An antenna module for a microwave diagnostic system

Abstract

The application relates to microwave diagnosis of nuclear fusion, and discloses an antenna module for a microwave diagnosis system, which comprises a bottom plate, a focusing mirror, a waveguide switching switch, a plurality of first horn antennas and a plurality of first waveguides; the bottom plate is provided with a first support and a second support, the second support is lower than the first support, and the focusing mirror is fixed on the top of the first support; the waveguide switching switch is provided with an input channel and a plurality of output channels, and is used for switching the input channel to be conducted with one of the output channels; the plurality of first horn antennas are arranged on the top of the second support and face the focusing mirror; the number of the first horn antennas, the number of the output channels and the number of the first waveguides are the same; the plurality of first waveguides are arranged side by side, one end of each first waveguide is conducted with the first horn antenna, and the other end is conducted with the output channel, so that the plurality of first horn antennas and the plurality of output channels are conducted one by one; the antenna module with the non-rotating structure has improved reliability.

Description

Technical Field

[0001] This invention relates to microwave diagnostics of nuclear fusion, and in particular to an antenna module for a microwave diagnostic system. Background Technology

[0002] In magnetic confinement nuclear fusion research, tokamak devices stably confine plasma within a toroidal vacuum chamber. The plasma contains a large number of microscopic turbulences, which exacerbate energy loss. To study these turbulences and find solutions, it is necessary to accurately measure several key physical quantities of the plasma at different radial positions.

[0003] Doppler backscatterers and cross-polarized scatterers are widely used in the measurement process as common microwave diagnostic systems. At the optical path front end of these diagnostic systems, a rotating mirror is usually installed. Its core function is to drive the mirror surface of the rotating mirror to rotate precisely by a motor. After the rotation, the angle between the mirror surface and the microwave beam changes, thereby changing the direction of the microwave beam incident into the plasma. By superimposing and scanning the frequency of the incident microwave beam, multiple key physical quantities of the plasma at different radial positions can be measured.

[0004] However, the large amount of high-energy neutron radiation and extremely high heat load generated by the combustion plasma may cause problems such as failure of the drive motor of the rotating mirror and bearing jamming, which may cause the rotating mirror to fail to rotate and the microwave diagnostic system to malfunction.

[0005] Therefore, improving the reliability of the reflection structure in microwave diagnostic systems has become an urgent technical problem to be solved. Summary of the Invention

[0006] The technical problem to be solved by this invention is: how to improve the reliability of the reflection structure in a microwave diagnostic system.

[0007] To address the aforementioned technical problems, this invention provides an antenna module for a microwave diagnostic system, comprising: a base plate, a first support at a first end of the base plate, and a second support at a second end of the base plate, the height of the second support being lower than the height of the first support; a focusing mirror fixed to the top of the first support; a waveguide switching switch having an input channel and several output channels, the waveguide switching switch being used to switch the input channel to be connected to one of the output channels; several first horn antennas arranged on the top of the second support, the first horn antennas facing the focusing mirror, the number of first horn antennas being the same as the number of output channels; and several first waveguides, the number of first waveguides being the same as the number of output channels, the several first waveguides arranged side by side, one end of the first waveguide being connected to the first horn antenna, and the other end of the first waveguide being connected to the output channel, such that the several first horn antennas are connected to the several output channels in a one-to-one correspondence; wherein, microwave signals emitted by the first horn antennas at different arrangement positions correspond to different detection positions after being reflected by the focusing mirror.

[0008] In one embodiment, the antenna module further includes a third bracket suspended above the focusing mirror. A second waveguide and a second horn antenna are mounted on the third bracket, and the second waveguide and the second horn antenna are in communication. The first horn antenna is used to transmit a microwave signal with a first polarization direction. After the microwave signal with the first polarization direction enters the plasma, it will generate an additional microwave signal with a second polarization direction. The first polarization direction and the second polarization direction are perpendicular to each other. The first horn antenna is used to receive the echo signal corresponding to the first polarization direction, and the second horn antenna is used to receive the echo signal corresponding to the second polarization direction.

