Aerosol-generating device

Abstract

The invention provides an aerosol generating device, a bi-directional coupler in the aerosol generating device comprises a main transmission line, a forward coupling microstrip line and a reverse coupling microstrip line, a second coupling part in the forward coupling microstrip line is close to one side of a first coupling part, and a second coupling part in the reverse coupling microstrip line is close to one side of a second coupling part. Interdigitated coupling structures are formed on one side, close to the first coupling part, of the third coupling part in the reverse coupling microstrip line and on one side, close to the first coupling part, of the third coupling part in the reverse coupling microstrip line, each interdigitated coupling structure comprises a plurality of toe parts extending towards the direction of the first coupling part, and the toe parts are arranged at intervals. Specifically, an interdigital coupling structure is arranged on a second coupling part and a third coupling part, and distributed capacitance is formed by slits arranged among a plurality of toe parts in the interdigital coupling structure, so that electromagnetic coupling aliasing between transmission lines is reduced, a regulatory factor is increased, and directivity is improved; and the distributed capacitor is connected in parallel with the forward and reverse coupling microstrip line equivalent inductor, so that the high-pass effect is realized, the working bandwidth is wide, the in-band flatness is small, the structure size is small, and the product design is flexible.

Description

Technical Field

[0001] The present application relates to the field of atomization technology, and in particular to an aerosol generating device. Background Art

[0002] An aerosol generating device using heat not burning (HNB) heats the aerosol generating substrate in the aerosol generating product to a temperature that can generate aerosol but is not high enough to burn, so that the aerosol generating substrate can generate the aerosol required by the user without burning.

[0003] At present, the HNB devices on the market mainly use resistance heating, that is, using a central heating sheet or heating needle to insert from the center of the aerosol generating matrix into the inside of the aerosol generating matrix for heating. This device needs a long preheating waiting time before use, cannot be withdrawn and stopped freely, and the carbonization of the atomized medium in the aerosol generating matrix is ​​uneven, resulting in insufficient baking of the atomized medium and low utilization rate; secondly, the heating sheet of the HNB device is easy to produce dirt in the aerosol generating matrix extractor and the heating sheet base, which is difficult to clean; it will cause the temperature of the local aerosol generating matrix that contacts the heating body to be too high, partially cracked, and release substances that are harmful to the human body. Microwave heating technology has the characteristics of high efficiency, timeliness, selectivity and no delay in heating, so microwave heating technology has gradually replaced resistance heating as a new heating method.

[0004] However, in the existing HNB devices using microwave heating technology, the couplers in the microwave generating units are mainly adopted in two ways. One way is to adopt a multi-stage cascade coupler, which has a complex structure, high cost and large size; the other way is to adopt a parallel line dual directional coupler, which has a large flatness fluctuation and poor isolation. It is easy to cause system instability when used in HNB devices in the downlink simplex atomization field. Summary of the invention

[0005] The present application provides an aerosol generating device, which can solve the problems of complex coupler structure, high cost, large fluctuation of radio frequency flatness and poor isolation in existing HNB devices using microwave heating technology, while having a small structure size and flexible product design.

[0006] In order to solve the above problems, a technical solution provided by the present application is as follows: a microwave generating unit is provided, which is applied to an aerosol generating device, wherein the microwave generating unit comprises a microwave generator and a dual directional coupler connected to each other, wherein the dual directional coupler comprises: a main transmission line, comprising a first input end, a first output end and a first coupling portion located between the first input end and the first output end; a forward coupling microstrip line, comprising a first coupling output end, a first isolation end and a second coupling portion located between the first coupling output end and the first isolation end; wherein the second coupling portion is parallel to at least part of the first coupling portion and is arranged at intervals; a reverse coupling microstrip line, which is arranged at intervals from the forward coupling microstrip line, and comprises a second coupling output end, a second isolation end and a third coupling portion located between the second coupling output end and the second isolation end; wherein the third coupling portion is parallel to at least part of the first coupling portion and is arranged at intervals; wherein a side of the second coupling portion close to the first coupling portion and a side of the third coupling portion close to the first coupling portion are both formed with an interdigital coupling structure, wherein the interdigital coupling structure comprises a plurality of toes extending in the direction of the first coupling portion, and the plurality of toes are arranged at intervals.

[0007] In one embodiment, the forward coupling microstrip line and the reverse coupling microstrip line are located on the same side of the first coupling portion.

