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EP1083772A1 - Microwave oven antenna - Google Patents

Microwave oven antenna Download PDF

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Publication number
EP1083772A1
EP1083772A1 EP00402442A EP00402442A EP1083772A1 EP 1083772 A1 EP1083772 A1 EP 1083772A1 EP 00402442 A EP00402442 A EP 00402442A EP 00402442 A EP00402442 A EP 00402442A EP 1083772 A1 EP1083772 A1 EP 1083772A1
Authority
EP
European Patent Office
Prior art keywords
axis
emitting surface
antenna
cavity
slot
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP00402442A
Other languages
German (de)
French (fr)
Other versions
EP1083772B1 (en
Inventor
Claudy Thomson-CSF P.I. Dept. Brevets Bellion
Antoine Thomson-CSF P.I. Dept. Brevets Boutin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FagorBrandt SAS
Original Assignee
Brandt Cooking SAC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Brandt Cooking SAC filed Critical Brandt Cooking SAC
Publication of EP1083772A1 publication Critical patent/EP1083772A1/en
Application granted granted Critical
Publication of EP1083772B1 publication Critical patent/EP1083772B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/74—Mode transformers or mode stirrers
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/72—Radiators or antennas
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/72—Radiators or antennas
    • H05B6/725—Rotatable antennas