[0009] In one embodiment, the first horn antenna is a biconical horn antenna, and the second horn antenna is a pyramidal horn antenna.

[0010] In one embodiment, the first waveguide is a rectangular waveguide; the second waveguide includes a circular torque segment and a curved waveguide segment, one end of the curved waveguide segment is connected to the circular torque segment, and the other end of the curved waveguide segment is connected to the second horn antenna.

[0011] In one embodiment, the inner wall of the rectangular waveguide and the inner wall of the curved waveguide section are both provided with a conductive coating.

[0012] In one embodiment, the main body of the second horn antenna and the upper cover of the second waveguide are provided with a protective cover, which is an integrally formed structure and is fixedly connected to the third bracket.

[0013] In one embodiment, the second support is provided with a baffle, the top of which is higher than the top of any of the first horn antennas.

[0014] In one embodiment, the base plate, the first bracket, the second bracket, and the baffle are integrally formed.

[0015] In one embodiment, the first horn antenna is arranged on the focal plane of the focusing mirror.

[0016] In one embodiment, the waveguide switching switch is located outside the vacuum chamber.

[0017] Compared with the prior art, the antenna module for a microwave diagnostic system according to an embodiment of the present invention has the following advantages: The antenna module for a microwave diagnostic system in this embodiment of the invention abandons the rotating reflector that is paired with a single signal source. Instead, it uses multiple first horn antennas to form an antenna array, which is used in conjunction with a fixed focusing reflector. Since the position of each first horn antenna is different, the microwave signal emitted by each first horn antenna will reach different positions of the plasma after being reflected by the fixed focusing reflector, thereby realizing the measurement of multiple key physical quantities of the plasma at different radial positions.

[0018] Since no rotating structure is required during the measurement process, the first horn antenna is shielded by the second bracket, and the focusing mirror is fixedly connected to the first bracket. Therefore, the tolerance of all components, including the reflection structure and the antenna structure, is greatly improved. This antenna module without a rotating structure can withstand the neutron impact of burning plasma in a magnetic confinement nuclear fusion scenario, which means that the reliability of the reflection structure is improved. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an antenna module for a microwave diagnostic system, as exemplarily shown in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the waveguide switching device for an antenna module in a microwave diagnostic system, as exemplarily shown in an embodiment of the present invention.

[0021] Figure 3 This is an exemplary embodiment of the optical path diagram of an antenna module for a microwave diagnostic system.

[0022] Figure 4 This is a schematic diagram of the base plate and support structure of an antenna module for a microwave diagnostic system, as exemplarily shown in an embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram illustrating the structure of the second support and the first horn antenna of an antenna module for a microwave diagnostic system, as exemplarily shown in an embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the structure of the second waveguide of an antenna module for a microwave diagnostic system, as exemplarily shown in an embodiment of the present invention.

[0025] Figure 7 This is a schematic diagram of the structure of the second horn antenna of an antenna module for a microwave diagnostic system, as exemplarily shown in an embodiment of the present invention.

[0026] Figure 8 This is a schematic diagram of the back structure of a focusing reflector for an antenna module used in a microwave diagnostic system, as exemplarily shown in an embodiment of the present invention.

[0027] Figure 9 This is a schematic diagram of the structure of the first waveguide of an antenna module for a microwave diagnostic system, as exemplarily shown in an embodiment of the present invention.

[0028] Figure 10 This is an exemplary embodiment of the present invention, showing the optical path of the first horn antenna of an antenna module for a microwave diagnostic system.

[0029] Figure 11 This is an exemplary embodiment of the present invention, showing the logic diagram of the waveguide switching switch of an antenna module for a microwave diagnostic system, in which each channel is turned on under different states.

[0030] Figure 12 This is an exemplary embodiment of the present invention, showing the DBS beamline trajectory (frequency sweep) and CPS receiving line of sight of an antenna module for a microwave diagnostic system.

