Electrically tunable waveguide switch with choke structure

Abstract

The application discloses an electric waveguide switch with a choke structure and relates to the technical field of waveguide transmission devices for microwave communication. The electric waveguide switch comprises an electric drive assembly and a microwave switch assembly. The microwave switch assembly comprises a microwave rotor and a microwave stator. The microwave rotor is internally formed with a curved microwave channel. The microwave stator is formed with standard waveguide ports. The microwave rotor is installed in the microwave stator through bearings and has a gap with the microwave stator. Under the drive of the electric drive assembly, the microwave rotor rotates around the center of the microwave stator. When two ports of the curved microwave channel are simultaneously connected with any two standard waveguide ports on the microwave stator, the waveguide switch is in an open state; otherwise, the waveguide switch is in a closed state. The waveguide switch can effectively choke electromagnetic waves, reduce electromagnetic wave leakage and improve transmission effect.

Description

Technical Field

[0001] This invention relates to the field of waveguide transmission devices for microwave communication, and in particular to an electric waveguide switch with a choke structure that provides good transmission performance. Background Technology

[0002] Waveguide switches are crucial components for signal path control. Their primary function is to select the transmission channel by switching microwave channels, thereby significantly improving the reliability of the link system. Compared to other waveguide switches, electromechanical microwave waveguide switches feature low VSWR, low insertion loss, and high power capacity. They are widely used as backup path switches in high-power radar and communication transmitters; they are also applied in microwave transmitting equipment for satellite communication systems and microwave measurement and control engineering.

[0003] In existing electric waveguide switches, in order to extend the service life of the waveguide switch, there is generally a gap of a certain width between the inner wall of the cavity (stator) and the rotating shaft (rotor) so that the rotating shaft can rotate in the cavity without friction with the cavity. This causes electromagnetic waves to leak into the gap, resulting in poor signal transmission. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to provide an electric waveguide switch with a choke structure that can effectively choke electromagnetic waves, reduce electromagnetic wave leakage, and improve transmission performance.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an electric waveguide switch with a choke structure, comprising an electric drive assembly and a microwave switch assembly. The microwave switch assembly includes a microwave rotor and a microwave stator. A curved microwave path is formed inside the microwave rotor, and standard waveguide ports are formed on the microwave stator. The microwave rotor is mounted in the microwave stator through bearings, with a gap between them. Driven by the electric drive assembly, the microwave rotor rotates cyclically in the center of the microwave stator. When both ports of the curved microwave path are simultaneously connected to any two standard waveguide ports on the microwave stator, the waveguide switch is in the open state; otherwise, it is in the closed state. A choke structure is formed on the microwave stator to prevent electromagnetic wave leakage between the microwave rotor and the microwave stator.

[0006] A further technical solution is as follows: the electric drive assembly includes a drive motor and a housing top cover. The motor is inverted, and the power output end of the drive motor is connected to an extension column. The extension column passes through the housing top cover and enters the grooved cover plate. The lower end of the extension column extends into the microwave switch assembly on the lower side of the grooved cover plate. The housing top cover is fixedly connected to the cover plate, and the drive motor is fixedly connected to the housing top cover.

[0007] A further technical solution is as follows: the microwave switch assembly includes a microwave rotor and a microwave stator. The microwave stator includes a microwave cavity and a cavity flange. The upper and lower end faces of the microwave cavity each have a through-hole communicating with the inner cavity. The through-hole on the upper end face of the microwave cavity allows the microwave rotor to enter, while the through-hole on the lower end face is sealed by a bottom cover. The left, right, front, and rear end faces of the microwave cavity each have a through-hole communicating with the inner cavity. A cavity flange is installed within each of the through-holes on the front, rear, left, and right end faces of the microwave cavity. A standard waveguide interface is installed on the inner and outer sides of each cavity flange, and the two standard waveguide interfaces are interconnected. The microwave rotor includes a shaft, and two curved microwave paths are formed inside the shaft. The shaft rotates cyclically in the center of the microwave cavity under the drive of the drive motor. When both ports of the microwave paths are simultaneously connected to the standard waveguide interfaces on any two cavity flanges, the waveguide switch is in the open state; otherwise, it is in the closed state.

