CN114401565A

CN114401565A - Aerosol generating device and microwave heating device thereof

Info

Publication number: CN114401565A
Application number: CN202111579843.8A
Authority: CN
Inventors: 梁峰; 杜靖; 张益�
Original assignee: Shenzhen Maishi Technology Co Ltd
Current assignee: Shenzhen Maishi Technology Co Ltd
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-04-26
Also published as: WO2023116230A1

Abstract

The invention relates to an aerosol generating device and a microwave heating device thereof, wherein the microwave heating device comprises a substrate integrated waveguide structure and a coaxial connector; the coaxial connector comprises an inner conductor and an outer conductor, the substrate integrated waveguide structure comprises a first metal layer, a dielectric substrate layer and a second metal layer which are sequentially arranged, the first metal layer is connected with the inner conductor, and the second metal layer is connected with the outer conductor. The substrate integrated waveguide structure is provided with a waveguide cavity, and the waveguide cavity is internally provided with a through hole for the aerosol-forming substrate to pass through. The microwave heating device is based on the substrate integrated waveguide technology, the microwave field is concentrated in the through hole, the aerosol forming substrate can be quickly and uniformly heated, and the substrate integrated waveguide structure can not be in contact with the aerosol forming substrate, so that the aerosol forming substrate is prevented from being adhered to the substrate integrated waveguide structure.

Description

Aerosol generating device and microwave heating device thereof

Technical Field

The invention relates to the field of atomization, in particular to an aerosol generating device and a microwave heating device thereof.

Background

Conventional heated non-combustible aerosol generating devices typically employ resistive heating of the aerosol-forming substrate. The resistance heating is to heat the resistance element through an external power supply, and the resistance element heats and then transfers heat to the aerosol formation substrate in a heat conduction mode, so that the technology is mature, and the structure is simple. However, resistive heating generally has the following disadvantages: 1. the resistance heating is a local heating mode, and because the aerosol forming substrate has poor heat conductivity and certain temperature gradient, the problems of uneven heating and overhigh local temperature are easily caused, and the smoking taste and consistency are influenced; 2. in the pumping process, the heating part is continuously heated, potential safety risk exists, and high-temperature cracking is easy to generate harmful substances; 3. resistance-type heating belongs to contact heating, and aerosol formation matrix contacts with the piece that generates heat for a long time, appears the carbon deposit easily, appears burnt flavor, and the clearance is also very inconvenient.

Disclosure of Invention

The present invention is directed to an improved microwave heating device and an aerosol generating device having the same, which overcome the above-mentioned disadvantages of the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows: constructing a microwave heating device for heating an aerosol-forming substrate, the microwave heating device comprising a substrate integrated waveguide structure and a coaxial connector; the coaxial connector comprises an inner conductor and an outer conductor, the substrate integrated waveguide structure comprises a first metal layer, a dielectric substrate layer and a second metal layer which are sequentially arranged, the first metal layer is connected with the inner conductor, and the second metal layer is connected with the outer conductor;

a waveguide cavity is formed on the substrate integrated waveguide structure, and a through hole for the aerosol-forming substrate to pass through is formed in the waveguide cavity.

In some embodiments, a plurality of metalized vias are disposed on the substrate integrated waveguide structure and communicate with the first metal layer and the second metal layer, and the plurality of metalized vias surround to form the waveguide cavity.

In some embodiments, the substrate integrated waveguide structure is polygonal, and at least two adjacent edges of the substrate integrated waveguide structure are respectively provided with a plurality of the metalized via holes along the length direction.

In some embodiments, a plurality of metal strips connecting the first metal layer and the second metal layer are disposed on a side surface of the substrate integrated waveguide structure, and the plurality of metal strips surround the waveguide cavity.

In some embodiments, the substrate integrated waveguide structure is a polygon, and at least two adjacent side surfaces of the substrate integrated waveguide structure are respectively provided with a plurality of metal strips along the length direction.