[0031] Figure label: 1. Base plate; 2. Focusing mirror; 3. Waveguide switching switch; 4. First horn antenna; 5. First waveguide; 6. Second waveguide; 7. Second horn antenna; 8. Protective cover; 11. First bracket; 12. Second bracket; 13. Baffle; 14. First fixing bracket; 15. Second fixing bracket; 31. Input channel; 32. Output channel; 61. Circular torque section; 62. Bent waveguide section. Detailed Implementation

[0032] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0033] It should be understood that although the terms first, second, third, etc., may be used to describe various structures in this invention, these structures should not be limited to these terms. These terms are only used to distinguish structures of the same type from each other. For example, a first structure may also be referred to as a second structure without departing from the scope of this invention, and similarly, a second structure may also be referred to as a first structure. Depending on the context, the word "if" as used herein can be interpreted as "when," "when," or "in response to determination." DBS (Doppler Backscattering) and CPS (Cross-polarization Scattering) in this invention are commonly used terms in the field of plasma diagnostics.

[0034] In magnetic confinement nuclear fusion research, tokamak devices stably confine plasma within a toroidal vacuum chamber. The plasma contains a large number of microscopic turbulences, which exacerbate energy loss. To study these turbulences and find solutions, it is necessary to accurately measure several key physical quantities of the plasma at different radial positions.

[0035] Doppler backscatterers and cross-polarized scatterers are widely used in the measurement process as common microwave diagnostic systems. At the optical path front end of these diagnostic systems, a rotating mirror is usually installed. Its core function is to drive the mirror to rotate precisely by a motor, thereby changing the direction of the microwave beam incident on the plasma, so as to measure multiple key physical quantities of the plasma at different radial positions.

[0036] However, the large amount of high-energy neutron radiation and extremely high heat load generated by the combustion plasma may cause problems such as failure of the drive motor of the rotating reflector and bearing jamming, which will lead to reduced accuracy or even failure of the rotation adjustment function, making it difficult to meet the diagnostic requirements of long-term, high-reliability operation.

[0037] Therefore, improving the reliability of the reflection structure in microwave diagnostic systems has become an urgent technical problem to be solved.

[0038] like Figure 1 and Figure 2 As shown in the figure, an antenna module for a microwave diagnostic system is provided in an embodiment of the present invention. The antenna module may include: a base plate 1, a focusing mirror 2, a waveguide switching switch 3, a plurality of first horn antennas 4 and a plurality of first waveguides 5.

[0039] A first support 11 is provided at the first end of the base plate 1, and a second support 12 is provided at the second end of the base plate 1. The height of the second support 12 is lower than the height of the first support 11. The focusing mirror 2 is fixed to the top of the first support 11. Figure 2As shown, the waveguide switching switch 3 has an input channel 31 and several output channels 32. The waveguide switching switch 3 is used to switch the input channel 31 to be connected to one of the output channels 32. Several first horn antennas 4 are arranged on the top of the second bracket 12. The first horn antennas 4 face the focusing mirror 2. The number of first horn antennas 4 is the same as the number of output channels 32. The number of first waveguides 5 is the same as the number of output channels 32. Several first waveguides 5 are arranged side by side. One end of the first waveguide 5 is connected to the first horn antenna 4, and the other end of the first waveguide 5 is connected to the output channel 32, so that several first horn antennas 4 are connected to several output channels 32 in a one-to-one correspondence.

[0040] Among them, the microwave signals emitted by the first horn antenna 4 at different arrangement positions correspond to different detection positions after being reflected by the focusing mirror 2.

[0041] The above scheme eliminates the rotating reflector and replaces it with a fixed focusing reflector 2. However, instead of a movable antenna, it uses an array of fixed first horn antennas 4. By switching different first horn antennas 4 through a waveguide switching switch 3, the position of the transmitting source can be changed. As the rated position of the transmitting source changes, the position where the microwave arrives will change when the focusing reflector 2 remains stationary. Under this condition, the microwave can reach several fixed and different measurement positions to measure several key physical quantities of the plasma at different radial positions.