[0008] A further technical solution is as follows: the cavity flange includes a first frustum, a first standard waveguide port is formed at the center of the outer surface of the first frustum, a first rectangular boss is formed on the inner surface of the first frustum, a first cylinder is formed on the inner side surface of the first rectangular boss, a second standard waveguide port is formed on the cylinder at a position corresponding to the first standard waveguide port, a straight microwave channel is formed between the first standard waveguide port and the second standard waveguide port, the surface of the first cylinder corresponding to the rotating shaft is an arc-shaped surface adapted to the outer surface of the rotating shaft, there is a gap between the arc-shaped surface and the outer surface of the rotating shaft, a concave inclined surface is formed on the first cylinder on the left and right sides of the second standard waveguide port, so that the second standard waveguide port is concave relative to the arc-shaped surface of the first cylinder, the inclined surface is the first quarter-wavelength transmission structure, and an annular groove is formed on the first cylinder outside the concave inclined surface, the annular groove is the second quarter-wavelength transmission structure.

[0009] A further technical solution is as follows: the rotating shaft includes an upper rotating shaft and a lower rotating shaft, which are fixed together by screws. The upper rotating shaft includes a first rotating shaft cylinder, on the upper surface of which a first insertion post is fixed. A bearing is sleeved on the lower middle part of the first insertion post, and the lower end of the extension post is inserted into the end of the first insertion post. The lower rotating shaft includes a second rotating shaft cylinder, on the lower surface of which a second insertion post is fixed. The second insertion post is fixed to the cavity by a bearing. Two microwave paths are formed on the upper surface of the second rotating shaft cylinder, and the two side ports of the microwave paths are located on the side walls of the second rotating shaft cylinder.

[0010] The beneficial effects of adopting the above technical solution are as follows: In order to ensure that electromagnetic waves propagate in the specified direction and reduce leakage, the waveguide switch described in this application adds a choke groove structure between the cavity flange and the rotating shaft to prevent electromagnetic waves from leaking out. The choke groove structure uses a radial gap of one-quarter wavelength and a groove depth of one-quarter wavelength to realize the conversion between short circuit, open circuit and short circuit, providing a low-resistance transmission path for current at the connection point. The design of the choke groove achieves the effect of being physically disconnected but electrically connected, so that the transmission of electromagnetic waves in the waveguide is almost unaffected, thus improving the transmission quality of electromagnetic waves. Attached Figure Description

[0011] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0012] Figure 1 This is a schematic diagram of the waveguide switch described in an embodiment of the present invention;

[0013] Figure 2 This is an exploded structural diagram of the waveguide switch described in an embodiment of the present invention;

[0014] Figure 3 This is a schematic diagram of the front view structure of the waveguide switch according to an embodiment of the present invention;

[0015] Figure 4 This is a schematic diagram of the left-side structure of the waveguide switch described in an embodiment of the present invention;

[0016] Figure 5 This is a right-side view of the waveguide switch described in an embodiment of the present invention.

[0017] Figure 6 This is a top view schematic diagram of the waveguide switch described in an embodiment of the present invention;

[0018] Figure 7 This is a bottom view of the waveguide switch described in an embodiment of the present invention;

[0019] Figure 8 This is a cross-sectional view of the waveguide switch described in an embodiment of the present invention;

[0020] Figure 9 This is a schematic diagram of the motor cover in the waveguide switch described in an embodiment of the present invention;

[0021] Figure 10 This is a schematic diagram of the structure of the top cover of the waveguide switch in the embodiment of the present invention;

[0022] Figure 11 This is a schematic diagram of the grooved cover plate in the waveguide switch according to an embodiment of the present invention;

[0023] Figure 12This is a schematic diagram of the structure of the extension column in the waveguide switch described in an embodiment of the present invention;

[0024] Figure 13 This is a schematic diagram of the structure of the aviation plug in the waveguide switch described in an embodiment of the present invention;

[0025] Figure 14 This is a schematic diagram of the tactile switch in the waveguide switch described in an embodiment of the present invention;

[0026] Figure 15 This is a schematic diagram of the microwave cavity structure in the waveguide switch described in an embodiment of the present invention;

