Microwave assembly for heating and microwave heating device

Abstract

The utility model relates to the field of microwave heating, in particular to a microwave assembly for heating. The microwave assembly comprises a microwave generator, a waveguide power division network and a shell, a heating cavity is formed in the shell; at least one side of the heating cavity is provided with a microwave assembly, and the microwave assembly comprises a plurality of antenna units and a rotating assembly; the antenna units are distributed in an array; the microwave generator is connected with the antenna unit through a waveguide power division network; the rotating assembly is connected with the antenna units, and the antenna units rotate in the array distribution to form a phased array. The stirring of microwave energy is realized through the rotation of the antenna unit, so that microwaves radiated into the heating cavity through the antenna change continuously, and the purpose of uniform heating is achieved. Through the combination of the dynamic antenna and the static heated object, the utilization of the heated object to the heating cavity almost reaches the maximum size of the diagonal line in the heating cavity, and the space occupation of a rotating disc required by the rotation of the rotating disc type heated object to the heating cavity is also eliminated.

Description

Technical Field

[0001] The utility model relates to the field of microwave heating, and more specifically, to a microwave component and a microwave heating device for heating. Background Art

[0002] Microwave heating is a non-contact heating method. For example, common microwave ovens achieve heating through microwave components, which directly apply microwave energy to the heated object. Heat energy can be conducted without heating the container first. It can be seen that microwave heating can save some energy conversion and reduce transmission losses, and is an efficient heating method. But at the same time, microwave heating also has the problem of uneven heating. Compared with traditional heating, microwave heating has a fast heating speed. Too fast heating leads to a short heat transfer time in the heated object, which easily causes local overheating and serious uneven heating. The interior of the microwave oven is almost a completely closed electromagnetic environment. The microwave energy interferes with each other in the heating cavity, and a large part of it exists in the form of standing waves, which makes the electric field strength at different positions in space vary greatly, resulting in uneven heating. Existing microwave ovens mostly use 2.45GHz, resulting in the average spatial distance between the "hot spot" and the "cold spot" in the cavity reaching 30mm. The large distance between the "hot spot" and the "cold spot" further leads to uneven heating.

[0003] Existing microwave heating components usually adopt two designs to deal with the problem of uneven heating, one is a turntable type and the other is a flat plate type. The turntable type uses a single antenna in conjunction with a carrier that drives the heated object to rotate horizontally, and improves the uniformity of heating by rotating the heated object. However, this method can only achieve relative uniformity in the circumferential direction, and cannot achieve spatial uniformity. It also leads to low space utilization. The flat plate type replaces a single static antenna with a stirrer antenna. However, the stirrer antenna not only needs to radiate microwave energy, but also needs to act as a rotating component to stir the emitted microwave energy. Since it plays the role of antenna and stirring at the same time, it is difficult to achieve good impedance matching as a whole, causing a considerable part of the microwave energy to be directly reflected back to the microwave generator, reducing efficiency. In addition, the working stability is poor and the heating uniformity is not ideal. Utility Model Content

[0004] The utility model aims to overcome at least one defect (deficiency) of the above-mentioned prior art and provide a microwave component for heating, so as to solve the problem of insufficient heating uniformity in the existing microwave heating device.

[0005] The technical solution adopted by the utility model is to provide a microwave component for heating, comprising: at least two antenna units and a rotating component; the antenna units are connected to the rotating component, and the antenna units form a phased array through rotational motion.

[0006] The phased array includes: a dynamic antenna and a static antenna. The static antenna is an antenna unit whose rotation speed is 0 during operation, and the dynamic antenna is an antenna unit whose rotation speed is not 0 during operation.

[0007] The phased array includes: a dynamic antenna, which is an antenna unit whose rotation speed is not zero during operation; and at least two dynamic antennas have different rotation speeds.

[0008] The phased array includes a dynamic antenna, which is an antenna unit whose rotation speed is not 0 during operation; and at least two dynamic antennas have different rotation directions.

