Lightweight ultra-short wave antenna

Abstract

The utility model discloses a kind of lightweight ultra-short wave antennas, it is related to antenna technical field, the antenna includes antenna oscillator by the upper cone and lower cone of relative arrangement, hollow foam support is arranged outside oscillator, the support is composed of upper foam, lower foam and split middle foam, its outer surface is evenly provided with grid-like lightening groove, to reduce weight and reduce the contact area of foam and oscillator. Conical bottom cover is provided at the lower end of antenna oscillator, for plugging bottom and realizing shell smooth transition. The outer cover is formed by layer-by-layer winding epoxy cloth and coating glue curing outside hollow foam and bottom cover, integrally formed and the thickness is only 0.8-1.5 millimeter. Compared with the structure of existing thick-walled epoxy outer cover and overall foaming filling, the utility model significantly reduces the weight of antenna, improves radiation efficiency and bandwidth performance, and improves assembly and maintenance convenience.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology, specifically a lightweight ultra-shortwave antenna. Background Technology

[0002] Ultra-shortwave antennas are widely used in communications, radar, navigation, and other fields. Among them, biconical antennas, as a typical broadband antenna, are widely used due to their wide impedance bandwidth and good omnidirectional radiation performance. Traditional biconical antennas typically consist of two opposing conical or triangular conductors, with broadband matching achieved through intermediate feeding, such as using a coaxial cable. The inner conductor is connected to one cone, and the outer conductor is connected to the other cone, thereby obtaining relatively good electrical performance.

[0003] In existing technologies, biconical antennas are mostly used in the ultra-shortwave band (108–512 MHz), thus their physical size is relatively large. A typical biconical antenna element has a maximum cone diameter of around 300 mm and a height of up to 1300 mm. To achieve good environmental adaptability, the antenna usually requires an epoxy shroud, with a diameter generally not less than 320 mm. Because large cylindrical parts need to maintain high roundness and rigidity, the thickness of existing epoxy shrouds is usually above 3 mm to prevent deformation during use.

[0004] To ensure the stability of the antenna element within the housing, existing technologies typically fill the space between the housing and the element with polyurethane foam. However, this approach has the following drawbacks:

[0005] Heavy weight: The foaming agent completely fills the entire cavity, combined with the thick-walled epoxy outer cover, which greatly increases the overall weight of the antenna, limiting its application in shipborne, airborne and other applications with high lightweight requirements.

[0006] Performance degradation: Since the foaming agent has limited wave transmittance and completely covers the outer wall of the antenna element, its dielectric effect will significantly affect the electrical characteristics of the element, thereby reducing the antenna's radiation efficiency and bandwidth performance.

[0007] Maintenance difficulties: The foaming agent filling method is irreversible. Once the antenna is damaged or its performance degrades, it is difficult to repair and replace the internal vibrator, making use and maintenance inconvenient.

[0008] Patent document KR102144910B1 proposes to coat a foamed layer (porous foam) with a fiberglass reinforced plastic (FRP) layer and add an outer coating to achieve both lightweighting and environmental durability. While this solution achieves some degree of weight reduction in the radome structure, its foam layer is a continuous solid structure and is not designed to accommodate the shape characteristics of the biconical antenna vibrator. Furthermore, it does not consider reducing the contact area between the dielectric and the vibrator through a hollow frame or weight-reduction grooves. Therefore, it still falls short in terms of maintaining electrical performance and further weight reduction.

[0009] In summary, existing biconical antennas suffer from problems such as heavy weight, compromised performance, and poor maintainability in terms of structural and material design. There is an urgent need for a new lightweight design scheme that can ensure the mechanical strength of the antenna, minimize the adverse effects of the medium on electrical performance, and improve the maintainability of the equipment. Utility Model Content

[0010] The technical problem to be solved by this utility model is to overcome the existing defects and provide a lightweight ultra-shortwave antenna. By setting a segmented hollow foam skeleton outside the biconical antenna vibrator and then wrapping and curing epoxy cloth layer by layer to form an extremely thin outer cover, both lightweight and structural stability are achieved, which can effectively solve the problems in the background technology.