[0042] Since no rotating structure is required during the measurement process, the first horn antenna 4 is shielded by the second bracket 12, and the focusing mirror 2 is fixedly connected to the first bracket 11. Therefore, the tolerance of each component, including the reflection structure and the antenna structure, is greatly improved. This antenna module without a rotating structure can cope with the neutron impact of the burning plasma in the magnetic confinement nuclear fusion scenario.

[0043] To improve durability, in one embodiment of the present invention, the base plate 1, the first support 11, the second support 12 and the baffle 13 are integrally formed. The integrally formed structure reduces loosening and deformation caused by vibration and thermal shock. Compared with the separate device, it can effectively ensure the relative positional accuracy between the optical elements, thereby improving the long-term stability and measurement reliability of the system.

[0044] Furthermore, the first horn antenna 4 can be arranged on the focal plane of the focusing mirror 2. By arranging multiple antennas on the focal plane of the focusing mirror 2, the present invention can generate multiple detection beams using a single mirror, enabling parallel or rapid switching measurements of different radial regions of the plasma, thereby significantly improving diagnostic efficiency and system reliability, and simplifying the system structure.

[0045] The focusing mirror 2 can be an ellipsoidal mirror, a parabolic mirror, or a spherical mirror.

[0046] The ellipsoidal mirror has two focal points, and waves emitted from one focal point are perfectly converged to the other focal point, resulting in better focusing performance, no spherical aberration, and the highest point-to-point energy transmission efficiency. It can be used as a preferred embodiment, which helps to achieve high-resolution and high-sensitivity diagnostic measurements as much as possible without rotating the reflection, thus compensating for the limited adjustment capability of fixed reflection positions.

[0047] Specifically, the first horn antenna can be arranged on the focal plane of the first focus of the ellipsoidal mirror, and the antenna module can be adjusted so that the second focus corresponds to the location of the plasma, thereby achieving higher energy transmission efficiency.

[0048] like Figure 8 As shown, in order to achieve higher connection strength and durability, several reinforcing ribs can be provided on the back of the focusing mirror 2 to enhance the structural strength and to reliably connect the mounting boss of the first bracket 11 with the focusing mirror 2.

[0049] For example, the focusing reflector 2 is a one-piece fabricated structure with the following basic design parameters: 316L stainless steel material, ellipsoidal reflector diameter of 120mm, focal length of 1280mm, offset height of 117.6mm, eccentricity e of 0.733, and vertex radius of curvature of 431.33mm. The main structure of the reflector is a curved plate with a uniform thickness of 2mm to meet the thermal deformation requirements of the reflector surface within the vacuum chamber of the nuclear fusion device. A mounting boss is designed on the back of the reflector surface, which is fixed to the corresponding support structure on the first bracket 11 using screws.

[0050] like Figure 10 As shown, to achieve multi-beam operation, based on the principle of reflector-defocused scanning, when the feed position (i.e., the position of the first horn antenna 4) is vertically defocused, the aperture field phase of the reflector will exhibit a linear deviation. This deviation, when combined, causes the maximum direction of the main radiation lobe to deviate from the horn antenna's output direction by a certain angle. This defocusing induces beam scanning, forming a multi-beam scan in the elevation direction. Considering the specific practical needs of diagnostic applications, exemplary scanning angles in a horizontal and vertical spatial coordinate system can be 8°, 11°, 17°, and 20° forward and downward.

[0051] It is understood that in this invention, the waveguide switching switch 3 does not need to enter a vacuum environment and will not be subjected to additional forces. Therefore, there are no specific limitations on the installation position and installation method of the waveguide switching switch 3, as long as the output channel 32 of the waveguide switching switch 3 can be connected to the first waveguide 5 one by one.