[0008] In one embodiment, the forward coupling microstrip line and the reverse coupling microstrip line are symmetrically arranged.

[0009] In one embodiment, the forward coupling microstrip line and the reverse coupling microstrip line are located on opposite sides of the first coupling portion.

[0010] In one embodiment, the forward coupling microstrip line and the reverse coupling microstrip line are centrally symmetrically arranged with the central point of the first coupling portion as the center of symmetry.

[0011] In one embodiment, the dual directional coupler further includes a first capacitor, a second capacitor, a first resistor, and a second resistor; wherein the first coupling output terminal is electrically connected to one plate of the first capacitor, and the other plate of the first capacitor is used to connect to the detection circuit; the second coupling output terminal is electrically connected to one plate of the second capacitor, and the other plate of the second capacitor is used to connect to the detection circuit; the first isolation terminal is electrically connected to one end of the first resistor, and the other end of the first resistor is grounded; the second isolation terminal is electrically connected to one end of the second resistor, and the other end of the second resistor is grounded.

[0012] In one embodiment, the resistance of the main transmission line is a first resistance, the first resistor has a second resistance, and the second resistor has a third resistance; wherein the first resistance, the second resistance, and the third resistance are equal.

[0013] In one embodiment, the vertical distance between the second coupling portion and the first coupling portion is a first distance; the vertical distance between the third coupling portion and the first coupling portion is a second distance; wherein the first distance is equal to the second distance and is 0.20-0.24 mm.

[0014] In one embodiment, the distance between the multiple toes in each of the interdigital coupling structures is 0.3-0.5 mm, and the multiple toes are evenly arranged.

[0015] In one embodiment, the number of the plurality of toes in each of the interdigital coupling structures is 4, the width of each toe is 0.3-0.5 mm, and the height of each toe is 0.16-0.20 mm.

[0016] Different from the prior art, the beneficial effect of the present application is that the aerosol generating device provided by the present application includes a microwave heating component and a microwave generating unit, and the microwave generating unit is used to generate microwaves and feed into the microwave heating component so that the microwave heating component heats the aerosol generating matrix. Among them, the microwave generating unit includes a dual directional coupler, and the dual directional coupler includes a main transmission line, a forward coupling microstrip line and a reverse coupling microstrip line, wherein the second coupling part in the forward coupling microstrip line is close to the side of the first coupling part, and the third coupling part in the reverse coupling microstrip line is close to the side of the first coupling part, and both form a cross-toe coupling structure, and the cross-toe coupling structure includes a plurality of toes extending in the direction of the first coupling part, and the plurality of toes are arranged at intervals. Specifically, by arranging the cross-toe coupling structure on the second coupling part and the third coupling part, the fine gaps between the plurality of toes in the cross-toe coupling structure form distributed capacitance, reduce the electromagnetic coupling aliasing between the transmission lines, increase the adjustment factor, and improve the directivity; and the distributed capacitance is connected in parallel with the equivalent inductance of the forward and reverse coupling microstrip lines to achieve a high-pass effect, a wide working bandwidth, a small in-band flatness, and a small structural size, and a flexible product design. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0018] Figure 1A schematic structural diagram of an embodiment of an aerosol generating device provided in the present application;

[0019] Figure 2 A schematic structural diagram of an embodiment of a microwave generating unit provided in the present application;

[0020] Figure 3 A schematic structural diagram of an embodiment of a dual directional coupler provided in the present application;

[0021] Figure 4 A schematic structural diagram of another embodiment of the dual directional coupler provided in the present application;

[0022] Figure 5 A schematic structural diagram of another embodiment of the dual directional coupler provided in the present application;

[0023] Figure 6 A schematic structural diagram of another embodiment of the dual directional coupler provided in the present application;

[0024] Figure 7 for Figure 3 A magnified view of the structure in area A. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] The terms "first", "second", and "third" in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", and "third" can explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products, or devices.

[0027] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] The present application is described in detail below with reference to the accompanying drawings and embodiments.

[0029] See also Figure 1 and Figure 2 , Figure 1 A schematic structural diagram of an embodiment of an aerosol generating device provided in the present application; Figure 2 This is a schematic structural diagram of an embodiment of a microwave generating unit provided in the present application.

