KR101752299B1 - Structure with Radome for RCS reduction - Google Patents

Abstract

A radar cross section reduction structure of a radome type according to the present invention is a radar cross section reduction structure of a radar cross section which is formed in a first shape in a front region in which electromagnetic waves are incident and in a rear region corresponding to a rear region of the front region, (Low Probability of Intercept, LPI) structual part; And a radome formed on the outside of the first shape to protect at least the first shape of the gingham structure, wherein a foremost point of the first shape formed in the front region is a spinode shape And the aerodynamic characteristics of the airfoil can be maintained while the shape of the front region is optimized to the low-pitched structure.

Description

Radome-based RCS reduction structure {Structure with Radome for RCS reduction}

The present invention relates to a radar cross section (RCS) reduction structure of a radome type. More particularly, the present invention relates to a method of designing an RCS reduction structure using a radome method in a leading edge area of a stealth structure.

The Low Observable (LO) weapon system uses a method of reducing the radar cross section (RCS) through external shape design to minimize the exposure to the enemy radar network. In order to effectively implement the stealth technology, it has a generally sharp shape. In order to easily control the angle of the reflected wave, Rather than flat.

However, the design of such a method conflicts with the implementation of other performance of the weapon system. For example, in the case of an aircraft, aerodynamic characteristics of flight are a crucial factor in its operation. However, there is a problem that the gypsum fleet is designed to give up some flight characteristics instead of improving the low fleet performance by adopting a sharp airfoil.

Therefore, a problem to be solved by the present invention is to propose a RCS reduction structure using a radome method in a leading edge region of a stealth structure.

According to an aspect of the present invention, there is provided a radar cross section reduction structure for a radar system, the radar cross section reduction structure having a first shape in a front region in which electromagnetic waves are incident and a rear region corresponding to a rear region of the front region, A low observeable (LO) structural part formed in a second shape; And a radome formed on the outside of the first shape to protect at least the first shape of the gingham structure, wherein a foremost point of the first shape formed in the front region is a spinode shape And the aerodynamic characteristics of the airfoil can be maintained while the shape of the front region is optimized to the low-pitched structure.

In one embodiment, the first shape is formed in a multi-dimensional curved shape from the apex to the boundary region with the second shape so that the incident electromagnetic wave reflects to the non-hazardous area.

In one embodiment, the inner and outer sides of the radome are positioned with a low dielectric loss composite material layer to transmit the incident electromagnetic wave at a target frequency, And may be formed of an air form or a honeycomb so that the material layer can be attached or fixed.

In one embodiment, the first shape is a downward convex multi-dimensional curved shape, and the shape of the radome is a convex multi-dimensional curved shape for optimizing aerodynamic characteristics of the airfoil.

In one embodiment, the first shape and the radome may include a radio wave absorber configured to absorb the incident electromagnetic waves so as to reduce the RCS.

The RCS reduction structure using the radome method according to the present invention is advantageous in that the aerodynamic characteristics of the airfoil can be maintained while optimizing the shape of the front region to the low-pitched structure.

In addition, the RCS reduction structure using the radome method according to the present invention can improve the low-pitched performance by arranging the electromagnetic wave absorber in the radome and the low-fat tread structure while designing the radome and the low- .

On the other hand, the GFVs sharpen the outer shape to achieve excellent stealth performance, while some flight performance deteriorates. When looking at the operational environment of the aircraft, proper maneuverability and aerodynamic characteristics should be secured. As a result, the gypsum fleet generally has many limitations in its operating environment. If the present invention is applied in such a situation, there is an advantage that not only the stealth performance but also the required flight performance can be satisfied.

Fig. 1 shows a radome-type RCS reduction structure in an airfoil shape according to the present invention.
FIG. 2 shows a side view and a cross-sectional view of the RCS reduction structure of the surveillance system according to the present invention.
FIG. 3 shows a simulation result of a method of designing a radome-type lid according to the present invention and a radome-type lid.
Figure 4 illustrates different types of RCS abatement structures in accordance with the present invention.
5 shows a simulation result of an RCS value according to an elevation angle change for different types of RCS reduction structures in FIG.
6 is a conceptual diagram for parameter optimization of an internal structural shape of an RCS reduction structure according to an embodiment of the present invention.
FIG. 7 illustrates an internal structure having different parameters in an RCS reduction structure according to an embodiment of the present invention.
FIG. 8 shows the RCS simulation result according to the change of the internal structure shape having different parameters according to FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It will be possible. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

The suffix "module "," block ", and "part" for components used in the following description are given or mixed in consideration of ease of specification only and do not have their own distinct meanings or roles .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, a radar cross section reduction structure of a radome type according to the present invention will be described. In this regard, Fig. 1 shows a radome-based RCS reduction structure in an airfoil configuration according to the invention. 2 is a side view and a cross-sectional view of the RCS reduction structure of the surveillance system according to the present invention.

