delay for each frequency band, eliminating the need for precise analog component matching and reducing hardware complexity while maintaining control flexibility

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent dynamically adjusts calibration parameters (gain, phase, delay) for each frequency band through digital calibration actuators. This allows the system to adapt to component variations and frequency-dependent effects by changing digital parameters rather than relying on fixed analog component values

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If analog RF splitting is used, then implementation simplicity is improved, but frequency independence deteriorates

Engineering Contradiction:
Improveimplementation simplicityVSAvoidfrequency independence
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent replaces analog RF splitting with digital signal splitting followed by digital upconversion. This substitution enables frequency-independent control because digital processing can independently manipulate signals at any frequency without being constrained by analog component frequency responses

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent performs digital signal splitting and calibration before upconversion. By pre-calibrating each frequency band independently in the digital domain, the system establishes accurate gain, phase, and delay relationships before the signals are converted to RF, ensuring frequency-independent operation across all bands

Inventive Principle:
Principle #10Preliminary action

3Power

If higher order MOPA is used, then amplification capability is improved, but calibration complexity increases

Engineering Contradiction:
Improveamplification capabilityVSAvoidcalibration complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent divides the calibration process into separate frequency band segments. Each frequency band is calibrated independently using dedicated digital calibration actuators, which simplifies the overall calibration complexity by breaking down the higher order MOPA calibration into manageable, independent tasks rather than requiring simultaneous calibration of all paths

Inventive Principle:
Principle #1Segmentation

4Productivity

If analog upconversion is used, then signal processing capability is improved, but gain phase delay matching accuracy deteriorates

Engineering Contradiction:
Improvesignal processing capabilityVSAvoidgain phase delay matching accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces analog upconversion with digital upconversion. Digital upconverters provide precise, programmable control over gain, phase, and delay parameters without the component tolerances and drift issues inherent in analog circuits. This substitution maintains signal processing capability while dramatically improving matching accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements self-calibration through digital calibration actuators that automatically adjust gain, phase, and delay parameters. The system can compensate for component variations and environmental changes without manual intervention, maintaining high accuracy through automated digital correction rather than relying on precision analog component selection

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2878078B1Digital upconversion for multi-band multi-order power amplifiers
Publication Date: 2020.02.19 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2878078B1 patent drawingFigure 1
  • EP2878078B1 patent drawingFigure 2
  • EP2878078B1 patent drawingFigure 3

AI summary

The present disclosure relates to digital up-conversion for a multi-band Multi-Order Power Amplifier (MOPA) that enables precise and accurate control of gain, phase, and delay of multi-band split signals input to the multi-band MOPA. In general, a multi-band MOPA is configured to amplify a multi-band signal that is split across a number, N, of inputs of the multi-band MOPA as a number, N, of multi-band split signals, where N is an order of the multi-band MOPA and is greater than or equal to 2. A digital upconversion system for the multi-band MOPA is configured to independently control a gain, phase, and delay for each of a number, M, of frequency bands of the multi-band signal for each of at least N-1, and preferably all, of the multi-band split signals.