[0030] Specifically, the present application provides an electronic microwave product for use in the field of atomization, which may be an aerosol generating device 1000, comprising a microwave generating unit 100 and a microwave heating component 200. Specifically, the microwave generating unit 100 is used to generate microwaves and feed the microwave heating component 200, so that the microwave heating component 200 heats an aerosol generating substrate contained in the aerosol generating device 1000.

[0031] The microwave generating unit 100 includes a microwave generating source 10, a power amplifier circuit 20 and a dual directional coupler 30 connected in sequence. The microwave generating source 10 is used to generate microwaves, which are fed into the microwave heating component 200 through the power amplifier circuit 20 and the dual directional coupler 30, so that the microwave heating component 200 heats the aerosol generating matrix. In the present application, the microwave generating unit 100 also includes a detection circuit 40, which is connected to the dual directional coupler 30 to detect the microwave signal coupled to the dual directional coupler 30.

[0032] Specifically, when the aerosol generating device 1000 is working, the microwave generating source 10 generates microwaves of a specific frequency (wavelength), which are amplified by the power amplifier circuit 20 and output to the dual-directional coupler 30. The dual-directional coupler 30 feeds the amplified microwaves into the microwave heating component 200, so that the microwave heating component 200 uses the microwaves to heat the aerosol generating matrix to generate an aerosol that can be used by the user. In addition, the dual-directional coupler 30 also couples out a part of the microwave energy, and the coupled energy is input into the detection circuit 40 for signal detection, so as to adjust the microwave frequency output by the microwave generating source 10, so that the microwave frequency output by the microwave generating source 10 reaches the optimal frequency point, thereby improving the atomization effect.

[0033] Among them, in the electronic microwave products in the field of downlink simplex atomization, the coupler is used to distribute the power of the RF signal in a certain proportion, transmit power and couple. However, the electronic microwave products in the field of atomization are small in size and the load is not fixed, so the requirements for the coupler are more stringent. The applicant found that the existing technology uses a multi-stage cascade structure, which leads to a large coupler volume and high cost, affecting the design flexibility of the product. In addition, the parallel line dual directional coupler has poor flatness and isolation performance, which is easy to cause system instability when used in electronic microwave products in the field of downlink simplex atomization.

[0034] In order to overcome the shortcomings of the prior art, the present application provides a microstrip dual directional coupler design, which solves the problems of complex structure, high cost, large fluctuation of RF flatness, and poor coupling through this technology. It is particularly suitable for electronic microwave products in the field of atomization with relatively demanding requirements. At the same time, it has a small structure size, flexible product design, wide working bandwidth and high flatness.

[0035] See also Figure 3-Figure 7 , Figure 3 A schematic structural diagram of an embodiment of a dual directional coupler provided in the present application; Figure 4 A schematic structural diagram of another embodiment of the dual directional coupler provided in the present application; Figure 5 A schematic structural diagram of another embodiment of the dual directional coupler provided in the present application; Figure 6 A schematic structural diagram of another embodiment of the dual directional coupler provided in the present application; Figure 7 for Figure 3 A magnified view of the structure in area A.

[0036] The dual directional coupler 30 includes a main transmission line 31 , a forward coupling microstrip line 32 , and a reverse coupling microstrip line 33 .

[0037] The main transmission line 31 includes a first input terminal P1, a first output terminal P2, and a first coupling portion 311 located between the first input terminal P1 and the first output terminal P2. The first input terminal P1 and the first output terminal P2 may be opposite ends of the first coupling portion 311, or the first input terminal P1 and the first output terminal P2 may be bent from opposite ends of the first coupling portion 311 toward a direction away from the forward coupling microstrip line 32 and / or the reverse coupling microstrip line 33, so as to facilitate connection with other devices or circuits. In addition, the first input terminal P1 and the first output terminal P2 may be swapped.

[0038] The forward coupling microstrip line 32 includes a first coupling output terminal P3, a first isolation terminal P4, and a second coupling portion 321 located between the first coupling output terminal P3 and the first isolation terminal P4; wherein the second coupling portion 321 is parallel to and spaced from at least a portion of the first coupling portion 311. Specifically, the second coupling portion 321 is used to couple the forward input power of the main transmission line 31, the first coupling output terminal P3 is used to connect to the detection circuit to monitor the forward input power of the main transmission line 31, and the first isolation terminal P4 is used to be grounded.