Definitions

  • the invention relates to the field of antennas for microwave ovens, especially for household microwave ovens.
  • microwaves are sent into the oven cavity to make a heating operation.
  • This heating operation can constitute a simple reheating of food or cooking food.
  • microwaves form a standing wave network in the oven cavity.
  • This standing wave network has hot spots and cold spots.
  • the food whether it should be cooked or simply reheated, must be as uniformly as possible.
  • the distribution of microwaves in the oven cavity must therefore be homogenized so as to attenuate the points hot and cold spots existing in this cavity.
  • the cavity also includes a turntable for food which allows to achieve fairly uniform heating of the food.
  • the invention proposes to achieve a homogeneous heating of the food, without resorting to the presence of a turntable in the cavity.
  • the invention provides an antenna for homogenizing the distribution of microwaves in the cavity.
  • an antenna comprising an axis conductive and a conductive emitting surface bonded to one end of the axis, characterized in that the antenna has a dielectric junction linking the axis and the emitting surface so as to establish a discontinuity electric between the axis and the emitting surface and in that the surface emitter does not have a symmetry of revolution around the direction axis average.
  • a microwave oven comprising a microwave transmitter, a cooking cavity, a guide wave connecting the transmitter to the cavity, an antenna according to the invention, characterized in that the axis is partially located in the waveguide, the emitting surface is located in the cavity and is movable in rotation around of the axis, the emitting surface not having a symmetry of revolution around the mean direction of the axis in order to disturb the waves which may exist in the cavity.
  • Figure 1A schematically shows a perspective view of a preferred embodiment of an antenna according to the invention.
  • Figure 1B schematically represents a sectional view along the axis AA of the figure 1A.
  • the axis AA is shown in dotted lines.
  • the different elements shown in Figures 1A and 1B are not necessarily the same scale, this remaining true for FIGS. 2A to 3D.
  • the antenna has a axis 1 to which an emitting surface 2 is linked by means of a junction 3. Junction 3 does not have hatching in Figure 1B for better readability of the figure.
  • the axis 1 is linked to the emitting surface 2, by the junction 3, at the end 11 of the axis 1.
  • the axis 1 and the surface transmitter 2 are made of conductive material.
  • the conductive material is preferably very conductive, of the metallic type, so as to minimize energy losses in the antenna.
  • the metal considered is by example of copper or brass.
  • the highly conductive nature of the material is more critical for axis 1 than for emitting surface 2 because it is generally a part with a more surface shape than the axis 1.
  • the junction 3 is made of dielectric material. Junction 3 links emitting surface 2 to axis 1 so as to establish an electrical discontinuity between axis 1 and the surface emitting surface 2.
  • the emitting surface 2 does not have a symmetry of revolution around the mean direction ⁇ M of the axis 1.
  • the straight line AM is shown in dashed lines.
  • the emitting surface 2 comprises for example a slot 4 which breaks its symmetry of revolution even when the shape of the emitting surface 2 is for example that of a disc or a crown.
  • the axis 1 of the antenna is partially located in the waveguide from the oven as explained in Figure 2A.
  • the function of the antenna is to emit microwaves into the oven cavity.
  • the antenna has a microwave reception / emission function. Indeed, the part of the axis 1 located in the waveguide receives the energy present in the waveguide while the part of the axis 1 located in the cavity radiates, in the cavity from the oven, the energy received by the part of axis 1 located in the waveguide.
  • the part of axis 1 located in the cavity is that which is in contact with the dielectric junction 3, at the end 11.
  • the emitting surface 2 then plays the role of auxiliary waveguide for the energy radiated by the part of axis 1 located in the oven cavity.
  • Slot 4 can then reflect the energy conveyed in the annex waveguide constituted by the emitting surface 2 as well as through the wall of the cavity opposite the Emitting surface 2.
  • the emitting surface 2 does not emit strictly speaking, it is only the radiating slot 4 that comprises the emitting surface 2, which transmits. Part of the energy thus conveyed is emitted to the rest of the cavity at the outer edges 21 of the emitting surface 2.
  • a shape and adequate size of the axis 1, the emitting surface 2, the dielectric junction 3 which are adapted to the oven cavity, allow to obtain a homogeneous distribution of microwaves in the oven cavity. To achieve this homogenization, the dielectric nature of the Junction 3 is essential.
  • the absence of symmetry of revolution of the surface transmitter 2 around the axis 1 of rotation of the antenna allows the antenna to adequately disturb the distribution of microwaves in the cavity oven when the antenna is rotating around its axis 1.
  • Axis 1 is preferably centered relative to the emitting surface 2, as in FIGS. 1A and 1B. If axis 1 is off-center, i.e. if axis 1 is closer to a particular location on the periphery 21 than other, the slot 4 will preferably be located between this location and the axis 1 of so as to maintain maximum efficiency at slot 4 in terms of amount of energy returned.
  • the emitting surface 2 is preferably substantially planar.
  • the angle a that axis 1 makes with the mean plane of the emitting surface 2 is preferably substantially equal to a right angle. If the angle ⁇ is not a right angle, the slot 4 will preferably be located on the side of the surface emitter 2 which makes the greatest angle with axis 1. If the emitting surface 2 is not planar, if for example it is curved, it is preferable that axis 1 is not on the side of the concavity of the curved shape of so as to avoid a risk of electric arc between the emitting surface 2 and the antenna walls when the antenna is operating in the oven.
  • the emitting surface 2 preferably has a rounded shape.
  • the emitting surface 2 whether on its edges or on its surface, does not then presents no angle, corner or point which would risk being at the source of electric arc phenomena.
  • the emitting surface 2 a advantageously either a crown shape as in FIGS. 1A and 1B, i.e. a disc shape if the mechanical assembly of the three parts that are the axis 1, the emitting surface 2 and the junction 3 does not require the presence of a hole in the emitting surface 2.
  • This crown shape or in disc has a symmetry of revolution around axis 1.
  • Axis 1 is preferably entirely located on the same side of the emitting surface 2.
  • the axis 1 then does not cross the emitting surface 2.
  • the energy is generally radiated perpendicular to axis 1 of the antenna to be conveyed between the wall of the oven cavity and the emitting surface 2, before being partially re-radiated by the slot 4. If the end 11 of axis 1 leads to the other side of the emitting surface 2, a significant part of the energy radiated by axis 1 is in the extension of axis 1 and not perpendicular to axis 1.
  • Such a directional character of the antenna makes it more difficult to homogenize the wave distribution in the oven cavity.
  • the asymmetrical nature of the emitting surface 2 is ensured by the presence of a radiating slot 4 which is advantageously rectangular.
  • the radiant slot 4 distributes the energy time-averaged in the oven cavity, i.e. distributed over the oven cavity the average energy over a given period of time corresponding for example to the antenna rotation period when the latter rotates at constant speed.
  • FIG. 2A schematically represents a front view of a preferential embodiment of a microwave oven according to the invention.
  • the figure 2B schematically represents an enlarged detail of FIG. 2A.
  • the oven microwave described in Figures 2A and 2B is a microwave oven domestic cooking for food. But this oven can also have other applications as explained later.
  • the oven has a transmitter 5 microwave, preferably a magnetron 5.
  • the microwave transmitter 5 which will be considered later as a magnetron, emits microwaves in a waveguide 6.
  • the propagation direction of the energy carried by the waves is indicated throughout FIG. 2A by solid line arrows.
  • the oven comprises an antenna according to the invention, with its axis 1, its emitting surface 2 and its junction 3.
  • the axis 1 is preferably distant from the end of the waveguide 6 situated on the side opposite to that of magnetron 5, from a distance substantially equal to one-eighth of the average wavelength of microwaves in waveguide 6, so that a maximum of energy can be received in the waveguide 6 then re-emitted in the cavity 7 by the antenna.
  • the length of the part of the axis 1 located outside the waveguide 6 is greater or substantially equal to the length of the part of axis 1 located in the guide 6. In this way, most of the energy received by the antenna in the waveguide 6 is radiated by the antenna in the cavity 7.
  • the oven has a cavity 7 in which the antenna is located, excluding a part of its axis 1 located in the waveguide 6.
  • the waveguide annex 60 previously mentioned is the space between the surface emitter 2 and the wall 70 of the cavity 7 which is opposite the surface transmitter 2.
  • the radiant slot 4 then appears as a "hole” in this waveguide annex 60, hole which radiates part of the energy found in the annex waveguide 60.
  • the wall 70 is advantageously the bottom wall of the cavity 7.
  • the axis 1 is preferably perpendicular to the wall 70 so as to allow a more homogeneous distribution of the waves radiated by the antenna.
  • Axis 1 is preferably perpendicular to the direction X of the length of the waveguide 6 connecting the magnetron 5 to the cavity 7.
  • the directions X and Y correspond respectively to the horizontal and vertically in Figures 2A and 2B.
  • the oven also includes, for example, a plate 8 supporting a food 9. These are located so that the energy radiated by the antenna is at least partially directed towards the food 9.
  • the antenna according to the invention is advantageously located in the lower part of the cavity 7, heating food 9 directly mainly by below. The reflections of the waves on the walls of the cavity 7 allow also to heat food 9 from above.
  • the cavity 7 has a bottom wall 70, top wall 72 and side walls 71.
  • the cavity 7 can also advantageously include an antenna complementary 10, this one for example of the classic type, that is to say all metal, located in the upper part of the cavity 7 so that it can optionally heat or cook food 9 directly from both sides, from above and from below.
  • the additional antenna is then preferably located at the level of the upper wall 72 of the cavity 7.
  • the additional antenna 10 allows, if necessary, to perform a "two level" cooking, that is to say cooking two at the same time foods each placed on a separate baking tray; when there is only one antenna, one of the foods risks under certain conditions of hide the other food.
  • This complementary antenna 10 can be powered by another magnetron, not shown here.
  • the speed of rotation is substantially constant and is worth a few tens of revolutions per minute, advantageously of the order of thirty revolutions per minute.
  • An antenna rotation speed too low can lead to insufficient homogenization of the distribution microwaves in cavity 7, while too much rotational speed high may eventually hide the slot 4 and thus also deteriorate homogenization of the distribution of microwaves in the cavity 7.
  • the rotation of the antenna which has no symmetry of revolution around of its axis 1, constantly disturbs over time the waves located in cavity 7 and homogenizes their distribution in cavity 7 by disrupting the establishment of a standing wave regime in the cavity, which diet would still have hot spots and cold spots.
  • FIG. 2B schematically represents an enlarged detail of FIG. 2A, namely the region of the oven which surrounds the antenna according to the invention.
  • the width I 1 of the waveguide 6 is substantially 14mm.
  • the thickness e 1 of the lower wall 70 of the cavity 7 is substantially 1.6 mm.
  • the width I 2 of the annex waveguide 60 is substantially 12mm.
  • the diameter D of the emitting surface 2 is substantially 110mm. It is preferable to avoid taking a diameter D too close to the average wavelength of microwaves in air, here around 122mm, because the efficiency of the antenna is then reduced.
  • the thickness e 2 of the emitting surface is approximately 1mm.
  • the emitting surface 2 shown in FIG. 2B is in the form of a crown and the distance d 2 in the direction X between the interior of the crown and the axis 1 is substantially 8 mm while the distance d 3 in the direction Y between l inside the crown and the axis 1 is substantially 1mm.
  • the distance d 1 in the direction of the direction Y between the axis 1 and the wall of the waveguide 6 is substantially 3mm.
  • the average wavelength of the microwaves in the waveguide 6 being approximately 168mm
  • the distance d 4 in the direction of the direction Y between the axis 1 and the end of the waveguide 6 located on the opposite side the magnetron 5 is approximately 20mm, or approximately one-eighth of the average wavelength of the microwaves in the waveguide 6.
  • the dimensions of the cavity 7 in this preferred example are substantially 420mm in the X direction, 210mm in the Y direction and 372mm in the depth of the cavity 7, that is to say in a direction perpendicular to the plane of the Figures 2A and 2B. With different dimensions for the cavity 7, the dimensions of the antenna itself and of its relative positioning in the oven would be different, but the general shape of the antenna and its general arrangement would advantageously remain similar.
  • the antenna according to the invention comprises a dielectric junction 3, which allows a better distribution of microwaves at the level of the antenna and therefore a better homogenization of the distribution of microwave in cavity 7. If the antenna was entirely metallic as in the prior art, the waves would be radiated especially according to the direction X which is the direction of the length of the waveguide 6 connecting the magnetron 5 to the cavity 7.
  • the antenna is movable in rotation around its axis 1.
  • the different parts of the antenna are stationary the relative to each other, and axis 1 rotates around itself the emitting surface 2 in its rotation.
  • Axis 1 can also be fixed by relative to the oven while the rest of the antenna rotates around axis 1.
  • the axis 1 is for example hollow and the emitting surface 2 is then linked to axis 1 by a dielectric junction 3 comprising a part axial mobile in rotation and located in the hollow of axis 1.
  • the antenna preferably has at least one slot 4 radiant so as to disturb the waves located in the cavity 7, which otherwise would be in standing wave regime.
  • a wave regime stationary has corresponding hot spots and cold spots to a somewhat homogeneous distribution of the waves in the cavity 7.
  • the radiant slot 4 is elongated and the length direction of the slot 4 is substantially perpendicular to the straight line connecting the center of the slot 4 to the center of gravity of the end 11 of the axis 1 linked to the emitting surface 2.
  • the perimeter of the radiating slot 4 is substantially equal to the average wavelength in the air of the microwaves carried by the waveguide 6.
  • All the points on the periphery of the slot 4 radiant are preferentially distant from the center of gravity of the end 11 of the axis 1 linked to the emitting surface 2, from a distance greater than or substantially equal to one-eighth of the wavelength mean in the air of the microwaves carried by the waveguide 6.
  • FIGS. 3A to 3D schematically represent a view of above respectively a first, a second, a third, and of a fourth preferred embodiment of the emitting surface of a antenna according to the invention.
  • Figures 3A to 3C show different emitting surfaces 2 comprising different radiating slots 4.
  • the figure 3D represents an emitting surface 2 not comprising any radiant slit but rather a fin 20 as a disturbing element waves located in the cavity 7.
  • FIG. 3A represents an emitting surface 2 in the form of an outer edge crown 21.
  • the end 11 of the axis 1 of the antenna has a center of gravity 10.
  • the radiating slot 4 is of substantially elongated rectangular shape. Its perimeter p is the average wavelength in the air of the microwaves located in the cavity 7 of the oven. All the points of the periphery of the slot 4, that is to say all the points located along the perimeter p are at a distance greater than or equal to the distance b, which is greater than or equal to the eighth of the length d medium wave in the air of the microwaves located in the cavity 7 of the oven.
  • the slot 4 has a center 41 and a length in the direction ⁇ 1.
  • the line ⁇ 1 is perpendicular to the line joining the center 41 to the center of gravity 10.
  • the radiation from such a slot is more homogeneous than the radiation from a slot whose length would be parallel to the straight line joining the center 41 at the center of gravity 10.
  • This slot of length parallel to the radius of the emitting surface 2 would have a radiation of decreasing intensity from the center of the emitting surface 2 towards its edge 21, while the radiation of a slit cutting the radii of the emitting surface 2 as in FIG. 3A is substantially constant over the entire surface of the slot 4.
  • the strip of conductive material separating the inner circle 22 of the crown from the periphery of the slot 4 should be sufficiently wide to avoid excessive heating at this level: in practice a few millimeters are sufficient.
  • the length L f of the slot 4 is worth substantially 60mm while its width l f is worth substantially 10mm.
  • FIG. 3B represents an emitting surface 2 comprising two elongated radiating slots 4 of the type described in FIG. 3A.
  • the lengths of these slots 4 have the respective directions the lines ⁇ 1 and ⁇ 2 shown in dotted lines.
  • the slots 4 are arranged so not to be parallel to each other.
  • the directions ⁇ 1 and ⁇ 2 intersect in preferably forming an acute angle between them.
  • an antenna corresponding to FIG. 3B radiates less energy at level of its periphery, that is to say of its edge 21, that an antenna corresponding to FIG. 3A. In the case of Figure 3B, most of the energy is radiated towards the center of the cavity 7.
  • FIG. 3C represents an emitting surface 2 comprising a radiant V-shaped slot 4 with truncated point 43, the extensions 42 of the two branches of the V passing substantially through the center of gravity 10 of the emitting surface 2.
  • the constraints concerning the distance b remain the same as for Figures 3A and 3B.
  • the angle between them two branches 42 of the V allow the slot to pass a range microwave frequencies wider than a shape allows rectangular slot, however determining the parameters of the V shape remains more critical than that corresponding to a shape rectangular.
  • FIG. 3D represents an emitting surface comprising a fin 20 as a disturbing element of the waves located in the cavity of oven.
  • the presence of the fin 20 has the same function as the presence of the radiant slots 4 on the other figures, namely to break the symmetry of revolution of the emitting surface 2 around axis 1 and modulating the intensity of energy radiated by the antenna to the oven cavity.
  • the fin 20 has a homogenization efficiency lower than that of a radiant slot 4.
  • the microwave oven previously described applies to preferably domestic cooking ovens, but can also apply to any other type of oven in which a microwave distribution in a cavity must be homogenized, such as for example industrial heating or drying ovens.
  • the industrial ovens of drying can relate to areas like drying wood, textile or tobacco as well as the drying carried out in the tunnels of screen printing.
  • the microwave oven concerns purely microwave ovens as well as combi ovens, i.e. traditional ovens having minus a cooking and / or heating mode carried out by microwave.
  • the antenna according to the invention can also exist in conjunction with a turntable.
  • the antenna will placed for example in the upper part of the oven cavity, while the turntable will traditionally remain at the bottom from the oven cavity.
  • the antenna according to the invention In the oven operating modes where the turntable is stopped, for example in the case of cooking with a large rectangular dish, homogenization of the microwave distribution in the oven cavity will then be ensured by the antenna according to the invention. It is likewise possible to envisage modes making simultaneously operate a traditional turntable with a antenna according to the invention, in order to obtain homogenization optimal in the oven cavity.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Constitution Of High-Frequency Heating (AREA)

Abstract

The antenna consists of an electrically conducting spindle (1) which receives magnetron energy at one end and is connected to an emitting surface (2) at the other by a dielectric tee piece (3). Microwaves are directed into the oven from the emitting surface and adjacent portion of shaft and an asymmetric element (4) which rotates with the emitting surface aids a homogeneous heat distribution. An Independent claim is also included for the microwave oven.

