Antenna housing with a composite sandwich structure

Abstract

The present invention discloses an antenna housing with a composite sandwich structure. The present invention comprises a housing for an antenna applied to a medium / long-range ground radar system, constructed as a sandwich structure made of a composite material (CFRP). Accordingly, by utilizing the high specific stiffness of the composite material, the housing itself is made lighter relative to the same stiffness, thereby resolving self-weight deflection and reducing the amount of deformation caused by this by more than 40% compared to metal materials, thereby ensuring the directional precision of the radar beam. Furthermore, the weight of the antenna housing is maintained within 20% of the total weight of the medium / long-range ground radar system, while minimizing the moment of inertia transmitted to the rotary drive unit, and performing overall miniaturization and weight reduction of the radar. At the same time, it satisfies the maximum takeoff weight and center of gravity limit conditions of the aircraft, maximizing transport efficiency to provide rapid strategic deployment capabilities, providing corrosion resistance to the equipment to ensure reliability for the structure of the equipment operated for a long period, controlling the internal temperature by supplying cooling water internally, improving shielding from external high heat, and providing environmental resistance against vibration, shock, temperature, and sunlight.

Description

Technology Field

[0001] The present invention relates to an antenna housing applied to a medium / long-range ground radar system, and more specifically, to an antenna housing with a composite sandwich structure that reduces the weight of the antenna structure and ensures rigidity and shape stability while configuring the antenna housing with a sandwich structure made of a composite material (CFRP; Carbon Fiber Reinforced Plastic). Background Technology

[0003] Generally, antennas applied to medium / long-range ground radar systems are directly exposed to the external environment (e.g., wind load, rainfall, temperature changes, etc.) and are formed as large flat plates or array structures.

[0004] In particular, for large antennas with a total weight of about 4.5 tons and external dimensions of 4m or more, housings based on aluminum alloy (e.g., Al6061) were previously used to ensure structural rigidity.

[0005] However, antenna housings made of aluminum alloy structures were unable to meet aviation requirements (e.g., C-17 allowable weight and center of gravity requirements) due to the weight of the antenna set, and the load on the drive unit increased due to the increased weight of the antenna, which is the driven part. In large structures over 3m in size that must support a heavy weight of 4.5 tons, sagging of the bottom due to self-weight and resulting distortion of the antenna surface occurred, and the low specific stiffness made it vulnerable to vibration during operation, thereby degrading the beam direction precision of the radar. Furthermore, in high-temperature environments such as the Middle East, structural distortion occurred due to the high coefficient of thermal expansion of the metal, causing phase errors between antenna elements and degrading detection performance. Additionally, there were problems such as corrosion issues during long-term use and increased installation and maintenance costs. Prior art literature

[0007] Registered Patent Publication No. 10-2662283 (Published May 3, 2024) Registered Patent Publication No. 10-2794291 (Published April 11, 2025) The problem to be solved

[0008] The problem that the present invention aims to solve is to provide an antenna housing with a composite sandwich structure that can secure the directional precision of a radar beam by utilizing the high specific stiffness of the composite material to lighten the weight of the housing itself compared to the same stiffness, thereby improving the amount of deformation caused by self-weight by more than 40% compared to metal materials. means of solving the problem

[0010] An antenna housing with a composite sandwich structure, which is a means for solving the problem of the present invention, comprises: a core layer having a honeycomb structure made of aluminum material; an outer layer having a multi-stage laminated structure made of a composite material (CFRP) formed on both sides of the core layer; and an adhesive film that bonds the core layer and the outer layer.

[0011] In addition, the core layer is formed with a first thickness, and the outer layer is formed with a second thickness that is thinner than the first thickness.

[0012] In addition, the outer layer is formed by laminating multiple layers of CFRP prepreg.

[0013] In addition, the corner portion of the antenna housing further includes a strength reinforcement layer to provide strength reinforcement due to the unfolding phenomenon of the CFRP prepreg forming a multi-stage laminated structure.