[0039] The reverse coupling microstrip line 33 is spaced apart from the forward coupling microstrip line 32, and includes a second coupling output terminal P5, a second isolation terminal P6, and a third coupling portion 331 located between the second coupling output terminal P5 and the second isolation terminal P6; wherein the third coupling portion 331 is parallel to and spaced apart from at least a portion of the first coupling portion 311. Specifically, the second coupling portion 321 is parallel to and spaced apart from at least a portion of the first coupling portion 311. Specifically, the third coupling portion 331 is used to couple the reverse reflection power of the main transmission line 31, the second coupling output terminal P5 is used to connect to the detection circuit to monitor the reverse reflection power of the main transmission line 31, and the second isolation terminal P6 is used to be grounded.

[0040] Among them, in the direction from the first input terminal P1 to the first output terminal P2, the first coupling output terminal P3 of the forward coupling microstrip line 32 is located before the first isolation terminal P4, and the second coupling output terminal P5 of the reverse coupling microstrip line 33 is located after the second isolation terminal P6. Therefore, it can be understood that when the first input terminal P1 and the first output terminal P2 of the main transmission line 31 are swapped, the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are swapped.

[0041] The first coupling output terminal P3 can be regarded as a coupling signal output port of the dual directional coupler 30 , and the second coupling output terminal P5 can be regarded as an isolation port of the dual directional coupler 30 .

[0042] Furthermore, in the forward coupled microstrip line 32 and the reverse coupled microstrip line 33 provided in the present application, a side of the second coupling portion 321 close to the first coupling portion 311, and a side of the third coupling portion 331 close to the first coupling portion 311, are both formed with a cross-toe coupling structure 34, wherein the cross-toe coupling structure 34 includes a plurality of toe portions 341 extending toward the first coupling portion 311, and the plurality of toe portions 341 are arranged at intervals.

[0043] Specifically, by setting a cross-toe coupling structure 34 on the second coupling part 321 and the third coupling part 331, the fine gaps between the multiple toe parts 341 in the cross-toe coupling structure 34 form distributed capacitance, which reduces the electromagnetic coupling aliasing between the microstrip transmission lines and increases the adjustment factor, thereby improving the directivity; and the distributed capacitance is connected in parallel with the equivalent inductance of the forward and reverse coupled microstrip lines 33 to achieve a high-pass effect, thereby solving the physical characteristics of microstrip parallel lines in electromagnetic field transmission, such as the problem that as the frequency increases, the loss increases and the coupling degree decreases, thereby achieving a wide working bandwidth and a small in-band flatness. The dual directional coupler 30 provided in the present application has a small structural size and flexible product design.

[0044] In some embodiments, the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 may be located on the same side of the first coupling portion 311 ; the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 may also be located on opposite sides of the first coupling portion 311 .

[0045] For example, Figure 3 As shown, the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are located on the same side of the first coupling portion 311 and are symmetrically arranged.

[0046] Specifically, the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 adopt a bilaterally symmetrical structure, which can maintain the continuity of the coupling microstrip line impedance, thereby improving the directionality of the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 and stabilizing the forward and reverse coupling signal transmission.

[0047] like Figure 4-6 As shown, the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are located at opposite sides of the first coupling portion 311 , and the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are symmetrically arranged with the center point of the first coupling portion 311 as the symmetry center.

[0048] Specifically, by arranging the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 symmetrically, the continuity of the coupling microstrip line impedance can be maintained, thereby improving the directivity of the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 and stabilizing the forward and reverse coupling signal transmission.

[0049] Among them, Figure 4 As shown, the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are located on opposite sides of the first coupling portion 311, and the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are centrally symmetrically arranged with the center point of the first coupling portion 311 as the symmetry center, and the projections of the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 on the first coupling portion 311 do not overlap.

[0050] Among them, Figure 5 and Figure 6As shown, the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are located on opposite sides of the first coupling portion 311, and the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are centrally symmetrically arranged with the center point of the first coupling portion 311 as the symmetry center, and the projections of the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 on the first coupling portion 311 overlap. However, Figure 5 and Figure 6 In the dual directional coupler 30 shown, the positions of the first input end P1 and the first output end P2 of the main transmission line 31 are swapped, so the positions of the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 are also swapped.

[0051] In one embodiment, the dual directional coupler 30 further includes a first capacitor C1 , a second capacitor C2 , a first resistor R1 , and a second resistor R2 .