In some embodiments, the substrate-integrated waveguide structure is provided with a feed hole, and the inner conductor is inserted into the feed hole to be connected to the first metal layer.

In some embodiments, the feed hole includes a first hole section disposed on the first metal layer and the dielectric substrate layer, and a second hole section disposed on the second metal layer, an aperture of the first hole section matches an outer diameter of the inner conductor, and an aperture of the second hole section is larger than the outer diameter of the inner conductor.

In some embodiments, the second bore section has a bore diameter that matches an outer diameter of the outer conductor.

In some embodiments, the microwave heating device further comprises a microwave feed-in structure, and the first metal layer is connected with the inner conductor through the microwave feed-in structure.

In some embodiments, the microwave feeding structure includes a microstrip feeding line disposed on a side of the dielectric substrate layer where the first metal layer is disposed, and both ends of the microstrip feeding line are connected to the first metal layer and the inner conductor, respectively.

In some embodiments, the microwave heating device further comprises an impedance matching structure, and the first metal layer and the microwave feeding structure are respectively connected to the impedance matching structure.

In some embodiments, the aperture of the through-holes is equal to or greater than the outer diameter of the aerosol-forming substrate.

In some embodiments, the central axis of the through-hole is parallel to or coincident with the central axis of the waveguide cavity.

The invention also provides an aerosol generating device, which comprises a microwave generating module, a shell and the microwave heating device as described in any one of the above items; the microwave heating device and the microwave generating module are contained in the shell, and the coaxial connectors are respectively connected with the substrate integrated waveguide structure and the microwave generating module.

In some embodiments, a receptacle is formed in the housing for insertion of the aerosol-forming substrate, and an air inlet is provided in the housing in communication with the receptacle for entry of ambient air.

In some embodiments, the outer shell includes an upper shell and a lower shell fitted to each other, the upper shell includes a cylindrical shell and a receiving tube extending downward from a top wall of the cylindrical shell, and an inner wall surface of the receiving tube defines the insertion hole.

In some embodiments, the microwave generating module is accommodated in the lower shell, the substrate integrated waveguide structure is accommodated in the upper shell, and a wire passing hole for the coaxial connector to pass through is further formed in the bottom wall of the upper shell.

In some embodiments, a cavity is formed in the cylindrical housing between the lower end surface of the accommodating tube and the substrate integrated waveguide structure, and the air inlet is opened on the wall of the cavity and communicated with the cavity.

In some embodiments, the aerosol generating device comprises a plurality of the substrate integrated waveguide structures, and the through holes of the plurality of the substrate integrated waveguide structures are sequentially communicated correspondingly.

In some embodiments, the aerosol-generating device further comprises a drive assembly for driving movement of the substrate-integrated waveguide structure or the aerosol-forming substrate to produce relative movement between the substrate-integrated waveguide structure and the aerosol-forming substrate.

In some embodiments, the aperture of the through-holes is larger than the outer diameter of the aerosol-forming substrate.

The implementation of the invention has at least the following beneficial effects: the microwave heating device is based on the substrate integrated waveguide technology, the microwave field is concentrated in the through hole, the aerosol forming substrate can be quickly and uniformly heated, and the substrate integrated waveguide structure can not be in contact with the aerosol forming substrate, so that the aerosol forming substrate is prevented from being adhered to the substrate integrated waveguide structure.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic perspective view of an aerosol generating device according to some embodiments of the present invention;

FIG. 2 is a schematic longitudinal cross-sectional view of the aerosol generating device of FIG. 1;

FIG. 3 is a schematic cross-sectional view of the upper shell of FIG. 2;

FIG. 4 is a schematic perspective view of the microwave heating apparatus of FIG. 2;

FIG. 5 is a schematic sectional view of the microwave heating apparatus shown in FIG. 4;

FIG. 6 is a top view of the microwave heating apparatus shown in FIG. 4;

FIG. 7 is a bottom view of the microwave heating apparatus of FIG. 4;

FIG. 8 is a schematic cross-sectional view of an alternative embodiment of the aerosol generating device of FIG. 2;

FIG. 9 is a schematic cross-sectional view of another alternative to the aerosol generating device of FIG. 2;

FIG. 10 is a top view of a first alternative to the substrate-integrated waveguide structure of FIG. 4;

FIG. 11 is a bottom view of the substrate-integrated waveguide structure of FIG. 10;

fig. 12 is a schematic perspective view of a second alternative of the substrate integrated waveguide structure of fig. 4.

