KR20000050823A - Waveguide system for electronic range - Google Patents

Abstract

PURPOSE: A waveguide system of a microwave oven is provided to achieve a compactness of the oven while remarkably reducing the length and width of the waveguide and eliminate an electric arc by removing an aperture portion. CONSTITUTION: A waveguide system of a microwave oven in which the microwave oven includes a magnetron(100) having an antenna for generating microwaves and a microwave guiding device for guiding and radiating via a microwave inlet of a cavity(120) microwaves generated from the magnetron to a cooking chamber, the waveguide system comprising a square waveguide(200) having a predetermined length, width, and height and which has an open side contacting the microwave inlet of the cavity, the magnetron arranged at an approximate center of an outer surface of the waveguide so as to radiate microwaves into the waveguide via the antenna, a reflecting member(201) arranged at an inner surface of the waveguide with a predetermined angle, the inner surface being opposite to the surface contacting the cavity, the reflection member delays and reflects a phase to have a circularly polarized wave characteristic with respect to microwaves radiated from the antenna, and a stub(202) arranged at an approximate center of an inner bottom surface of the waveguide so as to guide the reflection wave energy from the reflection member and microwave energy from the antenna into the cavity.

Description

Waveguide system for microwave ovens {Waveguide system for electronic range}

The present invention relates to a waveguide of a microwave oven for heating the food evenly as a whole, and more particularly, by efficiently impedance matching the electromagnetic wave leaked between the contact surface of the waveguide and the antenna of the magnetron for guiding large-wave electromagnetic energy A waveguide system of a microwave oven for generating circular polarization for uniformly heating food without opening of the waveguide.

In general, the ultra-short wave required for a broadcast device or a device using high-power electromagnetic energy such as a dryer or a microwave oven is usually obtained from an antenna of a magnetron.

An accelerating voltage such as 4.2 KV is applied to the magnetron device to generate energy of a very high frequency, for example, 2.45 GHz, through the antenna.

In order to efficiently cook food by applying such a magnetron to a specific device, for example, a cooking device such as a microwave oven, a guide device such as a waveguide for guiding large-power electromagnetic energy to a cooking chamber in a cavity is required.

By the way, the antenna of the magnetron generates energy by linear polarization (Liner Polarzation) and the energy of the linear polarization is radiated to the cooking chamber of the cavity through the opening of the waveguide as a guide device to heat food.

As such, there is a device as shown in FIG. 1 as a device for heating food by guiding high-frequency electromagnetic energy generated from an antenna of a magnetron to a cooking chamber of a cavity.

The apparatus shown in FIG. 1 is described as an example of an electromagnetic wave guide device of a microwave oven according to the prior art.

The electromagnetic wave guide device is a magnetron 100 coupled to the side wall of the cavity 120 and generating electromagnetic energy of a large power through the antenna 100a by an acceleration high voltage input from a high voltage transformer not shown in the drawing. The waveguide 110 is installed on the sidewall of the cavity 120 to guide and radiate the electromagnetic energy generated by the magnetron 100 through the opening 110b, and is formed on the outer surface of the waveguide 110 and is formed of the magnetron 100. The cavity 110a having a short circuit and the same length as that of the antenna 100a, and formed on the sidewall of the cavity 120 to radiate electromagnetic energy emitted through the opening 110a of the waveguide 110. An electromagnetic wave inlet (120a) to be introduced into the 120, the cooking chamber 130 for heating and cooking the food 150 with the introduced electromagnetic energy, and installed in the lower portion of the cavity 120 to rotate the food 150 Consists of turntable 140 .

As an example of the prior art configured as described above will be further embodied in the electromagnetic wave guide device of the microwave oven.

When the acceleration high voltage generated in the high-voltage transformer is applied to the magnetron 100 and started, the magnetron 100, which is a source of electromagnetic energy, generates electromagnetic energy of 2.45 GHz. In addition, the turntable 140 on which the food 150 is placed is rotated.

Electromagnetic energy generated from the magnetron 100 is radiated to the waveguide 110 through the antenna 100a, and the electromagnetic wave energy radiated to the waveguide 110 forms a protruding portion of the waveguide 110 forming a short-circuit with the antenna 100a. After being formed as a standing wave at 110a, the food 150 is heated to be inclined through the opening 110b and the electromagnetic inlet 120a of the cavity 120 to be inclined to heat the food 150.