[0052] Among them, the first capacitor C1 is used to output the forward input power coupled on the second coupling part 321 to the detection circuit, and the first resistor R1 is used to ground the first isolation end P4; the second capacitor C2 is used to output the reverse reflection power coupled on the third coupling part 331 to the detection circuit, and the second resistor R2 is used to ground the second isolation end P6.

[0053] Specifically, the first coupling output terminal P3 is electrically connected to one plate of the first capacitor C1, and the other plate of the first capacitor C1 is used to connect to the detection circuit. The second coupling output terminal P5 is electrically connected to one plate of the second capacitor C2, and the other plate of the second capacitor C2 is used to connect to the detection circuit. The first isolation terminal P4 is electrically connected to one end of the first resistor R1, and the other end of the first resistor R1 is grounded. The second isolation terminal P6 is electrically connected to one end of the second resistor R2, and the other end of the second resistor R2 is grounded.

[0054] In one embodiment, the resistance of the main transmission line 31 is a first resistance, the first resistor R1 has a second resistance, and the second resistor R2 has a third resistance, wherein the first resistance, the second resistance, and the third resistance are equal to maintain optimal port matching, thereby solving the poor directivity caused by impedance pulling at the port of the dual directional coupler 30, thereby improving the directivity of the forward and reverse couplers and stabilizing the forward and reverse coupled signal transmission.

[0055] For example, in the embodiment of the present application, the main transmission line 31 adopts a 50-ohm microstrip transmission line structure for transmitting radio frequency signals, and the physical conductor length is specified as a quarter wavelength of the center frequency of the working frequency band, with minimal signal loss and optimal transmission, which can achieve good coupling performance. At the same time, the forward coupling microstrip line 32 and the reverse coupling microstrip line 33 form two independent directional couplers on the structure of the main transmission line 31, and the isolation of each directional coupler is connected to the ground through a 50-ohm radio frequency resistor (R1, R2), ensuring that the load absorption capacity meets the maximum power value of the signal and maintaining the best matching of the port, thereby solving the poor directivity caused by the impedance pulling of the dual directional coupler 30 ports, thereby improving the directivity of the forward and reverse couplers and stabilizing the forward and reverse coupling signal transmission.

[0056] In addition, the number and parameters of the multiple toe portions 341 of each interdigital coupling structure 34 are determined according to the lengths of the first coupling portion 311 , the second coupling portion 321 and the third coupling portion 331 , and the distances between the first coupling portion 311 and the second coupling portion 321 and the third coupling portion 331 .

[0057] For example, the longer the lengths of the first coupling portion 311, the second coupling portion 321 and the third coupling portion 331 are, the greater the number and / or the greater the width of the multiple toe portions 341 of the interdigital coupling structure 34; the greater the distance between the first coupling portion 311 and the second coupling portion 321 and the third coupling portion 331 respectively, the higher the height of each toe portion 341.

[0058] The present application takes the working frequency band of the radio frequency signal transmitted on the main transmission line 31 as 2.4-2.5 GHz, and the length of the main transmission line 31 as one quarter of the wavelength of the center frequency 2.45 GHz as an example.

[0059] Among them, see Figure 4 , a vertical distance between the second coupling portion 321 and the first coupling portion 311 is a first distance H1, and the first distance H1 is used to characterize the inter-toe depth between the inter-toe coupling structure 34 on the second coupling portion 321 and the first coupling portion 311; a vertical distance between the third coupling portion 331 and the first coupling portion 311 is a second distance H2, and the second distance H2 is used to characterize the inter-toe depth between the inter-toe coupling structure 34 on the third coupling portion 331 and the first coupling portion 311; wherein the first distance H1 is equal to the second distance H2, and is 0.20-0.24 mm, for example, the first distance H1 and the second distance H2 may be 0.20 mm, 0.218 mm, 0.22 mm or 0.24 mm, which is not limited here.

[0060] Specifically, Figure 4As shown, the extension direction of the second coupling portion 321 is parallel to the extension direction of the first coupling portion 311 , and the extension direction of the third coupling portion 331 is parallel to the extension direction of the first coupling portion 311 . The “vertical distance” refers to the distance between two parallel lines.

[0061] Among them, see Figure 7 The distance H3 between the multiple toes 341 in each interdigital coupling structure 34 is 0.3-0.5 mm, such as 0.3 mm, 0.4 mm or 0.5 mm, which is not limited here, and the multiple toes 341 are evenly arranged so that the distributed capacitance formed between two adjacent toes 341 is consistent.