In one embodiment of the present invention, an application to a shape for forward RCS reduction in an airfoil applied to an aircraft is shown. RCS reduction effect can be expected by changing the shape of the airfoil up to 25% of the cord length which has a major influence on the forward RCS. Referring to Fig. 1, the outline curve in the cross-sectional shape is the shape of the airfoil. That is, according to the present invention, as shown in FIG. 1 and FIG. 2, in a perfect electric conductor (PEC), a lid portion for designing a low profile structure (structure) and aligning the outermost shape (OML) It is a concept to mount.

On the other hand, FIG. 2 relates to the entire shape (left) and the sectional shape (right) in which the sandwich radome structure is mounted in front of the airfoil. The curved lid portion mounted on the front is a part for implementing the outermost shape for aerodynamic characteristics of the airfoil and also transmits an electromagnetic wave having a specific frequency incident from the outside. Transmitted electromagnetic waves are reflected or scattered into non-hazardous areas by a fully electrical conductor (PEC) implemented inside.

As described above, this radome-type RCS abatement structure can be referred to as an airfoil front structure. Referring to FIGS. 1 and 2, a radome-based RCS reduction structure includes a Low Probability of Intercept (LPI) structure 100 and a radome 200. The RCS reduction structure may further include a spatial region 300 between the radiopaque structure 100 and the radome 200. Meanwhile, a microwave absorber may be disposed in the space region 300.

The low-fat-comb structure 100 is formed in a first shape in a front region where electromagnetic waves are incident, and a second shape in a rear region corresponding to a rear region of the front region. On the other hand, the foremost point of the first shape formed in the front region may be in the form of a spinode. In addition, the first shape may be formed in a multi-dimensional curved shape from the apex to the boundary region with the second shape so that the incident electromagnetic wave is reflected to the non-hazardous area.

A radome (200) is formed on the outside of the first shape to protect at least the first shape of the gingham structure (100). Also, the first shape may be a downward convex multi-dimensional curved shape, and the shape of the radome 200 may be a convex multi-dimensional curved shape for optimizing aerodynamic characteristics of the airfoil. And a microwave absorber configured to absorb the incident electromagnetic waves so that the RCS is reduced in the space region 300 between the first shape and the radome 200. [

The above-described low-frequency structure 100, the radome 200 and the spatial region 300 of the RCS reduction structure will be described in more detail as follows.

As a method for realizing the technology related to the radar cross section reduction structure of the radome, there is a method of implementing the low-energy tomography that scatters the wave incident from the front most effectively into the non-hazardous area do. Here, the dangerous area refers to the forward angular area when considering the environment during flight. The leading edge area ahead of the airfoil shape of the blade functions to transmit the electromagnetic wave in the target frequency area and is provided with a cover structure for expressing the outermost curve shape of the airfoil. On the inner side, a perfect electric conductor (PEC) structure capable of scattering electromagnetic waves more effectively in a non-hazardous area is disposed, and a forward RCS reduction effect is realized by the shape in which the electromagnetic wave transmitted from the cover is arranged on the inner side .

In this specification, as an embodiment, a method of implementing the above technique using a radome cover configured as a sandwich type is introduced. The radome 200 generally transmits electromagnetic waves with respect to frequency, reflects the unwanted frequency band when necessary, and also protects the internal equipment from the external environment. Here, the radome 200 may be configured in various forms. May be designed as a single layer with low dielectric loss and may be designed as a sandwich type as in one embodiment. It can be designed differently depending on the operating conditions of the object. In the sandwich type radome 200 of this embodiment, a foam material having a very low permittivity and a loss rate is placed in the core portion, and a low dielectric loss composite material is placed on skins on both sides. At this time, the thickness of the sandwich type radome can be determined according to the target frequency band and the permittivity of the material used.