[0014] In addition, the strength reinforcing layer is a resin layer in which resin is filled into the gap formed between the core layer and the outer layer.

[0015] In addition, a flexible core made of aluminum material is formed to replace the core layer on the curvature surface where a flat surface cannot be maintained in the antenna housing, and the outer layer is formed on the flexible core that replaces the core layer.

[0016] In addition, at the corner end where a flat surface cannot be maintained in the antenna housing, the inner and outer layers are formed to overlap from the point where the core layer ends in order to increase the corner strength and prevent unfolding.

[0017] In addition, a conductive paint layer for electromagnetic shielding is formed on the above outer layer. Effects of the invention

[0019] As such, the present invention comprises a housing of an antenna applied to a medium / long-range ground radar system as a sandwich structure made of a composite material (CFRP). By utilizing the high specific stiffness of the composite material, the housing itself is made lighter relative to the same stiffness, thereby resolving self-weight deflection and reducing the amount of deformation caused by this by more than 40% compared to metal materials, thereby ensuring the directional precision of the radar beam. Furthermore, the weight of the antenna housing is maintained within 20% of the total weight of the medium / long-range ground radar system, while minimizing the moment of inertia transmitted to the rotary drive unit, and performing overall miniaturization and weight reduction of the radar. At the same time, it is expected to provide rapid strategic deployment capabilities by maximizing transport efficiency while satisfying the maximum takeoff weight and center of gravity limit conditions of the aircraft, ensure reliability for the structure of the equipment operated for a long period by providing corrosion resistance to the equipment, control the internal temperature by supplying cooling water internally, improve shielding from external high heat, and provide environmental resistance against vibration, shock, temperature, sunlight, etc.

[0020] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0022] FIG. 1 is a schematic perspective view showing the structure of an antenna housing with a composite material sandwich structure applied as an embodiment of the present invention. FIG. 2 is a schematic diagram of the structure of an antenna housing with a composite material sandwich structure applied as an embodiment of the present invention, viewed from the front. FIG. 3 is a schematic side view showing the structure of an antenna housing with a composite material sandwich structure applied as an embodiment of the present invention. FIG. 4 is a cutaway perspective view showing the structure of an antenna housing with a composite material sandwich structure applied as an embodiment of the present invention. FIG. 5 is a schematic detailed view of a laminated cross-section of an antenna housing with a composite sandwich structure applied as an embodiment of the present invention. FIG. 6 is a schematic cross-sectional view along the CC line of FIG. 2 showing an enlarged cross-section of the corner portion as an embodiment of the present invention. FIG. 7 is a schematic cross-sectional view along the GG line of FIG. 3 showing an enlarged cross-section of the corner portion as an embodiment of the present invention. FIG. 8 is a structural diagram showing a state in which a flexible core, an inner layer, and an outer layer are laminated and formed at the curvature-generating surface and the corner end, respectively, as an embodiment of the present invention. Specific details for implementing the invention

[0023] The detailed description of the invention refers to the accompanying drawings, which illustrate specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that various embodiments of the invention are different but need not be mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in relation to one embodiment. It should also be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. Accordingly, the following detailed description is not intended to be limiting, and the scope of the invention is limited only by the appended claims, including all equivalents to those claimed therein, provided appropriately described. Similar reference numerals in the drawings refer to the same or similar functions across various aspects.

[0024] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.

[0025] FIG. 1 is a schematic perspective view showing the structure of an antenna housing with a composite sandwich structure applied as an embodiment of the present invention, FIG. 2 is a schematic front view of the structure of an antenna housing with a composite sandwich structure applied as an embodiment of the present invention, FIG. 3 is a schematic side view showing the structure of an antenna housing with a composite sandwich structure applied as an embodiment of the present invention, FIG. 4 is a cutaway perspective view showing the structure of an antenna housing with a composite sandwich structure applied as an embodiment of the present invention, and FIG. 5 is a schematic detailed view of the laminated cross-section of an antenna housing with a composite sandwich structure applied as an embodiment of the present invention.