[0052] Therefore, in one embodiment, the waveguide switching switch 3 can be located outside the vacuum chamber to reduce the influence and impact of the vacuum environment and neutron flow on the waveguide switching switch 3.

[0053] To facilitate understanding of the working principle of waveguide switching switch 3, such as Figure 11 As shown, a one-to-four waveguide switch is used as an example of a waveguide switching switch 3. The one-to-four waveguide switch has four states. When the switch is in state 1, the first output channel will be connected to the input; when the switch is in state 2, the second output channel will be connected to the input; when the switch is in state 3, the third output channel will be connected to the input; and when the switch is in state 4, the fourth output channel will be connected to the input.

[0054] like Figure 1 Structural diagram and Figure 3 As shown in the optical path diagram, in one embodiment of the present invention, the antenna module further includes a third bracket, which is suspended above the focusing mirror 2. A second waveguide 6 and a second horn antenna 7 are mounted on the third bracket, and the second waveguide 6 and the second horn antenna 7 are connected.

[0055] The first horn antenna 4 is used to transmit microwave signals with a first polarization direction. After the microwave signal with the first polarization direction enters the plasma, it will generate a microwave signal with a second polarization direction. The first polarization direction and the second polarization direction are perpendicular to each other. The first horn antenna 4 is used to receive echo signals corresponding to the first polarization direction, and the second horn antenna 7 is used to receive echo signals corresponding to the second polarization direction.

[0056] By introducing a third support and installing a second horn antenna 7, multiplexing of the transmission optical path can be achieved by combining different transmission and reception methods. The first horn antenna 4 is responsible for transmitting linearly polarized microwaves, i.e., in the first polarization direction. After the linearly polarized microwaves enter the plasma, they will additionally generate microwave signals in the second polarization direction. Figure 3 As shown, when the microwave signal in the first polarization direction reaches the plasma density cutoff layer, the reflected echo signal returns along the optical path and is received by the first horn antenna 4. The incident microwave signal interacts with the magnetic field disturbance inside the plasma, generating an additional microwave signal in the second polarization direction. The echo signal in the second polarization direction is received by the second horn antenna 7 located above. In this way, different parameter measurement functions are achieved through different receiving optical paths.

[0057] For example, the first horn antenna 4 can be used to implement the function of a Doppler backscatterer, while the second horn antenna 7 can be used to implement the function of a cross-polarized scatterer. One antenna module can supply the signals required by the two instruments.

[0058] Specifically, the antenna of the Doppler backscatterer (i.e., the first horn antenna 4) adopts the X-mode, which means that the polarization direction of the diagnostic microwave beam electric field line is perpendicular to the plasma magnetic field. The antenna module of the mutual polarization scatterer adopts the O-mode, which means that the polarization direction of the mutual polarization scattering microwave electric field line is parallel to the plasma magnetic field. It can be seen that the polarization directions of the X-mode and the O-mode are perpendicular to each other.

[0059] Specifically, in one embodiment of the present invention, such as Figure 5 As shown, the first horn antenna 4 is a biconical horn antenna, as... Figure 7 As shown, the second horn antenna 7 is a pyramidal horn antenna.

[0060] The first horn antenna 4 (transceiver integrated antenna) uses a biconical horn antenna instead of a corrugated horn antenna because, given similar linear polarization, the biconical horn antenna is easier to manufacture and has a higher cost-effectiveness ratio. For example, the basic design parameters of the biconical horn antenna are: transmit microwave frequency range 140-220GHz, material brass, voltage standing wave ratio <2.5:1, surface smoothness <5μm, and vertical polarization.

[0061] Understandably, when linear polarization is similar, choosing a pyramidal horn antenna as the signal receiving antenna offers advantages such as high gain, high directivity, and simple structure, and is also easier to manufacture. For example, the basic design parameters of a pyramidal horn antenna are: microwave frequency range of 140-220GHz, brass material, voltage standing wave ratio <2.5:1, surface smoothness <5μm, and vertical polarization.