Meanwhile, FIG. 3 shows a simulation result of a method of designing a radome-type lid according to the present invention and a performance of a radome-type lid. Referring to FIG. 3, a low dielectric loss composite material layer 210, 220 is disposed on the inner and outer surfaces of the radome 200 to transmit the electromagnetic waves incident on the target frequency. do. The radome 200 is formed of an air form 230 or a honeycomb 230 so that the low dielectric loss composite material layers 210 and 220 can be attached or fixed. can do.

On the other hand, the design of the radome 200 corresponding to the lid portion is determined according to the target frequency. Various designs are possible depending on the target frequency and the materials used. Embodiments of the present patent are constructed to minimize transmission of incident electromagnetic waves at the target frequency and loss in the outer lid portion. FIG. 3 shows the basic modeling for the A-sandwich type and shows the electromagnetic wave transmission performance thereof. At this time, the radome type cover may be designed as a sandwich type as shown in FIG. 2, or an additional functional material may be used. On the other hand, a single shell or a laminated shell type can be designed for a structural role. On the other hand, in all of these cases, the concept of the design of the radome 200 for low-loss transmission in the target frequency band is applied equally.

Meanwhile, the radome 200 is constructed so as to be able to express the outer shape of the airfoil applied to the air vehicle, and is positioned on the front lid part, and the above-mentioned low-fat tread structure 100 is positioned inside. A space region 300 corresponding to a vacant space exists between the low-fat tomestructure 100 and the radome 200 corresponding to the front lid. The space region 300 may be filled with electromagnetic wave absorbers for additional electromagnetic wave absorption, or may be provided as an empty space for electromagnetic performance.

Here, the electromagnetic wave incident from the front is transmitted through the radome 200 corresponding to the cover portion, and the transmitted electromagnetic wave does not return to the direction in which the electromagnetic wave is incident by the inwardly positioned gimp structure 100, Reflected or scattered. Thus, the forward RCS of the structure can be reduced. Further, since the outer shape is determined by the lid portion, it is possible to improve the flying performance of the structure by mounting the airfoil-shaped lid portion considering aerodynamic characteristics.

 The design method of this patent should be regarded as a method that can be applied not only to the airfoil shape but also to the weapon systems in which both the hydrodynamic (or aerodynamic) performance and the low-fat performance are required.

The RCS reducing structure according to the present invention has been described above. Next, a simulation result according to the radome-based RCS reduction structure according to the present invention will be described.

Figure 4 illustrates different types of RCS abatement structures in accordance with the present invention. Meanwhile, FIG. 5 shows a simulation result of an RCS value according to an elevation angle change for different types of RCS reduction structures in FIG.

4, the round shape in the front (front) region forms a vertical reflecting surface with respect to the electromagnetic wave incident from the outside, and thus has a high RCS value in a dangerous region (for example, front (front region) . Therefore, it is necessary to propose a new internal shape that is not a round shape in the front (front) area, and check the effect on it through simulation.

Referring to FIG. 4, Case A, Case B, and Case C correspond to cases where first shapes are different in a front region where electromagnetic waves are incident. In Case A, Case B, and Case C, the foremost point of the first shape is in the form of a spinode. Case A and Case C are formed in a multi-dimensional curved shape from the cusp to the boundary region with the second shape of the rear region. In Case B, the first shape is formed in a straight line from the apex to the boundary region with the second shape.

In Case A, in the case A, the first shape is curved upward from the apex to a certain point, and the shape from the certain point to the boundary is convex downward.

On the other hand, in Case C, the first shape from the apex to the boundary region has a shape of a downward convex multi-dimensional curved shape.

Referring to FIG. 5, the RCS value is simulated while changing the elevation angle of the forward reference of the RCS reduction structure corresponding to the object. It is analytically confirmed that the shape of the case C (the shape of the multi-dimensional curve in which the first shape is convex downward to the boundary region with the second shape of the rear region from the cusp) shows the lowest RCS (the best performance) .