[0027] Figure 16 This is a schematic diagram of the cavity flange in the waveguide switch described in an embodiment of the present invention;

[0028] Figure 17 This is an enlarged structural schematic diagram of the cavity flange in the waveguide switch described in an embodiment of the present invention;

[0029] Figure 18 This is a cross-sectional magnified structural diagram of the cavity flange in the waveguide switch described in an embodiment of the present invention;

[0030] Figure 19 This is a schematic diagram of the bottom cover structure of the waveguide switch described in an embodiment of the present invention;

[0031] Figure 20 This is a schematic diagram of the structure of the rotating shaft in the waveguide switch according to an embodiment of the present invention;

[0032] Figure 21 This is an exploded structural diagram of the rotating shaft in the waveguide switch described in an embodiment of the present invention;

[0033] Figure 22 This is a schematic diagram of the upper half of the rotating shaft in the embodiment of the present invention;

[0034] Figure 23 This is a schematic diagram of the lower half of the rotating shaft in the embodiment of the present invention;

[0035] The components include: 1. Microwave path; 2. Drive motor; 3. Top cover of the housing; 4. Extension column; 5. Groove cover; 6. Motor cover; 7. Position sensor; 8. Limiting column; 9. Aviation connector; 10. Microwave cavity; 11. Bottom cover;

[0036] 12. Cavity flange; 12-1. First frustum; 12-2. First standard waveguide port; 12-3. First rectangular boss; 12-4. On the first cylinder; 12-5. Second standard waveguide port; 12-6. Concave slope; 12-7. Annular groove;

[0037] 13. Rotating shaft; 13-1. Upper rotating shaft; 13-1-1. First rotating shaft cylinder; 13-1-2. First insertion post; 13-2. Lower rotating shaft; 13-2-1. Second rotating shaft cylinder; 13-2-2. Second insertion post;

[0038] 14. Sealing ring; 15. Screw; 16. Bearing. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0041] like Figures 1-8 As shown in the figure, this invention discloses an electric waveguide switch with a choke structure, comprising two main parts: an electric drive assembly and a microwave switch assembly. The microwave switch assembly mainly includes a microwave rotor and a microwave stator. A curved microwave path 1 is formed inside the microwave rotor, and standard waveguide ports are formed on the microwave stator. The microwave rotor is mounted in the microwave stator via bearings, and there is a radial gap between them. Generally, the length of the radial gap is one-quarter wavelength. Under the drive of the electric drive assembly, the microwave rotor rotates cyclically in the center of the microwave stator. When both ports of the curved microwave path 1 are simultaneously connected to any two standard waveguide ports on the microwave stator, the waveguide switch is in the open state; otherwise, it is in the closed state. A choke structure is formed on the microwave stator to prevent electromagnetic wave leakage between the microwave rotor and the microwave stator.

[0042] like Figure 2 as well as Figures 8-11 As shown, the electric drive assembly includes a drive motor 2 and a housing top cover 3. The drive motor 2 is inverted, with its power output end facing downwards. An extension column 4 is connected to the power output end of the drive motor 2. The specific structure of the extension column is as follows... Figure 12As shown, the extension column 4 passes through the top cover 3 of the housing and enters the recessed cover plate 5. The lower end of the extension column 4 extends into the microwave switch assembly on the lower side of the recessed cover plate 5. The top cover 3 of the housing is fixedly connected to the recessed cover plate 5, and the drive motor 2 is fixedly connected to the top cover 3 of the housing. A motor cover 6 is provided on the outer side of the drive motor 2. After the motor cover 6 is fixedly connected to the top cover 3 of the housing, it forms a receiving space for the drive motor 2.

[0043] like Figure 2 as well as Figure 8 As shown, the top cover 3 of the housing and the grooved cover plate 5 are fixedly connected to form a receiving space for the position sensor 7. The position sensor 7 is located within the receiving space and is in direct contact with the extension column 4, used to sense the rotational position of the extension column 4. The position sensor 7 is a tactile switch, and two tactile switches are provided, located on both sides of the extension column 4 respectively, with the movable end of the tactile switch in direct contact with the extension column 4.