[0009] There is one static antenna. Among the dynamic antennas, assuming that the number of the dynamic antennas rotating in the forward direction is m and the number of the dynamic antennas rotating in the reverse direction is n, then m is (0.5-2)n.

[0010] The antenna units are distributed in a matrix array of multiple rows and columns in a plane; the rotation speed of the antenna units in the same row gradually increases from the middle to both sides.

[0011] The rotation speed of the antenna units in the same column gradually increases from one end to the other end.

[0012] The antenna unit comprises: a sheet antenna, a coaxial structure and a dielectric rod; one end of the coaxial structure is connected to the sheet antenna to form a coaxial feed, and the other end is used to connect to the waveguide; one end of the dielectric rod is connected to the coaxial structure, and the other end is connected to the rotating component.

[0013] The patch antenna is a circular polarization antenna, and a centrally symmetrical notch is arranged at the edge of the patch antenna.

[0014] Furthermore, a microwave heating device is provided, comprising: a microwave generator, a plurality of waveguides, and the microwave assembly for heating, wherein the microwave generator is connected to the antenna unit via the waveguide.

[0015] Compared with the prior art, the beneficial effects of the utility model are as follows: the stirring of microwave energy is achieved through the rotation of the antenna unit, so that the microwave radiated into the heating cavity through the antenna unit is constantly changing, thereby achieving the purpose of uniform heating. The antenna unit forms a phased array in a mechanical motion through different rotation combinations, so that microwave energy forms a beam scan in a limited and confined space. Further, through the combination of dynamic antennas and static antennas, the combination of dynamic antennas with different rotation speeds, and the combination of dynamic antennas with different steering directions, the stability and reliability of the microwave assembly are improved. Not only does the space utilization almost reach the maximum size of the inner diagonal, so that food can use a larger space without being constrained by the turntable. It also achieves better heat conduction and uniform distribution at the existing frequency, and achieves good impedance matching, improves the utilization rate of microwave energy, and improves the working stability of the microwave generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional schematic diagram of the microwave component in the utility model.

[0017] Figure 2 It is a side schematic diagram of the microwave component in the utility model.

[0018] Figure 3 Schematic diagram of the antenna unit in the utility model Figure 1 .

[0019] Figure 4 Schematic diagram of the antenna unit in the utility model Figure 2 .

[0020] Figure 5 Schematic diagram of the antenna unit in the utility model Figure 3 .

[0021] Figure 6 It is a schematic diagram of the microwave heating device in the utility model.

[0022] Figure 7 It is a perspective view of the waveguide power division network in the utility model.

[0023] Figure 8 It is a bottom-up stereoscopic diagram of the waveguide power division network in the utility model.

[0024] Fig. 9 It is a three-dimensional schematic diagram of a phase-controlled microwave oven in a comparative example of the present utility model.

[0025] Fig.10 It is a cross-sectional schematic diagram of a phase-controlled microwave oven in a comparative example of the present utility model.

[0026] Fig.11 This is a comparison diagram of the beam far-field coverage of the flat-panel type and the phased-control type in the comparative example of the utility model.

[0027] Fig.12 This is the S11 curve diagram of the electromagnetic simulation of the flat-plate medium stirrer antenna in the comparative example of the utility model.

[0028] Fig.13 This is a relative heat scatter diagram when a flat plate is used to heat 9 physical states in the comparative example of the present invention.

[0029] Fig.14 This is a relative heat scatter diagram when nine physical states are heated by phase-controlled heating in the comparative example of the present invention.

[0030] Fig.15 It is a three-dimensional heat distribution and statistical diagram of the phase-controlled type and the flat plate type acting on the physical state 1 in the comparative example of the present utility model during the same heating cycle.

[0031] Fig.16 This is the heat distribution diagram of the rotating disk heating of the object 1 in the comparative example of the present invention.

[0032] Fig.17 A rotation speed relationship diagram of the phase-controlled antenna unit in the comparative example of the utility model.