Description

L'invention concerne le domaine des antennes pour four à micro-ondes, notamment pour four à micro-ondes de cuisson domestiques. Des micro-ondes sont envoyées dans la cavité de four pour réaliser une opération de chauffage. Cette opération de chauffage peut constituer un simple réchauffage d'aliment ou bien une cuisson d'aliment. En régime permanent, les micro-ondes forment un réseau d'ondes stationnaires dans la cavité de four. Ce réseau d'ondes stationnaires présente des points chauds et des points froids.The invention relates to the field of antennas for microwave ovens, especially for household microwave ovens. Of microwaves are sent into the oven cavity to make a heating operation. This heating operation can constitute a simple reheating of food or cooking food. In regime permanent, microwaves form a standing wave network in the oven cavity. This standing wave network has hot spots and cold spots.

L'aliment, qu'il doive être cuit ou simplement réchauffé, doit l'être le plus uniformément possible. La distribution des micro-ondes dans la cavité de four doit donc être homogénéisée de façon à atténuer les points chauds et les points froids existant dans cette cavité. Dans toute la suite du texte, sauf mention contraire, on parlera indifféremment d'ondes ou de micro-ondes.The food, whether it should be cooked or simply reheated, must be as uniformly as possible. The distribution of microwaves in the oven cavity must therefore be homogenized so as to attenuate the points hot and cold spots existing in this cavity. In the rest of the text, unless otherwise stated, we will speak indifferently of waves or microwave.

Selon un art antérieur, il existe une antenne entièrement métallique placée en sortie de guide d'onde qui envoie les micro-ondes dans la cavité. Mais la répartition obtenue des micro-ondes manque d'homogénéité. Afin de remédier à ce manque d'homogénéité, la cavité comporte également un plateau tournant pour aliment lequel permet d'aboutir à un chauffage assez homogène de l'aliment.According to a prior art, there is an antenna entirely metallic placed at the waveguide outlet which sends microwaves into the cavity. But the distribution obtained from microwaves is missing homogeneity. In order to remedy this lack of homogeneity, the cavity also includes a turntable for food which allows to achieve fairly uniform heating of the food.

L'invention se propose d'aboutir à un chauffage homogène de l'aliment, sans recourir à la présence d'un plateau tournant dans la cavité. Pour cela, l'invention propose une antenne permettant d'homogénéiser la répartition des micro-ondes dans la cavité.The invention proposes to achieve a homogeneous heating of the food, without resorting to the presence of a turntable in the cavity. For this, the invention provides an antenna for homogenizing the distribution of microwaves in the cavity.

Selon l'invention, il est prévu une antenne comportant un axe conducteur et une surface émettrice conductrice liée à une extrémité de l'axe, caractérisé en ce que l'antenne comporte une jonction diélectrique liant l'axe et la surface émettrice de manière à établir une discontinuité électrique entre l'axe et la surface émettrice et en ce que la surface émettrice ne présente pas une symétrie de révolution autour de la direction moyenne de l'axe.According to the invention, there is provided an antenna comprising an axis conductive and a conductive emitting surface bonded to one end of the axis, characterized in that the antenna has a dielectric junction linking the axis and the emitting surface so as to establish a discontinuity electric between the axis and the emitting surface and in that the surface emitter does not have a symmetry of revolution around the direction axis average.

Selon l'invention, il est encore prévu un four à micro-ondes comportant un émetteur de micro-ondes, une cavité de cuisson, un guide d'onde reliant l'émetteur à la cavité, une antenne selon l'invention, caractérisé en ce que l'axe est partiellement situé dans le guide d'onde, la surface émettrice est située dans la cavité et est mobile en rotation autour de l'axe, la surface émettrice ne présentant pas une symétrie de révolution autour de la direction moyenne de l'axe afin de perturber les ondes stationnaires pouvant exister dans la cavité.According to the invention, a microwave oven is also provided. comprising a microwave transmitter, a cooking cavity, a guide wave connecting the transmitter to the cavity, an antenna according to the invention, characterized in that the axis is partially located in the waveguide, the emitting surface is located in the cavity and is movable in rotation around of the axis, the emitting surface not having a symmetry of revolution around the mean direction of the axis in order to disturb the waves which may exist in the cavity.

L'invention sera mieux comprise et d'autres particularités et avantages apparaítront à l'aide de la description ci-après et des dessins joints, donnés à titre d'exemples, où :

  • la figure 1A représente schématiquement une vue en perspective d'une réalisation préférentielle d'une antenne selon l'invention ;
  • la figure 1B représente schématiquement une vue en coupe selon l'axe AA de la figure 1A;
  • la figure 2A représente schématiquement une vue de face d'une réalisation préférentielle d'un four à micro-ondes selon l'invention ;
  • la figure 2B représente schématiquement un détail agrandi de la figure 2A;
  • les figures 3A à 3D représentent schématiquement une vue de dessus respectivement d'une première, d'une deuxième, d'une troisième, et d'une quatrième réalisation préférentielle de la surface émettrice d'une antenne selon l'invention.
The invention will be better understood and other features and advantages will become apparent with the aid of the description below and of the attached drawings, given by way of examples, in which:
  • FIG. 1A schematically represents a perspective view of a preferred embodiment of an antenna according to the invention;
  • FIG. 1B schematically represents a sectional view along the axis AA of FIG. 1A;
  • FIG. 2A schematically represents a front view of a preferred embodiment of a microwave oven according to the invention;
  • Figure 2B schematically shows an enlarged detail of Figure 2A;
  • Figures 3A to 3D schematically represent a top view respectively of a first, a second, a third, and a fourth preferred embodiment of the emitting surface of an antenna according to the invention.

La figure 1A représente schématiquement une vue en perspective d'une réalisation préférentielle d'une antenne selon l'invention. La figure 1B représente schématiquement une vue en coupe selon l'axe AA de la figure 1A. L'axe AA est représenté en traits pointillés. Les différents éléments représentés sur les figures 1A et 1B ne sont pas tous forcément à la même échelle, ceci restant vrai pour les figures 2A à 3D. L'antenne comporte un axe 1 auquel est liée une surface émettrice 2 par l'intermédiaire d'une jonction 3. La jonction 3 ne comporte pas de hachures sur la figure 1B pour une meilleure lisibilité de la figure. L'axe 1 est liée à la surface émettrice 2, par la jonction 3, au niveau de l'extrémité 11 de l'axe 1. L'axe 1 et la surface émettrice 2 sont en matériau conducteur. Le matériau conducteur est préférentiellement très conducteur, du type métallique, de manière à minimiser les pertes d'énergie dans l'antenne. Le métal considéré est par exemple du cuivre ou du laiton. Le caractère très conducteur du matériau est plus critique pour l'axe 1 que pour la surface émettrice 2 car celle-ci est généralement une pièce de forme plus surfacique que l'axe 1. La jonction 3 est en matériau diélectrique. La jonction 3 lie la surface émettrice 2 à l'axe 1 de manière à établir une discontinuité électrique entre l'axe 1 et la surface émettrice 2. La surface émettrice 2 ne présente pas une symétrie de révolution autour de la direction moyenne ΔM de l'axe 1. La droite AM est représentée en traits mixtes. La surface émettrice 2 comporte par exemple une fente 4 qui brise sa symétrie de révolution même lorsque la forme de la surface émettrice 2 est par exemple celle d'un disque ou d'une couronne.Figure 1A schematically shows a perspective view of a preferred embodiment of an antenna according to the invention. Figure 1B schematically represents a sectional view along the axis AA of the figure 1A. The axis AA is shown in dotted lines. The different elements shown in Figures 1A and 1B are not necessarily the same scale, this remaining true for FIGS. 2A to 3D. The antenna has a axis 1 to which an emitting surface 2 is linked by means of a junction 3. Junction 3 does not have hatching in Figure 1B for better readability of the figure. The axis 1 is linked to the emitting surface 2, by the junction 3, at the end 11 of the axis 1. The axis 1 and the surface transmitter 2 are made of conductive material. The conductive material is preferably very conductive, of the metallic type, so as to minimize energy losses in the antenna. The metal considered is by example of copper or brass. The highly conductive nature of the material is more critical for axis 1 than for emitting surface 2 because it is generally a part with a more surface shape than the axis 1. The junction 3 is made of dielectric material. Junction 3 links emitting surface 2 to axis 1 so as to establish an electrical discontinuity between axis 1 and the surface emitting surface 2. The emitting surface 2 does not have a symmetry of revolution around the mean direction ΔM of the axis 1. The straight line AM is shown in dashed lines. The emitting surface 2 comprises for example a slot 4 which breaks its symmetry of revolution even when the shape of the emitting surface 2 is for example that of a disc or a crown.

