A microwave oven

Abstract

This application discloses a microwave oven, which includes a transformer, a voltage doubler rectifier assembly, and a magnetron connected in sequence. The connection between the magnetron and the voltage doubler rectifier assembly is a first connection, and the connection between the transformer and the voltage doubler rectifier assembly is a second connection. The first connection, the voltage doubler rectifier assembly, and the second connection are disposed within a shielding cavity. By integrating the magnetron and the transformer, the radiation emission source of the microwave oven is shielded within the shielding cavity of the integrated connection, isolating it from the outside world, thereby reducing the external radiation emission of the microwave oven and improving EMC performance. Furthermore, the integrated design of the magnetron and the transformer can reduce the size of the microwave oven.

Description

Technical Field

[0001] This application relates to the field of electrical technology, and in particular to a microwave oven. Background Technology

[0002] Electromagnetic compatibility (EMC) of electrical products is a very important quality indicator. It not only relates to the reliability and safety of the electrical products themselves, but also affects the normal operation of other equipment and systems.

[0003] There are two main pathways for EMC radiation emissions from a fixed-frequency microwave oven. The first pathway is generated by the magnetron and the diodes on the secondary side of the transformer, which radiate outwards through the cathode wire and then through the gaps in the microwave oven casing. The second pathway is generated by the magnetron and the diodes on the secondary side of the transformer, which radiate outwards from the secondary side to the primary side and then through the input line, based on the distributed parameters between the primary and secondary sides of the transformer.

[0004] The existing solution involves adding an LC filter to the cathode wire port of the magnetron to suppress radiated emissions in the 30MHz-1GHz range. However, this solution only addresses radiated emissions from the cathode wire of a fixed-frequency microwave oven; it is ineffective against noise at the high-voltage diode, and degraded filter performance may lead to excessive radiation levels during testing.

[0005] The above statements are for the purpose of providing background information in relation to this application only and do not necessarily constitute prior art. Summary of the Invention

[0006] The main technical problem addressed in this application is how to reduce the external radiation emitted by microwave ovens.

[0007] To solve the above-mentioned technical problems, one technical solution adopted in this application is: to provide a microwave oven, which includes a transformer, a voltage doubler rectifier assembly and a magnetron connected in sequence; the connection between the magnetron and the voltage doubler rectifier assembly is the first connection, the connection between the transformer and the voltage doubler rectifier assembly is the second connection, and the first connection, the voltage doubler rectifier assembly and the second connection are disposed in a shielded cavity.

[0008] In one specific embodiment, the first connection is the electrical connection between the voltage doubler rectifier assembly and the cathode wire of the magnetron, with one end of the magnetron having the cathode wire disposed inside the shielding cavity.

[0009] In one specific embodiment, the second connection is the electrical connection between the voltage doubler rectifier assembly and the secondary winding of the transformer, and the secondary winding of the transformer and at least a portion of the core near the secondary winding are disposed in the shielding cavity.

[0010] In one specific embodiment, the voltage doubler rectifier assembly includes a high-voltage capacitor and a high-voltage diode.

[0011] In one specific embodiment, the shielding cavity includes a side panel and a side end cap. The side panel encloses a space with openings at both ends, including a first opening and a second opening. The side end cap is disposed at the first opening and fitted into the side panel. The side end cap has a third opening in the middle, which is fitted into the outer shell of the magnetron. The transformer includes a shielding magnetic leakage sheet, which is fitted into the second opening. The side panel, the side end cap, and the shielding magnetic leakage sheet surround and form the shielding cavity.

[0012] In one specific embodiment, the shielding cavity is electrically connected to the magnetron and the transformer, the outer shell of the magnetron is grounded, and the core of the transformer is grounded.

[0013] In one specific embodiment, the side end cap of the shielding cavity is welded to the outer shell of the magnetron; and / or, the side end cap of the shielding cavity is connected to the outer shell of the magnetron by screws.

[0014] In one specific embodiment, the side panel of the shielding cavity is welded to the shielding leakage magnetic sheet of the transformer.

[0015] In one specific embodiment, the shielding cavity and the shielding leakage magnetic sheet are made of a high magnetic permeability material.

