High-power resonant cavity coupled antenna assembly
By opening through holes on the side walls of the resonant cavity and combining air coaxial waveguides and dielectric coaxial waveguides to form a stepped impedance transformation structure, the problems of resonant cavity side wall flatness and low heat exchange efficiency are solved, and high power capacity and efficient microwave transmission are achieved.
Patent Information
- Application Number
- CN202422963753.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-12-03
AI Technical Summary
The microwave feeding method of the traditional high-frequency metal resonant cavity results in poor flatness of the resonant cavity side wall, low heat exchange efficiency and small power capacity, which cannot meet the high power capacity requirements and has low microwave transmission efficiency.
Electromagnetic waves are transmitted by combining air coaxial waveguides and dielectric coaxial waveguides. Through holes are opened on the side walls of the resonant cavity, and a stepped impedance transformation structure and a fin structure are used to improve heat exchange efficiency and power capacity, and reduce antenna reflection.
The smoothness of the side wall of the resonant cavity and the heat exchange efficiency are improved, the power capacity is increased, and the microwave transmission efficiency and stable working time are improved.
Smart Images
Figure CN223487314U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the microwave field, specifically a high-power resonant cavity coupled antenna assembly. Background Technology
[0002] Traditional high-frequency metal resonant cavities typically employ slot coupling, using waveguides to feed microwave energy into the metal cavity. Due to the increasing demand for commercial low-frequency microwaves, the traditional waveguide feeding method involves directly inserting the antenna into a rectangular waveguide box and connecting the waveguide box directly to the resonant cavity. This necessitates creating a large rectangular opening on the cavity sidewall, significantly impacting its flatness and cleanliness. Furthermore, the aforementioned antenna structure for feeding microwaves into the resonant cavity exhibits poor high-temperature resistance, low heat exchange efficiency, and limited power capacity, failing to meet high-power requirements and consequently reducing microwave transmission efficiency. Utility Model Content
[0003] To address the aforementioned shortcomings in the existing technology, this utility model aims to provide a high-power resonant cavity coupled antenna assembly, thereby reducing the area of the resonant cavity sidewall openings, improving heat exchange efficiency and power capacity, and ultimately enhancing microwave transmission efficiency.
[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A high-power resonant cavity coupled antenna assembly includes an antenna device and a coaxial cable inserted into the antenna device; the antenna device includes an antenna body and a device body, and a disc-shaped fixing base for supporting the device body is fixedly disposed between the antenna body and the device body; the device body includes an outer conductor fixedly disposed on the upper surface of the fixing base, the outer conductor having a hollow structure inside, the hollow structure including, from top to bottom, a cylindrical coarse cavity and a cylindrical dielectric cavity, the coarse cavity containing air, the coarse cavity serving as the air... A coaxial waveguide includes a hollow cylindrical dielectric material fixedly disposed within a dielectric cavity, which has a narrow cavity extending through it. A central hole is provided at the center of a fixed base, the diameter of which is smaller than the outer diameter of the hollow cylindrical dielectric material. The narrow cavity is coaxially arranged with the central hole. Several fixing holes are provided around the central hole for fixing the fixed base to the resonant cavity. The coaxial cable includes a cylindrical inner conductor that can penetrate the hollow structure, the diameter of which is the same as the diameter of the narrow cavity. The lower end of the inner conductor passes through the central hole and is fixedly connected to the antenna body.
[0005] As a limitation of this utility model: the antenna body includes an elongated antenna radiating arm parallel to the fixed base and an elongated antenna balancing arm perpendicular to the fixed base, the antenna radiating arm and the antenna balancing arm are an integral structure; the end of the antenna radiating arm away from the antenna balancing arm is the radiating end, and the upper end of the antenna balancing arm is fixedly connected to the lower surface of the fixed base.
[0006] As a limitation of this utility model: the device body also includes a first metal connector fixedly disposed on the upper end of the outer conductor for detachable connection with a coaxial cable, the outer conductor and the first metal connector having a hollow structure that is internally interconnected, and the axial length of the coarse cavity being greater than the axial length of the first metal connector.
[0007] As a limitation of this utility model: the inner conductor comprises, from top to bottom, an inner conductor body and an inner conductor extension, which are integral structures. The end of the inner conductor extension away from the inner conductor body is vertically and fixedly connected to the antenna radiating arm.