L'axe 1 de l'antenne est partiellement situé dans le guide d'onde du four comme expliqué au niveau de la figure 2A. La fonction de l'antenne est d'émettre les micro-ondes dans la cavité de four. L'antenne a une fonction de réception / émission des micro-ondes. En effet, la partie de l'axe 1 située dans le guide d'onde reçoit l'énergie présente dans le guide d'onde tandis que la partie de l'axe 1 située dans la cavité rayonne, dans la cavité du four, l'énergie reçue par la partie de l'axe 1 située dans le guide d'onde. La partie de l'axe 1 située dans la cavité est celle qui est en contact avec la jonction diélectrique 3, au niveau de l'extrémité 11. La surface émettrice 2 joue ensuite le rôle de guide d'onde annexe pour l'énergie rayonnée par la partie de l'axe 1 située dans la cavité de four. La fente 4 peut alors rerayonner l'énergie véhiculée dans le guide d'onde annexe constitué par la surface émettrice 2 ainsi que par la paroi de la cavité en regard de la surface émettrice 2. La surface émettrice 2 n'émet pas à proprement parler, ce n'est que la fente rayonnante 4 que comprend la surface émettrice 2, qui émet. Une partie de l'énergie ainsi véhiculée est émise vers le reste de la cavité au niveau des bords extérieurs 21 de la surface émettrice 2. Une forme et une taille adéquate de l'axe 1, de la surface émettrice 2, de la jonction diélectrique 3 qui sont adaptés à la cavité de four, permettent d'obtenir une répartition homogène des micro-ondes dans la cavité de four. Pour aboutir à cette homogénéisation, le caractère diélectrique de la jonction 3 est essentiel. L'absence de symétrie de révolution de la surface émettrice 2 autour de l'axe 1 de rotation de l'antenne permet à l'antenne de perturber de manière adéquate la répartition des micro-ondes dans la cavité de four lorsque l'antenne est en rotation autour de son axe 1.The axis 1 of the antenna is partially located in the waveguide from the oven as explained in Figure 2A. The function of the antenna is to emit microwaves into the oven cavity. The antenna has a microwave reception / emission function. Indeed, the part of the axis 1 located in the waveguide receives the energy present in the waveguide while the part of the axis 1 located in the cavity radiates, in the cavity from the oven, the energy received by the part of axis 1 located in the waveguide. The part of axis 1 located in the cavity is that which is in contact with the dielectric junction 3, at the end 11. The emitting surface 2 then plays the role of auxiliary waveguide for the energy radiated by the part of axis 1 located in the oven cavity. Slot 4 can then reflect the energy conveyed in the annex waveguide constituted by the emitting surface 2 as well as through the wall of the cavity opposite the Emitting surface 2. The emitting surface 2 does not emit strictly speaking, it is only the radiating slot 4 that comprises the emitting surface 2, which transmits. Part of the energy thus conveyed is emitted to the rest of the cavity at the outer edges 21 of the emitting surface 2. A shape and adequate size of the axis 1, the emitting surface 2, the dielectric junction 3 which are adapted to the oven cavity, allow to obtain a homogeneous distribution of microwaves in the oven cavity. To achieve this homogenization, the dielectric nature of the Junction 3 is essential. The absence of symmetry of revolution of the surface transmitter 2 around the axis 1 of rotation of the antenna allows the antenna to adequately disturb the distribution of microwaves in the cavity oven when the antenna is rotating around its axis 1.

L'axe 1 est de préférence centré par rapport à la surface émettrice 2, comme sur les figures 1A et 1B. Si l'axe 1 est décentré, c'est-à-dire si l'axe 1 est plus près d'un endroit particulier de la périphérie 21 que des autres, la fente 4 sera de préférence située entre cet endroit et l'axe 1 de manière à conserver une efficacité maximale à la fente 4 en terme de quantité d'énergie rerayonnée.Axis 1 is preferably centered relative to the emitting surface 2, as in FIGS. 1A and 1B. If axis 1 is off-center, i.e. if axis 1 is closer to a particular location on the periphery 21 than other, the slot 4 will preferably be located between this location and the axis 1 of so as to maintain maximum efficiency at slot 4 in terms of amount of energy returned.

La surface émettrice 2 est préférentiellement sensiblement plane. L'angle a que fait l'axe 1 avec le plan moyen de la surface émettrice 2 est de préférence sensiblement égal à un angle droit. Si l'angle α n'est pas un angle droit, la fente 4 sera de préférence située du côté de la surface émettrice 2 qui fait l'angle le plus grand avec l'axe 1. Si la surface émettrice 2 n'est pas plane, si par exemple elle est de forme courbe, il est préférable que l'axe 1 ne soit pas du côté de la concavité de la forme courbe de manière à éviter un risque d'arc électrique entre la surface émettrice 2 et les parois de l'antenne lors du fonctionnement de l'antenne dans le four.The emitting surface 2 is preferably substantially planar. The angle a that axis 1 makes with the mean plane of the emitting surface 2 is preferably substantially equal to a right angle. If the angle α is not a right angle, the slot 4 will preferably be located on the side of the surface emitter 2 which makes the greatest angle with axis 1. If the emitting surface 2 is not planar, if for example it is curved, it is preferable that axis 1 is not on the side of the concavity of the curved shape of so as to avoid a risk of electric arc between the emitting surface 2 and the antenna walls when the antenna is operating in the oven.

La surface émettrice 2 a préférentiellement une forme arrondie. La surface émettrice 2, que ce soit sur ses bords ou sur sa surface, ne présente alors pas d'angle, de coin ou de pointe qui risquerait d'être à la source de phénomènes d'arc électrique. La surface émettrice 2 a avantageusement soit une forme de couronne comme sur les figures 1A et 1B, soit une forme de disque si l'assemblage mécanique des trois pièces que sont l'axe 1, la surface émettrice 2 et la jonction 3 ne nécessite pas la présence d'un trou dans la surface émettrice 2. Cette forme en couronne ou en disque présente une symétrie de révolution autour de l'axe 1. Elle permet une répartition régulière des ondes émises au niveau des bords 21 du disque 2 ou de la couronne 2 tandis que la répartition, dans la cavité de four, des ondes émises au niveau de la fente 4, varie au rythme de la vitesse de rotation de l'antenne dans le four. La superposition de ces deux types d'onde dans la cavité, les ondes émises au niveau des bords 21 de la surface émettrice 2 et celles émises par la fente 4, doit aboutir à une répartition sensiblement homogène de l'énergie moyenne dans le temps dans la cavité de four. The emitting surface 2 preferably has a rounded shape. The emitting surface 2, whether on its edges or on its surface, does not then presents no angle, corner or point which would risk being at the source of electric arc phenomena. The emitting surface 2 a advantageously either a crown shape as in FIGS. 1A and 1B, i.e. a disc shape if the mechanical assembly of the three parts that are the axis 1, the emitting surface 2 and the junction 3 does not require the presence of a hole in the emitting surface 2. This crown shape or in disc has a symmetry of revolution around axis 1. It allows a regular distribution of the waves emitted at the edges 21 of the disc 2 or crown 2 while the distribution, in the cavity of oven, waves emitted at slot 4, varies with the speed of rotation of the antenna in the oven. The superposition of these two types wave in the cavity, the waves emitted at the edges 21 of the emitting surface 2 and those emitted by the slot 4, must lead to a substantially homogeneous distribution of average energy over time in the oven cavity.

L'axe 1 est préférentiellement situé tout entier d'un même côté de la surface émettrice 2. L'axe 1 ne traverse alors pas la surface émettrice 2. De cette manière, l'énergie est globalement rayonnée perpendiculairement à l'axe 1 de l'antenne pour être véhiculée entre la paroi de la cavité de four et la surface émettrice 2, avant d'être partiellement rerayonnée par la fente 4. Si l'extrémité 11 de l'axe 1 débouche de l'autre côté de la surface émettrice 2, une partie importante de l'énergie rayonnée par l'axe 1 l'est dans le prolongement de l'axe 1 et non perpendiculairement à l'axe 1. Un tel caractère directionnel de l'antenne rend plus difficile l'homogénéisation de la répartition des ondes dans la cavité de four.Axis 1 is preferably entirely located on the same side of the emitting surface 2. The axis 1 then does not cross the emitting surface 2. In this way, the energy is generally radiated perpendicular to axis 1 of the antenna to be conveyed between the wall of the oven cavity and the emitting surface 2, before being partially re-radiated by the slot 4. If the end 11 of axis 1 leads to the other side of the emitting surface 2, a significant part of the energy radiated by axis 1 is in the extension of axis 1 and not perpendicular to axis 1. Such a directional character of the antenna makes it more difficult to homogenize the wave distribution in the oven cavity.

De manière préférentielle, le caractère dissymétrique de la surface émettrice 2 est assurée par la présence d'une fente rayonnante 4 laquelle est avantageusement rectangulaire. Lorsque l'antenne est en rotation dans la cavité de four, la fente rayonnante 4 répartit l'énergie moyenne dans le temps dans la cavité de four, c'est-à-dire répartit dans la cavité de four l'énergie moyenne sur une période de temps donnée correspondant par exemple à la période de rotation l'antenne lorsque celle-ci tourne à vitesse constante.Preferably, the asymmetrical nature of the emitting surface 2 is ensured by the presence of a radiating slot 4 which is advantageously rectangular. When the antenna is in rotation in the oven cavity, the radiant slot 4 distributes the energy time-averaged in the oven cavity, i.e. distributed over the oven cavity the average energy over a given period of time corresponding for example to the antenna rotation period when the latter rotates at constant speed.