[0011] To achieve the above objectives, this utility model provides the following technical solution: a lightweight ultra-shortwave antenna, comprising an antenna element, a perforated foam support, and an outer cover. The antenna element is composed of an upper cone and a lower cone arranged opposite to each other. The outer surface of the perforated foam support has weight-reducing grooves, and the weight-reducing grooves are evenly distributed in a grid-like structure on the outer surface of the perforated foam support. The perforated foam support is fitted onto the outside of the antenna element. The perforated foam support includes an upper perforated foam for wrapping the upper cone, a lower perforated foam for wrapping the lower cone, and a layer located between the two. The antenna features a central perforated foam section. This section is a split structure consisting of two halves, facilitating assembly after the antenna element is installed. Specifically, the central perforated foam is fitted onto the upper cone and the lower cone. After the antenna element is assembled, the two halves of the central perforated foam are pushed between the upper and lower perforated foam sections to complete the assembly. A support rod is provided at the lower end of the antenna element, and a bottom cover is provided between the lower end of the antenna element and the support rod. The bottom cover is conical and is used to seal the bottom and smooth the transition of the outer shell, reducing stress concentration and improving aesthetics.

[0012] Furthermore, it also includes an outer cover, which is formed by wrapping epoxy cloth layer by layer, applying adhesive, and then curing. This outer cover is then applied to the outer surface of the hollowed-out foam support and the bottom cover, forming an integral antenna cover that dries naturally. Since the outer cover does not need to maintain its overall rigidity and roundness, it only needs to ensure surface hardness and impact resistance, resulting in a significant reduction in thickness.

[0013] Furthermore, the thickness of the outer cover is 0.8–1.5 mm.

[0014] Furthermore, the perforated foam support is made of rigid polyurethane foam, PVC foam or pearl cotton foam. The advantage of using rigid foam is that when wrapping the epoxy cloth, the epoxy cloth can be tightened to wrap the perforated foam, ensuring that the surface of the antenna cover is flat and the wrapping is tighter.

[0015] Furthermore, the outer cover is a one-piece molded structure that continuously covers the entire length of the antenna element.

[0016] Furthermore, the top of the upper perforated foam is equipped with a perforated cap, which ensures proper installation when it comes into contact with the upper cone.

[0017] Furthermore, a connector is provided at the lower end of the support rod, and a slot is provided on the lower surface of the connector in the circumferential direction.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] 1. This utility model adopts a hollow foam skeleton support and wraps a thin layer of epoxy cloth on the outside to form an integral molded structure, which avoids the practice of using a lot of thick-walled epoxy outer cover and integral foam filling in traditional biconical antennas; since the foam can provide sufficient support strength by only bearing compressive stress, the outer cover does not need to have overall rigidity and roundness, thus the thickness can be significantly reduced.

[0020] 2. While maintaining the necessary support strength, the perforated foam reduces the area of ​​the medium in direct contact with the antenna element through evenly distributed weight-reducing grooves, avoiding the problems of insufficient transmittance and deteriorated radiation performance caused by the overall encapsulation of traditional foaming agents. This not only improves the radiation efficiency and impedance bandwidth of the antenna, but also reduces the adverse effects of the medium on the electric field distribution, thereby ensuring the stability of electrical performance in the UHF band.

[0021] 3. This utility model divides the perforated foam into three parts: upper, middle, and lower. The middle section is a split structure, which can be pushed in and assembled after the antenna vibrator and the upper and lower foams are in place, making the operation simple. This segmented structure not only facilitates manufacturing and installation, but also avoids the problem of non-removability caused by the traditional foam filling method, so that the antenna can be quickly replaced or repaired when it is damaged or its performance degrades, which greatly improves the maintainability of the equipment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is a schematic diagram of the structure of the present invention with the outer cover removed;

[0024] Figure 3 This is a schematic diagram of the antenna vibrator structure of this utility model.

[0025] In the diagram: 1 slot, 2 connector, 3 support rod, 4 bottom cover, 5 outer cover, 6 weight reduction groove, 7 top cover with holes, 8 upper hollow foam, 9 middle hollow foam, 10 lower hollow foam, 11 upper cone, 12 antenna vibrator, 13 lower cone. Detailed Implementation

