Power Amplifier Voltage Control for Linearity-Efficiency Tradeoffs

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing power amplifiers in radio transmitters face a tradeoff between efficiency and linearity, with voltage reduction increasing nonlinearity and degrading radio performance, leading to energy waste and suboptimal performance.

Innovation Solution

A method and controller for dynamically controlling the supply voltage of power amplifiers based on nonlinearity thresholds, adjusting voltage levels to maintain optimal efficiency and linearity through dynamic voltage adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If PA voltage is reduced to improve energy efficiency, then power consumption decreases, but nonlinearity increases and radio performance degrades

Engineering Contradiction:
Improvepower consumptionVSAvoidradio performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic voltage control by continuously monitoring nonlinearity metrics (such as ACLR or EVM) and adjusting the PA supply voltage in real-time based on current operating conditions. The controller dynamically selects from multiple voltage levels (e.g., 5V, 3.3V, 1.8V, 0.9V) depending on the measured nonlinearity, allowing the system to adapt to changing signal conditions and maintain optimal performance while minimizing power consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the supply voltage parameter of the PA based on nonlinearity measurements. By monitoring nonlinearity metrics and comparing them against thresholds, the system adjusts the voltage parameter to optimal values - reducing voltage when nonlinearity is acceptable to save power, and increasing voltage when nonlinearity exceeds thresholds to maintain radio performance.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If voltage margins are maintained to ensure radio performance, then linearity is preserved, but energy efficiency decreases

Engineering Contradiction:
Improveradio performanceVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of maintaining fixed voltage margins, the system dynamically adjusts voltage levels based on actual nonlinearity measurements. The controller monitors performance metrics in real-time and only applies voltage margins when necessary, rather than continuously maintaining elevated voltage levels that would consume excess power during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses its own performance measurements (nonlinearity metrics) to automatically control its own supply voltage. The controller monitors the PA's output characteristics and self-regulates the voltage supply, eliminating the need for external intervention or conservative fixed-margin design approaches.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3635874B1Method and controller for controlling power amplifier in radio transmitter as well as radio unit and radio device
Publication Date: 2026.01.14 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3635874B1 patent drawingFigure 1~2
  • EP3635874B1 patent drawingFigure 3~4
  • EP3635874B1 patent drawingFigure 5

AI summary

Method and controller are disclosed for controlling a power amplifier in a radio transmitter. According to an embodiment, a nonlinearity of the power amplifier is determined. A supply voltage to the power amplifier is controlled based on the determined nonlinearity. A radio unit comprising the radio transmitter and a radio device comprising the radio unit are also disclosed.