La figure 2A représente schématiquement une vue de face d'une réalisation préférentielle d'un four à micro-ondes selon l'invention. La figure 2B représente schématiquement un détail agrandi de la figure 2A. Le four à micro-ondes décrit sur les figures 2A et 2B est un four à micro-ondes de cuisson domestique pour aliment. Mais ce four peut aussi avoir d'autres applications comme expliqué ultérieurement. Le four comporte un émetteur 5 de micro-ondes, avantageusement un magnétron 5. L'émetteur 5 de micro-ondes qui sera dans la suite considéré comme étant un magnétron, émet des micro-ondes dans un guide 6 d'onde. La direction de propagation de l'énergie véhiculée par les ondes est indiquée sur toute la figure 2A par des flèches en trait plein. Le four comporte une antenne selon l'invention, avec son axe 1, sa surface émettrice 2 et sa jonction 3. L'axe 1 est préférentiellement distant du bout du guide d'onde 6 situé du côté opposé à celui du magnétron 5, d'une distance valant sensiblement le huitième de la longueur d'onde moyenne des micro-ondes dans le guide d'onde 6, afin qu'un maximum d'énergie puisse être reçu dans le guide d'onde 6 puis réémis dans la cavité 7 par l'antenne. Avantageusement, la longueur de la partie de l'axe 1 située hors du guide d'onde 6 est supérieure ou sensiblement égale à la longueur de la partie de l'axe 1 située dans le guide d'onde 6. De cette manière, la plupart de l'énergie reçue par l'antenne dans le guide d'onde 6 est rayonnée par l'antenne dans la cavité 7. L'optimum est atteint pour l'égalité des longueurs des parties de l'axe, auquel cas presque toute l'énergie reçue par l'antenne est ensuite rayonnée par elle dans la cavité 7. Une fente 4 rayonnante est représentée dans la surface émettrice 2, mais d'autres éléments perturbateurs des ondes régnant dans la cavité de four, comme des ailettes par exemple, peuvent être envisagés. Si cet élément perturbateur n'existait pas, il s'établirait au bout d'un moment un régime d'ondes stationnaires présentant des points chaudes et des points froids, ce que l'antenne selon l'invention se propose d'éviter. Le four possède une cavité 7 dans laquelle est située l'antenne à l'exclusion d'une partie de son axe 1 se trouvant dans le guide d'onde 6. Le guide d'onde annexe 60 mentionné antérieurement est l'espace situé entre la surface émettrice 2 et la paroi 70 de la cavité 7 qui est en regard de la surface émettrice 2. La fente 4 rayonnante apparaít alors comme un « trou » dans ce guide d'onde annexe 60, trou qui rerayonne une partie de l'énergie se trouvant dans le guide d'onde annexe 60. La paroi 70 est avantageusement la paroi inférieure de la cavité 7. L'axe 1 est de préférence perpendiculaire à la paroi 70 de manière à permettre une répartition plus homogène des ondes rayonnées par l'antenne. L'axe 1 est de préférence perpendiculaire à la direction X de la longueur du guide d'onde 6 reliant le magnétron 5 à la cavité 7. Les directions X et Y correspondent respectivement à l'horizontale et à la verticale sur les figures 2A et 2B.FIG. 2A schematically represents a front view of a preferential embodiment of a microwave oven according to the invention. The figure 2B schematically represents an enlarged detail of FIG. 2A. The oven microwave described in Figures 2A and 2B is a microwave oven domestic cooking for food. But this oven can also have other applications as explained later. The oven has a transmitter 5 microwave, preferably a magnetron 5. The microwave transmitter 5 which will be considered later as a magnetron, emits microwaves in a waveguide 6. The propagation direction of the energy carried by the waves is indicated throughout FIG. 2A by solid line arrows. The oven comprises an antenna according to the invention, with its axis 1, its emitting surface 2 and its junction 3. The axis 1 is preferably distant from the end of the waveguide 6 situated on the side opposite to that of magnetron 5, from a distance substantially equal to one-eighth of the average wavelength of microwaves in waveguide 6, so that a maximum of energy can be received in the waveguide 6 then re-emitted in the cavity 7 by the antenna. Advantageously, the length of the part of the axis 1 located outside the waveguide 6 is greater or substantially equal to the length of the part of axis 1 located in the guide 6. In this way, most of the energy received by the antenna in the waveguide 6 is radiated by the antenna in the cavity 7. The optimum is reached for the equality of the lengths of the parts of the axis, in which case almost all the energy received by the antenna is then radiated by it in the cavity 7. A radiating slot 4 is represented in the emitting surface 2, but other disturbing elements of the waves prevailing in the cavity of oven, such as fins for example, can be envisaged. If this disruptive element did not exist, it would establish itself after a while a standing wave regime with hot spots and dots cold, which the antenna according to the invention proposes to avoid. The oven has a cavity 7 in which the antenna is located, excluding a part of its axis 1 located in the waveguide 6. The waveguide annex 60 previously mentioned is the space between the surface emitter 2 and the wall 70 of the cavity 7 which is opposite the surface transmitter 2. The radiant slot 4 then appears as a "hole" in this waveguide annex 60, hole which radiates part of the energy found in the annex waveguide 60. The wall 70 is advantageously the bottom wall of the cavity 7. The axis 1 is preferably perpendicular to the wall 70 so as to allow a more homogeneous distribution of the waves radiated by the antenna. Axis 1 is preferably perpendicular to the direction X of the length of the waveguide 6 connecting the magnetron 5 to the cavity 7. The directions X and Y correspond respectively to the horizontal and vertically in Figures 2A and 2B.

Le four comporte aussi par exemple un plateau 8 supportant un aliment 9. Ceux-ci sont situés de manière à ce que l'énergie rayonnée par l'antenne soit au moins partiellement dirigée vers l'aliment 9. L'antenne selon l'invention est avantageusement située dans la partie basse de la cavité 7, chauffant l'aliment 9 de manière directe principalement par en dessous. Les réflexions des ondes sur les parois de la cavité 7 permettent également de chauffer l'aliment 9 par au-dessus. La cavité 7 comporte une paroi inférieure 70, une paroi supérieure 72 et des parois latérales 71. La cavité 7 peut également comporter avantageusement une antenne complémentaire 10, celle-la par exemple de type classique c'est-à-dire tout en métal, située dans la partie haute de la cavité 7 de manière à pouvoir éventuellement chauffer ou cuire l'aliment 9 de manière directe des deux côtés, par au-dessus et par en dessous. L'antenne complémentaire est alors préférentiellement située au niveau de la paroi supérieure 72 de la cavité 7. L'antenne complémentaire 10 permet, le cas échéant, de réaliser une cuisson « deux niveaux », c'est-à-dire une cuisson simultanée de deux aliments placés chacun sur un plateau de cuisson distinct ; lorsqu'il n'y a qu'une seule antenne, l'un des aliments risque dans certaines conditions de masquer l'autre aliment. Cette antenne complémentaire 10 peut être alimentée par un autre magnétron, non représenté ici. En mode de fonctionnement, préférentiellement la vitesse de rotation est sensiblement constante et vaut quelques dizaines de tours par minute, avantageusement de l'ordre de trente tours par minute. Une vitesse de rotation de l'antenne trop faible peut aboutir à une homogénéisation insuffisante de la répartition des micro-ondes dans la cavité 7, tandis qu'une vitesse de rotation trop élevée peut finir par masquer la fente 4 et ainsi détériorer également l'homogénéisation de la répartition des micro-ondes dans la cavité 7. La rotation de l'antenne qui ne présente pas de symétrie de révolution autour de son axe 1, perturbe constamment au cours du temps les ondes situées dans la cavité 7 et homogénéise leur répartition dans la cavité 7 en perturbant l'établissement d'un régime d'ondes stationnaires dans la cavité, lequel régime comporterait encore des points chauds et des points froids.The oven also includes, for example, a plate 8 supporting a food 9. These are located so that the energy radiated by the antenna is at least partially directed towards the food 9. The antenna according to the invention is advantageously located in the lower part of the cavity 7, heating food 9 directly mainly by below. The reflections of the waves on the walls of the cavity 7 allow also to heat food 9 from above. The cavity 7 has a bottom wall 70, top wall 72 and side walls 71. The cavity 7 can also advantageously include an antenna complementary 10, this one for example of the classic type, that is to say all metal, located in the upper part of the cavity 7 so that it can optionally heat or cook food 9 directly from both sides, from above and from below. The additional antenna is then preferably located at the level of the upper wall 72 of the cavity 7. The additional antenna 10 allows, if necessary, to perform a "two level" cooking, that is to say cooking two at the same time foods each placed on a separate baking tray; when there is only one antenna, one of the foods risks under certain conditions of hide the other food. This complementary antenna 10 can be powered by another magnetron, not shown here. In mode of operation, preferably the speed of rotation is substantially constant and is worth a few tens of revolutions per minute, advantageously of the order of thirty revolutions per minute. An antenna rotation speed too low can lead to insufficient homogenization of the distribution microwaves in cavity 7, while too much rotational speed high may eventually hide the slot 4 and thus also deteriorate homogenization of the distribution of microwaves in the cavity 7. The rotation of the antenna which has no symmetry of revolution around of its axis 1, constantly disturbs over time the waves located in cavity 7 and homogenizes their distribution in cavity 7 by disrupting the establishment of a standing wave regime in the cavity, which diet would still have hot spots and cold spots.