Detailed Description

For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships that are based on the orientations and positional relationships shown in the drawings or the orientations and positional relationships that the products of the present invention will ordinarily place when in use, and are used merely for convenience in describing and simplifying the description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Figures 1-2 show an aerosol-generating device 1 in some embodiments of the invention, the aerosol-generating device 1 being operable to apply low-temperature baking heat to an aerosol-forming substrate 2 inserted therein to release an aerosol extract from the aerosol-forming substrate 2 in a non-combustible state. The aerosol-forming substrate 2 may be cylindrical and the aerosol-generating device 1 may be generally square cylindrical. It is understood that in other embodiments, the aerosol generating device 1 is not limited to a square column shape, but may have other shapes such as a cylindrical shape, an elliptical cylindrical shape, and the like.

The aerosol generating device 1 may comprise a microwave heating device 10, a microwave generating module 20, a power supply module 30, a control module 40 and a housing 50. The microwave heating device 10, the microwave generating module 20, the control module 40 and the power module 30 are all accommodated in the housing 50. Formed in the housing 50 is a receptacle 5120 for insertion of an aerosol-forming substrate 2 and for circumferentially locating the aerosol-forming substrate 2, and formed on the microwave heating device 10 is a through-hole 110 for passage of the aerosol-forming substrate 2, the aerosol-forming substrate 2 being insertable into the receptacle 5120 and passing through the through-hole 110. The microwave generating module 20 and the power module 30 are electrically connected to the control module 40, respectively, and the microwave generating module 20 is configured to generate microwaves and emit a microwave source to the microwave heating device 10, thereby microwave-heating the aerosol-forming substrate 2 inserted into the microwave heating device 10. The power module 30 is used for supplying power to the microwave generating module 20 and the control module 40, and the control module 40 is used for controlling the microwave generating module 20 to generate microwaves.

Specifically, as shown in fig. 2-3, the housing 50 may include an upper shell 51 and a lower shell 52 that are fitted to each other. The lower case 52 may be in a square tube shape, and the microwave generating module 20, the power supply module 30, and the control module 40 are all accommodated in the lower case 52. The upper case 51 is disposed above the lower case 52 in a longitudinal direction, and may include a cylindrical case 511 and a receiving pipe 512 integrally formed by extending a top wall of the cylindrical case 511 downward. The receiving tube 512 is tubular with an inner wall defining an insertion aperture 5120 for receiving the aerosol-forming substrate 2. The insertion hole 5120, the accommodating tube 512, and the cylindrical housing 511 may be coaxially provided. The aerosol-forming substrate 2 may be inserted from the receptacle 5120 and through the through-hole 110 and the bottom of the aerosol-forming substrate 2 may rest against the bottom wall of the upper shell 51. It is understood that in other embodiments, the cylindrical housing 511 and the accommodating tube 512 may be separately manufactured and then assembled together.

Further, the upper case 51 may further include at least one reinforcing wall 513 connected to the cylindrical housing 511 and the accommodating tube 512, respectively. Specifically, both lateral sides of each reinforcing wall 513 are connected to the outer wall surface of the accommodating tube 512 and the inner wall surface of the cylindrical case 511, respectively. In this embodiment, there are four reinforcing walls 513, the four reinforcing walls 513 may be uniformly spaced along the circumferential direction of the accommodating tube 512, and each reinforcing wall 513 may be formed by integrally extending downward from the top wall of the cylindrical housing 511. It is understood that in other embodiments, the number of the reinforcing walls 513 is not limited to four, for example, it may be two, three, etc.

