Class-F Amplifier Filtering for Aerosol Heater Power Control

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Solution Overview

Problem

Existing aerosol generating devices face challenges in efficiently controlling power delivery for induction heating due to harmonic components, which affect power efficiency and device size.

Innovation Solution

An aerosol generating device utilizing a class-F amplifier to amplify power signals and eliminate harmonic components through a series of filters, including a first filter to remove even harmonics, a second filter to remove odd harmonics, and a third filter to remove resonance frequency components, ensuring efficient power delivery to the heating element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If power amplification is used to improve power efficiency, then power efficiency is improved, but harmonic components are generated that affect signal quality

Engineering Contradiction:
Improvepower efficiencyVSAvoidharmonic components
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies class-F power amplifier technology that intentionally utilizes harmonic components to improve power efficiency. The amplifier is designed to operate in a nonlinear region where harmonic frequencies are generated, but these harmonics are then recycled and reused through feedback circuits to enhance the fundamental output power, converting what would normally be wasted energy into useful power output.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces intermediate filtering stages and feedback circuits that selectively process different frequency components. These intermediary elements separate the harmful harmonic components from the useful fundamental frequency, allowing the harmonics to be redirected and utilized constructively while maintaining signal quality for the primary aerosol generation function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If device size is reduced for portability, then portability is improved, but power control capability deteriorates

Engineering Contradiction:
Improvedevice sizeVSAvoidpower control capability
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The patent integrates multiple functions into compact components. The power amplifier circuit performs both power enhancement and harmonic management functions simultaneously. The control system integrates temperature sensing, power regulation, and harmonic filtering control in a single integrated circuit, allowing sophisticated power control capability to be maintained in a miniaturized form factor suitable for portable aerosol generation devices.

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

Solution Approach 2:

The patent employs nested circuit architectures where control circuits are integrated within amplifier stages, and filtering functions are embedded within the power delivery path. This nesting allows multiple control and processing functions to be contained within progressively smaller integrated packages, maintaining full power control capability while minimizing overall device volume for portability.

Inventive Principle:
Principle #7Nested doll (Nesting)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables efficient power control for induction heating, reducing the device size while maintaining signal linearity and improving power efficiency.

Implementation Method 1

generate a first signal by amplifying a power signal provided by the battery through a switching element

Methodology Applied
Scientific EffectPower amplification:

Implementation Method 2

generate a second signal through a filter by eliminating a harmonic component from the first signal

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Implementation Method 3

a heating body configured to heat at least a part of an aerosol generating article, wherein the heating body includes an induction coil

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 4

aerosol generating device comprises a resonance circuit to which a capacitor is connected

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP4333658B1Aerosol generating device for controlling heating through power amplification and operating method thereof
Publication Date: 2026.02.04 KT&G CO LTD
  • EP4333658B1 patent drawingFigure 1~3
  • EP4333658B1 patent drawingFigure 4~5
  • EP4333658B1 patent drawingFigure 6~7

AI summary

According to an embodiment, an aerosol generating device includes: a battery configured to provide power; a heating body configured to heat at least a part of an aerosol generating article; and an amplifier circuit electrically connected to the battery and the heating body, wherein the amplifier circuit generates a first signal by amplifying a power signal provided by the battery through a switching element, generates a second signal through a filter by eliminating a harmonic component from the first signal, and delivers the second signal to the heating body.