[0033] Explanation of the reference numerals: waveguide power division network 100, parallel power division segment 110, series power division segment 120, antenna mounting position 121, metal matching diaphragm 122, microwave generator 200, heating cavity 300, top surface 310, microwave assembly 400, antenna unit 410, sheet antenna 411, coaxial inner conductor 412, dielectric rod 413, notch 414, matching cavity 415, rotating assembly 420, gear set 421, motor 422, forward antenna 423, reverse antenna 424, static antenna 425, wave-transmitting plate 430. DETAILED DESCRIPTION

[0034] The drawings of the present invention are only used for illustrative purposes and cannot be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0035] Example 1

[0036] like Figure 1 and Figure 2 This embodiment is a microwave assembly 400 for heating, comprising: at least two antenna units 410 and a rotating assembly 420; the antenna unit 410 is connected to the rotating assembly 420, and the antenna unit 410 forms a phased array through rotational motion.

[0037] The microwave assembly 400 is used to form microwave energy emission on a plane. The antenna is used to radiate the microwave energy provided by the microwave generator 200 into a specified space. The rotating assembly 420 is used to drive the antenna unit 410 to rotate.

[0038] The purpose of forming a phased array is to scan the microwave energy in a specified enclosed space, that is, to form a beam scan in the heating cavity. This makes the microwave energy more evenly distributed in the heating cavity 300 and can reduce useless reflections in the transmission waveguide, thereby delivering more microwave energy to the specified enclosed space and acting on the heated object, thereby improving the heating efficiency. The rotational combination between the antenna units 410 forms a dynamic scan of the microwave energy that continuously and constantly changes the radiation direction, so that the microwave distribution can continuously change, so that the heated object can be heated evenly in a static state, thereby achieving greater space utilization.

[0039] The phased array includes: a dynamic antenna and a static antenna 425 . The static antenna 425 is an antenna unit 410 whose rotation speed is 0 during operation, and the dynamic antenna is an antenna unit 410 whose rotation speed is not 0 during operation.

[0040] The term “in operation” refers to the time when the microwave assembly 400 is heating the object to be heated.

[0041] By combining the static antenna 425 and the dynamic antenna, differential rotation is achieved in the combination of the antenna units 410, and a phased array is formed by the combination of differential rotation.

[0042] The phased array includes: a dynamic antenna, which is an antenna unit 410 whose rotation speed is not zero during operation; and at least two dynamic antennas have different rotation speeds 410.

[0043] Differential rotation is also achieved in the combination of antenna units 410 with different rotation speeds, and a phased array is formed by the combination of differential rotation.

[0044] The phased array includes a dynamic antenna, which is an antenna unit 410 whose rotation speed is not zero during operation; at least two dynamic antennas have different rotation directions.

[0045] The combination of antenna units 410 with different rotation directions also realizes different rotation states, thereby forming a phased array.

[0046] There is one static antenna 420. Among the dynamic antennas, assuming that the number of the forward-rotating dynamic antennas is m and the number of the reverse-rotating dynamic antennas is n, then m is (0.5-2)n.

[0047] By combining different speeds with different directions and controlling their quantity in proportion, the difference between speeds can be reduced while maintaining the diversity of rotation states, thereby reducing the demand for maximum speed and improving overall stability and life.

[0048] The antenna units 410 are distributed in a matrix array of multiple rows and columns in a plane; the rotation speed of the antenna units 410 in the same row gradually increases from the middle to both sides.

[0049] The change of antenna units 410 in the same row forms a change in the microwave energy radiation angle of the phased array, forming different beam characteristics of microwave energy radiation. The scanning beam continuously changes in direction, forming an electromagnetic field that changes with time and space. The change of the electromagnetic field is reflected in the continuous change of the distribution of strength and weakness covering all directions, thereby achieving uniform heating.

[0050] The rotation speed of the antenna units 410 in the same row gradually increases from one end to the other end.

[0051] Further changes to the antenna unit 410 contribute to the diversity of rotation changes within the same column, reducing the difference in average electromagnetic field strength at different positions in the heating cavity 300, thereby making the scanning beam more varied and further achieving uniform heating.