[0016] In one specific embodiment, the high magnetic permeability material includes at least one of iron-based nanocrystalline alloys, ferrites, and silicon steel.

[0017] The beneficial effects of this application embodiment are as follows: The microwave oven of this application embodiment includes a transformer, a voltage doubler rectifier assembly, and a magnetron connected in sequence; the connection between the magnetron and the voltage doubler rectifier assembly is the first connection, and the connection between the transformer and the voltage doubler rectifier assembly is the second connection. The first connection, the voltage doubler rectifier assembly, and the second connection are disposed within a shielding cavity. By integrating the magnetron and the transformer, the radiation emission source of the microwave oven is shielded within the shielding cavity of the integrated connection, isolating it from the outside world, which can reduce the external radiation emission of the microwave oven and improve EMC performance; secondly, by setting up a shielding cavity to solve the radiation emission problem, there is no need for a filter assembly, which can avoid the decrease in filtering effect due to temperature rise, improve the reliability of the microwave oven EMC solution, simplify the manufacturing process, and reduce production costs; at the same time, the integrated design of the magnetron and the transformer can reduce the size of the microwave oven.

[0018] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural diagram of a microwave oven according to an embodiment of this application; Figure 2 This is an exploded structural diagram of a microwave oven according to an embodiment of this application; Figure 3 This is the circuit connection diagram of the microwave oven of this application; Figure 4 This is a schematic diagram of the shielding principle of the microwave oven's shielding cavity according to this application.

[0021] Explanation of icon numbers: 100. Microwave oven; 1. Magnetron; 2. Voltage doubler rectifier assembly; 3. Transformer; 31. Shielding magnetic leakage sheet; 32. Iron core; 4. Shielding cavity; 41. Side panel; 42. Side end cover; 411. First opening; 412. Second opening; 423. Third opening; 102. First connection; 203. Second connection. Detailed Implementation

[0022] To make the objectives, technical solutions, and effects of this application clearer and more explicit, the embodiments of the technical solutions of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of this application, and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0024] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces), unless otherwise explicitly specified.

[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0027] There are two main pathways for EMC radiation emissions from a fixed-frequency microwave oven. The first pathway is generated by the magnetron and the diodes on the secondary side of the transformer, which radiate outwards through the cathode wire and then through the gaps in the microwave oven casing. The second pathway is generated by the magnetron and the diodes on the secondary side of the transformer, which couple from the secondary side to the primary side through the distributed parameters between the primary and secondary sides of the transformer, and then radiate outwards through the input line.

[0028] The existing solution involves adding an LC filter component to the cathode wire port of the magnetron to suppress radiated emissions from 30MHz to 1GHz, and then adding a shielding box around the filter component. However, this solution only addresses radiated emissions from the cathode wire of a fixed-frequency microwave oven and is ineffective against noise at the high-voltage diode. Furthermore, the filter component consists of a feedthrough capacitor and two differential-mode inductors. Due to the high temperature of the magnetron, the temperature inside the shielding cavity of the filter component is also high during microwave oven operation, which can lead to a decrease in the performance of the filter component and unstable radiated emission suppression, potentially resulting in exceeding radiation test limits.

[0029] Therefore, this application provides a microwave oven, such as Figure 1 and Figure 2 As shown, Figure 1 This is a three-dimensional structural diagram of a microwave oven according to an embodiment of this application; Figure 2 This is an exploded structural diagram of a microwave oven according to an embodiment of this application. The microwave oven 100 includes a transformer 3, a voltage doubler rectifier assembly 2, and a magnetron 1 connected in sequence. The connection between the magnetron 1 and the voltage doubler rectifier assembly 2 is a first connection 102, and the connection between the transformer 3 and the voltage doubler rectifier assembly 2 is a second connection 203. The first connection 102, the voltage doubler rectifier assembly 2, and the second connection 203 are disposed within a shielding cavity 4.