[0026] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Example 1

[0027] Please see Figure 1-3 This utility model provides a technical solution: a lightweight ultra-shortwave antenna, including an antenna element 12, a hollow foam support, an outer cover 5, a support rod 3, and a connector 2; the antenna element 12 is composed of an upper cone 11 and a lower cone 13 arranged opposite to each other; in order to reduce the overall weight and reduce the adverse effects of the medium on the antenna's electrical performance, a hollow foam support is provided on the outside of the antenna element 12. The outer surface of the support is provided with uniformly distributed weight-reducing grooves, forming a grid structure, thereby significantly reducing the weight while ensuring the support strength; the hollow foam support is composed of an upper hollow foam 8, a middle hollow foam 9, and a lower hollow foam 10, wherein the upper hollow foam 8 is used to wrap the upper cone 11, the lower hollow foam 10 is used to wrap the lower cone 13, and the middle hollow foam 9 is located between the two; the middle hollow foam 9 is a split structure, composed of two halves, which can be pushed in from both sides after the upper and lower hollow foams are installed, achieving simple assembly.

[0028] A perforated top cover 7 is provided at the top of the upper hollow foam 8. When the top cover 7 abuts against the upper cone 11, it can provide positioning and limiting function to ensure that the installation is in place. The lower end of the antenna vibrator 12 is connected to the support rod 3 through the bottom cover 4. The bottom cover 4 has a conical structure to seal the bottom and achieve a smooth transition of the shell. This not only reduces stress concentration but also improves the aesthetics and streamline of the overall appearance. The lower end of the support rod 3 is connected to the connector 2. The lower surface of the connector 2 has slots 1 evenly distributed in the circumferential direction for firmly installing the antenna on the ship, airborne, or ground platform by bolts or screws.

[0029] To ensure the antenna's environmental adaptability and impact resistance, an outer cover 5 is placed over the outer surface of the perforated foam support and the base 4. The outer cover 5 is formed by wrapping epoxy cloth layer by layer, applying adhesive, and then curing it, resulting in a one-piece structure through natural drying. Since the foam support provides the necessary shape and rigidity, the outer cover 5 does not need to maintain overall rigidity and roundness, but only needs to have surface hardness and impact resistance. Therefore, its thickness is greatly reduced, typically controlled within the range of 0.8–1.5 mm to achieve a balance between lightweight and strength. Compared with traditional outer covers with a thickness of 3 mm or more, this solution significantly reduces weight. The outer cover 5 preferably has a one-piece molding structure, continuously covering the entire length of the antenna element 12, avoiding insufficient strength and water leakage risks caused by splicing seams, thereby further improving sealing and durability.

[0030] The perforated foam support is preferably made of rigid polyurethane foam, PVC foam or pearl cotton foam; these rigid foams can provide reliable support during the outer cover winding process, so that the epoxy cloth can be stretched and adhered to the surface, ensuring that the surface of the outer cover is flat and tightly wrapped after the outer cover is formed; through this design, the overall structural stability and durability of the antenna are improved, and the appearance is also improved.

[0031] Working principle

[0032] The antenna achieves broadband impedance matching and omnidirectional radiation characteristics in the ultra-short band through a biconical vibrator 12; the hollow foam support provides physical support, while the weight-reducing groove reduces the coupling between the dielectric and the electric field, ensuring radiation efficiency and bandwidth performance; the split structure of the hollow foam 9 simplifies the assembly process, facilitating rapid frame assembly after the vibrator is installed; the outer cover 5 provides protection without adding too much weight, ensuring the antenna's reliability in complex environments; the conical structure of the bottom cover 4 effectively disperses stress and improves overall mechanical performance; the connector 2 and its slot 1 provide a stable installation method, ensuring the antenna remains stable under wind loads and vibration conditions.

[0033] This implementation method has the following advantages:

[0034] The overall weight is significantly reduced by using hollowed-out foam support and weight-reducing groove design, while avoiding the adverse effects on electrical performance caused by the complete filling of traditional foaming agents.

[0035] The outer cover 5 has been thinned to 0.8–1.5 mm, which maintains its impact resistance while further improving its lightweight performance, making it particularly suitable for weight-sensitive applications such as shipborne and airborne applications.

[0036] The split-type hollow foam 9 structure enhances the flexibility of installation and maintenance, and the internal vibrator of the antenna can be quickly inspected or replaced.

[0037] The rigid foam frame ensures the quality of the outer casing molding, making its surface smooth and firm, thus improving its appearance and durability.

[0038] The structural design of the base cover 4 and the connector 2 enhances the overall mechanical stability of the antenna and provides a reliable mounting interface.