In addition, an air inlet hole 5110 for allowing external air to enter is formed on the sidewall of the cylindrical housing 511, and is communicated with the insertion hole 5120. A cavity 5112 is formed between the lower end surface of the accommodating tube 512 and the upper end surface of the microwave heating device 10 in the cylindrical shell 511, and an air inlet 5110 can be opened on the cavity wall of the cavity 5112 and is communicated with the cavity 5112. Further, the air intake hole 5110 may be disposed near an upper end surface of the microwave heating apparatus 10. It is understood that in other embodiments, the air intake holes 5110 can be opened on the lower case 52.

The microwave heating apparatus 10 may include a substrate integrated waveguide structure 11 and a coaxial connector 12. The coaxial connector 12 is connected to the microwave generating module 20 and the substrate integrated waveguide structure 11 at two ends, and may include an inner conductor 121 and an outer conductor 122 coaxially disposed. The substrate-integrated waveguide structure 11 may be disposed in the upper case 51, and accordingly, the bottom wall of the upper case 51 is provided with a wire passing hole 5111 for the coaxial connector 12 to pass through.

As shown in fig. 4 to 7, the substrate-integrated waveguide structure 11 includes a first metal layer 111, a dielectric substrate layer 112 and a second metal layer 113 sequentially arranged from top to bottom, wherein the first metal layer 111 is connected to the inner conductor 121, and the second metal layer 113 is connected to the outer conductor 122. The substrate-integrated waveguide structure 11 is formed with a waveguide cavity 115, and the waveguide cavity 115 is opened with a through-hole 110 for passing the aerosol-forming substrate 2 therethrough.

The dielectric substrate layer 112 may be a rectangular flat plate-shaped dielectric substrate, the first metal layer 111 may be disposed on a side of the dielectric substrate layer 112 facing the insertion hole 5120, and the second metal layer 113 may be disposed on a side of the dielectric substrate layer 112 facing away from the insertion hole 5120. The first metal layer 111 and the second metal layer 113 may be formed on the dielectric substrate layer 112 by printing, physical vapor deposition, or the like. In this embodiment, a plurality of metalized vias 114 communicating the first metal layer 111 and the second metal layer 113 are formed on the substrate integrated waveguide structure 11, and the plurality of metalized vias 114 surround to form a waveguide cavity 115. Specifically, the substrate integrated waveguide structure 11 is in a shape of a sheet with a polygonal cross section, a plurality of metalized via holes 114 are respectively arranged on at least two adjacent edges of the substrate integrated waveguide structure 11 along the length direction of each edge, the first metal layer 111 and the second metal layer 113 are electrically connected through the metalized via holes 114, and the waveguide cavity 115 is enclosed by the first metal layer 111, the second metal layer 113 and the metalized via holes 114. Further, in this embodiment, the substrate integrated waveguide structure 11 is in a square sheet shape, a plurality of metalized via holes 114 arranged at equal intervals are respectively arranged on four sides of the substrate integrated waveguide structure 11 along the length direction of each side, and the plurality of metalized via holes 114 on the four sides surround to form a rectangular waveguide cavity 115. It is understood that in other embodiments, the cross-sectional shapes of the substrate integrated waveguide structure 11 and the waveguide cavity 115 are not limited to being polygonal, and may be circular, for example. When the waveguide cavity 115 has a circular cross-sectional profile, the waveguide cavity 115 has a plurality of metallized vias 114 disposed about at least one-quarter of the circumference of the outer edge of the cross-section.