[0030] Among them, such as Figure 3 As shown, Figure 3This is the circuit diagram of the microwave oven of this application. Transformer 3 boosts the 220V AC mains power to approximately 2000V high-voltage AC, while simultaneously providing low voltage to the filament of magnetron 1. The voltage doubler rectifier assembly 2, composed of high-voltage diodes and high-voltage capacitors, performs half-wave voltage doubler rectification on the high-voltage AC output from transformer 3, ultimately outputting approximately 4000V DC negative high voltage, which is applied between the cathode (filament) and anode (cavity) of magnetron 1. Under the action of high voltage, electrons emitted from the cathode of magnetron 1 form a rotating electron cloud under the combined action of a vertical magnetic field (provided by an external magnet) and an electric field. The electron cloud interacts with the internal resonant cavity of magnetron 1, generating microwave oscillations with a frequency of 2.45GHz, which are then coupled out to the oven cavity through an antenna to heat the food.

[0031] The EMC radiation emissions from a microwave oven mainly originate from high-frequency leakage of the microwave oscillator itself and high-frequency transient interference from the voltage doubler rectifier circuit. Magnetron 1 is the microwave energy generating device in the microwave oven. When magnetron 1 is working, it generates a high-power high-frequency oscillation signal with a frequency of approximately 2.45 GHz. Its cathode circuit not only carries a DC operating current but also a superimposed high-frequency alternating current component. When this high-frequency current propagates along the cathode lead connecting to the cathode of magnetron 1, it causes the cathode lead to function as an equivalent electric dipole antenna, directly exciting a high-frequency electromagnetic field into the surrounding space, forming initial radiation. Meanwhile, the high-voltage diode in the voltage doubler rectifier component 2 operates in a high-voltage half-wave rectification state. During the switching process between conduction and cutoff, a transient pulse current and pulse voltage with an extremely high rate of change will be generated due to the reverse recovery effect of charge carriers. This pulse has rich high-frequency harmonic components, which will also be coupled to the cathode power supply circuit and superimposed on the cathode lead, further enhancing the high-frequency interference current on the lead and aggravating the initial radiation intensity. Moreover, the pulse energy can also be easily coupled to the primary side power line through the parasitic capacitance between the windings of transformer 3, and then radiated to the outside by the input power line.

[0032] In the embodiments of this application, the magnetron 1 and the transformer 3 are integrated to control the radiation emission source of the microwave oven 100 (i.e., as shown in the figure). Figure 3 The circuit portion (highlighted by the gray dashed rectangle in the circuit diagram) is shielded within the shielding cavity 4 at the integrated connection point, isolating it from the outside environment. This reduces the microwave oven's external radiation emissions and improves EMC performance. Secondly, by setting up the shielding cavity 4 to solve the radiation emission problem, there is no need for a filter component. This avoids the decrease in filtering effect due to temperature rise, improves the reliability of the microwave oven's EMC solution, simplifies the manufacturing process, and reduces production costs. At the same time, the integrated design of the magnetron 1 and the transformer 3 reduces the size of the microwave oven 100.

[0033] Specifically, isolating the high-frequency radiation-emitting part of the microwave oven from the outside world through electromagnetic shielding can effectively suppress the microwave oven's external radiation emission. The principle of electromagnetic shielding is as follows: Figure 4 As shown, Figure 4 This is a schematic diagram of the shielding principle of the shielding cavity 4 of the microwave oven 100 of this application. The core of electromagnetic shielding is to attenuate electromagnetic energy through the synergistic effect of reflection, absorption and multiple reflections using conductive or magnetic materials. Electric field shielding relies on the Faraday cage effect and good grounding. Low-frequency magnetic field shielding uses high-permeability materials to concentrate magnetic flux, and high-frequency magnetic field shielding relies on conductor eddy currents to cancel the magnetic field, ultimately preventing the disordered propagation of electromagnetic fields and ensuring the electromagnetic compatibility (EMC) of electronic equipment.

[0034] In one specific embodiment, the first connection 102 is the electrical connection between the voltage doubler rectifier assembly 2 and the cathode wire (not shown) of the magnetron 1, and the end of the magnetron 1 with the cathode wire is disposed in the shielding cavity 4.

[0035] By placing one end of the magnetron 1 with the cathode wire inside the shielding cavity 4, the path of radiation emission from the main radiation source, namely the cathode lead, to the outside can be effectively cut off. At the same time, by placing only one end of the magnetron 1 with the cathode wire inside the shielding cavity 4, instead of placing the entire magnetron 1 inside the shielding cavity 4, the volume of the shielding cavity 4 can be effectively reduced, thereby reducing the volume of the microwave oven 100 and lowering production costs.