[0052] like Figure 3 , 4 , 5, the antenna unit includes 410: a sheet antenna 411, a coaxial structure and a dielectric rod 413; one end of the coaxial structure is connected to the sheet antenna 411 to form a coaxial feed, and the other end is used to be connected to the waveguide; one end of the dielectric rod is connected to the coaxial structure, and the other end is connected to the rotating component.

[0053] The coaxial structure forms a coaxial feed for the antenna unit 410, and the microwave energy in the waveguide is fed into the antenna unit 410 through the coupling of the coaxial structure. The dielectric rod 413 is used to connect the coaxial structure and the rotating assembly 420 to drive the antenna unit 410 to rotate.

[0054] The coaxial feed is formed so that the input impedance from the waveguide to the antenna unit 410 is kept stable, thereby improving the overall stability.

[0055] The patch antenna 411 is a circularly polarized antenna, and a centrally symmetrical notch 414 is provided at the edge of the patch antenna 411 .

[0056] Center-fed circularly polarized antennas are more suitable for use in rotating environments. They are easier to maintain a stable state during rotation, which helps reduce vibration, improves radiation stability, and can be suitable for higher rotation speeds. Symmetry helps reduce the centrifugal effect generated during rotation and improves rotation stability. Center-fed circularly polarized antennas can reduce the space occupied by rotation.

[0057] Example 2

[0058] like Figure 6 As shown, this embodiment is a microwave heating device, comprising: a microwave generator 200, a plurality of waveguides, and a microwave component for heating, wherein the microwave generator is connected to an antenna unit 410 via a waveguide. The microwave generator 200 is used to generate microwave energy. The waveguide is used for the transmission of microwave energy. The microwave component 400 comprises: at least two antenna units 410 and a rotating component 420; the antenna unit 410 is connected to the rotating component 420, and the antenna unit 410 forms a phased array through rotational motion. The waveguide forms a waveguide power division network 100. This allows multiple antenna units 410 to be provided with microwave energy by one microwave generator 200. After the waveguide forms the waveguide power division network 100, it can be used for the distribution of microwave energy. As shown Figure 7 , 8As shown, the waveguide power division network 100 includes: a parallel power segment 110 and a plurality of series power segments 120 connected to the parallel power segment 110 , a plurality of antenna mounting positions 121 are formed on the series power segment 120 through a metal matching diaphragm 122 ; and the antenna unit 410 is rotatably disposed on the antenna mounting position 121 .

[0059] The parallel power segment 110 is used to distribute microwave energy to each series power segment 120. The series power segment 120 is used to distribute microwave energy to each antenna installation position 121. The metal matching diaphragm 122 is used to form a partition of the antenna installation position 121 in the series power segment 120. The antenna installation position 121 is used to install the antenna unit 410. The phased array includes: a dynamic antenna and a static antenna 425, the static antenna 425 is an antenna unit 410 with a rotation speed of 0 during operation, and the dynamic antenna is an antenna unit 410 with a rotation speed not equal to 0 during operation. The static antenna 425 does not rotate. The phased array includes: a dynamic antenna, which is an antenna unit 410 with a rotation speed not equal to 0 during operation; at least two dynamic antennas have different rotation speeds. The phased array includes a dynamic antenna, which is an antenna unit with a rotation speed not equal to 0 during operation; at least two dynamic antennas have different directions of rotation.

[0060] There is one static antenna 425. In the dynamic antenna, the number of the forward-rotating dynamic antennas is m, and the number of the reverse-rotating dynamic antennas is n, then m is (0.5-2)n. The phased array includes: a forward rotation interval formed by a plurality of forward-rotating antenna units 410; a reverse rotation interval formed by a plurality of reverse-rotating antenna units 410; and a static interval formed by at least one static antenna unit 410; the number ratio of the antenna units 410 in the forward rotation interval, the reverse rotation interval, and the static interval is (0.8-1.2):1:(0.1-0.2). The forward-rotating antenna unit 410 is the forward-rotating antenna 423. The reverse-rotating antenna unit 410 is the reverse rotation antenna 424. During the operation of the antenna unit 410, the forward-rotating antenna 423 and the reverse rotation antenna 424 rotate in opposite directions. The forward rotation interval is used for the aggregation of the forward-rotating antenna 423. The reverse rotation interval is used for the aggregation of the reverse antenna 424. The static interval is used for the aggregation of the static antenna 425.