The through hole 110 is disposed in the waveguide cavity 115, which may be cylindrical and may be disposed coaxially with the waveguide cavity 115 and the substrate-integrated waveguide structure 11. The coaxial connector 12 transmits the microwave signal of the microwave generating module 20 to the substrate integrated waveguide structure 11, and the plurality of metallized vias 114 confine the microwave signal to the waveguide cavity 115 to heat the aerosol-forming substrate 2 within the through-hole 110. The microwave field is concentrated within the through-hole 110 and may effectively heat the aerosol-forming substrate 2 within the through-hole 110; the area of the through-holes 110 is small and the Q-value (quality factor) of the cavity is high, so that a fast heating of the aerosol-forming substrate 2 can be achieved. Furthermore, as the aerosol-forming substrate 2 is heated using SIW (substrate integrated waveguide) technology, the aerosol-forming substrate 2 may or may not be in contact with the substrate integrated waveguide structure 11, i.e. the aperture diameter of the through-hole 110 may be equal to or larger than the outer diameter of the aerosol-forming substrate 2. Preferably, there is no contact between the substrate-integrated waveguide structure 11 and the aerosol-forming substrate 2, for example a loose fit between the substrate-integrated waveguide structure 11 and the aerosol-forming substrate 2, which facilitates insertion of the aerosol-forming substrate 2 and also avoids adhesion of the aerosol-forming substrate 2 to the substrate-integrated waveguide structure 11.

The SIW can be viewed approximately as a fill mediumThe SIW has an operation mode of TE_n0Where n is 1, 2, …, TM mode cannot propagate in SIW.

After the SIW is equivalent to a rectangular waveguide, its equivalent width can be expressed as:

wherein h is the thickness of the dielectric substrate, w is the distance between two parallel rows of the metalized vias 114, s is the distance between two adjacent metalized vias 114, and d is the diameter of the metalized via 114.

There is another way to express the equivalent width:

for operation in single mode TE₁₀In the SIW design in the mode, the width dimension a of the rectangular waveguide needs to satisfy

a<λ<2a

Wherein λ is the working wavelength and the calculation formula is

Wherein f is the operating frequency of the waveguide, ε_rIs the relative dielectric constant of the fill medium.

In the design of the SIW structure, the loss of the SIW itself is minimized, wherein three loss mechanisms mainly need to be considered: conductor losses, dielectric losses and possibly radiation losses. Conductor losses can be reduced by increasing the thickness h of the dielectric substrate, while dielectric losses can only be reduced by using a better dielectric substrate. When s, d and w satisfy s/d <2.5 and d/w <0.2, the radiation loss is minimized.

Meanwhile, in order to enable the SIW to work efficiently, the thickness of the metal layer covered on the surface of the dielectric substrate needs to be larger than the skin depth of the metal layer, and the calculation formula of the skin depth delta is as follows

ω is the operating angular frequency of the waveguide, ω is 2 pi f, f is the operating frequency of the waveguide, μ is the metal permeability, ρ is the metal resistivity, and σ is the metal conductivity.

Further, in this embodiment, the substrate-integrated waveguide structure 11 may further be provided with a feeding hole 116, and the inner conductor 121 may be inserted into the feeding hole 116 so as to be connected to the first metal layer 111. Specifically, in the present embodiment, the feeding hole 116 sequentially penetrates through the first metal layer 111, the dielectric substrate layer 112, and the second metal layer 113 from top to bottom, and may include a first hole segment 1161 disposed on the first metal layer 111 and the dielectric substrate layer 112, and a second hole segment 1162 disposed on the second metal layer 113. The aperture of the first hole segment 1161 is matched to the outer diameter of the inner conductor 121, so that the inner conductor 121 can pass through the first hole segment 1161 and the outer circumferential surface of the inner conductor 121 can make ohmic contact with the first metal layer 111. The aperture of the second hole segment 1162 is larger than the aperture of the first hole segment 1161 and the outer diameter of the inner conductor 121, so as to prevent the second metal layer 113 from contacting the inner conductor 121. The diameter of the second hole 1162 may be matched to the outer diameter of the outer conductor 122, so that the outer conductor 122 may pass through the second hole 1162, and the outer circumferential surface of the outer conductor 122 makes ohmic contact with the second metal layer 113. In other embodiments, the diameter of the second hole segment 1162 may be smaller than the outer diameter of the outer conductor 122, and the upper end surface of the outer conductor 122 may abut against the second metal layer 113 and make ohmic contact with the second metal layer 113.