[0062] Figure 12 In the diagram, 16 solid curves represent the propagation paths of the microwave beams from the Doppler backscatterer at different incident frequencies in the fusion plasma, while gray dashed lines represent the single-channel microwave signal receiving line of sight of the second horn antenna 7 corresponding to the interpolarized scatterer.

[0063] In one embodiment of the present invention, as follows: Figure 9 As shown, the first waveguide 5 is a rectangular waveguide; as Figure 6 As shown, the second waveguide 6 includes a circular torque section 61 and a bent waveguide section 62. One end of the bent waveguide section 62 is connected to the circular torque section 61, and the other end of the bent waveguide section 62 is connected to the second horn antenna 7.

[0064] It is understood that, for ease of conduction and connection, in this invention, the rectangular waveguide and the waveguide switching switch 3 can adopt the same flange structure, such as... Figure 9 As shown in the figure, the left end is the flange portion of the rectangular waveguide, and the right end is the main body of the rectangular waveguide. Figure 1 and Figure 3 It can be seen that the first fixing bracket 14 is used to fix the flange part, and the second fixing bracket 15 is used to fix the main body part.

[0065] For example, both the rectangular waveguide and the waveguide switching switch 3 can use UG-387 / U-shaped flanges. Figure 9 Taking the example of the first waveguide 5, which is parallel to each other, it integrates four WR-5 fundamental mode channels, which enhances the anti-torsion characteristics.

[0066] Understandably, the circular torque section 61 and the bent waveguide section 62 can be made of 316L stainless steel. The bent waveguide section 62 is mainly used to connect to the second horn antenna 7, and its curved channel prevents neutrons from entering the interior of the circular torque section 61 and the bent waveguide section 62. The circular torque section 61 is mainly used to convert the microwave fundamental mode signal received by the second horn antenna 7 into an HE11 mode signal, facilitating low-loss, long-distance signal transmission.

[0067] In one embodiment, the inner wall of the rectangular waveguide and the inner wall of the bent waveguide section 62 are provided with a conductive coating, which may be silver, copper or gold.

[0068] The skin effect causes current to concentrate on the inner wall surface, and the higher the signal frequency, the thinner the surface layer where the current is concentrated. After using a conductive coating, the conductivity of the inner wall surface of the first waveguide 5 or the second waveguide 6 is stronger, so the transmission loss of the entire waveguide is lower.

[0069] Furthermore, in one embodiment of the present invention, such as Figure 1 As shown, the main body of the second horn antenna 7 and the second waveguide 6 are covered with a protective cover 8. The protective cover 8 is an integrally formed structure and is fixedly connected to the third bracket.

[0070] The protective cover 8 can be made of 316L stainless steel, which can resist the electromagnetic force, neutron and radiation heat flow in the burning plasma in the nuclear fusion device to the greatest extent to the pulling and bombardment of the second waveguide 6, and ensure the spatial stability and performance stability of the second horn antenna 7 in receiving signals.

[0071] In another embodiment of the invention, such as Figure 4 and Figure 5 As shown, the second bracket 12 is provided with a baffle 13, the top of which is higher than the top of any of the first horn antennas 4.

[0072] By using a baffle 13 to shield the first horn antenna 4, the impact of radiated heat flow on the first horn antenna 4 can be reduced, thereby reducing the heat and damage borne by the first horn antenna 4 and improving the overall antenna module's resilience.