[0062] In one embodiment, please continue to refer to Figure 7 The number of the multiple toes 341 in each interdigital coupling structure 34 is 4, the width H4 of each toe 341 is 0.3-0.5 mm, for example, 0.3 mm, 0.4 mm or 0.5 mm, etc., and the height H5 of each toe 341 is 0.16-0.20 mm, for example, 0.16 mm, 0.18 mm or 0.20 mm, etc.

[0063] In a specific embodiment of the present application, the first isolation end P4 of the forward coupling microstrip line 32 is connected to the ground through the first resistor R1, and the first resistor R1 is a high-power RF resistor with an impedance of 50 ohms, which ensures that the load absorption capacity meets the maximum power value of the signal and ensures good port matching. The forward coupling microstrip line 32 has an interdigital coupling structure 34, and the interdigital depth of the forward coupling microstrip line 32 and the main transmission is 0.218mm. The width of each toe 341 in the interdigital coupling structure 34 is 0.4mm, the height is 0.18mm, the toe spacing is 0.4mm, and the toe array is 4 groups, thereby reducing the microstrip area, reducing electromagnetic coupling aliasing and increasing the adjustment factor, and it is relatively easy to obtain a more ideal directivity, working bandwidth and in-band flatness. The second isolation end P6 of the reverse coupling microstrip line 33 is connected to the ground through the second resistor R2, and the second resistor R2 is a high-power RF resistor with an impedance of 50 ohms, which ensures that the load absorption capacity meets the maximum power value of the signal and ensures good port matching. The reverse coupled microstrip line 33 adopts an interdigital coupling structure 34, and the interdigital depth between the reverse coupled microstrip line 33 and the main transmission line is 0.218 mm. The width of each toe 341 in the interdigital coupling structure 34 is 0.4 mm, the height is 0.18 mm, the toe spacing is 0.4 mm, and there are 4 toe arrays, thereby reducing the microstrip area, reducing electromagnetic coupling aliasing and increasing the adjustment factor, and it is relatively easy to obtain a more ideal directivity, working bandwidth and in-band flatness. The forward coupled microstrip line 32 and the reverse coupled microstrip line 33 adopt a horizontal left-right symmetrical structure to maintain the continuity of the impedance of the microstrip transmission line. At the same time, the forward coupled microstrip line 32 and the reverse coupled microstrip line 33 form two independent directional couplers with the main transmission line 31 structure. The isolation of each directional coupler is connected to the ground through a 50-ohm RF resistor to ensure that the load absorption capacity meets the maximum power value of the signal and maintains the best matching of the port, thereby solving the poor directivity caused by the impedance pulling of the port of the dual directional coupler 30, thereby improving the directivity of the forward and reverse couplers and stabilizing the forward and reverse coupled signal transmission.

[0064] The dual directional coupler 30 is tested by a network analyzer (such as E5071C), with the operating frequency band of the RF signal transmitted on the main transmission line 31 being 2.4-2.5 GHz, and its operating frequency point f0=2.45 GHz. The P1-P2 port, the P1-P3 port and the P1-P5 port are tested respectively, as shown in Table 1, which is the test data of the dual directional coupler 30.

[0065]

[0066] Table 1

[0067] The return losses of the ports are: the first input port P1 (dB (S (1, 1)) -20.2dB, the first output port P2 (dB (S (2, 2)) -18.79dB, the first coupling port P3 (dB (S (3, 3)) -19.29dB, the second coupling port P5 (dB (S (4, 4)) -17.1dB); the forward directivity indexes of 2.4GHz, 2.45GHz, and 2.5GHz in the working frequency are -24.39dB, -24.41dB, and -23.94dB respectively; the reverse directivity indexes of 2.4GHz, 2.45GHz, and 2.5GHz in the working frequency are -17. The forward and reverse directivities within the working frequency band are relatively ideal. The forward coupling index (dB(S(3,1)) of 2.4GHz, 2.45GHz and 2.5GHz within the working frequency are -32.16dB, -32dB and -31.86dB respectively, and the flatness (s) is <0.16dB. The reverse coupling index (dB(S(4,2)) of 2.4GHz, 2.45GHz and 2.5GHz within the working frequency are -32.39dB, -32.2dB and -31.06dB respectively, and the flatness is <0.32dB. Therefore, a relatively ideal optimal effect can be achieved.

