ML Envelope Tracking for RF Front-End Power Amplifiers

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Solution Overview

Problem

Existing RFFE modules in wireless communication devices face challenges in efficiently managing power consumption and efficiency, particularly in environments with increasing complexity and throughput, leading to significant power dissipation and inefficiencies in power amplifiers.

Innovation Solution

Implementing envelope tracking systems with machine learning circuitry to monitor and adjust power supply controls, using local feedback loops for linear amplifiers and switching regulators, and incorporating a replica power amplifier for performance tracking to optimize power usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional power management is used in RFFE modules, then device complexity is reduced, but power efficiency deteriorates due to significant power dissipation

Engineering Contradiction:
Improvepower dissipationVSAvoidpower management complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements feedback loops that continuously monitor the power amplifier's operating state and dynamically adjust the power supply voltage accordingly. The envelope tracking circuit receives feedback from the power amplifier's output stage and modulates the supply voltage to match the instantaneous power requirements, minimizing power dissipation while maintaining optimal performance. This feedback mechanism resolves the contradiction by enabling adaptive power management that reduces energy loss without requiring overly complex manual intervention.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The power supply system transitions from a static voltage supply to a dynamic envelope tracking architecture where the supply voltage continuously adapts to the instantaneous power demands of the power amplifier. The system uses dynamic voltage scaling based on the envelope of the modulated signal, allowing the power amplifier to operate at optimal efficiency across varying power levels. This dynamic approach reduces overall power dissipation while managing complexity through automated control circuits.

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If envelope tracking with machine learning is implemented, then power efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvepower efficiencyVSAvoidcircuit complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent introduces machine learning circuitry as an intermediary layer between the power amplifier and the power supply control. This ML intermediary analyzes operating patterns, predicts optimal supply voltage levels, and adjusts power delivery accordingly. By placing the ML block as a mediator, the system achieves improved power efficiency through intelligent prediction and adaptation, while the complexity is contained within a dedicated module rather than distributed throughout the entire RFFE system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The machine learning circuitry performs preliminary analysis of power amplifier operating states and pre-adjusts the power supply voltage before the amplifier actually requires the power. By predicting future power demands based on learned patterns from historical operating data, the system proactively optimizes power delivery, improving overall efficiency. This preliminary action approach allows the system to stay ahead of power requirements rather than reactively responding to them.

Inventive Principle:
Principle #10Preliminary action

3Power

If linear amplifiers and switching regulators are used together, then power performance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvepower performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The patent segments the power supply function into two distinct stages: a switching regulator stage for efficient bulk power conversion, and a linear amplifier stage for precise fine-tuning of the supply voltage. The switching regulator handles the majority of power conversion at high efficiency, while the linear amplifier provides the final voltage precision needed for optimal power amplifier performance. This segmentation allows each component to be optimized independently for its specific function, improving overall power performance while making manufacturing more manageable through modular design.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12500552B2Radio frequency (RF) front end envelope tracking with machine learning
Publication Date: 2025.12.16 QUALCOMM INC
  • US12500552B2 patent drawing
  • US12500552B2 patent drawing
  • US12500552B2 patent drawing

AI summary

Aspects described herein include devices and methods for an envelope tracking power supply. In some aspects, the envelope tracking power supply includes an envelope signal input port, an output power port, an input interface circuit coupled to the envelope signal input port, sensing and conditioning circuitry, and amplifier circuitry coupled between the input interface circuit and the sensing and conditioning circuitry, the amplifier circuitry having one or more control inputs. The envelope tracking power supply additionally includes switcher circuitry coupled to the output of the sensing and conditioning circuitry, and the output power port, and the supply further includes output filter circuitry coupled to the output power port and machine learning circuitry configured to receive state tracking data for performance of a transmit power amplifier (PA) that receives power via the output power port.