[0073] This invention discloses an antenna module for a magnetic confinement fusion diagnostic system. By replacing the rotating reflector with a fixed focusing reflector 2 and combining it with a waveguide switching switch 3, multi-beam transmission and reception are achieved, significantly improving the system reliability of the Doppler backscatterer antenna module. The antenna module employs a biconical horn antenna and a rectangular waveguide, with optimized materials and structural design enhancing its robustness and effectively coping with neutron impacts from burning plasma. The flange structure of the waveguide switching switch 3 and the first waveguide 5 adopts a UG-387 / U-type design, enabling signal conduction and connection, ensuring high efficiency in multi-beam scanning. Furthermore, the protective cover 8 protects the antenna module from radiated heat flux and electromagnetic forces, ensuring signal stability. The overall structure eliminates rotating components, achieving rotation-free optical element robustness, significantly improving long-term stability and measurement accuracy.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. An antenna module for a microwave diagnostic system, characterized in that, include: A base plate (1) is provided with a first support (11) at its first end and a second support (12) at its second end. The height of the second support (12) is lower than the height of the first support (11). A focusing mirror (2) is fixed to the top of the first bracket (11); A waveguide switching switch (3) is provided with an input channel (31) and several output channels (32). The waveguide switching switch (3) is used to switch the input channel (31) to be connected to one of the output channels (32). A plurality of first horn antennas (4) are arranged on the top of the second bracket (12), the first horn antennas (4) facing the focusing mirror (2), and the number of the first horn antennas (4) is the same as the number of the output channels (32); A plurality of first waveguides (5) are arranged side by side, the number of first waveguides (5) being the same as the number of output channels (32). One end of the first waveguide (5) is connected to the first horn antenna (4), and the other end of the first waveguide (5) is connected to the output channel (32), so that the plurality of first horn antennas (4) and the plurality of output channels (32) are connected in a one-to-one correspondence. Among them, the microwave signals emitted by several of the first horn antennas (4) are reflected by the focusing mirror (2) and correspond to different detection positions respectively.

2. The antenna module for a microwave diagnostic system according to claim 1, characterized in that, The antenna module also includes a third bracket, which is suspended above the focusing mirror (2). A second waveguide (6) and a second horn antenna (7) are mounted on the third bracket, and the second waveguide (6) and the second horn antenna (7) are connected. The first horn antenna (4) is used to transmit a microwave signal with a first polarization direction. After the microwave signal with the first polarization direction enters the plasma, it will generate a microwave signal with a second polarization direction. The first polarization direction and the second polarization direction are perpendicular to each other. The first horn antenna (4) is used to receive the echo signal corresponding to the first polarization direction. The second horn antenna (7) is used to receive the echo signal corresponding to the second polarization direction.

3. The antenna module for a microwave diagnostic system according to claim 2, characterized in that, The first horn antenna (4) is a double-cone horn antenna, and the second horn antenna (7) is a pyramidal horn antenna.

4. The antenna module for a microwave diagnostic system according to claim 2, characterized in that, The first waveguide (5) is a rectangular waveguide; the second waveguide (6) includes a circular torque segment (61) and a bent waveguide segment (62), one end of the bent waveguide segment (62) is connected to the circular torque segment (61), and the other end of the bent waveguide segment (62) is connected to the second horn antenna (7).

5. The antenna module for a microwave diagnostic system according to claim 4, characterized in that, The inner wall of the rectangular waveguide and the inner wall of the curved waveguide section (62) are both provided with a conductive coating.

6. The antenna module for a microwave diagnostic system according to claim 2, characterized in that, The main body of the second horn antenna (7) and the second waveguide (6) are covered with a protective cover (8). The protective cover (8) is an integrally formed structure and is fixedly connected to the third bracket.

7. The antenna module for a microwave diagnostic system according to claim 1, characterized in that, The second bracket (12) is provided with a baffle (13), the top of which is higher than the top of any of the first horn antennas (4).

8. The antenna module for a microwave diagnostic system according to claim 7, characterized in that, The base plate (1), the first bracket (11), the second bracket (12) and the baffle (13) are integrally formed.

9. The antenna module for a microwave diagnostic system according to claim 1, characterized in that, The first horn antenna (4) is arranged on the focal plane of the focusing mirror (2).

10. The antenna module for a microwave diagnostic system according to claim 1, characterized in that, The waveguide switching switch (3) is located outside the vacuum chamber.

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