Power Amplifier Bias and Clipping Control for Variable Network Load

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Solution Overview

Problem

Current amplification systems, particularly those using Doherty architecture, are inefficient at managing varying signal power levels, leading to high energy consumption and greenhouse gas emissions, as they are optimized for high load conditions but often operate at low average daily loads in mobile networks.

Innovation Solution

An amplification system comprising a crest factor reduction module, power amplifiers, a drain bias controller, a gate bias controller, and a controller module that dynamically adjusts clipping parameters and bias voltages based on input signal information, including load factor and modulation, to optimize energy consumption and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If Doherty power amplifier architecture is used to optimize for full power, then high efficiency is achieved at high load, but efficiency deteriorates at low average daily load (5-30%)

Engineering Contradiction:
Improvepower amplifier energy consumptionVSAvoidadaptation to varying load conditions
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The power amplifier system dynamically adjusts its operating parameters including bias voltages and clipping thresholds based on real-time signal characteristics and load conditions. The controller module continuously monitors input signal parameters and adapts the amplification system accordingly, transitioning from static Doherty optimization to dynamic adaptation across varying load scenarios.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes multiple operating parameters simultaneously including drain bias voltage, gate bias voltage, and clipping parameters based on input signal information. This multi-parameter adjustment enables the power amplifier to maintain high efficiency across different load conditions by optimizing each parameter for the current operating point.

Inventive Principle:
Principle #35Parameter changes

2Power

If power amplifier biasing is maintained for continuous operation, then high power output is ensured, but energy consumption increases during low load periods

Engineering Contradiction:
Improvepower amplifier output powerVSAvoidpower amplifier energy consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The system applies partial biasing to the power amplifier based on actual load requirements. Instead of maintaining full bias continuously, the controller adjusts bias levels to match the required power output, applying only the necessary amount of biasing to achieve the needed power level while minimizing energy consumption during low load periods.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The power amplifier system monitors its own operating conditions and automatically adjusts its biasing and clipping parameters without external intervention. The controller module uses input signal information to self-regulate the amplification process, optimizing the balance between power output and energy consumption based on real-time conditions.

Inventive Principle:
Principle #25Self-service

3Device complexity

If clipping parameters are fixed, then amplifier design is simplified, but efficiency cannot be optimized for varying signal characteristics

Engineering Contradiction:
Improveamplifier control system complexityVSAvoidamplification system efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The controller module implements a feedback mechanism that monitors input signal parameters and uses this information to dynamically adjust clipping parameters and bias voltages. The system continuously measures signal characteristics and feeds this information back to the controller, which then optimizes the amplification parameters accordingly, creating a closed-loop control system that adapts to varying signal conditions.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3309960B1Amplification system and enodeb
Publication Date: 2019.08.21 NOKIA TECHNOLOGIES OY
  • EP3309960B1 patent drawingFigure 1-a~2-a
  • EP3309960B1 patent drawingFigure 2-b~3-b

AI summary

Amplification system and associated eNodeB. This amplification system comprises: a crest factor reduction module configured to clip an input signal and at least one power amplifier configured to amplify the clipped signal and a drain bias controller, providing a drain bias voltage to the power amplifier and a gate bias controller, providing a gate bias voltage to the power amplifier and a controller module. Furthermore, within this amplification system, the controller module is configured to use an information parameters of the input signal to control clipping parameters of the crest factor reduction module and the drain bias controller and the gate bias controller.