[0036] In one specific embodiment, the second connection 203 is the electrical connection between the voltage doubler rectifier assembly 2 and the secondary winding (not shown) of the transformer 3, and the secondary winding of the transformer 3 and at least a portion of the iron core 32 near the secondary winding are disposed in the shielding cavity 4.

[0037] The transformer 3 includes at least an iron core 32, a primary winding (not shown), a secondary winding (not shown), and a shielding magnetic leakage sheet 31. The primary winding and the secondary winding are respectively mounted on the iron core 32, and the shielding magnetic leakage sheet 31 is located between the primary winding and the secondary winding to suppress magnetic leakage coupling.

[0038] In this embodiment, by incorporating the secondary winding of transformer 3 and at least a portion of the core 32 near the secondary winding into the shielding cavity 4, the electromagnetic radiation generated by the voltage doubler rectifier assembly 2 on the secondary side of transformer 3 can be effectively suppressed from being coupled to the primary power line through the parasitic capacitance between the primary and secondary windings of transformer 3, and then radiated outwards from the input power line. Secondly, the material used for the shielding magnetic leakage sheet 31 between the primary and secondary windings of transformer 3 inherently possesses microwave shielding capabilities. By placing a portion of the transformer 3's structure within the shielding cavity 4 using the shielding magnetic leakage sheet 31 as an interface, the multi-level blocking effect against high-frequency electromagnetic interference is further enhanced. Optionally, by directly using the shielding magnetic leakage sheet 31 as one sidewall of the shielding cavity 4, the electromagnetic shielding function of the shielding cavity 4 can be maintained while reducing the material required for the shielding cavity 4, thus lowering production costs.

[0039] In one specific embodiment, the voltage doubler rectifier assembly 2 includes a high-voltage capacitor (not shown) and a high-voltage diode (not shown).

[0040] Among them, the high-voltage capacitor and the high-voltage diode together form a voltage multiplier rectifier circuit. The high-voltage capacitor and the high-voltage diode will generate high-voltage pulse spikes, which are accompanied by strong transient electromagnetic radiation and can easily interfere with the surrounding circuits through power lines and spatial coupling. Placing the whole in the shielding cavity 4 can effectively suppress the radiation diffusion path.

[0041] In one specific embodiment, please continue to refer to Figure 2 The shielding cavity 4 includes a side panel 41 and a side end cap 42. The side panel 41 encloses a space with openings at both ends, including a first opening 411 and a second opening 412. The side end cap 42 is disposed at the first opening 411 and fitted into the side panel 41. The side end cap 42 has a third opening 423 in the middle, which is fitted into the outer shell of the magnetron 1. The transformer 3 includes a shielding magnetic leakage sheet 31. The transformer 3 is fitted into the second opening 412 through the shielding magnetic leakage sheet 31. The side panel 41, the side end cap 42, and the shielding magnetic leakage sheet 31 surround to form the shielding cavity 4.

[0042] Specifically, the side panel 41 of the shielding cavity 4 is formed by splicing metal plates to form a space that can shield the radiation emission source of the microwave oven 100 with openings at both ends, namely the first opening 411 and the second opening 412. Electrical continuity is achieved between the plates through conductive adhesive or welding to ensure that the entire cavity forms a complete Faraday cage structure. Preferably, the side panel 41 of the shielding cavity 4 is formed by splicing four rectangular metal plates.

[0043] Specifically, the side end cover 42 includes a side end plate (not shown) with a central third opening 423 and an annular sidewall (not shown) extending perpendicularly from the edge of the side end plate. The edge shape of the side end plate is adapted to the contour of the first opening 411 of the side panel 41. After the annular sidewall is fitted with the side end plate, it fits tightly against the outer wall of the side panel 41, ensuring electromagnetic sealing. Optionally, the side end cover 42 includes only one side end plate, the edge of which is connected to the first opening 411 of the side panel 41 by welding or by fastening with conductive screws to achieve a reliable conductive connection between the side end cover 42 and the side panel 41. Specifically, the contour of the central third opening 423 of the side end cover 42 is adapted to the contour of the magnetron 1 housing, ensuring that there is no electromagnetic leakage gap after the two are fitted together.