La figure 2B représente schématiquement un détail agrandi de la figure 2A, à savoir la région du four qui environne l'antenne selon l'invention. Sont représentées, une partie du guide d'onde 6 ainsi qu'une partie de la cavité 7. Toutes les valeurs numériques qui suivent concernent un exemple préférentiel de réalisation. La largeur I1 du guide d'onde 6 vaut sensiblement 14mm. L'épaisseur e1 de la paroi inférieure 70 de la cavité 7 vaut sensiblement 1,6mm. La largeur I2 du guide d'onde annexe 60 vaut sensiblement 12mm. Le diamètre D de la surface émettrice 2 vaut sensiblement 110mm. IL est préférable d'éviter de prendre un diamètre D trop voisin de la longueur d'onde moyenne des micro-ondes dans l'air, ici environ 122mm, car l'efficacité de l'antenne est alors diminuée. L'épaisseur e2 de la surface émettrice vaut sensiblement 1mm. La surface émettrice 2 représentée sur la figure 2B est en forme de couronne et la distance d2 dans la direction X entre l'intérieur de la couronne et l'axe 1 vaut sensiblement 8mm tandis que la distance d3 dans la direction Y entre l'intérieur de la couronne et l'axe 1 vaut sensiblement 1mm. La distance d1 dans le sens de la direction Y entre l'axe 1 et la paroi du guide d'onde 6 vaut sensiblement 3mm. La longueur d'onde moyenne des micro-ondes dans le guide d'onde 6 valant environ 168mm, la distance d4 dans le sens de la direction Y entre l'axe 1 et le bout du guide d'onde 6 situé du côté opposé au magnétron 5 vaut environ 20mm, soit environ le huitième de la longueur d'onde moyenne des micro-ondes dans le guide d'onde 6. La longueur h2 de la partie de l'axe 1 située dans le guide d'onde 6 comme la longueur h1 de la partie de l'axe 1 située hors du guide d'onde 6 c'est-à-dire dans la cavité 7, valent chacune sensiblement 11mm. Les dimensions de la cavité 7 de cet exemple préférentiel sont sensiblement de 420mm dans la direction X, de 210mm dans la direction Y et de 372mm dans la profondeur de la cavité 7, c'est-à-dire selon une direction perpendiculaire au plan des figures 2A et 2B. Avec des dimensions différentes pour la cavité 7, les dimensions de l'antenne elle-même et de son positionnement relatif dans le four seraient différentes, mais la forme générale de l'antenne et sa disposition générale resteraient avantageusement similaires.FIG. 2B schematically represents an enlarged detail of FIG. 2A, namely the region of the oven which surrounds the antenna according to the invention. Are shown, part of the waveguide 6 as well as part of the cavity 7. All the numerical values which follow relate to a preferred embodiment. The width I 1 of the waveguide 6 is substantially 14mm. The thickness e 1 of the lower wall 70 of the cavity 7 is substantially 1.6 mm. The width I 2 of the annex waveguide 60 is substantially 12mm. The diameter D of the emitting surface 2 is substantially 110mm. It is preferable to avoid taking a diameter D too close to the average wavelength of microwaves in air, here around 122mm, because the efficiency of the antenna is then reduced. The thickness e 2 of the emitting surface is approximately 1mm. The emitting surface 2 shown in FIG. 2B is in the form of a crown and the distance d 2 in the direction X between the interior of the crown and the axis 1 is substantially 8 mm while the distance d 3 in the direction Y between l inside the crown and the axis 1 is substantially 1mm. The distance d 1 in the direction of the direction Y between the axis 1 and the wall of the waveguide 6 is substantially 3mm. The average wavelength of the microwaves in the waveguide 6 being approximately 168mm, the distance d 4 in the direction of the direction Y between the axis 1 and the end of the waveguide 6 located on the opposite side the magnetron 5 is approximately 20mm, or approximately one-eighth of the average wavelength of the microwaves in the waveguide 6. The length h 2 of the part of the axis 1 located in the waveguide 6 like the length h 1 of the part of the axis 1 located outside of the waveguide 6, that is to say in the cavity 7, each is substantially equal to 11mm. The dimensions of the cavity 7 in this preferred example are substantially 420mm in the X direction, 210mm in the Y direction and 372mm in the depth of the cavity 7, that is to say in a direction perpendicular to the plane of the Figures 2A and 2B. With different dimensions for the cavity 7, the dimensions of the antenna itself and of its relative positioning in the oven would be different, but the general shape of the antenna and its general arrangement would advantageously remain similar.

L'antenne selon l'invention comporte une jonction diélectrique 3, laquelle permet une meilleure répartition des micro-ondes au niveau de l'antenne et partant, une meilleure homogénéisation de la répartition des micro-ondes dans la cavité 7. Si l'antenne était entièrement métallique comme dans l'art antérieur, les ondes seraient rayonnées surtout selon la direction X qui est la direction de la longueur du guide d'onde 6 reliant le magnétron 5 à la cavité 7. L'antenne est mobile en rotation autour de son axe 1. De préférence, les différentes parties de l'antenne sont immobiles les unes par rapport aux autres, et l'axe 1 tourne autour de lui-même entraínant la surface émettrice 2 dans sa rotation. L'axe 1 peut aussi être fixe par rapport au four tandis que le reste de l'antenne tourne autour de l'axe 1. Dans ce dernier cas, l'axe 1 est par exemple creux et la surface émettrice 2 est alors liée à l'axe 1 par une jonction diélectrique 3 comportant une partie axiale mobile en rotation et située dans le creux de l'axe 1.The antenna according to the invention comprises a dielectric junction 3, which allows a better distribution of microwaves at the level of the antenna and therefore a better homogenization of the distribution of microwave in cavity 7. If the antenna was entirely metallic as in the prior art, the waves would be radiated especially according to the direction X which is the direction of the length of the waveguide 6 connecting the magnetron 5 to the cavity 7. The antenna is movable in rotation around its axis 1. Preferably, the different parts of the antenna are stationary the relative to each other, and axis 1 rotates around itself the emitting surface 2 in its rotation. Axis 1 can also be fixed by relative to the oven while the rest of the antenna rotates around axis 1. In the latter case, the axis 1 is for example hollow and the emitting surface 2 is then linked to axis 1 by a dielectric junction 3 comprising a part axial mobile in rotation and located in the hollow of axis 1.

L'antenne comporte de préférence au moins une fente 4 rayonnante de manière à perturber les ondes situées dans la cavité 7, qui sinon seraient en régime d'ondes stationnaires. Un régime d'ondes stationnaires présente des points chauds et des points froids correspondant à une répartition peu homogène des ondes dans la cavité 7. De préférence, la fente 4 rayonnante est allongée et la direction de la longueur de la fente 4 est sensiblement perpendiculaire à la droite reliant le centre de la fente 4 au centre de gravité de l'extrémité 11 de l'axe 1 liée à la surface émettrice 2. Avantageusement, le périmètre de la fente 4 rayonnante est sensiblement égal à la longueur d'onde moyenne dans l'air des micro-ondes véhiculées par le guide d'onde 6. Tous les points de la périphérie de la fente 4 rayonnante sont préférentiellement éloignés du centre de gravité de l'extrémité 11 de l'axe 1 liée à la surface émettrice 2, d'une distance supérieure ou sensiblement égale au huitième de la longueur d'onde moyenne dans l'air des micro-ondes véhiculées par le guide d'onde 6.The antenna preferably has at least one slot 4 radiant so as to disturb the waves located in the cavity 7, which otherwise would be in standing wave regime. A wave regime stationary has corresponding hot spots and cold spots to a somewhat homogeneous distribution of the waves in the cavity 7. Preferably, the radiant slot 4 is elongated and the length direction of the slot 4 is substantially perpendicular to the straight line connecting the center of the slot 4 to the center of gravity of the end 11 of the axis 1 linked to the emitting surface 2. Advantageously, the perimeter of the radiating slot 4 is substantially equal to the average wavelength in the air of the microwaves carried by the waveguide 6. All the points on the periphery of the slot 4 radiant are preferentially distant from the center of gravity of the end 11 of the axis 1 linked to the emitting surface 2, from a distance greater than or substantially equal to one-eighth of the wavelength mean in the air of the microwaves carried by the waveguide 6.

Les figures 3A à 3D représentent schématiquement une vue de dessus respectivement d'une première, d'une deuxième, d'une troisième, et d'une quatrième réalisation préférentielle de la surface émettrice d'une antenne selon l'invention. Les figures 3A à 3C présentent différentes surfaces émettrices 2 comportant différentes fentes 4 rayonnantes. La figure 3D, quant à elle, représente une surface émettrice 2 ne comportant pas de fente rayonnante mais plutôt une ailette 20 en guise d'élément perturbateur des ondes situées dans la cavité 7.FIGS. 3A to 3D schematically represent a view of above respectively a first, a second, a third, and of a fourth preferred embodiment of the emitting surface of a antenna according to the invention. Figures 3A to 3C show different emitting surfaces 2 comprising different radiating slots 4. The figure 3D, on the other hand, represents an emitting surface 2 not comprising any radiant slit but rather a fin 20 as a disturbing element waves located in the cavity 7.

