Solid State RF Amplifier for Microwave Cooking Control

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Solution Overview

Problem

Current microwave cooking appliances using powerful tubes have limited control over microwave emissions, making it difficult to achieve precise heating for specific food items and efficient cooking.

Innovation Solution

A method and apparatus that generate and amplify radio frequency signals using a small signal generator and solid state amplifier, allowing for pulse width modulation and controlled delivery of electromagnetic energy to the cooking cavity based on the gain of the amplifier and desired heating cycle, enabling more precise control over cooking strategies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If powerful tubes are used to generate microwaves, then high power output is achieved, but control over microwave emissions is limited

Engineering Contradiction:

Improvepower outputVSAvoidcontrol over emissions

Core Design Contradiction:

PowerVSEase of operation

Solution Approach 1:

The patent segments the microwave generation system into multiple solid state amplification stages (first amplifier, second amplifier, third amplifier) instead of using a single powerful tube. Each stage can be independently controlled, enabling precise regulation of microwave emissions while maintaining high power output capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the operation of individual amplifier stages based on cooking requirements. The controller can selectively activate or deactivate specific amplifiers (e.g., using only the first and third amplifiers for certain modes, or all three for maximum power), providing flexible and dynamic control over power output and emission characteristics.

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If solid state sources are used, then controlled emissions are achieved, but cooking strategies for specific food items are limited

Engineering Contradiction:

Improvecontrol of emissionsVSAvoidcooking strategies

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements a universal cooking system where the same solid state amplifier infrastructure supports multiple cooking strategies and food types. By combining controlled emission capability with a controller that can select different amplifier combinations and power levels, the system adapts to various cooking requirements (defrosting, reheating, cooking different food types) using the same hardware platform.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system changes operational parameters (which amplifiers are active, power levels, duty cycles) based on the desired cooking strategy. The controller adjusts these parameters dynamically to optimize heating for specific food items while maintaining the benefits of solid state control.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If conventional microwaves are used, then simple operation is maintained, but heating uniformity and efficiency are reduced

Engineering Contradiction:

Improvesimplicity of operationVSAvoidheating uniformity

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent segments the microwave generation into multiple independently controllable solid state amplifiers, each contributing to different spatial or temporal aspects of heating. This segmentation enables more uniform energy distribution throughout the food while maintaining user-friendly operation through automated controller management.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system incorporates feedback mechanisms where the controller monitors heating progress and adjusts amplifier operation accordingly. This feedback loop ensures uniform heating by compensating for variations in food composition, density, and microwave absorption, while the user simply selects from preset cooking modes.

Inventive Principle:

Principle #23Feedback

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 enhances cooking efficiency and uniformity by allowing for tailored cooking cycles and increased electrical efficiency, reducing temperature oscillations and improving the overall performance of microwave cooking appliances.

Implementation Method 1

generating, with a small signal generating component, a radio frequency signal at a first power level that is pulse width modulated at a predetermined duty cycle

Methodology Applied

Scientific EffectPulse Width Modulation:

Implementation Method 2

amplifying the radio frequency signal to a second power level greater than the first power level with a radio frequency amplification component

Methodology Applied

Scientific EffectRadio Frequency Amplification:

Implementation Method 3

Method and apparatus for delivering radio frequency electromagnetic energy to cook foodstuff

Methodology Applied

Scientific EffectDielectric Heating: Dielectric Heating

Data Source

PatentUS10820382B2Method and apparatus for delivering radio frequency electromagnetic energy to cook foodstuff

Publication Date: 2020.10.27 PANASONIC HOLDINGS CORP

AI summary

A method and apparatus for delivering radio frequency electromagnetic energy to cook foodstuff in an enclosed cavity of a cooking device includes generating, with a small signal generating component, a radio frequency signal at a first power level, amplifying the radio frequency signal to a second power level greater than the first power level with a radio frequency amplification component, and feeding the amplified radio frequency signal to the enclosed cavity.