Further, since the substrate-integrated waveguide structure 11 using the SIW technology is sheet-like and has a small thickness (typically 0.7 to 1.5mm, typically around 1 mm), and the aerosol-forming substrate 2 has a length of typically around 10mm of the portion of the aerosol-forming substrate to be heated with the atomized material, a plurality of substrate-integrated waveguide structures 11 may be provided in the aerosol-generating device 1 to heat the aerosol-forming substrate 2; alternatively, the substrate-integrated waveguide structure 11 may be heated in stages in such a way that it is movable relative to the aerosol-forming substrate 2, for example a drive assembly may be provided in the aerosol-generating device 1 to drive movement of the substrate-integrated waveguide structure 11 or the aerosol-forming substrate 2.

As shown in fig. 8, the aerosol-generating device 1 in this embodiment includes a plurality of substrate-integrated waveguide structures 11, the plurality of substrate-integrated waveguide structures 11 are sequentially arranged along the thickness direction thereof, and the through holes 110 of the plurality of substrate-integrated waveguide structures 11 are sequentially and correspondingly communicated. The plurality of substrate integrated waveguide structures 11 may be heated simultaneously or may be separately controlled to provide a segmented heating of the aerosol-forming substrate 2. In addition, since the substrate integrated waveguide structure 11 is thin and thin, a large amount of space is not occupied by using a plurality of substrate integrated waveguide structures 11.

As shown in fig. 9, the aerosol-generating device 1 in this embodiment further comprises a drive assembly 60, which drive assembly 60 may be arranged in the housing 50 for driving the substrate-integrated waveguide structure 11 up and down in the axial direction of the aerosol-forming substrate 2. By moving the substrate-integrated waveguide structure 11 up and down, it is possible to achieve a segmented heating of different regions of the aerosol-forming substrate 2, and furthermore the heating process may be suspended. The driving assembly 60 includes, but is not limited to, a linear motor or an electric motor screw structure, etc., which may be electrically connected to the power module 30 and the control module 40 to start or stop under the control of the control module 40. No contact (e.g. a loose fit) between the substrate-integrated waveguide structure 11 and the aerosol-forming substrate 2, i.e. the aperture of the through-hole 110 is larger than the outer diameter of the aerosol-forming substrate 2, facilitates relative movement of the substrate-integrated waveguide structure 11 and the aerosol-forming substrate 2. It will be appreciated that in other embodiments, the relative movement between the substrate-integrated waveguide structure 11 and the aerosol-forming substrate 2 may also be caused by driving the aerosol-forming substrate 2 in motion, including directly driving the aerosol-forming substrate 2 in motion or indirectly driving the aerosol-forming substrate 2 in motion, for example by driving the aerosol-forming substrate 2 in motion by driving a component, such as the containment tube 512 or the bottom wall of the upper shell 51, which holds the aerosol-forming substrate 2.

Fig. 10 to 11 show a substrate integrated waveguide structure 11 according to a first alternative of the present invention, which is different from the above-mentioned embodiments mainly in that, in this embodiment, a plurality of metalized vias 114 arranged at equal intervals are respectively arranged on three sides of the substrate integrated waveguide structure 11 along the extending direction of each side, and the plurality of metalized vias 114 on the three sides surround to form a square waveguide cavity 115. The via 110 is disposed in a waveguide cavity 115, which may be cylindrical and disposed coaxially with the substrate integrated waveguide structure 11. In this embodiment, the central axis of the through-hole 110 is parallel to but not coincident with the central axis of the waveguide cavity 115.

In addition, in the present embodiment, the substrate-integrated waveguide structure 11 further includes a microwave feeding structure 117, the first metal layer 111 is connected to the inner conductor 121 through the microwave feeding structure 117, and the second metal layer 113 is connected to the outer conductor 122. The microwave feed structure 117 may generally include a microstrip feed line, which may be disposed on the side of the dielectric substrate layer 112 on which the first metal layer 111 is disposed, and which has one end connected to the first metal layer 111 and the other end connected to the inner conductor 121.