La figure 3A représente une surface émettrice 2 en forme de couronne de bord extérieur 21. L'extrémité 11 de l'axe 1 de l'antenne a un centre de gravité 10. La fente rayonnante 4 est de forme sensiblement rectangulaire allongée. Son périmètre p vaut la longueur d'onde moyenne dans l'air des micro-ondes situées dans la cavité 7 du four. Tous les points de la périphérie de la fente 4, c'est-à-dire tous les points situés le long du périmètre p sont à une distance supérieure ou égale à la distance b, laquelle est supérieure ou égale au huitième de la longueur d'onde moyenne dans l'air des micro-ondes situées dans la cavité 7 du four. La fente 4 a un centre 41 et une longueur selon la direction Δ1. La droite Δ1, représentée en traits pointillés, est perpendiculaire à la droite joignant le centre 41 au centre de gravité 10. Le rayonnement d'une telle fente est plus homogène que le rayonnement d'une fente dont la longueur serait parallèle à la droite joignant le centre 41 au centre de gravité 10. Cette fente de longueur parallèle au rayon de la surface émettrice 2 aurait un rayonnement d'intensité décroissante du centre de la surface émettrice 2 vers son bord 21, tandis que le rayonnement d'une fente coupant les rayons de la surface émettrice 2 comme sur la figure 3A est sensiblement constant sur toute la surface de la fente 4. Par ailleurs, la bande de matériau conducteur séparant le cercle intérieur 22 de la couronne de la périphérie de la fente 4 devrait être suffisamment large pour éviter un échauffement excessif à ce niveau : en pratique quelques millimètres suffisent. Selon un exemple numérique préférentiel, pour un diamètre D du cercle 21 valant environ 110mm, la longueur Lf de la fente 4 vaut sensiblement 60mm tandis que sa largeur lf vaut sensiblement 10mm.FIG. 3A represents an emitting surface 2 in the form of an outer edge crown 21. The end 11 of the axis 1 of the antenna has a center of gravity 10. The radiating slot 4 is of substantially elongated rectangular shape. Its perimeter p is the average wavelength in the air of the microwaves located in the cavity 7 of the oven. All the points of the periphery of the slot 4, that is to say all the points located along the perimeter p are at a distance greater than or equal to the distance b, which is greater than or equal to the eighth of the length d medium wave in the air of the microwaves located in the cavity 7 of the oven. The slot 4 has a center 41 and a length in the direction Δ1. The line Δ1, represented in dotted lines, is perpendicular to the line joining the center 41 to the center of gravity 10. The radiation from such a slot is more homogeneous than the radiation from a slot whose length would be parallel to the straight line joining the center 41 at the center of gravity 10. This slot of length parallel to the radius of the emitting surface 2 would have a radiation of decreasing intensity from the center of the emitting surface 2 towards its edge 21, while the radiation of a slit cutting the radii of the emitting surface 2 as in FIG. 3A is substantially constant over the entire surface of the slot 4. Furthermore, the strip of conductive material separating the inner circle 22 of the crown from the periphery of the slot 4 should be sufficiently wide to avoid excessive heating at this level: in practice a few millimeters are sufficient. According to a preferred numerical example, for a diameter D of the circle 21 being worth approximately 110mm, the length L f of the slot 4 is worth substantially 60mm while its width l f is worth substantially 10mm.

La figure 3B représente une surface émettrice 2 comportant deux fentes 4 rayonnantes allongées du type de celle décrite à la figure 3A. Les longueurs de ces fentes 4 ont pour directions respectives les droites Δ1 et Δ2 représentées en traits pointillés. Les fentes 4 sont disposées de manière à ne pas être parallèles entre elles. Les directions Δ1 et Δ2 se coupent en faisant entre elles un angle de préférence aigu. A même vitesse de rotation, une antenne correspondant à la figure 3B rayonne moins d'énergie au niveau de sa périphérie, c'est-à-dire de son bord 21, qu'une antenne correspondant à la figure 3A. Dans le cas de la figure 3B, la plupart de l'énergie est rayonnée vers le centre de la cavité 7.FIG. 3B represents an emitting surface 2 comprising two elongated radiating slots 4 of the type described in FIG. 3A. The lengths of these slots 4 have the respective directions the lines Δ1 and Δ2 shown in dotted lines. The slots 4 are arranged so not to be parallel to each other. The directions Δ1 and Δ2 intersect in preferably forming an acute angle between them. At the same rotation speed, an antenna corresponding to FIG. 3B radiates less energy at level of its periphery, that is to say of its edge 21, that an antenna corresponding to FIG. 3A. In the case of Figure 3B, most of the energy is radiated towards the center of the cavity 7.

La figure 3C représente une surface émettrice 2 comportant une fente 4 rayonnante en forme de V à pointe 43 tronquée, les prolongements 42 des deux branches du V passant sensiblement par le centre de gravité 10 de la surface émettrice 2. Les contraintes concernant la distance b restent les mêmes que pour les figures 3A et 3B. L'angle que font entre elles les deux branches 42 du V permettent à la fente de laisser passer une gamme de fréquences de micro-ondes plus étendue que ce que permet une forme de fente rectangulaire, cependant la détermination des paramètres de la forme en V reste plus critique que celle correspondant à une forme rectangulaire.FIG. 3C represents an emitting surface 2 comprising a radiant V-shaped slot 4 with truncated point 43, the extensions 42 of the two branches of the V passing substantially through the center of gravity 10 of the emitting surface 2. The constraints concerning the distance b remain the same as for Figures 3A and 3B. The angle between them two branches 42 of the V allow the slot to pass a range microwave frequencies wider than a shape allows rectangular slot, however determining the parameters of the V shape remains more critical than that corresponding to a shape rectangular.

La figure 3D représente une surface émettrice comportant une ailette 20 en guise d'élément perturbateur des ondes situées dans la cavité de four. La présence de l'ailette 20 a la même fonction que la présence des fentes 4 rayonnantes sur les autres figures, à savoir briser la symétrie de révolution de la surface émettrice 2 autour de l'axe 1 et moduler l'intensité de l'énergie rayonnée par l'antenne vers la cavité de four. L'ailette 20 a une efficacité d'homogénéisation moindre que celle d'une fente 4 rayonnante.FIG. 3D represents an emitting surface comprising a fin 20 as a disturbing element of the waves located in the cavity of oven. The presence of the fin 20 has the same function as the presence of the radiant slots 4 on the other figures, namely to break the symmetry of revolution of the emitting surface 2 around axis 1 and modulating the intensity of energy radiated by the antenna to the oven cavity. The fin 20 has a homogenization efficiency lower than that of a radiant slot 4.

Le four à micro-ondes précédemment décrit s'applique de préférence à des fours de cuisson domestique, mais peut également s'appliquer à tout autre type de four dans lequel une répartition de micro-ondes dans une cavité doit être homogénéisée, comme par exemple des fours industriels de chauffage ou de séchage . Les fours industriels de séchage peuvent concerner des domaines comme le séchage du bois, du textile ou du tabac ainsi que le séchage effectué dans les tunnels de sérigraphie.The microwave oven previously described applies to preferably domestic cooking ovens, but can also apply to any other type of oven in which a microwave distribution in a cavity must be homogenized, such as for example industrial heating or drying ovens. The industrial ovens of drying can relate to areas like drying wood, textile or tobacco as well as the drying carried out in the tunnels of screen printing.

Dans le cas de l'application préférentielle à des fours de cuisson domestique, le four à micro-ondes concerne les fours purement micro-ondes aussi bien que les fours mixtes, c'est-à-dire les fours traditionnels ayant au moins un mode de cuisson et/ou chauffage réalisé par micro-ondes. Dans un four de cuisson domestique, l'antenne selon l'invention peut également exister conjointement à un plateau tournant. Dans ce cas, l'antenne sera placée par exemple dans la partie supérieure de la cavité de four, tandis que le plateau tournant restera traditionnellement placé dans la partie inférieure de la cavité de four. Dans les modes de fonctionnement du four où le plateau tournant est arrêté, par exemple dans le cas de cuisson avec un grand plat rectangulaire, l'homogénéisation de la répartition des micro-ondes dans la cavité de four sera alors assurée par l'antenne selon l'invention. Il est de même possible d'envisager des modes faisant fonctionner simultanément un plateau tournant traditionnel avec une antenne selon l'invention, dans le but d'obtenir une homogénéisation optimale dans la cavité de four.In the case of preferential application to baking ovens domestic, the microwave oven concerns purely microwave ovens as well as combi ovens, i.e. traditional ovens having minus a cooking and / or heating mode carried out by microwave. In one domestic cooking oven, the antenna according to the invention can also exist in conjunction with a turntable. In this case, the antenna will placed for example in the upper part of the oven cavity, while the turntable will traditionally remain at the bottom from the oven cavity. In the oven operating modes where the turntable is stopped, for example in the case of cooking with a large rectangular dish, homogenization of the microwave distribution in the oven cavity will then be ensured by the antenna according to the invention. It is likewise possible to envisage modes making simultaneously operate a traditional turntable with a antenna according to the invention, in order to obtain homogenization optimal in the oven cavity.