[0026] Referring to the attached FIGS. 1 to 5, an antenna housing (100) with a composite material sandwich structure according to an embodiment of the present invention is applied to a medium / long-range ground radar system and includes a core layer (10), an outer skin layer (20), and an adhesive film (30).

[0027] The above core layer (10) is formed of aluminum material in a honeycomb structure with a first thickness (e.g., 25.4 mm).

[0028] The outer layer (20) is formed with a structure in which multi-stage CFRP prepreg (21) with high tensile strength is laminated, and has a second thickness (e.g., 1.6 to 3.2 mm) that is thinner than the first thickness, and can be formed on both sides of the core layer (10).

[0029] That is, the CFRP prepreg (21) forming a multi-layer laminated structure is an 8-layer laminated or 5-layer laminated structure, which can secure a uniform strength of 60.19 GPa when laminated in 11 directions (orthogonal) depending on the lamination direction, and can secure a uniform strength of 62.48 GPa when laminated in 22 directions (radial), and additionally, a conductive paint layer (not shown) for electromagnetic shielding (EMI) can be formed on the outer layer (20).

[0030] Here, when the CFRP prepreg (21) is stacked in an 8-layer cross-layer multi-layer configuration, the stacking angle is set to 0° or 45° to withstand twisting or bending loads. In this case, the outer layer is stacked based on a mold (80) that determines the exposed shape, and when the stacking of the CFRP prepreg (21) on the opposite side is finished with the core layer (10) as the center, it is covered and fixed with a cover (70) called a cowl plate.

[0031] The adhesive film (e.g., AF 163-2K Film) (30) is configured to bond the core layer (10) and the outer layer (20).

[0032] Here, the reason for bonding the core layer (10) and the outer layer (20) with the adhesive film (30) is that the coefficients of thermal expansion according to the applied materials of the core layer (10) and the outer layer (20) are different, and the shear load due to temperature is up to 19.98 MPa, so the adhesive film (30) is intended to have a safety factor of more than twice the strength of 48.26 MPa.

[0033] That is, the adhesive film (30) can maintain a firm adhesive state even with deformation caused by temperature changes of the core layer (10) and the outer layer (20), which have different coefficients of thermal expansion.

[0034] Meanwhile, the antenna housing composed of the core layer (10) and the outer layer (20) may have a flat section and a corner section, and the corner section may further include a strength reinforcing layer (40) to reinforce strength weakening caused by the unfolding phenomenon of the CFRP prepreg (21) forming a multi-stage laminated structure (e.g., about 60 GPa), and the strength reinforcing layer (40) is a resin layer in which resin is filled into a gap (e.g., empty space) formed between the core layer (10) and the outer layer (20), as shown in the attached FIGS. 6 and 7.

[0035] That is, when the antenna housing according to the embodiment of the present invention is composed of a core layer (10) and an outer layer (20), the flat portion is stable with the same thickness due to the multi-layer stacking structure, but the thickness due to the multi-layer stacking structure may not be maintained equally in the core portion where thickness difference and / or curvature occurs, and this is because the CFRP prepreg (21) forming the multi-layer stacking structure in the corner portion of the antenna housing is compressed more than the multi-layer stacking structure in the flat portion, and accordingly, strength reinforcement is achieved through the strength reinforcement layer (40).

[0036] In addition, at the curvature surface where a flat surface cannot be maintained in the antenna housing, a flexible core (50) made of aluminum material is formed to replace the core layer (10) as shown in the attached Fig. 8, and at the corner end where a flat surface cannot be maintained in the antenna housing, the inner layer (60) and the outer layer (20) can be formed to overlap from the point where the core layer (10) ends so as to increase the corner strength and prevent unfolding.

[0037] That is, the outer layer (20), which is formed with a second thickness (e.g., 1.6 to 3.2 mm) as a structure in which multi-stage CFRP prepreg (21) with high tensile strength is laminated, has a strength that is approximately 1.8 times higher than that of a single 3.2 mm skin layer compared to two 1.6 mm skin layers stacked together, so the flexible core (50) and the inner layer (60) are formed to replace the core layer (10) so that the CFRP prepreg (21), which forms a multi-stage laminated structure extending from the flat portion, can be formed as continuously as possible.