[0039] In the above scheme, the shape of the weight-reducing groove can be designed as a grid, honeycomb, or strip; the hollow foam 9 can be made of two, three, or more pieces spliced ​​together; the bottom cover 4 can be a conical, arc, or spherical transition structure; the outer cover 5 can be made of fiberglass cloth, carbon fiber cloth, or aramid fiber cloth instead of epoxy cloth, and the curing method can be selected as heat curing or ultraviolet curing process; the plug-in 2 can be designed as a flange type, plug-in type, or multi-hole reinforced structure according to the application scenario; the thickness of the outer cover can also be adjusted between 0.6–2.0 mm according to different environments.

[0040] The manufacturing method of this utility model is as follows: First, an antenna vibrator 12 composed of an upper cone 11 and a lower cone 13 is provided and fixed on a support rod 3. A conical bottom cover 4 is installed at the lower end of the vibrator to seal the bottom and smooth the transition. Then, a perforated foam 8 is fitted onto the outside of the upper cone 11, and a lower perforated foam 10 is fitted onto the outside of the lower cone 13. The two halves of the split perforated foam 9 are then pushed between the upper perforated foam 8 and the lower perforated foam 10, so that the three foam sections fit together to conform to the first contour of the antenna vibrator 12. The outer surfaces of the perforated foams 8, 9, and 10 are uniformly provided with a grid-like weight-reducing structure. The groove is designed to reduce weight and the contact area with the vibrator. Then, epoxy cloth is wrapped layer by layer around the outer surface of the perforated foam and the base cover 4 and coated with epoxy adhesive. During the wrapping process, appropriate tension is maintained to ensure that the outer surface is flat and tightly wrapped. After wrapping to the predetermined thickness, curing treatment is performed. Preferably, the thickness of the outer cover 5 is controlled between 0.8 and 1.5 mm, and finally an integrally molded antenna cover 5 is obtained. The perforated foam can be made of rigid polyurethane foam, PVC foam or pearl cotton foam. The molded outer cover 5 only needs to have surface hardness and impact resistance, thereby achieving the overall lightweighting and electrical performance optimization of the antenna.

[0041] The foregoing has shown and described the basic principles, main features and advantages of this utility model. Various changes and modifications may be made to this utility model without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this utility model as claimed.

Claims

1. A lightweight ultra-shortwave antenna, comprising an antenna element (12), a perforated foam support, and an outer cover (5), characterized in that: The antenna vibrator (12) is composed of an upper cone (11) and a lower cone (13) arranged opposite to each other. The outer surface of the hollow foam support has a weight-reducing groove, and the weight-reducing groove is a grid structure evenly distributed on the outer surface of the hollow foam support. The hollow foam support is sleeved on the outside of the antenna vibrator (12). The hollow foam support includes an upper hollow foam (8) for wrapping the upper cone (11), a lower hollow foam (10) for wrapping the lower cone (13), and a middle hollow foam (9) located between the two. The middle hollow foam (9) is a split structure, consisting of two halves. A support rod (3) is provided at the lower end of the antenna vibrator (12). A bottom cover (4) is provided between the lower end of the antenna vibrator (12) and the support rod (3). The bottom cover (4) is conical.

2. The lightweight ultra-shortwave antenna according to claim 1, characterized in that: It also includes an outer cover (5), which is formed by wrapping epoxy cloth layer by layer, applying adhesive and curing, and covering the outer surface of the hollow foam support and the bottom cover (4).

3. A lightweight ultra-shortwave antenna according to claim 2, characterized in that: The thickness of the outer cover (5) is 0.8–1.5 mm.

4. A lightweight ultra-shortwave antenna according to claim 1, characterized in that: The perforated foam support is made of rigid polyurethane foam, PVC foam, or pearl cotton foam.

5. A lightweight ultra-shortwave antenna according to claim 1, characterized in that: The outer cover (5) is a one-piece molded structure that continuously covers the entire length of the antenna vibrator (12).

6. A lightweight ultra-shortwave antenna according to claim 1, characterized in that: The top of the perforated foam (8) is provided with a perforated top cover (7).

7. A lightweight ultra-shortwave antenna according to claim 1, characterized in that: The lower end of the support rod (3) is provided with a connector (2), and the lower surface of the connector (2) is provided with a slot (1) in the circumferential direction.

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