Further, the substrate integrated waveguide structure 11 may further include an impedance matching structure, the first metal layer 111 and the microwave feeding structure 117 are respectively connected to the impedance matching structure, and the impedance of the microwave signal transmission line formed by the microwave feeding structure 117 and the waveguide cavity 115 is matched to a preset impedance value through the impedance matching structure. The impedance matching structure may comprise a microstrip line, such as a tapered width microstrip line or a gradient microstrip line.

Fig. 12 shows a substrate integrated waveguide structure 11 in a second alternative of the present invention, which is different from the above embodiments mainly in that, in this embodiment, a plurality of metal strips 118 connecting the first metal layer 111 and the second metal layer 113 are disposed on the side surface of the substrate integrated waveguide structure 11, and the plurality of metal strips 118 surround to form a waveguide cavity 115. Specifically, the substrate integrated waveguide structure 11 is a polygonal sheet, such as a square sheet, a plurality of metal strips 118 arranged at equal intervals are respectively arranged on at least two adjacent side surfaces of the substrate integrated waveguide structure 11 along the length direction thereof, the first metal layer 111 and the second metal layer 113 are electrically connected through the metal strips 118, and the plurality of metal strips 118 on the at least two side surfaces, the first metal layer 111 and the second metal layer 113 together enclose a square waveguide cavity 115. The through hole 110 is disposed in the waveguide cavity 115, which may be cylindrical and disposed coaxially with the substrate integrated waveguide structure 11 and the waveguide cavity 115.

It is understood that in other embodiments, the cross-sectional shapes of the substrate integrated waveguide structure 11 and the waveguide cavity 115 are not limited to being polygonal, and may be circular, for example. When the substrate-integrated waveguide structure 11 is a circular slab, the plurality of metal strips 118 are arranged over at least a quarter of the circumference of the outer edge of the cross-section of the substrate-integrated waveguide structure 11.

It is to be understood that the above-described respective technical features may be used in any combination without limitation.

The above examples only express the preferred embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention; it should be noted that, for those skilled in the art, the above technical features can be freely combined, and several changes and modifications can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention; therefore, all equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the claims of the present invention.

Claims

1. A microwave heating device for heating an aerosol-forming substrate (2), characterised in that the microwave heating device (10) comprises a substrate-integrated waveguide structure (11) and a coaxial connector (12); the coaxial connector (12) comprises an inner conductor (121) and an outer conductor (122), the substrate integrated waveguide structure (11) comprises a first metal layer (111), a dielectric substrate layer (112) and a second metal layer (113) which are sequentially arranged, the first metal layer (111) is connected with the inner conductor (121), and the second metal layer (113) is connected with the outer conductor (122);

a waveguide cavity (115) is formed in the substrate integrated waveguide structure (11), and a through hole (110) for the aerosol-forming substrate (2) to pass through is formed in the waveguide cavity (115).

2. The microwave heating device according to claim 1, wherein a plurality of metalized vias (114) communicating the first metal layer (111) and the second metal layer (113) are disposed on the substrate-integrated waveguide structure (11), and the plurality of metalized vias (114) enclose to form the waveguide cavity (115).

3. Microwave heating device according to claim 2, characterized in that said substrate-integrated waveguide structure (11) is polygonal, and at least two adjacent sides of said substrate-integrated waveguide structure (11) are respectively arranged with a plurality of said metallized vias (114) along its length direction.

4. Microwave heating device according to claim 1, characterized in that a plurality of metal strips (118) communicating the first metal layer (111) and the second metal layer (113) are arranged on the side of the substrate integrated waveguide structure (11), the plurality of metal strips (118) enclosing to form the waveguide cavity (115).

5. Microwave heating device according to claim 4, characterized in that the substrate-integrated waveguide structure (11) is polygonal, and at least two adjacent sides of the substrate-integrated waveguide structure (11) are respectively arranged with a plurality of metal strips (118) along its length direction.