[0044] A vertical limiting post 8 is provided within the housing space of the position sensor. The limiting post 8 is used to ensure that after the microwave rotor is in position, the standard waveguide port of the waveguide path on the microwave rotor is aligned with the standard waveguide port on the microwave stator. An aviation plug mounting hole is formed on one side wall of the grooved cover plate 5. An aviation plug 9 is provided in the aviation plug mounting hole. The drive motor 2 and the position sensor 7 are connected to the aviation plug 9 through wires. The aviation plug 9 is used to connect to an external control device. The specific structure of the aviation plug is as follows. Figure 13 As shown, the specific structure of the tactile switch is as follows: Figure 14 As shown.

[0045] The microwave switching assembly includes a microwave rotor and a microwave stator. The microwave stator includes a microwave cavity 10 and a cavity flange 12. The specific structure of the microwave cavity 10 is as follows: Figure 15 As shown. The microwave cavity 10 has a through hole on its upper and lower end faces, each communicating with the inner cavity. The through hole on the upper end face allows the microwave rotor to enter, while the through hole on the lower end face is sealed by a bottom cover 11. The microwave cavity 10 also has a through hole on its left, right, front, and rear end faces, each communicating with the inner cavity. A sealing ring 14 is provided between the bottom cover 11 on the lower side of the microwave cavity 10 and the microwave cavity 10. The specific structure of the bottom cover 11 is as follows. Figure 17 As shown; a cavity flange 12 is installed in each of the through holes on the front, rear, left, and right end faces of the microwave cavity 10. The specific structure of the cavity flange is as follows. Figure 16As shown; each of the cavity flanges 12 has a standard waveguide interface on its inner and outer sides, and the two standard waveguide interfaces are interconnected; the microwave rotor includes a rotating shaft 13, and two curved microwave paths 1 are formed inside the rotating shaft 13. The rotating shaft 13 rotates cyclically in the center of the microwave cavity under the drive of the drive motor 2. When both ports of the microwave path 1 are simultaneously connected to the standard waveguide interfaces on any two cavity flanges 12, the waveguide switch is in the open state; otherwise, the waveguide switch is in the closed state.

[0046] like Figures 16-18 As shown, the cavity flange 12 includes a first frustum 12-1. A first standard waveguide port 12-2 is formed at the center of the outer surface of the first frustum 12-1. A first rectangular boss 12-3 is formed on the inner surface of the first frustum 12-1. A first cylinder 12-4 is formed on the inner surface of the first rectangular boss 12-3. A second standard waveguide port 12-5 is formed on the first cylinder 12-4 at a position corresponding to the first standard waveguide port 12-2. A straight microwave channel is formed between the first standard waveguide port 12-2 and the second standard waveguide port 12-5. The surface of the first cylinder 12-4 corresponding to the rotating shaft 13 is... The outer surface of the rotating shaft 13 is fitted with an arc-shaped surface, and there is a gap between the arc-shaped surface and the outer surface of the rotating shaft 13. A concave inclined surface 12-6 is formed on the left and right sides of the first cylinder 12-4 of the second standard waveguide port 12-5, so that the second standard waveguide port 12-5 is concave relative to the arc-shaped surface of the first cylinder 12-4. The concave inclined surface 12-6 is the first quarter-wavelength transmission structure. An annular groove 12-7 is formed on the first cylinder 12-4 outside the concave inclined surface 12-6. The annular groove 12-7 is the second quarter-wavelength (generally the quarter-wavelength of the center frequency) transmission structure.

[0047] like Figures 19-23As shown, the rotating shaft 13 includes an upper rotating shaft 13-1 and a lower rotating shaft 13-2. The upper rotating shaft 13-1 and the lower rotating shaft 13-2 are fixed together by screws 15. The upper rotating shaft 13-1 includes a first rotating shaft cylinder 13-1-1. A first insertion post 13-1-2 is fixed on the upper surface of the first rotating shaft cylinder 13-1-1. A bearing 16 is sleeved on the lower middle part of the first insertion post 13-1-2. The lower end of the extension post 4 is inserted into the first insertion post 13-1-2. The end of the connector 13-1-1; the lower half of the rotating shaft 13-2 includes a second rotating shaft cylinder 13-2-1, the lower surface of the second rotating shaft cylinder 13-2-1 is fixed with a second connector 13-2-2, the second connector 13-2-2 is fixed to the microwave cavity 10 by a bearing 16, the upper surface of the second rotating shaft cylinder 13-2-1 forms two microwave paths 1, and the two side ports of the microwave paths 1 are located on the side walls of the second rotating shaft cylinder 13-2-1.