[0061] The antenna units are distributed in a matrix array of multiple rows and columns in a plane; the rotation speed of the antenna units in the same row gradually increases from the middle to both sides. The rotation speed of the antenna units in the same column gradually increases from one end to the other end. The antenna unit 410 includes: a sheet antenna 411, a coaxial structure and a dielectric rod 413; one end of the coaxial structure is connected to the sheet antenna 411 to form a coaxial feed, and the other end is used to connect to the waveguide; one end of the dielectric rod 413 is connected to the coaxial structure, and the other end is connected to the rotating component 420. The coaxial structure includes a coaxial inner conductor 412 and a coaxial outer conductor; one end of the coaxial inner conductor 412 is connected to the sheet antenna 411, and the other end is connected to the rotating component 420 through the dielectric rod 413, and a coaxial outer conductor is formed between the sheet antenna 411 and the waveguide. The sheet antenna 411 is located in the same plane.

[0062] The rotating assembly 420 is connected to each antenna unit 410 through an independent rotating shaft, and drives the rotation of the antenna unit 410 respectively. When working, the antenna unit 410 rotates around its own rotating shaft, and can realize differential rotation of multiple antenna units 410 under the action of the rotating assembly 420. The rotating shafts of the antenna units 410 located in the same microwave heating structure 400 are perpendicular to the same plane. The antenna unit 410 has a transmitting end, and the transmitting ends of the antenna units 410 in the same microwave heating structure 400 are coplanar. When the microwave heating device is in a heating state, the microwave energy emitted by the microwave generator 200 is fed into each antenna unit 410 through the waveguide power division network 100. The microwave generator 200 can be a magnetron, a traveling wave tube, or a solid-state power amplifier. In the forward rotation interval, the forward rotation antenna 423 rotates clockwise; in the reverse rotation interval, the reverse rotation antenna 424 rotates counterclockwise. Assume that there are n forward antennas 423, m reverse antennas 424, and o static antennas 425, m≥n>o, or n≥m>o. Assume that the minimum rotation speed of the forward antenna 423 is a, and the rotation speeds of the forward antenna 423 are a, a+c, a+2c...a+(n-1)c. Assume that the minimum rotation speed of the reverse antenna 424 is b, and the rotation speeds of the reverse antenna 424 are b, b+a, b+2a...b+(m-1)a.

[0063] The patch antenna 411 is a circularly polarized antenna, and a centrally symmetrical notch 414 is provided on the edge of the patch antenna 411. The patch antenna 411 can specifically be an air dielectric patch antenna. The distance between two adjacent patch antennas 411 is equal. The rotating assembly 420 includes: a gear set 421 and a motor 422; the dielectric rod 413 is connected to the coaxial inner conductor 412 in the waveguide; the motor 422 drives the dielectric rod 413 to rotate through the gear set 421, so that under the drive of one motor 422, each patch antenna 411 on the same side can form a rotation with different speeds and directions. The gear set 421 is used to drive the antenna unit 410 to rotate. The motor 422 is used to drive the differential operation of the gear set 421. The cross section of the dielectric rod 413 is square, and a matching cavity 415 is provided at the lower part of the coaxial inner conductor 412; the matching cavity 415 matches the dielectric rod 413 and is used to connect the dielectric rod 413 and the coaxial inner conductor 412; the cross section of the matching cavity 415 is square. The matching cavity 415 is used for transmission and combination of the dielectric rod 413 and the coaxial inner conductor 412.