Here, electromagnetic energy is radiated from the antenna 100a having a wave property.

Accordingly, the electromagnetic waves reflected through the protrusion 110a of the waveguide 110 forming the short circuit with the antenna 100a and the electromagnetic waves propagated from the antenna 100a open the open side of the waveguide 110. Are synthesized at, resulting in standing waves.

In addition, the electromagnetic wave energy is combined into a strong portion and a weak portion to uniformly heat the food 150 in the cavity 120 of the microwave oven.

The microwave guide device of the microwave oven according to the related art described above protrudes a protrusion forming the antenna and the short-circuit surface of the magnetron separately to the waveguide to synthesize the electromagnetic wave propagated from the antenna and the electromagnetic wave reflected from the protrusion at the opening to food in the cavity. It can be seen that the uniform heating.

However, in the conventional electromagnetic wave guide device, the waveguide structure is complicated because the protrusions forming the antenna and the short-circuit surface must be separately projected to the waveguide in order to easily form the standing wave, and the short-circuit surface of the waveguide and the contact area between the antenna Due to this narrowness, electromagnetic energy is not leaked between them, and as a result of the narrow contact surface, electromagnetic energy is not properly radiated from the antenna, thereby causing a problem in that food cooking performance is degraded.

In addition, one or more openings may be formed while designing the opening of the waveguide to satisfy the electromagnetic wave output and efficiency, heating performance, and safety at no load, but this may be a distance between the magnetron antenna and the opening surface. In this case, there is a problem that an arc occurs, and also a problem that discoloration around the opening occurs.

In addition, since the electromagnetic wave generated from the antenna is a linear polarization of which the polarization plane is constant with respect to the traveling direction, there is a weakness due to the effect of electromagnetic interference in the cavity to increase the uniform heating performance when using such an antenna.

The linearly polarized wave refers to an electromagnetic wave whose temporal polarization plane in which the electromagnetic field is directed in a constant direction is constant. That is, a strong point (weak point) and a weak point (weak point) are generated due to the interference of the electromagnetic waves, and under such conditions, there is a problem in that the uniform heating performance of cooking performance is limited.

Accordingly, unlike the linear polarization, when the polarization plane of the electric field forms a circular polarization that rotates with respect to the propagation direction of the radio wave in time, the direction of the electric field is continuously changed with time, so the reflection angle of the electromagnetic wave transmitted into the cavity is also increased. It will change over time, spreading the radio waves over a wider range, allowing food to be heated evenly.

Therefore, in order to prevent imbalance of food heating caused by the interference of electromagnetic waves, the electromagnetic wave energy generated from the antenna of the magnetron is formed by circular polarization in the waveguide, which is an electromagnetic wave guide device, to uniformly heat the food in the cavity. It is a situation that a lot of drafted and commercialized.

Most of these circular polarization generators divide electromagnetic energy generated by magnetron into radiator and then change the energy of electromagnetic wave into phase wave through mechanical variable phase shifter to form the original wave, and uniform the food in the cavity using the circular polarization. Most of the heating.

However, such a circular polarization generator has a long waveguide length in order to have a mechanical variable phase shifter and a radiator in the waveguide, and also has a problem in that the material cost and processing cost are increased due to the complicated structure, and the waveguide length is long. Therefore, it is difficult to arrange the electrical equipment in the battle room, and the problem is that the battle room becomes large.

In addition, as a method of avoiding the complexity of the structure caused by the use of a radiator and a variable phase shifter, a guide piece having a narrow width in the longitudinal direction is provided at the inner center of the waveguide, and divided into two parts. Although it is also conceivable to generate a circular polarization by forming a pair of rectangular openings at an angle of 45 degrees, it requires a separate guide piece to be installed, and also requires a difficulty of setting the pair of openings at an angle of 45 degrees.

Therefore, a microwave waveguide system which can prevent the complexity of the structure of the waveguide, the difficulty of disposing an electric field, and the leakage of electromagnetic wave energy, and also minimize the length and width of the waveguide and obtain an effect equal to or higher than the conventional one. Do.

