Microwave Heating Device Uniform Distribution via Waveguide Node Placement

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Solution Overview

Problem

Conventional microwave heating devices face challenges in achieving uniform heating without the use of driving mechanisms, leading to non-uniform microwave distribution and increased size and complexity due to the need for rotating tables or antennas, which also reduces reliability and efficiency.

Innovation Solution

A microwave heating device with microwave radiating portions arranged orthogonal to the electric field and propagation direction within the waveguide, positioned at approximate node positions to achieve uniform microwave distribution without the need for driving mechanisms, utilizing circular polarization to enhance heating uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a rotatable table or antenna mechanism is used to achieve uniform heating, then heating uniformity is improved, but device complexity and size increase

Engineering Contradiction:
Improveheating uniformityVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The waveguide tube is divided into multiple sections along the propagation direction, with each section containing a microwave radiating portion. These radiating portions are positioned at different locations (including node positions of the electric field) to segment the microwave radiation into multiple zones, achieving uniform heating without requiring mechanical rotation or movement of the entire system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of achieving uniformity through temporal changes (rotation over time), the invention uses spatial distribution by arranging multiple microwave radiating portions at different positions within the waveguide tube, including at node positions of the electric field. This transforms the problem from a temporal to a spatial solution, eliminating the need for rotating mechanisms.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If a rotatable table or antenna mechanism is used to achieve uniform heating, then heating uniformity is improved, but reliability decreases

Engineering Contradiction:
Improveheating uniformityVSAvoidreliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention extracts and eliminates the rotating table or antenna mechanism from the system. By using a fixed waveguide tube with multiple strategically positioned microwave radiating portions, the patent removes the unreliable moving parts while maintaining heating uniformity through proper spatial arrangement of the radiating elements.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If multiple microwave radiating portions are arranged at node positions, then heating uniformity is improved, but waveguide tube length increases

Engineering Contradiction:
Improveheating uniformityVSAvoidwaveguide tube length
Core Design Contradiction:
Manufacturing precisionVSLength of stationary object

Solution Approach 1:

The waveguide tube is designed with non-uniform characteristics by positioning microwave radiating portions at specific locations including node positions of the electric field. This creates local variations in the electromagnetic field distribution, allowing uniform heating to be achieved in the heating chamber without requiring excessive overall waveguide tube length.

Inventive Principle:
Principle #3Local quality

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 configuration allows for uniform heating of objects within the microwave heating device, reducing size and complexity while improving reliability and efficiency by ensuring consistent microwave distribution across the heating chamber.

Implementation Method 1

microwave heating devices such as microwave ovens which radiate microwaves to objects to be heated so as to perform dielectric heating

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Implementation Method 2

a microwave generation portion adapted to generate a microwave; a waveguide portion adapted to propagate the microwave; and a plurality of microwave radiating portions

Methodology Applied
Scientific EffectMicrowave radiation: Microwave Radiation

Data Source

PatentEP2824991B1Microwave heating device
Publication Date: 2019.11.27 PANASONIC HOLDINGS CORP
  • EP2824991B1 patent drawingFigure 1
  • EP2824991B1 patent drawingFigure 2(a)~2(b)
  • EP2824991B1 patent drawingFigure 3

AI summary

A microwave heating device of the present invention comprises a heating chamber 103 housing an object to be heated, a microwave generation portion 202 generating a microwave, a waveguide portion 201 propagating the microwave, and a plurality of microwave radiating portions 102 radiating the microwave in the heating chamber 103, wherein the microwave radiating portions are arranged in a direction orthogonal to a direction of electric field and to a direction of propagation within the waveguide portion 201 , and centers of the microwave radiating portions are arranged at positions corresponding to approximate node positions of the electric field within the waveguide portion. The microwave heating device is enabled to make uniform heat distribution in the object to be heated, without using a driving mechanism.