[0048] In this application:

[0049] First quarter-wavelength transmission line: A smooth plane extending outwards from the second standard waveguide port 12-5 is a quarter-wavelength in diameter. When connected to the pivot 13, the concave slope 12-6 portion forms a very thin slit, approximately a quarter-wavelength in length, which forms an effective radial transmission line.

[0050] The second quarter-wavelength transmission line: The other quarter-wavelength transmission line is formed by an axial groove formed by an annular groove 12-7. This transmission line converts the short path at the end of the groove into an open path at the contact point between the extended plane and the structure of the rotating shaft 13.

[0051] Due to the presence of the second quarter-transmission line conversion process, any resistance at the contact point between the extended plane and the rotating shaft 13 will be in series with the infinite open-circuit resistance, so the effect of the contact resistance will become very small.

[0052] Then, the aforementioned infinite resistance is transformed into a short-circuit resistance (extremely small resistance) at the standard waveguide port through the first quarter-wavelength transmission line. This provides an effective low-impedance path for the current passing through the waveguide port, making the transmission of electromagnetic waves in the waveguide almost unaffected and improving the transmission quality of electromagnetic waves.

Claims

1. An electrically powered waveguide switch having a choke structure, characterized by: The microwave switch assembly comprises a microwave rotor and a microwave stator, the microwave rotor is internally formed with a curved microwave passage (1), the microwave stator is formed with standard waveguide ports, the microwave rotor is mounted in the microwave stator through bearings, and a gap is formed between the microwave rotor and the microwave stator; under the driving of the electric drive assembly, the microwave rotor rotates around the center of the microwave stator; when the two ports of the curved microwave passage (1) are connected with any two standard waveguide ports on the microwave stator at the same time, the waveguide switch is in an open state, otherwise, the waveguide switch is in a closed state; the microwave stator is formed with a choke structure, and electromagnetic wave leakage between the microwave rotor and the microwave stator is suppressed through the choke structure. The microwave stator comprises a microwave cavity (10) and a cavity flange (12), and the microwave rotor comprises a rotating shaft (13), and the rotating shaft (13) is internally formed with two curved microwave passages (1). The cavity flange (12) is provided with a first standard waveguide port (12-2), a first cylinder (12-4) and a second standard waveguide port (12-5), a straight-through microwave passage is formed between the first standard waveguide port (12-2) and the second standard waveguide port (12-5); the surface of the first cylinder (12-4) corresponding to the rotating shaft (13) is an arc surface matched with the outer surface of the rotating shaft (13), and a gap is formed between the arc surface and the outer surface of the rotating shaft (13); a recessed inclined surface (12-6) is formed on the first cylinder (12-4) on the left side and the right side of the second standard waveguide port (12-5), so that the second standard waveguide port (12-5) is recessed relative to the arc surface of the first cylinder (12-4), the recessed inclined surface (12-6) is a first quarter wavelength transmission structure, and a circular ring type groove (12-7) is formed on the first cylinder (12-4) outside the recessed inclined surface (12-6), and the circular ring type groove (12-7) is a second quarter wavelength transmission structure.

2. The electrically powered waveguide switch with choke structure of claim 1, wherein: The electric drive assembly comprises a driving motor (2) and a machine shell top cover (3), the driving motor (2) is arranged in an inverted manner, a lengthening column (4) is connected to the power output end of the driving motor (2), the lengthening column (4) passes through the machine shell top cover (3) and enters a groove type cover plate (5), and the lower end of the lengthening column (4) extends into the microwave switch assembly on the lower side of the groove type cover plate (5), the machine shell top cover (3) is fixedly connected with the groove type cover plate (5), and the driving motor (2) is fixedly connected with the machine shell top cover (3).