[0038] Accordingly, the overall size of the antenna housing (100) according to the embodiment of the present invention, which is composed of the core layer (10), the outer layer (20) and the adhesive film (30), the strength reinforcing layer (40), the flexible core (50) and the inner layer (60), is approximately 4m × 3.2m × 0.8m, the housing weight is approximately 880kg, and the total housing support weight is approximately 4.5ton, so that the ratio of the housing weight (approx. 880kg) to the total housing support weight (approx. 4.5ton) can be maintained at approximately 20% or less, thereby minimizing the moment of inertia transmitted to the rotary drive unit of the medium / long-range ground radar system, as well as enabling the overall miniaturization and weight reduction of the radar.

[0039] That is, the antenna housing (100) according to the embodiment of the present invention can secure the directional precision of the radar beam by utilizing the high specific stiffness of the composite material (CFRP) to reduce the housing's own weight compared to the same stiffness in a large structure of 3m or more that must support a heavy weight of 4.5 tons, thereby improving the deformation amount due to self-weight compared to a metal material (e.g., Al6061) and the resulting distortion of the antenna surface (deformation amount) due to self-weight, as shown in [Table 1] and [Table 2] below, which are comparison tables of deformation amount reduction due to the application of low thermal expansion material.

[0040] [Table 1]

[0041]

[0042] [Table 2]

[0043]

[0044] In addition, the antenna housing (100) according to the embodiment of the present invention utilizes a low density characteristic of 1.55 g / cm³ to satisfy the maximum takeoff weight and center of gravity limit conditions of the C-17 aircraft, and can provide rapid strategic deployment capability by maximizing transport efficiency, as well as provide corrosion resistance to the equipment to ensure long-term reliability for the structure of the equipment operated for more than 15 years, and can increase shielding from external high heat by controlling the internal temperature in a manner that supplies cooling water to the inside.

[0045] Although the technical concept of the antenna housing applying the composite sandwich structure of the present invention has been described above together with the attached drawings, this is merely an illustrative description of the best embodiment of the present invention and does not limit the present invention.

[0046] Accordingly, the present invention is not limited to the specific preferred embodiments described above, and anyone with ordinary knowledge in the art to which the invention pertains can make various modifications without departing from the essence of the invention as claimed in the claims, and such modifications will be within the scope of the claims. Explanation of the symbols

[0048] 10; Core layer 20; Skin layer 21; CFRP prepreg 30; adhesive film 40; Strength reinforcement layer 50; Flexible core 60; inner lining 70; cover 80; Mold plate 100; Antenna housing

Claims

Claim 1 A core layer having a honeycomb structure made of aluminum material; an outer layer having a multi-layered laminated structure made of a composite material (CFRP) formed on both sides of the core layer; and an adhesive film bonding the core layer and the outer layer. An antenna housing with a composite material sandwich structure, comprising: an outer skin layer formed by laminating multi-stage CFRP prepregs; a strength reinforcement layer further comprising, in the corner portion of the antenna housing, a strength reinforcement layer to reinforce strength due to the unfolding phenomenon of the CFRP prepreg forming a multi-stage laminated structure, wherein the strength reinforcement layer is a resin layer in which resin is filled into the gap formed between the core layer and the outer skin layer; a flexible core made of aluminum material is formed to replace the core layer on a surface of curvature where a flat surface cannot be maintained in the antenna housing, and the outer skin layer is configured to be formed on the flexible core replacing the core layer; and at the end of the corner portion where a flat surface cannot be maintained in the antenna housing, the inner skin and the outer skin layer are formed to overlap from the point where the core layer ends to increase the corner portion strength and prevent unfolding, and a conductive paint layer for electromagnetic shielding is formed on the outer skin layer. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete

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