Waveguide Antenna Step Structure for Uniform Microwave Heating
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Solution Overview
Problem
Existing microwave ovens face challenges in uniformly heating a heating-target object, particularly at the central area, due to the configuration of rotating antennas which can obstruct direct microwave radiation and result in complex structures that increase device size.
Innovation Solution
A microwave heating device with a waveguide structure antenna featuring a ceiling surface and side walls defining a waveguide section, including microwave extraction openings on the ceiling surface for emitting circularly polarized waves, and a step area near the coupling part to facilitate uniform heating of the central area without the need for complex mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a rotating antenna with waveguide structure is used to achieve uniform heating, then heating uniformity is improved, but device complexity and size increase
Solution Approach 1:
The waveguide structure is divided into multiple functional sections: a coupling section for microwave input, a resonant cavity section with specific dimensions for mode generation, and an emission section with extraction openings. This segmentation allows each part to perform its function optimally while keeping the overall structure compact and manageable.
Solution Approach 2:
Different regions of the waveguide structure are designed with different properties: the coupling section has specific impedance matching features, the resonant cavity has controlled dimensions for TE101 mode generation, and the emission section has strategically placed extraction openings. This local differentiation enables uniform heating without requiring complex rotating mechanisms.
2Area of stationary object
If a rotating antenna mechanism is implemented to heat central area objects, then heating coverage is improved, but device size increases
Solution Approach 1:
Instead of using mechanical rotation in the horizontal plane, the invention utilizes electromagnetic wave propagation in three-dimensional space within the resonant cavity. The TE101 mode creates standing wave patterns that naturally distribute energy throughout the heating chamber, eliminating the need for rotating mechanisms and reducing device volume.
Solution Approach 2:
The mechanical rotation system is replaced with an electromagnetic field-based solution. The waveguide structure generates and directs microwave energy through electromagnetic modes rather than mechanical movement, achieving uniform heating coverage without the complexity and size of rotating antenna mechanisms.
3Productivity
If microwave extraction openings are added to the waveguide structure, then microwave extraction efficiency is improved, but device complexity increases
Solution Approach 1:
The waveguide structure is pre-designed with optimized extraction opening positions and dimensions before operation. The openings are strategically located to maximize microwave coupling into the heating chamber while maintaining structural simplicity. This preliminary optimization achieves high extraction efficiency without requiring complex adjustable mechanisms.
Solution Approach 2:
The extraction openings have specific dimensional parameters (size, shape, position) that are optimized for maximum microwave energy transfer. By carefully controlling these geometric parameters, the design achieves high extraction efficiency while keeping the overall structure simple and manufacturable.
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
The device achieves uniform heating of the central area of the loading surface, preventing temperature decreases and enhancing microwave extraction efficiency, while maintaining a compact size.
Implementation Method 1
a waveguide structure antenna 5 having a ceiling surface 9 and side wall surfaces 10a, 10b, 10c
Implementation Method 2
emit circularly polarized waves from the microwave extraction opening 14 into the heating chamber 2a
Implementation Method 3
The waveguide structure section 8 has, at a portion of the ceiling surface 9, which is closer to the coupling part 7 than to the microwave extraction opening 14, a step area 9a
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
Waveguide structure antenna (5) has ceiling surface (9) and side wall surfaces (10a, 10b, 10c) defining waveguide structure section (8), as well as has front opening (13) to emit microwaves from front opening (13) toward a heating-target object. Waveguide structure section (8) includes a coupling part joined to ceiling surface (9) to couple microwaves into an internal space of waveguide structure section (8). Waveguide structure section (8) includes at least one microwave extraction opening (14) formed on ceiling surface (9) to emit circularly polarized waves from microwave extraction opening (14) into a heating chamber. Waveguide structure section (8) has, at a portion of ceiling surface (9), which is closer to the coupling part than to microwave extraction openings (14), step area (9a) having a height that differs from heights of other portions of ceiling surface (9). According to this configuration, a heating-target object loaded on a central area of a loading surface can uniformly be heated.