Accordingly, an object of the present invention is to provide a waveguide system of a microwave oven having no opening for eliminating an arc generated between antennas of a magnetron by eliminating an opening through which a wave guides the electromagnetic wave into the cavity.

Another object of the present invention is to provide at least one stub in a waveguide, which is an electromagnetic wave guide device, to enable impedance matching without opening of the waveguide.

Another object of the present invention is to provide a waveguide, which is an electromagnetic wave guide device, to provide a circular polarization by adjusting a width of the reflective member by adjusting a reflection member having an arbitrary shape.

1 and 2 is a schematic configuration diagram provided in the description of the microwave oven according to the prior art,

1 is a perspective view of a waveguide that is an electromagnetic wave guide device of the microwave oven,

2 is a sectional view of a waveguide, which is an electromagnetic wave guide device of the microwave oven, from the front,

3 to 7 is a configuration diagram showing an embodiment provided for the description of the electromagnetic wave guide device of the microwave oven according to the present invention,

3 is a perspective view showing a waveguide which is an electromagnetic wave guide device of the microwave oven according to the present invention;

4 is a cross-sectional view of a waveguide, which is an electromagnetic wave guide device of the microwave oven, from the front,

5 is an enlarged view of the waveguide of FIG. 3 seen from the right side;

FIG. 6 is an enlarged view of the waveguide of FIG. 3 seen from behind; FIG.

7 is an explanatory diagram showing a relationship between circular polarization and linear polarization according to the present invention.

<Description of the code | symbol about the principal part of drawing>

100: magnetron 100a: antenna

120: cavity 130: cooking chamber

140: turntable 200: waveguide

200a: opening 201: reflective member

202: stub

A waveguide system according to an aspect of the present invention for achieving the above object,

In a microwave oven having a magnetron having an antenna for generating electromagnetic waves by accelerating high voltage and an electromagnetic wave guide device for guiding and radiating electromagnetic waves generated from the magnetron through the electromagnetic inlet of the cavity:

(1) a waveguide having a predetermined length, a predetermined width, and a predetermined height and having an open surface in contact with the electromagnetic wave inlet of the cavity;

(2) a magnetron installed in the center of the outside of the waveguide and radiating electromagnetic waves vertically into the waveguide through an antenna;

(3) a reflection member installed on the other side wall of the waveguide in a direction opposite to the contact surface of the cavity to delay and reflect the phase so as to have a circular polarization characteristic with respect to the original electromagnetic energy emitted from the antenna;

(4) A stub is provided at approximately the center of the bottom surface of the waveguide, and has a stub having an arbitrary shape for guiding the reflected wave energy of the reflective member and the electromagnetic wave energy of the antenna into the cavity.

Optionally, the waveguide is square in cross section.

Optionally, the stub is cylindrical having a predetermined height and a predetermined diameter and the cylindrical stub impedance-matches the cavity and the waveguide.

Optionally, the stub is characterized in that it is a substantially hexahedron having a predetermined length, a predetermined width and a predetermined height.

Preferably, the reflecting member is a dielectric material or a metal material consisting of a substantially hexahedron having a predetermined length, a predetermined width, and a predetermined height.

Optionally, the reflective member is integrally formed with the waveguide.

In this way, after the electromagnetic wave energy emitted from the antenna of the magnetron is changed in phase in the reflection member of the waveguide, the original electromagnetic wave energy is combined with the opening of the waveguide to form a circular polarized wave, and the impedance is matched by a stub to produce food. It can be seen that the heating.

As a result, the length and width of the waveguide are significantly reduced, so that the electrical equipment can be easily arranged in the electrical equipment room, and there is an advantage in that the difficulty of designing the opening of the waveguide and the generation of arc due to the opening are excluded.

And, there may be a plurality of embodiments of the present invention, the following will be described in detail for the most preferred embodiment.

Through this preferred embodiment, it is possible to better understand the objects, features and advantages of the present invention.

Hereinafter, exemplary embodiments of the waveguide system according to the present invention will be described in detail with reference to the accompanying drawings.

In addition, the technique of the present invention can be applied to a variety of devices, such as a dryer, a lamp, a drying processor and the like to form and use high-power electromagnetic wave energy as a circular polarization.