[0008] As a limitation of this utility model: the coaxial cable also includes a filling medium, a metal shielding layer, and an external insulating medium that are fixedly wrapped around the inner conductor body from the inside to the outside. The lengths of the filling medium, the metal shielding layer, and the external insulating medium are all less than the length of the inner conductor body. A second metal connector for detachable connection with the first metal connector is fixedly sleeved at one end of the covering structure composed of the filling medium, the metal shielding layer, and the external insulating medium near the device body.
[0009] As a limitation of this utility model: the coaxial cable is capable of bending, and the coaxial cable also includes a metal retaining shell for wrapping and fixing the bent portion.
[0010] As a limitation of this utility model, screws are used to fix and connect the antenna balance arm and the fixed base, the inner conductor extension and the antenna radiating arm, and the fixed base and the resonant cavity.
[0011] As a limitation of this utility model: a fin structure is fixedly provided on the outer surface of the outer conductor.
[0012] As a limitation of this utility model, a metal coating is fixedly provided between the inner conductor and the hollow cylindrical medium, and between the hollow cylindrical medium and the outer conductor.
[0013] As a limitation of this utility model: the antenna radiating arm, the antenna balancing arm, the inner conductor, and the outer conductor are all made of copper.
[0014] Due to the adoption of the above technical solution, the beneficial effects achieved by this utility model compared with the prior art are as follows: by opening a through hole on the side wall of the resonant cavity for the antenna body to pass through, the rectangular waveguide box is avoided from being directly connected to the side wall of the resonant cavity, the area of the opening on the side wall of the resonant cavity is reduced, and the flatness and neatness of the side wall of the resonant cavity are improved.
[0015] Simultaneously, by utilizing an air coaxial waveguide formed by air within a coarse cavity and a dielectric coaxial waveguide formed by a hollow cylindrical dielectric material, the air coaxial waveguide and the dielectric coaxial waveguide are sequentially connected to the antenna body to jointly transmit electromagnetic waves. This overcomes the problems of low heat exchange efficiency caused by using only air as the dielectric coaxial waveguide and low power capacity caused by using only an insulator as the dielectric coaxial waveguide in traditional methods. Therefore, using both air and dielectric coaxial waveguides not only improves the heat exchange efficiency between the internal and external spaces but also increases the power capacity, thereby improving microwave transmission efficiency.
[0016] Furthermore, by sequentially arranging air coaxial waveguides, dielectric coaxial waveguides, and a fixed base with varying outer diameters, a stepped impedance transformation structure is formed. This helps reduce antenna reflection, increases the antenna's operating bandwidth, and further enhances power capacity. The fin structure fixed to the outer surface of the outer conductor increases the contact area between the outer conductor and the air, further improving the heat exchange efficiency between the inner and outer spaces and extending the overall structure's stable operating time under high-power microwave input. The metal coatings fixed between the inner conductor and the hollow cylindrical dielectric, and between the hollow cylindrical dielectric and the outer conductor, further improve the heat exchange efficiency between the inner and outer spaces. Attached Figure Description
[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0018] Figure 1 This is a schematic diagram of the internal structure of the antenna device and the fixing base according to an embodiment of the present invention;
[0019] Figure 2 This is a three-dimensional structural diagram of the antenna device and the fixing base according to an embodiment of the present utility model;
[0020] Figure 3 This is a schematic diagram of the internal structure of the coaxial cable according to an embodiment of the present invention;
[0021] Figure 4 This is a three-dimensional structural diagram of the coaxial cable according to an embodiment of the present utility model;
[0022] Figure 5 This is a schematic diagram of the internal structure of an embodiment of the present utility model;
[0023] Figure 6 This is a front view of an embodiment of the present utility model;
[0024] Figure 7 The standing wave diagram generated for an embodiment of this utility model.
[0025] In the figure: 1-outer conductor, 2-coarse cavity, 3-fine cavity, 4-hollow cylindrical medium, 5-first metal connector, 6-filling medium, 7-metal shielding layer, 8-external insulating medium, 9-second metal connector, 10-metal fixing shell, 11-fixed base, 12-center hole, 13-fixing hole, 14-antenna radiating arm, 15-antenna balancing arm, 16-inner conductor body, 17-inner conductor extension, 18-fin structure. Detailed Implementation
[0026] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the high-power resonant cavity coupled antenna assembly described herein is a preferred embodiment and is only used for illustration and explanation of the present invention, and does not constitute a limitation thereof.