6 is a conceptual diagram for parameter optimization of an internal structural shape of the RCS reduction structure according to an embodiment of the present invention. Referring to FIG. 6, it can be seen that, in the front shape section, the shape has a convex downward convex shape, and has a convex shape as it goes backward with respect to any inflection point between the shape sections. In the modified shape transition section, And smoothly connected. When the length of the front shape section is denoted by s, the first point and the second point, which are arbitrary points in the front shape section, can be selected. The distance (xp1 * s) from the apex to the first point and the distance (xp2 * s) from the apex to the second point may be expressed as a function of the length (s) of the front shape section, Here, a relation of 0 < xp1 < xp2 < 1 is established. Any inflection point expressed in the above may be located between the first point and the second point. Also, in the height relationship, it can be defined by the height (yp1 * h) of the first point and the height (yp2 * h) of the second point as a function of the length h of the front surface shape section, yp1 < yp2 < 1.

On the other hand, in order to determine the shape of the hypothetical tomographic structure, a study model can be formed by defining a spline as a parameter as shown in FIG. 6 so as to form a smooth curve with respect to several points. On the other hand, the shape of the curve can also be defined as a polynomial equation.

Meanwhile, FIG. 7 shows an internal structure having different parameters in the RCS reduction structure according to an embodiment of the present invention. In Case C-1, C-2, and C-3, the first shape is convex downward, but Case C-2 has the longest cusp section, and thus the slope of the curve increases the greatest. Or Case C-2 has the longest cusp section, so that the thickness of the cusp structure at the boundary of the changed shape transition section can be made the thinnest.

Meanwhile, FIG. 8 shows the RCS simulation result according to the change of the internal structure shape having different parameters according to FIG. As shown in FIG. 8, it can be seen that the RCS value does not show a large difference even if the inner structure is changed according to different parameters in the downwardly convex hollow structure. Therefore, depending on the application, it is possible to optimize the downward convex curve-shaped parameter to minimize the RCS value.

Also, if the first shape corresponding to the front (front) region is a downwardly convex curve shape, the fact that the RCS value does not show a large difference even if the internal structure is changed according to different parameters means that the sensitivity It means small. It can be seen that the downward convex curved low-fat tread structure with low sensitivity due to such design or manufacturing errors is very useful as the RCS reduction structure.

The RCS reduction structure using the radome method according to the present invention is advantageous in that the aerodynamic characteristics of the airfoil can be maintained while optimizing the shape of the front region to the low-pitched structure.

In addition, the RCS reduction structure using the radome method according to the present invention can improve the low-pitched performance by arranging the electromagnetic wave absorber in the radome and the low-fat tread structure while designing the radome and the low- .

On the other hand, the GFVs sharpen the outer shape to achieve excellent stealth performance, while some flight performance deteriorates. When looking at the operational environment of the aircraft, proper maneuverability and aerodynamic characteristics should be secured. As a result, the gypsum fleet generally has many limitations in its operating environment. If the present invention is applied in such a situation, there is an advantage that not only the stealth performance but also the required flight performance can be satisfied.

According to a software implementation, not only the procedures and functions described herein, but also each component may be implemented as a separate software module. Each of the software modules may perform one or more functions and operations of a software module that designs the Radar Cross Section (RCS) mitigation architecture of the radome type described herein. Software code can be implemented in a software application written in a suitable programming language. The software code is stored in a memory and can be executed by a controller or a processor.

100: Hippie Tomom structure 200: Radome
210, 200: low dielectric loss composite layer 230: air foam, honeycomb
300: space area

Claims (6)

In a radar cross section reduction structure of a radome type,
A low profile structure part formed in a first shape in a front area where electromagnetic waves are incident and a second shape in a rear area corresponding to a rear area of the front area; And
And a radome formed on the outside of the first shape to protect at least the first shape of the low-
And wherein the forefront point of the first shape formed in the front region is in the form of a spinode. The method according to claim 1,
Wherein the first shape is formed in a multi-dimensional curved shape from the apex to a boundary region with the second shape so that the incident electromagnetic wave is reflected to a non-hazardous area. The method according to claim 1,
And the second point of the second shape is in the form of a cusp. The method according to claim 1,
A low dielectric loss composite material layer is disposed on the inner and outer surfaces of the radome to transmit the incident electromagnetic waves at a target frequency.
Wherein the radome is formed of an air form or a honeycomb so that the low dielectric loss composite material layer can be attached or fixed. 3. The method of claim 2,
Wherein the first shape is a shape of a downward convex multidimensional curve shape,
Wherein the shape of the radome is a convex multidimensional curve shape for optimizing aerodynamic characteristics of the airfoil. 5. The method of claim 4,
And a radio wave absorber configured to absorb the electromagnetic waves incident thereon such that the RCS is reduced between the first shape and the radome.

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