In addition, in drawing used for description, about the same component, the same code | symbol is attached | subjected, and the overlapping description may be abbreviate | omitted.

In addition, in the following, an example of using a waveguide system in a microwave oven is considered to help understand the description.

3 is a perspective view showing a wave guide that is an electromagnetic wave guide device of the microwave oven according to the present invention, and FIG. 4 is a sectional view of the wave guide that is the electromagnetic wave guide device of the microwave oven viewed from the front.

The waveguide system of the microwave oven according to the present embodiment includes a substantially square waveguide 200 having an opening 200a on a surface in contact with the electromagnetic wave inlet 120a of the cavity 120, and an upper portion of the waveguide 200. The magnetron 100 is installed at the center and radiates electromagnetic waves vertically into the waveguide 200 through the antenna 100a and is installed at a predetermined angle on the other side wall of the waveguide 200 in a direction opposite to the contact surface of the cavity 120. It is installed in the center of the bottom surface of the hexahedral reflection member 201 and the waveguide 200 to delay and reflect the phase so as to have a circular polarization characteristic to the original electromagnetic energy radiated vertically from the antenna 100a of the magnetron 100 Impedance matching stub 202 for guiding the electromagnetic wave energy reflected from the reflection member 201 and the electromagnetic wave energy emitted from the antenna (100a) to the heating chamber 130 of the cavity 120.

In the above, the waveguide 200 has a substantially square shape having a cross-sectional shape L3 in the lateral direction, a length L1 in the longitudinal direction, and a constant width L2, as shown in FIGS. 3 and 5.

5 and 6, the reflective member 201 has a shape of a cube having different widths B1 in the vertical direction and widths B2 in the horizontal direction.

Also, as shown in FIG. 6, the stub 202 has a shape of a cube having a constant height S2 and a constant width S1.

The waveguide system of the microwave oven according to the present invention made as described above will be described in more detail with reference to FIGS. 3 to 7.

When the acceleration high voltage generated in the high voltage transformer (not shown) is applied to the magnetron 100 and started, the magnetron 100, which is a source of electromagnetic energy, generates electromagnetic energy of 2.45 GHz to radiate through the antenna 100a.

Electromagnetic energy generated by the magnetron 100 is radiated to the square waveguide 200 having a constant length L3 and L1 in the horizontal and vertical directions and the constant width L2 through the antenna 100a.

Part of the electromagnetic energy radiated to the waveguide 200 is the cooking chamber 130 in the cavity 120 through the opening 200a, and part of the electromagnetic energy is different from the width B1 in the vertical direction and the width B2 in the horizontal direction. It is supplied to the reflective member 201 of dielectric or metal material having a hexahedron shape and inclined at a predetermined angle to the back wall of the waveguide 200 at a predetermined angle, for example, in a diagonal direction.

The reflective member 201 of the dielectric material or the metal material delays the phase of the electromagnetic wave energy radiated from the antenna 100a to have circular polarization characteristics as shown in FIG. It is reflected to (200a) side. Here, the semi-acid member 201 may be integrally formed on the other side wall of the waveguide 200.

In this case, the stub 202 in the waveguide 200 distributes the electromagnetic energy radiated from the antenna 100a and the electromagnetic energy of which the phase is delayed by the reflecting member 201 to the opening 200a side efficiently and uniformly.

That is, the stub 202 described above may be formed in the shape of a cube having constant lengths S1 and S2 in the horizontal direction and the vertical direction, as shown in FIGS. 5 and 6, and also having a cylindrical shape having a constant length and diameter. It can also be formed.

By the shape and size of the stub 202, the electromagnetic energy of the antenna 100a and the electromagnetic energy of the reflecting member 201 out of phase are impedance-adjusted and transmitted to the open part 200a.

In the opening part 200a, the electromagnetic energy through the stub 202 for impedance matching and the electromagnetic energy of the reflecting member 201 out of phase are synthesized and transmitted to the heating chamber 130 in the cavity 120 by circular polarization. The food is uniformly heated.

In a typical microwave oven, since the nature of the electromagnetic energy generated by the antenna of the magnetron and radiated into the cavity has a characteristic of linear polarization as shown in (b) of FIG. 7, there is a limit in heating and cooking of food in the cavity. It is a well known fact.