[0064] Comparative Example

[0065] like Fig. 9 and Fig.10 As shown, the heating states of a microwave oven including the microwave heating device of the utility model (hereinafter referred to as phase-controlled type) are compared with those of an existing commercially available microwave oven using a flat plate type (hereinafter referred to as flat plate type) and an existing commercially available microwave oven using a turntable type (hereinafter referred to as turntable type). In the phase-controlled type, the microwave assembly 400 is arranged on the top surface 310 of the heating cavity 300 of the microwave oven, and includes: sixteen antenna units 410 and a rotating assembly 420; the antenna units 410 are distributed in a 4*4 matrix array to form a phased array. As shown Fig.17 As shown, the phased array includes one antenna unit 410 that is stationary during operation and fifteen antenna units 410 that continuously rotate during operation; specifically, the rotating antenna units 410 include: a forward rotation interval formed by seven forward rotating antenna units 410; and a reverse rotation interval formed by eight reverse rotating antenna units 410. The stationary interval is formed by the stationary antenna units 410. The waveguide power division network 100 composed of waveguides includes: a parallel power segment 110 and four series power segments 120 connected to the parallel power segment 110, and four antenna mounting positions 121 are formed on each series power segment 120 through a metal matching diaphragm 122.

[0066] The antenna unit 410 includes: a sheet antenna 411, and a coaxial inner conductor 412 connected to the sheet antenna 411; the sheet antenna 411 is a center-fed circularly polarized antenna. The sheet antenna 411 is a quasi-circular patch antenna, and a symmetrical notch 414 is provided on the edge of the sheet antenna 411; the distance between two adjacent sheet antennas 411 is equal. The cross section of the dielectric rod 413 is square, and a matching cavity 415 is provided at the lower part of the coaxial inner conductor 412; the matching cavity 415 matches the dielectric rod 413 and is used to connect the dielectric rod 413 and the coaxial inner conductor 412; the cross section of the matching cavity 415 is square.

[0067] Fig.11 The figure shows the comparison of the angular domain coverage of antenna radiation. The left side is a flat plate type and the right side is a phased-control type. It can be seen that for the flat plate type, within a 120° cone angle centered on the normal, the angular domain coverage of the microwave radiation energy is approximately circularly symmetrical; the central area and the annular area near 35° off-axis have relatively low radiation energy. In comparison, for the utility model, within a 120° cone angle centered on the normal, the angular domain coverage of the microwave radiation energy is basically uniform, and the radiation power density is significantly higher than that on the left. The spherical integral of the radiation coverage is performed to obtain the open field radiation efficiency ratio of the two, and the phased-control type is 1.61 times that of the flat plate type on the left. Fig.12 As shown, combined with the S parameters of the flat-plate radiator obtained by electromagnetic simulation, the radiation efficiencies of the flat-plate and phase-controlled radiators are 57.3% and 92.3%, respectively. Further, based on the relative dielectric constant, shape and volume of the heated object as basic parameters, 9 physical states of the heated object are formed, and the specific combinations are shown in Table 1: Physical state parameter table.

[0068] Physical State Basic parameter combination Physical State 1 Fluffy or dispersed small volume State of Matter 2 High dielectric constant, large volume, rectangular Physical State 3 Low dielectric constant, large volume, rectangular State of Matter 4 High dielectric constant, large volume, cylindrical Physical State 5 Low dielectric constant, large volume, cylindrical Physical State 6 High dielectric constant, small size, rectangular State of Matter 7 Low dielectric constant, small size, rectangular State of Matter 8 High dielectric constant, small size, cylindrical State of Matter 9 Low dielectric constant, small size, cylindrical

[0069] Through electromagnetic simulation and statistical calculation, the differences and changes between the flat plate type and the phase-controlled type during heating are obtained. Fig.13 and Fig.14 As shown in the figure, the 9 physical states are statistically analyzed to form a heating scatter plot. The average value and standard deviation of the relative heat are obtained through the heating scatter plot, and then the coefficient of variation is introduced to reflect the relative dispersion of the values ​​in a statistical sense. The smaller the coefficient of variation, the smaller the dispersion relative to the average value, that is, the better the uniformity. Fig.13 and Fig.14 The coefficient of variation results are shown in Table 2: Comparison table of heating data of 9 physical states.

