Microwave Heating Field Adjustment via Impedance Control
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Solution Overview
Problem
Existing microwave heating devices suffer from uneven heating due to standing waves and electric power loss, making it difficult to achieve uniform heating while maintaining efficiency, especially in consumer appliances like microwave ovens.
Innovation Solution
A low-cost electromagnetic field distribution adjustment device with a matrix arrangement of metal pieces and switches that connect them, allowing for impedance control by switching between zero and infinite impedance, thereby altering the standing wave distribution and preventing uneven heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If switches are operated to change impedance near metal pieces, then electromagnetic field distribution is adjusted, but electric power loss occurs and heating efficiency deteriorates
Solution Approach 1:
The electromagnetic field distribution adjustment device automatically adjusts impedance distribution without requiring external switch operations. The system self-regulates the electromagnetic field by utilizing the natural interaction between microwaves and the metal piece arrangement, eliminating the need for active switching control and associated power losses.
Solution Approach 2:
The adjustment device divides the heating chamber into multiple regions by arranging numerous metal pieces in specific patterns. This segmentation allows different impedance values to be created in different spatial zones, enabling localized electromagnetic field control and uniform energy distribution throughout the chamber without requiring power-intensive switching operations.
2Reliability
If a large number of switches are wired physically and controlled simultaneously, then impedance control is achieved, but device complexity and cost increase
Solution Approach 1:
The system eliminates the need for complex switch wiring and control mechanisms by using a passive metal piece arrangement that automatically creates the desired impedance distribution. The structure itself performs the control function without requiring external actuators, sensors, or control electronics.
Solution Approach 2:
The invention replaces expensive and complex switch mechanisms with simple, inexpensive metal pieces that can be easily manufactured and positioned. These metal pieces serve as permanent or semi-permanent impedance control elements, eliminating the need for costly switching infrastructure while maintaining effective impedance control.
3Reliability
If metal pieces are arranged in a matrix with multiple switches connecting them, then electromagnetic field distribution is adjusted, but manufacturing cost increases
Solution Approach 1:
The invention uses simple, inexpensive metal pieces instead of complex switch assemblies. These metal pieces can be manufactured using basic fabrication processes and arranged in the desired pattern, significantly reducing manufacturing costs while maintaining the ability to adjust electromagnetic field distribution.
Solution Approach 2:
The invention combines the functions of multiple switches and control mechanisms into a single passive metal piece structure. By merging these functions into the geometric arrangement and material properties of the metal pieces themselves, the system achieves electromagnetic field control without the need for separate switching components, thereby reducing overall manufacturing complexity and cost.
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 solution ensures uniform heating of objects while maintaining heating efficiency by selectively interchanging the positions of nodes and antinodes of standing waves, reducing energy loss and improving heating uniformity.
Implementation Method 1
The electromagnetic field distribution adjustment device is configured to change impedance near the plurality of metal pieces
Implementation Method 2
uneven heating occurs concentrically due to generation of standing waves in a heating chamber
Implementation Method 3
For microwave heating devices such as a microwave oven, it is desired to heat an object to be heated
Data Source
AI summary
A microwave heating device includes a heating chamber that accommodates an object to be heated, a microwave generator configured to generate microwaves, a wave guide tube configured to guide the microwaves to the heating chamber, and an electromagnetic field distribution adjustment device provided in a predetermined two-dimensional region within the heating chamber. The electromagnetic field distribution adjustment device has a plurality of metal pieces and a plurality of switches. The plurality of metal pieces are arranged to fill the predetermined two-dimensional region. The plurality of switches connect the plurality of metal pieces with one another. A serially connected row of metal pieces is configured by connecting one metal piece among the plurality of metal pieces to at most two metal pieces adjacent to the one metal piece through at least two of the plurality of switches. The present exemplary embodiment can achieve a low-cost electromagnetic field distribution adjustment device that heats an object to be heated more uniformly, while preventing a drop in heating efficiency.