[0027] The directional terms or positional relationships used in this utility model, such as "up," "down," "left," and "right," are based on the positional relationships in the accompanying drawings of this utility model. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component must have a specific orientation, or that it must be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the content protected by this utility model.
[0028] like Figures 1 to 6 As shown, a high-power resonant cavity coupled antenna assembly includes an antenna device and a coaxial cable inserted into the antenna device. The antenna device includes an antenna body and a device body. A disc-shaped fixing base 11 is fixedly disposed between the antenna body and the device body to support the device body. The upper end of the antenna body and the lower end of the device body are fixedly connected through the fixing base 11.
[0029] The antenna body includes an antenna radiating arm 14 and an antenna balancing arm 15, both of which are elongated copper strip structures. The antenna radiating arm 14 and antenna balancing arm 15 are an integral structure. One end of the antenna radiating arm 14 is perpendicularly fixed to the antenna balancing arm 15, with the radiating arm 14 parallel to the mounting base 11 and the antenna balancing arm 15 perpendicularly fixed to the mounting base 11. The other end of the antenna radiating arm 14 is the radiating end, capable of emitting electromagnetic waves into the resonant cavity. The upper end of the antenna balancing arm 15 is fixedly connected to the lower surface of the mounting base 11 by screws or welding.
[0030] The device body includes an outer conductor 1 fixedly mounted on the upper surface of a fixed base 11. The outer conductor 1 has a hollow structure inside, which includes, from top to bottom, a cylindrical coarse cavity 2 and a cylindrical dielectric cavity. Preferably, the outer conductor 1 is made of copper.
[0031] Furthermore, the device body also includes a first metal connector 5 fixedly mounted on the upper end of the outer conductor 1 for detachable connection with a coaxial cable. The first metal connector 5 is hollow inside, thus creating a hollow structure that communicates with the outer conductor 1. The axial length of the coarse cavity 2 is greater than the axial length of the first metal connector 5.
[0032] A hollow cylindrical medium 4 is fixedly disposed within the dielectric cavity. The hollow cylindrical medium 4 has a narrow cavity 3 penetrating through it. The sum of the axial lengths of the thick cavity 2 and the narrow cavity 3 is the same as the axial length of the hollow structure, allowing the coaxial cable to pass through the device body. The hollow cylindrical medium 4 is an insulating medium, preferably ceramic, which acts as a dielectric coaxial waveguide to improve the heat exchange efficiency between the inner and outer spaces.
[0033] The coaxial cable includes a cylindrical inner conductor that can pass through the hollow structure. The diameter of the inner conductor is the same as the diameter of the thin cavity 3, so that the inner conductor can pass through the thin cavity 3 and the lower end of the inner conductor can be fixedly connected to the antenna body. The inner conductor is preferably made of copper.
[0034] Furthermore, the coaxial cable also includes, from the inside out, a filling medium 6, a metal shielding layer 7, and an outer insulating medium 8, all of the same length and fixedly wrapped around the inner conductor. The lengths of the filling medium 6, the metal shielding layer 7, and the outer insulating medium 8 are all shorter than the length of the inner conductor. This helps protect the inner conductor, located outside the antenna device, from external environmental influences when the inner conductor is inserted into the antenna device. In addition, a second metal connector 9 is fixedly fitted at the end of the covering structure composed of the filling medium 6, the metal shielding layer 7, and the outer insulating medium 8 near the device body for detachable connection with the first metal connector 5. The internal structures of the first metal connector 5 and the second metal connector 9 are mutually compatible. When the two connectors are connected, the coaxial cable and the antenna device can become a single integrated structure.
[0035] When the coaxial cable is long, the inner conductor covered by the aforementioned sheathing structure is bent for use, which helps to reduce the size of the high-power resonant cavity coupled antenna assembly. At the bent portion of the coaxial cable, a metal fixing shell 10 is provided to secure the bent portion. Specifically, one end of the metal fixing shell 10 is fixedly connected to the second metal connector 9, and the other end of the metal fixing shell 10 has an opening through which the coaxial cable can pass. Simultaneously, the interior of the metal fixing shell 10 has a right-angled channel with the same diameter as the outer diameter of the external insulating medium 8, allowing the coaxial cable to pass smoothly through the metal fixing shell 10 and bend.