[0044] Specifically, the shielding magnetic leakage sheet 31 of the transformer 3 is sleeved on the iron core 32. The edge shape formed by the shielding magnetic leakage sheet 31 and the iron core 32 is adapted to the contour of the second opening 412 of the side plate 41 of the shielding cavity 4, so that the shielding magnetic leakage sheet 31 of the transformer 3 can be tightly fitted and connected to the shielding cavity 4. The material used for the shielding magnetic leakage sheet 31 itself has the function of shielding microwaves. By using the shielding magnetic leakage sheet 31 to form the shielding cavity 4, materials can be saved and costs can be reduced.

[0045] Preferably, the shielding leakage magnetic sheet 31 has an H-shaped cross-section, with its two side wings extending axially along the iron core 32 and covering the winding end face of the transformer 3, and its belly extending radially along the iron core 32 and fitting against the inner wall of the left and right windows of the iron core 32. The shielding leakage magnetic sheet 31 forms a magnetic shunt with a high magnetic reluctance gap in the transformer 3. When the high-voltage transformer 3 is working, a certain amount of leakage magnetic flux will be generated in the magnetic shunt, which controls the output current of the transformer 3 and keeps the operating current of the magnetron 1 relatively stable.

[0046] In one specific embodiment, the shielding cavity 4 is electrically connected to the magnetron 1 and the transformer 3. The outer shell of the magnetron 1 is grounded, and the core 32 of the transformer 3 is grounded. Electric field shielding relies on the Faraday cage effect and good grounding. By forming a low-impedance common ground path with the shielding cavity 4, the outer shell of the magnetron 1, and the core 32 of the transformer 3, the conduction path impedance of common-mode interference is significantly reduced, allowing high-frequency noise energy to be discharged to the ground more efficiently. Furthermore, the low impedance characteristics of the grounding path further suppress the conduction and radiation coupling of electromagnetic interference, thereby improving the overall electromagnetic compatibility of the microwave oven. This grounding design also avoids ground loop interference that may be caused by multiple grounding points, ensuring stable operation of the system in complex electromagnetic environments.

[0047] In one specific embodiment, the side end cap 42 of the shielding cavity 4 is welded to the outer shell of the magnetron 1; and / or, the side end cap 42 of the shielding cavity 4 is connected to the outer shell of the magnetron 1 by screws.

[0048] In one embodiment, the third opening 423 of the side end cover 42 of the shielding cavity 4 is welded to the outer shell sidewall of the magnetron 1 at the end with the cathode wire, ensuring that there is no electromagnetic leakage gap between the cathode wire lead-out path and the shielding cavity 4; optionally, the welding area covers the entire contact periphery between the third opening 423 and the outer shell sidewall of the magnetron 1.

[0049] In another embodiment, the side end cap 42 of the shielding cavity 4 is fastened to the outer shell sidewall of the magnetron 1 at the end with the cathode wire by conductive screws, and a conductive gasket is provided at the connection to enhance contact reliability.

[0050] In one specific embodiment, the side panel 41 of the shielding cavity 4 is welded to the shielding leakage magnetic sheet 31 of the transformer 3.

[0051] Specifically, the second opening 412 of the side panel 41 of the shielding cavity 4 is welded to the shielding magnetic leakage sheet 31 of the transformer 3; optionally, the welding area is continuously welded along the entire mating contour of the second opening 412 and the shielding magnetic leakage sheet 31 to form a continuous and uninterrupted conductive sealing weld, ensuring that a complete electromagnetic shielding boundary is formed between the shielding cavity 4 and the shielding magnetic leakage sheet 31.

[0052] Optionally, the side panel 41 of the shielding cavity 4 and the shielding leakage magnetic sheet 31 of the transformer 3 can also be fastened together by conductive screws, and conductive gaskets are provided at the connection to enhance contact reliability.