[0070]

[0071] It can be seen that the heating uniformity of the phase-controlled type in the nine states is better than that of a certain flat plate type currently available on the market. Especially for state 1, the heating uniformity is significantly improved. The coefficient of variation of states 4, 8 and 9 is also reduced by more than 13%, which has obvious advantages. Fig.15As shown, the three-dimensional heat distribution and statistics are obtained with physical state 1 as the heated object in one heating cycle. The upper and lower figures on the left correspond to a certain flat plate type currently available on the market, and the upper and lower figures on the right correspond to the phase-controlled type. It can be clearly seen that after adopting the phase-controlled type, the heating uniformity is greatly improved.

[0072] like Fig.16 As shown, the turntable type has rotational symmetry for heating state 1 and food with rotational symmetry relative to the axis of rotation. Although each layer has uniformity in the circumferential direction at the same height, it can be seen that the pattern of each layer is different, and the radial and height directions are not uniform. It is learned that the turntable type has obvious limitations on the uniformity of heating the heated object. Microwave heating of the heated object is a very complex process, which involves the interaction between the electromagnetic field and the material, the heat conduction of the heated material, and the change of the electromagnetic parameters of the material with temperature. At the same time, there is also a skin effect of the material on the electromagnetic wave. The skin effect makes the surface of the microwave heating stronger and faster. The further inward, the weaker the effect of the microwave energy, resulting in slower heating from the outside to the inside. The penetration depth of microwaves is affected by the dielectric constant of the heated object itself, as well as the frequency and loss tangent of the microwaves.

[0073] Obviously, the above embodiments of the utility model are only examples for clearly explaining the technical solution of the utility model, and are not intended to limit the specific implementation methods of the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the utility model shall be included in the protection scope of the claims of the utility model.

Claims

1. A microwave component for heating, characterized in that: include: at least two antenna units and a rotating assembly; The antenna unit is connected to the rotating assembly, and the antenna unit forms a phased array through rotational motion; The antenna unit comprises: a sheet antenna, a coaxial structure and a dielectric rod; one end of the coaxial structure is connected to the sheet antenna to form a coaxial feed, and the other end is used to connect to the waveguide; one end of the dielectric rod is connected to the coaxial structure, and the other end is connected to the rotating component.

2. A microwave component for heating according to claim 1, characterized in that: The phased array includes: a dynamic antenna and a static antenna. The static antenna is an antenna unit whose rotation speed is 0 during operation, and the dynamic antenna is an antenna unit whose rotation speed is not 0 during operation.

3. A microwave component for heating according to claim 1, characterized in that: The phased array includes: a dynamic antenna, which is an antenna unit whose rotation speed is not zero during operation; and at least two dynamic antennas have different rotation speeds.

4. A microwave component for heating according to claim 1, characterized in that: The phased array includes a dynamic antenna, which is an antenna unit whose rotation speed is not 0 during operation; and at least two dynamic antennas have different rotation directions.

5. A microwave component for heating according to claim 2, characterized in that: There is one static antenna. Among the dynamic antennas, assuming that the number of the dynamic antennas rotating in the forward direction is m and the number of the dynamic antennas rotating in the reverse direction is n, then m is (0.5-2)n.

6. A microwave component for heating according to claim 1, characterized in that: The antenna units are distributed in a matrix array of multiple rows and columns in a plane; the rotation speed of the antenna units in the same row gradually increases from the middle to both sides.

7. A microwave component for heating according to claim 6, characterized in that: The rotation speed of the antenna units in the same column gradually increases from one end to the other end.

8. A microwave component for heating according to claim 7, characterized in that: The patch antenna is a circular polarization antenna, and a centrally symmetrical notch is arranged at the edge of the patch antenna.

9. A microwave heating device, comprising: A microwave generator and a plurality of waveguides, characterized in that it also comprises a microwave assembly for heating as described in any one of claims 1 to 8, wherein the microwave generator is connected to the antenna unit via a waveguide.

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