6. A microwave heating arrangement according to any of the claims 1-5, characterized in that the substrate integrated waveguide structure (11) is provided with a feed hole (116), and that the inner conductor (121) is inserted into the feed hole (116) to be connected to the first metal layer (111).

7. Microwave heating device according to claim 6, characterized in that the feed hole (116) comprises a first hole section (1161) provided to the first metal layer (111) and the dielectric substrate layer (112) and a second hole section (1162) provided to the second metal layer (113), the aperture of the first hole section (1161) matching the outer diameter of the inner conductor (121), the aperture of the second hole section (1162) being larger than the outer diameter of the inner conductor (121).

8. Microwave heating device according to claim 7, characterized in that the aperture of the second hole section (1162) matches the outer diameter of the outer conductor (122).

9. Microwave heating device according to any of claims 1-5, wherein said microwave heating device (10) further comprises a microwave feed-in structure (117), said first metal layer (111) being connected to said inner conductor (121) through said microwave feed-in structure (117).

10. A microwave heating arrangement as claimed in claim 9, characterized in that the microwave feed-in structure (117) comprises a microstrip feed line arranged on the side of the dielectric substrate layer (112) on which the first metal layer (111) is arranged, both ends of the microstrip feed line being connected to the first metal layer (111) and the inner conductor (121), respectively.

11. Microwave heating device according to claim 9, characterized in that said microwave heating device (10) further comprises an impedance matching structure, to which said first metal layer (111) and said microwave feed-in structure (117) are connected, respectively.

12. A microwave heating device according to any of claims 1 to 5, characterized in that the aperture of the through-going hole (110) is equal to or larger than the outer diameter of the aerosol-forming substrate (2).

13. Microwave heating device according to any of claims 1-5, characterized in that the central axis of the through hole (110) is parallel to or coincides with the central axis of the waveguide cavity (115).

14. An aerosol generating device comprising a microwave generating module (20), a housing (50) and a microwave heating device (10) according to any of claims 1 to 13; the microwave heating device (10) and the microwave generating module (20) are contained in the shell (50), and the coaxial connector (12) is respectively connected with the substrate integrated waveguide structure (11) and the microwave generating module (20).

15. An aerosol-generating device according to claim 14 in which a socket (5120) is formed in the housing (50) for insertion of the aerosol-forming substrate (2), the housing (50) having an air inlet aperture (5110) provided therein which communicates with the socket (5120) for entry of ambient air.

16. An aerosol generating device according to claim 15, wherein the outer housing (50) comprises an upper shell (51) and a lower shell (52) fitted to each other, the upper shell (51) comprising a cylindrical housing (511) and a receiving tube (512) extending downwardly from a top wall of the cylindrical housing (511), an inner wall surface of the receiving tube (512) defining the insertion hole (5120).

17. The aerosol generating device of claim 16, wherein the microwave generating module (20) is received in the lower housing (52), the substrate-integrated waveguide structure (11) is received in the upper housing (51), and a wire through hole (5111) for the coaxial connector (12) to pass through is further disposed on a bottom wall of the upper housing (51).

18. The aerosol generating device according to claim 16, wherein a cavity (5112) is formed in the cylindrical housing (511) between a lower end surface of the accommodating tube (512) and the substrate-integrated waveguide structure (11), and the air inlet hole (5110) is opened in a wall of the cavity (5112) and communicates with the cavity (5112).

19. An aerosol generating device according to claim 14, wherein the device comprises a plurality of the substrate-integrated waveguide structures (11), the through-holes (110) of the plurality of substrate-integrated waveguide structures (11) being in sequential corresponding communication.

20. An aerosol-generating device according to claim 14, further comprising a drive assembly (60), the drive assembly (60) being configured to drive movement of the substrate-integrated waveguide structure (11) or the aerosol-forming substrate (2) to cause relative movement between the substrate-integrated waveguide structure (11) and the aerosol-forming substrate (2).

21. An aerosol-generating device according to claim 20 in which the aperture of the through-holes (110) is larger than the outer diameter of the aerosol-forming substrate (2).