[0053] In one specific embodiment, the shielding cavity 4 and the shielding magnetic leakage sheet 31 are made of high-permeability materials. The permeability μ of the high-permeability material is greater than 1000. By using high-permeability materials for both the shielding cavity 4 and the shielding magnetic leakage sheet 31, and by welding or screwing them together to form an electrically continuous shield after assembly, the near-field magnetic shielding effectiveness of key radiation sources such as the cathode lead of the magnetron 1, the winding lead of the transformer 3, and the connection node between the high-voltage diode and the high-voltage capacitor in the voltage doubler rectifier assembly 2 in the 30MHz~1GHz frequency band can be effectively improved. This significantly reduces the external radiation emission level of the microwave oven 100 in this frequency band without adding additional filtering components.

[0054] In one specific embodiment, the high-permeability material includes at least one of iron-based nanocrystalline alloys, ferrite, and silicon steel. Within the range of materials described, the high-permeability material can effectively enhance the electromagnetic shielding effect of the shielding cavity 4. It attenuates electromagnetic energy through the synergistic effects of reflection, absorption, and multiple reflections. For low-frequency magnetic field shielding, the high-permeability material concentrates the magnetic flux, while for high-frequency magnetic field shielding, eddy currents in the conductor cancel the magnetic field, ultimately preventing the disordered propagation of electromagnetic fields and ensuring the electromagnetic compatibility of the microwave oven 100.

[0055] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A microwave oven (100), characterized in that, It includes a transformer (3), a voltage multiplier rectifier assembly (2) and a magnetron (1) connected in sequence; the connection between the magnetron (1) and the voltage multiplier rectifier assembly (2) is the first connection (102), and the connection between the transformer (3) and the voltage multiplier rectifier assembly (2) is the second connection (203). The first connection (102), the voltage multiplier rectifier assembly (2) and the second connection (203) are disposed in a shielded cavity (4).

2. The microwave oven (100) according to claim 1, characterized in that, The first connection (102) is the electrical connection between the voltage doubler rectifier assembly (2) and the cathode wire of the magnetron (1), and the end of the magnetron (1) with the cathode wire is disposed in the shielding cavity (4).

3. The microwave oven (100) according to claim 1, characterized in that, The second connection (203) is the electrical connection between the voltage doubler rectifier assembly (2) and the secondary winding of the transformer (3). The secondary winding of the transformer (3) and at least a portion of the core (32) near the secondary winding are disposed in the shielding cavity (4).

4. The microwave oven (100) according to any one of claims 1 to 3, characterized in that, The voltage doubler rectifier assembly (2) includes a high-voltage capacitor and a high-voltage diode.

5. The microwave oven (100) according to claim 4, characterized in that, The shielding cavity (4) includes a side panel (41) and a side end cap (42). The side panel (41) forms a space with openings at both ends. The space includes a first opening (411) and a second opening (412). The side end cap (42) is disposed at the first opening (411) and fitted with the side panel (41). The side end cap (42) has a third opening (423) in the middle. The third opening (423) is fitted with the outer shell of the magnetron (1). The transformer (3) includes a shielding magnetic leakage sheet (31). The transformer (3) is fitted with the second opening (412) through the shielding magnetic leakage sheet (31). The side panel (41), the side end cap (42), and the shielding magnetic leakage sheet (31) surround to form the shielding cavity (4).

6. The microwave oven (100) according to claim 5, characterized in that, The shielding cavity (4) is electrically connected to the magnetron (1) and the transformer (3). The outer shell of the magnetron (1) is grounded, and the core (32) of the transformer (3) is grounded.

7. The microwave oven (100) according to claim 6, characterized in that, The side end cap (42) of the shielding cavity (4) is welded to the outer shell of the magnetron (1); and / or, the side end cap (42) of the shielding cavity (4) is connected to the outer shell of the magnetron (1) by screws.

8. The microwave oven (100) according to claim 7, characterized in that, The side panel (41) of the shielding cavity (4) is welded to the shielding leakage magnetic sheet (31) of the transformer (3).

9. The microwave oven (100) according to claim 8, characterized in that, The shielding cavity (4) and the shielding magnetic leakage sheet (31) are made of high magnetic permeability material.

10. The microwave oven (100) according to claim 9, characterized in that, The high magnetic permeability material includes at least one of iron-based nanocrystalline alloys, ferrites, and silicon steel.

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