3. The electrically powered waveguide switch with choke structure of claim 2, wherein: A motor cover (6) is arranged on the outer side of the driving motor (2), and the motor cover (6) and the machine shell top cover (3) form a containing space of the driving motor (2) after being fixedly connected.

4. The electrically powered waveguide switch with choke structure of claim 2, wherein: The shell top cover (3) and the groove type cover plate (5) are fixedly connected to form a position sensor (7) containing space, the position sensor (7) is located in the position sensor containing space, and the position sensor (7) is in direct contact with the extension column (4) and is used for sensing the rotating position of the extension column (4).

5. The electrically powered waveguide switch having a choke structure as recited in claim 4, wherein: A vertical limiting column (8) is arranged in the position sensor containing space, the limiting column (8) is used for ensuring that, after the microwave rotor is in place, the standard waveguide port of the microwave passage (1) on the microwave rotor is aligned with the standard waveguide port on the microwave stator, an aviation plug mounting hole is formed in one side wall of the groove type cover plate (5), an aviation plug (9) is arranged in the aviation plug mounting hole, the driving motor (2) and the position sensor (7) are connected with the aviation plug (9) through wires, and the aviation plug (9) is used for being connected with a peripheral control device.

6. The electrically powered waveguide switch with choke structure of claim 4, wherein: The position sensor (7) is a microswitch, two microswitches are arranged on the two sides of the extension column (4), and the movable end of the microswitch is in direct contact with the extension column (4).

7. The electrically powered waveguide switch with choke structure of claim 2, wherein: The upper and lower end faces of the microwave cavity (10) are each formed with a via hole communicating with the inner cavity, the via hole in the upper end face of the microwave cavity (10) is used for allowing the microwave rotor to enter, the via hole in the lower end face of the microwave cavity (10) is closed through a bottom cover (11), the left, right, front and rear end faces of the microwave cavity (10) are each formed with a via hole communicating with the inner cavity, a cavity flange (12) is arranged in each of the via holes in the front, rear, left and right end faces of the microwave cavity (10), the inner side and the outer side of each cavity flange (12) are each provided with a standard waveguide interface, and the two standard waveguide interfaces are in communication with each other; when the two ports of the microwave passage (1) are connected with the standard waveguide interfaces on any two cavity flanges (12) at the same time, the waveguide switch is in an open state, otherwise the waveguide switch is in a closed state.

8. The electrically powered waveguide switch having a choke structure as recited in claim 7, wherein: A sealing ring (14) is arranged between the bottom cover (11) of the lower side face of the microwave cavity (10) and the microwave cavity (10).

9. The electrically powered waveguide switch having a choke structure as recited in claim 7, wherein: The cavity flange (12) further comprises a first circular table (12-1), a first standard waveguide port (12-2) is formed in the center of the outer surface of the first circular table (12-1), a first rectangular boss (12-3) is formed in the inner surface of the first circular table (12-1), a first cylinder (12-4) is formed in the inner side surface of the first rectangular boss (12-3), and a second standard waveguide port (12-5) is formed in the position of the first cylinder (12-4) corresponding to the first standard waveguide port (12-2).

10. The electrically powered waveguide switch having a choke structure as recited in claim 7, wherein: The rotating shaft (13) comprises an upper half rotating shaft (13-1) and a lower half rotating shaft (13-2), the upper half rotating shaft (13-1) and the lower half rotating shaft (13-2) are fixed together through a screw (15), the upper half rotating shaft (13-1) comprises a first rotating shaft cylinder (13-1-1), the upper surface of the first rotating shaft cylinder (13-1-1) is fixed with a first inserting column (13-1-2), the middle lower part of the first inserting column (13-1-2) is sleeved with a bearing (16), the lower end of the extension column (4) is inserted into the end of the first inserting column (13-1-2); the lower half rotating shaft (13-2) comprises a second rotating shaft cylinder (13-2-1), the lower surface of the second rotating shaft cylinder (13-2-1) is fixed with a second inserting column (13-2-2), the second inserting column (13-2-2) is fixed on the microwave cavity (10) through the bearing (16), the upper surface of the second rotating shaft cylinder (13-2-1) is formed with two microwave channels (1), and the two side ports of the microwave channels (1) are located on the side wall of the second rotating shaft cylinder (13-2-1).

Images