In the linear polarization, the direction of the electric field is fixed with respect to the propagation direction of the radio wave, whereas in the circular polarization, the direction of the electric field continues to change with time as shown in FIG.

That is, the circular polarization described above has the characteristic that the electric field direction rotates on the X-Y plane with time as shown in FIG.

Accordingly, in the waveguide 200 according to the present invention, the electromagnetic wave energy radiated from the antenna 100a and the electromagnetic wave energy of the reflecting member 201 which is out of phase, that is, 90 degrees out of phase, are synthesized in the opening part 200a. It is formed by polarization and the food in the cavity 120 is uniformly heated by this circular polarization.

As a result, the shape of the opening of the present waveguide 200 has the same shape as the stub 202 having constant lengths S1 and S2 in the transverse and longitudinal directions.

On the other hand, as a comparative example, the conventional technology, that is, the protrusions forming the antenna and the short-circuit plane of the magnetron are separately projected to the waveguide to synthesize the electromagnetic wave propagated from the antenna and the electromagnetic wave reflected from the protrusion at the opening to heat food in the cavity Contrary to this, the present invention delays the phase of the electromagnetic wave emitted from the antenna of the magnetron in the waveguide reflector, synthesizes the original electromagnetic wave energy at the opening of the waveguide, forms a circular polarization, and matches an impedance through a stub. It can be seen that.

As a result, according to the present invention, the circular polarization generation and the impedance are matched without the difficulty of forming one or more openings in the waveguide when designing the aperture. It is possible to minimize the difficulty of the arrangement of electrical components along with the length of the waveguide, the complexity of the structure, and the increase of the material cost without generating an arc.

According to this application example, no additional parts are added during circular polarization, and the difficulty of disposing electrical components along the length of the waveguide is eliminated, thereby improving the reliability of the product.

In addition, although specific embodiments of the present invention have been described and illustrated above, it is obvious that the present invention may be variously modified and implemented by those skilled in the art.

Such modified embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments should fall within the appended claims of the present invention.

It is clear from the above description that, according to the waveguide system for generating circular polarization according to the present invention, since there is no special opening in the opening surface forming the antenna and the short-circuit surface, an arc is generated according to the distance between the opening and the antenna of the magnetron. And there is an effect that discoloration around the opening does not occur.

In addition, it is possible to reduce the width of the electric field due to the simplification of the waveguide and the reduction in size, so that it is possible to compact the microwave oven and to control the size of the reflecting member, thereby generating circular polarization, thereby improving uniform heating performance.

Claims (5)

In a microwave oven having a magnetron having an antenna for generating electromagnetic waves by accelerating high voltage and an electromagnetic wave guide device for guiding and radiating electromagnetic waves generated from the magnetron through the electromagnetic inlet of the cavity: (1) a square waveguide having a predetermined length, a predetermined width, and a predetermined height and having an open surface in contact with the electromagnetic wave inlet of the cavity; (2) a magnetron installed in the center of the outside of the waveguide and radiating electromagnetic waves vertically into the waveguide through an antenna; (3) a reflection member installed on the other side wall of the waveguide in a direction opposite to the contact surface of the cavity to delay and reflect the phase so as to have a circular polarization characteristic with respect to the original electromagnetic energy emitted from the antenna; (4) A waveguide system for a microwave oven, comprising: a stub provided at approximately the center of the bottom surface of the waveguide, the stub having an arbitrary shape for guiding the reflected wave energy of the reflecting member and the electromagnetic wave energy of the antenna into the cavity. The method of claim 1, Wherein said stub is a cylindrical having a predetermined height and a predetermined diameter and said cylindrical stub impedance-matches said cavity and said waveguide. The method of claim 1, Wherein said stub is an approximately hexahedron having a predetermined length, a predetermined width, and a predetermined height. The method of claim 1, The reflective member has a predetermined length, a predetermined width, and a predetermined height, and has a hexahedron shape installed on the other side wall of the waveguide in a diagonal direction, wherein the hexahedral reflection member is one of a dielectric material and a metal material. Microwave waveguide system. The method according to claim 1 or 4, And the reflecting member is integrally formed on the other side wall of the waveguide.