[0036] Furthermore, a central hole 12 is provided at the center of the fixed base 11, and the central hole 12 is coaxially arranged with the thin cavity 3. The inner conductor passes through the thin cavity 3 from top to bottom and then exits through the central hole 12, thereby being fixedly connected to the antenna body. Since the diameter of the fixed base 11 is larger than the outer diameter of the hollow cylindrical dielectric 4, it is beneficial to form a stepped impedance transformation structure. Several fixing holes 13 are provided on the fixed base 11 around the central hole 12. Screws or other fasteners can be inserted into the fixing holes 13 to fix the fixed base 11 to the side wall of the resonant cavity.
[0037] When the inner conductor is long, it can be processed and fixedly connected in two parts. This improves the overall processing accuracy of the inner conductor, reduces production costs, and facilitates its installation into the antenna device. Specifically, the inner conductor, from top to bottom, includes a separately manufactured inner conductor body 16 and an inner conductor extension 17. The inner conductor body 16 extends from below the second metal connector 9 and is fixedly connected to the upper end of the inner conductor extension 17. The lengths of the filling medium 6, the metal shielding layer 7, and the external insulating medium 8 are all shorter than the length of the inner conductor body 16. The fixed connection between the inner conductor body 16 and the inner conductor extension 17 can be welding or threaded, thereby reducing the processing difficulty of the inner conductor and connecting the inner conductor body 16 and the inner conductor extension 17 into a single structure.
[0038] The end of the inner conductor extension 17 furthest from the inner conductor body 16 passes through the hollow structure inside the outer conductor 1 and is vertically fixedly connected to the antenna radiating arm 14. Because the inner conductor extension 17 extends the length of the inner conductor, the risk of insulation breakdown is reduced during high-power microwave input. The fixed connection between the inner conductor extension 17 and the antenna radiating arm 14 is achieved by screws or welding to ensure that the lower end of the inner conductor extension 17 is tightly attached to the surface of the antenna radiating arm 14.
[0039] A fin structure 18 is fixedly provided on the outer surface of the outer conductor 1, which increases the contact area between the outer conductor 1 and the air, thereby improving the heat exchange efficiency and increasing the stable operating time of the overall structure under high-power microwave input. At the same time, metal coatings are fixedly provided between the inner conductor and the hollow cylindrical medium 4, and between the hollow cylindrical medium 4 and the outer conductor 1, to fill the gaps between them, thereby further improving the heat exchange efficiency.
[0040] In this embodiment, the air contained in the coarse cavity 2 can serve as an air coaxial waveguide to directionally guide electromagnetic waves. Simultaneously, the hollow cylindrical dielectric 4, made of an insulating material such as ceramic, can serve as a dielectric coaxial waveguide to further directionally guide electromagnetic waves. This method of using both air and dielectric coaxial waveguides to transmit electromagnetic waves simultaneously solves the technical problems of low heat exchange efficiency caused by using only air as the dielectric coaxial waveguide and low power capacity caused by using only an insulating dielectric coaxial waveguide in traditional methods. Therefore, the method of simultaneously using air and dielectric coaxial waveguides not only improves the heat exchange efficiency of the internal and external spaces but also increases the power capacity, thereby improving microwave transmission efficiency.
[0041] The air coaxial waveguide, dielectric coaxial waveguide, and fixed base 11 arranged sequentially from top to bottom form a stepped impedance transformation structure, which helps to reduce antenna reflection, improve the antenna operating bandwidth, and further improve the power capacity.
[0042] When using a high-power resonant cavity coupled antenna assembly with the above structure, the antenna device and coaxial cable are assembled together. A through-hole for inserting the antenna is opened in the cavity wall, allowing the assembly to pass through from inside the cavity to outside. The fixing base 11 is fixed to the inner side wall of the resonant cavity using screws. The end of the coaxial cable furthest from the antenna device is connected to the microwave source, completing the antenna installation. Microwaves sequentially pass through an air coaxial waveguide, a dielectric coaxial waveguide, and the antenna before being fed into the resonant cavity. Reflection on the inner wall of the resonant cavity excites the desired resonant frequency and mode. Figure 7 As shown in the standing wave diagram generated in a certain resonant cavity, the optimal reflection point is 915MHz, the return loss is about 33dB, and the power transmission efficiency can reach 99%, which has a high microwave utilization rate.