[0068] Specifically, in the dual directional coupler 30 provided by the present application, a cross-toe coupling structure 34 is provided on the second coupling portion 321 and the third coupling portion 331, and the fine gaps between the multiple toe portions 341 in the cross-toe coupling structure 34 form a distributed capacitance, which reduces the electromagnetic coupling aliasing between the microstrip transmission lines and increases the adjustment factor, thereby improving the directivity; and the distributed capacitance is connected in parallel with the equivalent inductance of the forward and reverse coupled microstrip lines 33 to achieve a high-pass effect, thereby solving the physical characteristics of the transmission of parallel microstrip lines in the electromagnetic field, such as the problem that as the frequency increases, the loss increases and the coupling degree decreases, thereby achieving a wide working bandwidth and a small in-band flatness, and the dual directional coupler 30 provided by the present application has a small structural size and flexible product design.

[0069] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An aerosol generating device, It is characterized in that include: Microwave heating components; A microwave generating unit, comprising a microwave generating source, a power amplifying circuit, a dual directional coupler and a detection circuit; The microwave generating source is used to generate microwaves, and the microwaves are fed into the microwave heating component through the power amplifier circuit and the dual directional coupler, so that the microwave heating component heats the aerosol generating substrate; The detection circuit is connected to the dual directional coupler to detect the microwave signal; Wherein, the dual directional coupler comprises: A main transmission line, comprising a first input end, a first output end, and a first coupling portion located between the first input end and the first output end; A forward coupled microstrip line, comprising a first coupled output end, a first isolated end, and a second coupled portion located between the first coupled output end and the first isolated end; wherein the second coupled portion is parallel to at least a portion of the first coupled portion and is spaced apart; a reverse coupling microstrip line, arranged at intervals from the forward coupling microstrip line, and comprising a second coupling output end, a second isolation end, and a third coupling portion located between the second coupling output end and the second isolation end; wherein the third coupling portion is parallel to at least part of the first coupling portion and arranged at intervals; A side of the second coupling portion close to the first coupling portion and a side of the third coupling portion close to the first coupling portion both form an interdigital coupling structure, and the interdigital coupling structure includes a plurality of toes extending toward the first coupling portion, and the plurality of toes are arranged at intervals.

2. The aerosol generating device according to claim 1, It is characterized in that The forward coupling microstrip line and the reverse coupling microstrip line are located on the same side of the first coupling portion.

3. The aerosol generating device according to claim 2, It is characterized in that The forward coupling microstrip line and the reverse coupling microstrip line are symmetrically arranged.

4. The aerosol generating device according to claim 1, It is characterized in that The forward coupling microstrip line and the reverse coupling microstrip line are located at two opposite sides of the first coupling portion.

5. The aerosol generating device according to claim 4, It is characterized in that Taking the center point of the first coupling portion as the symmetry center, the forward coupling microstrip line and the reverse coupling microstrip line are centrally symmetrically arranged.

6. The aerosol generating device according to claim 1, It is characterized in that The dual directional coupler further includes a first capacitor, a second capacitor, a first resistor, and a second resistor; Wherein, the first coupling output end is electrically connected to one plate of the first capacitor, and the other plate of the first capacitor is used to connect to the detection circuit; the second coupling output end is electrically connected to one plate of the second capacitor, and the other plate of the second capacitor is used to connect to the detection circuit; The first isolation end is electrically connected to one end of the first resistor, and the other end of the first resistor is grounded; the second isolation end is electrically connected to one end of the second resistor, and the other end of the second resistor is grounded.

7. The aerosol generating device according to claim 6, It is characterized in that The resistance of the main transmission line is a first resistance, the first resistor has a second resistance, and the second resistor has a third resistance; The first resistance, the second resistance and the third resistance are equal.

8. An aerosol generating device according to any one of claims 1 to 7, It is characterized in that The vertical distance between the second coupling portion and the first coupling portion is a first distance; the vertical distance between the third coupling portion and the first coupling portion is a second distance; The first distance is equal to the second distance and is 0.20-0.24 mm.

9. An aerosol generating device according to any one of claims 1 to 7, It is characterized in that The distance between the multiple toes in each of the interdigital coupling structures is 0.3-0.5 mm, and the multiple toes are evenly arranged.

10. The aerosol generating device according to claim 9, It is characterized in that The number of the plurality of toes in each of the interdigital coupling structures is 4, the width of each toe is 0.3-0.5 mm, and the height of each toe is 0.16-0.20 mm.

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