Magnetron Pole Piece Dimensions and Copper Plating for Efficiency
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Solution Overview
Problem
Conventional magnetrons face inefficiencies in oscillation and load stability due to mismatched loads and inadequate harmonic noise restriction, leading to reduced microwave power and non-compliance with noise standards.
Innovation Solution
The magnetron design is enhanced by adjusting the dimensions of pole pieces and choke coils, and incorporating a copper-plated metal body around the antenna lead to improve oscillation efficiency, load stability, and harmonic noise restriction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the magnetron uses conventional pole piece dimensions, then the structure is simple, but oscillation efficiency and load stability deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the dimensions of pole pieces (specifically the diameter of the second flat portion and first hole) to improve electron distribution and oscillation efficiency. The dimensional parameters are adjusted within specific ranges to achieve better load stability and oscillation characteristics without fundamentally changing the pole piece structure.
2Object-generated harmful factors
If metal cylinders are used in the λ/4 type choke structure, then harmonic noise is restricted, but Joule loss increases and circuit efficiency deteriorates
Solution Approach 1:
The patent applies composite materials by using copper plating on the metal cylinders of the λ/4 type choke structure. The copper layer reduces Joule loss and improves circuit efficiency while the underlying metal structure maintains the harmonic noise restriction function. This composite approach allows the system to achieve both noise filtering and energy efficiency.
3Loss of energy
If the magnetron is designed for high efficiency with smaller tube body, then energy saving is improved, but load stability deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the dimensional parameters of pole pieces and choke coils to achieve high oscillation efficiency and energy saving in a compact magnetron design, while maintaining load stability through precise parameter selection within specified ranges.
Solution Approach 2:
The patent applies feedback by considering load characteristics (Ricke diagram) in the design of pole piece dimensions and choke coil parameters. The optimized dimensions create a system that maintains stable oscillation under varying load conditions, effectively providing inherent feedback stability through the tuned electromagnetic parameters.
4Productivity
If conventional pole piece dimensions are used, then manufacturing is simple, but electron distribution and oscillation efficiency are insufficient
Solution Approach 1:
The patent specifies optimized dimensional parameters for pole pieces (second flat portion diameter: 9.5-10.5mm, first hole diameter: 8.0-8.2mm) that improve electron distribution and oscillation efficiency. These parameter changes require controlled manufacturing precision but remain within achievable tolerances for standard manufacturing processes.
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 design achieves higher oscillation efficiency, improved load stability, and reduced energy consumption while meeting noise standards by optimizing the distribution of electrons and reducing Joule losses through the copper plating.
Implementation Method 1
resistance of a skin based on skin effect, determined by permeability, resistivity, and frequency of a material
Implementation Method 2
a group of electrons is generated in the working space between the filament and the vanes. The group of electrons is spirally rotated under the influence of a strong electric field and a magnetic field created in the working space, causing radio waves to be directed to the vanes
Data Source
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AI summary
A magnetron includes a yoke (210), an anode unit (230) including an anode cylinder (232) , radially arranged vanes (233) , and first (234) and second (235) pole pieces at both sides of the anode cylinder, a cathode unit (240) having a filament (241) spaced apart from the vanes, and an output unit (270) having an antenna lead (271) connected to one vane to radiate high-frequency microwaves. The first pole piece (234) includes a first flat portion (234b), a slope (234a) at an inner side of the first flat portion, a second flat portion (234e) at an inner side of the slope and having a diameter (Dpa2) of 9.5∼10.5 mm, a first hole formed in the second flat portion and having a diameter (Dpa1) of 8∼8.2 mm, and a second hole (234d) formed in the slope for penetration of the antenna lead. The magnetron achieves higher and stabilized efficiency, restricted oscillation efficiency variation, lower energy consumption, and improved load stability without deterioration of oscillation efficiency.