Claims
1. A high-power resonant cavity coupled antenna assembly, characterized in that: This includes the antenna assembly and the coaxial cable inserted within the antenna assembly; The antenna device includes an antenna body and a device body, with a disc-shaped fixing base fixedly disposed between the antenna body and the device body to support the device body. The device body includes an outer conductor fixedly mounted on the upper surface of a fixed base. The outer conductor has a hollow structure inside. The hollow structure includes, from top to bottom, a cylindrical coarse cavity and a cylindrical dielectric cavity. The coarse cavity contains air and serves as an air coaxial waveguide. A hollow cylindrical dielectric serving as a dielectric coaxial waveguide is fixedly mounted in the dielectric cavity. The hollow cylindrical dielectric has a thin cavity penetrating through it. A central hole is provided at the center of the fixed base. The diameter of the central hole is smaller than the outer diameter of the hollow cylindrical medium. The thin cavity is coaxially arranged with the central hole. Several fixing holes are provided around the central hole for fixing the fixed base to the resonant cavity. The coaxial cable includes a cylindrical inner conductor that can pass through the hollow structure. The diameter of the inner conductor is the same as the diameter of the cavity. The lower end of the inner conductor passes through the central hole and is fixedly connected to the antenna body.
2. The high-power resonant cavity coupled antenna assembly according to claim 1, characterized in that: The antenna body includes a long strip antenna radiating arm parallel to the fixed base and a long strip antenna balancing arm perpendicular to the fixed base. The antenna radiating arm and the antenna balancing arm are an integral structure. The end of the antenna radiating arm furthest from the antenna balance arm is the radiating end, and the upper end of the antenna balance arm is fixedly connected to the lower surface of the fixed base.
3. The high-power resonant cavity coupled antenna assembly according to claim 2, characterized in that: The device body also includes a first metal connector fixedly mounted on the upper end of the outer conductor for detachable connection with a coaxial cable. The outer conductor and the first metal connector have a hollow structure that is internally interconnected, and the axial length of the bulky cavity is greater than the axial length of the first metal connector.
4. The high-power resonant cavity coupled antenna assembly according to claim 3, characterized in that: The inner conductor consists of an inner conductor body and an inner conductor extension, which are integral structures. The end of the inner conductor extension away from the inner conductor body is fixedly connected to the antenna radiating arm perpendicularly.
5. The high-power resonant cavity coupled antenna assembly according to claim 4, characterized in that: Coaxial cables also include, from the inside out, a filling medium, a metal shielding layer, and an outer insulating medium, which are fixedly wrapped around the inner conductor body. The lengths of the filling medium, the metal shielding layer, and the outer insulating medium are all less than the length of the inner conductor body. The encapsulation structure, consisting of a filling medium, a metal shielding layer, and an external insulating medium, has a second metal connector fixedly fitted at one end near the device body for detachable connection with the first metal connector.
6. The high-power resonant cavity coupled antenna assembly according to claim 5, characterized in that: Coaxial cables can be bent, and coaxial cables also include a metal retaining shell for wrapping and securing the bent portion.
7. The high-power resonant cavity coupled antenna assembly according to claim 6, characterized in that: The antenna balance arm is fixedly connected to the base, the inner conductor extension is fixed to the antenna radiating arm, and the base is fixed to the resonant cavity.
8. The high-power resonant cavity coupled antenna assembly according to any one of claims 1 to 7, characterized in that: A fin structure is fixedly installed on the outer surface of the outer conductor.
9. The high-power resonant cavity coupled antenna assembly according to claim 8, characterized in that: Metal coatings are fixedly installed between the inner conductor and the hollow cylindrical dielectric, and between the hollow cylindrical dielectric and the outer conductor.
10. The high-power resonant cavity coupled antenna assembly according to claim 9, characterized in that: The antenna radiating arm, antenna balancing arm, inner conductor, and outer conductor are all made of copper.