Claims (19)

Antenne comportant un axe (1) conducteur et une surface émettrice (2) conductrice liée à une extrémité (11) de l'axe (1), caractérisé en ce que l'antenne comporte une jonction diélectrique (3) liant l'axe (1) et la surface émettrice (2) de manière à établir une discontinuité électrique entre l'axe (1) et la surface émettrice (2) et en ce que la surface émettrice (2) ne présente pas une symétrie de révolution autour de la direction moyenne (ΔM) de l'axe (1).Antenna comprising a conductive axis (1) and a surface transmitting (2) conductive linked to one end (11) of the axis (1), characterized in that the antenna comprises a dielectric junction (3) connecting the axis (1) and the emitting surface (2) so as to establish an electrical discontinuity between the axis (1) and the emitting surface (2) and in that the emitting surface (2) does not not present a symmetry of revolution around the middle direction (ΔM) of the axis (1). Antenne selon la revendication 1, caractérisé en ce que la surface émettrice (2) a une forme arrondie.Antenna according to claim 1, characterized in that the emitting surface (2) has a rounded shape. Antenne selon la revendication 2, caractérisé en ce que la surface émettrice (2) a une forme de disque ou de couronne.Antenna according to claim 2, characterized in that the emitting surface (2) has a disc or crown shape. Antenne selon l'une quelconque des revendications 1 à 3, caractérisé en ce que l'axe (1) est situé tout entier d'un même côté de la surface émettrice (2).Antenna according to any one of claims 1 to 3, characterized in that the axis (1) is located entirely on the same side of the emitting surface (2). Antenne selon l'une quelconque des revendications 1 à 4, caractérisé en ce que la surface émettrice (2) comporte au moins une fente (4) rayonnante.Antenna according to any one of claims 1 to 4, characterized in that the emitting surface (2) has at least one slot (4) radiant. Antenne selon la revendication 5, caractérisé en ce que la fente (4) rayonnante est sensiblement rectangulaire.Antenna according to claim 5, characterized in that the radiant slot (4) is substantially rectangular. Antenne selon l'une quelconque des revendications 5 à 6, caractérisé en ce que la fente (4) rayonnante est allongée et en ce que la direction (Δ1) de la longueur de la fente est sensiblement perpendiculaire à la droite reliant le centre (41) de la fente (4) au centre de gravité (10) de l'extrémité (11) de l'axe (1) liée à la surface émettrice (2).Antenna according to any one of claims 5 to 6, characterized in that the radiating slot (4) is elongated and in that the direction (Δ1) of the length of the slit is substantially perpendicular to the straight line connecting the center (41) of the slot (4) to the center of gravity (10) of the end (11) of the axis (1) linked to the emitting surface (2). Antenne selon la revendication 5, caractérisé en ce que la fente (4) rayonnante est en forme de V à pointe (43) tronquée, les prolongements des deux branches (42) du V passant sensiblement par le centre de gravité (10) de la surface émettrice (2).Antenna according to claim 5, characterized in that the radiant slot (4) is V-shaped with truncated point (43), the extensions of the two branches (42) of the V passing substantially through the center of gravity (10) of the emitting surface (2). Antenne selon l'une quelconque des revendications 5 à 8, caractérisé en ce que la surface émettrice (2) comporte deux fentes (4) rayonnantes non parallèles entre elles.Antenna according to any one of claims 5 to 8, characterized in that the emitting surface (2) has two slots (4) radiant not parallel to each other. Antenne selon l'une quelconque des revendications 1 à 4, caractérisé en ce que la surface émettrice (2) comporte au moins une ailette (20).Antenna according to any one of claims 1 to 4, characterized in that the emitting surface (2) comprises at least one fin (20). Four à micro-ondes comportant un émetteur (5) de micro-ondes, une cavité (7) de cuisson, un guide d'onde (6) reliant l'émetteur (5) à la cavité (7), une antenne selon l'une quelconque des revendications 1 à 10, caractérisé en ce que l'axe (1) est partiellement situé dans le guide d'onde (6), la surface émettrice (2) est située dans la cavité (7) et est mobile en rotation autour de l'axe (1), la surface émettrice (2) ne présentant pas une symétrie de révolution autour de la direction moyenne (ΔM) de l'axe (1) afin de perturber les ondes stationnaires pouvant exister dans la cavité (7).Microwave oven comprising a microwave transmitter (5), a cooking cavity (7), a waveguide (6) connecting the transmitter (5) to the cavity (7), an antenna according to any one of claims 1 to 10, characterized in that the axis (1) is partially located in the waveguide (6), the emitting surface (2) is located in the cavity (7) and is movable in rotation about the axis (1), the emitting surface (2) not having a symmetry of revolution around the mean direction (ΔM) of the axis (1) so disturbing standing waves that may exist in the cavity (7). Four à micro-ondes selon l'une quelconque des revendications 5 à 9 et selon la revendication 11, caractérisé en ce que le périmètre (p) de la fente (4) rayonnante est sensiblement égal à la longueur d'onde moyenne dans l'air des micro-ondes situées dans la cavité (7) du four.Microwave oven according to any one of claims 5 to 9 and according to claim 11, characterized in that the perimeter (p) of the radiating slot (4) is substantially equal to the length wave in the air of the microwaves located in the cavity (7) of the oven. Four à micro-ondes selon la revendication 12, caractérisé en ce que tous les points de la périphérie (p) de la fente (4) rayonnante sont éloignés du centre de gravité (10) de l'extrémité (11) de l'axe (1) liée à la surface émettrice (2), d'une distance supérieure ou sensiblement égale au huitième de la longueur d'onde moyenne dans l'air des micro-ondes véhiculées par le guide d'onde (6).Microwave oven according to claim 12, characterized in that all the points of the periphery (p) of the radiating slot (4) are away from the center of gravity (10) from the end (11) of the axis (1) linked to the emitting surface (2), a distance greater than or substantially equal to the eighth of the average wavelength in microwave air conveyed by the waveguide (6). Four à micro-ondes selon l'une quelconque des revendications 11 à 13, caractérisé en ce que la longueur (h1) de la partie de l'axe (1) située hors du guide d'onde (6) est supérieure ou sensiblement égale à la longueur (h2) de la partie de l'axe (1) située dans le guide d'onde (6).Microwave oven according to any one of Claims 11 to 13, characterized in that the length (h 1 ) of the part of the axis (1) situated outside the waveguide (6) is greater or substantially equal to the length (h 2 ) of the part of the axis (1) located in the waveguide (6). Four à micro-ondes selon l'une quelconque des revendications 11 à 14, caractérisé en ce que la vitesse de rotation de l'antenne en mode de fonctionnement vaut quelques dizaines de tours par minute.Microwave oven according to any one of Claims 11 to 14, characterized in that the speed of rotation of the antenna in operating mode is worth a few tens of turns per minute. Four à micro-ondes selon l'une quelconque des revendications 11 à 15, caractérisé en ce que l'antenne est située au milieu de la partie basse de la cavité (7).Microwave oven according to any one of Claims 11 to 15, characterized in that the antenna is located in the middle of the lower part of the cavity (7). Four à micro-ondes selon l'une quelconque des revendications 11 à 16, caractérisé en ce que le four est un four de cuisson domestique.Microwave oven according to any one of Claims 11 to 16, characterized in that the oven is a baking oven domesticated. Four à micro-ondes selon la revendication 17, caractérisé en ce que le four comporte également un plateau tournant pour aliment.Microwave oven according to claim 17, characterized in what the oven also has a turntable for food. Four à micro-ondes selon l'une quelconque des revendications 11 à 16, caractérisé en ce que le four est un four industriel de séchage.Microwave oven according to any one of Claims 11 to 16, characterized in that the furnace is an industrial furnace of drying.
EP20000402442 1999-09-10 2000-09-05 Microwave oven antenna Expired - Lifetime EP1083772B1 (en)

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FR9911375 1999-09-10
FR9911375A FR2798549B1 (en) 1999-09-10 1999-09-10 ANTENNA FOR MICROWAVE OVEN

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EP1566986A1 (en) * 2004-02-19 2005-08-24 LG Electronics Inc. Microwave oven
JP2010199009A (en) * 2009-02-27 2010-09-09 Panasonic Corp Microwave heating device
WO2013021369A2 (en) * 2012-12-13 2013-02-14 Zhylkov Valerii Stepanovich Microwave oven
WO2019201616A1 (en) 2018-04-20 2019-10-24 BSH Hausgeräte GmbH Rotating microwave antenna for a domestic microwave device, and domestic microwave device
CN114009147A (en) * 2019-06-24 2022-02-01 Bsh家用电器有限公司 Domestic microwave device with rotating antenna

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US4642435A (en) * 1985-12-26 1987-02-10 General Electric Company Rotating slot antenna arrangement for microwave oven
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GB2039200A (en) * 1978-12-01 1980-07-30 Raytheon Co Microwave oven
US4430538A (en) * 1980-08-28 1984-02-07 Tokyo Shibaura Denki Kabushiki Kaisha High-frequency heating device
US4642435A (en) * 1985-12-26 1987-02-10 General Electric Company Rotating slot antenna arrangement for microwave oven
EP0632677A2 (en) * 1993-06-30 1995-01-04 SANYO ELECTRIC Co., Ltd. Microwave oven including antenna for radiating microwave

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1434466A1 (en) * 2002-12-27 2004-06-30 Sanyo Electric Co., Ltd. Microwave oven with antenna moving device
US6812443B2 (en) 2002-12-27 2004-11-02 Sanyo Electric Co., Ltd. Microwave oven capable of changing the way to supply microwaves into heating chambers
EP1566986A1 (en) * 2004-02-19 2005-08-24 LG Electronics Inc. Microwave oven
US7030347B2 (en) 2004-02-19 2006-04-18 Lg Electronics Inc. Microwave oven with mode stirrer
CN1316201C (en) * 2004-02-19 2007-05-16 Lg电子株式会社 Microwave oven
JP2010199009A (en) * 2009-02-27 2010-09-09 Panasonic Corp Microwave heating device
WO2013021369A2 (en) * 2012-12-13 2013-02-14 Zhylkov Valerii Stepanovich Microwave oven
WO2013021369A3 (en) * 2012-12-13 2013-12-27 Zhylkov Valerii Stepanovich Microwave oven
WO2019201616A1 (en) 2018-04-20 2019-10-24 BSH Hausgeräte GmbH Rotating microwave antenna for a domestic microwave device, and domestic microwave device
CN114009147A (en) * 2019-06-24 2022-02-01 Bsh家用电器有限公司 Domestic microwave device with rotating antenna

Also Published As

Publication number Publication date
DE60042870D1 (en) 2009-10-15
ES2332401T3 (en) 2010-02-04
FR2798549A1 (en) 2001-03-16
FR2798549B1 (en) 2002-01-11
EP1083772B1 (en) 2009-09-02

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