Hybrid unit low RCS array antenna

Abstract

The invention discloses a hybrid unit low RCS array antenna, and relates to the antenna technology, the hybrid unit low RCS array antenna comprises a radiation disc which is a metal plate with a set specification, the surface of one side of the radiation disc is provided with array type grooves, the specifications of the grooves are the same, the shape of the grooves is similar to that of the radiation disc, and the surface of the other side of the radiation disc is a feed network of the array antenna; the number of the micro-strip antennas is consistent with that of the grooves, the sizes of the micro-strip antennas are matched with those of the grooves, and any micro-strip antenna is embedded into the corresponding groove; the shapes of the upper radiation metal patches of any microstrip antenna are not completely the same. According to the array antenna provided by the embodiment of the invention, the upper-layer radiation metal patch of each microstrip antenna has different shapes and can generate scattered waves with different amplitude-phase characteristics, and the scattered waves are superposed and counteracted in the space, so that the RCS value of the array antenna in a broadband range is reduced under the condition that the radiation performance is not changed.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and particularly to a hybrid element low-RCS array antenna. Background Art

[0002] Stealth technology generally refers to radar stealth technology, which mainly reduces the RCS (Radar Cross Section) value of a target through means such as ingenious design of the structure and shape or coating with radar-absorbing materials, thereby changing the signal characteristics of the echo of the detected radar wave and shortening the detection range of the detecting radar. As one of the key components of a radio electronic system, an antenna is an important device for converting radio frequency signals in the radio electronic system into electromagnetic waves in free space. Compared with an independent antenna element, an array antenna composed of multiple antenna elements according to a specific rule has better directivity and higher gain, and can control the maximum pointing direction of the array antenna beam by mechanically rotating the radiation aperture of the array antenna or the transmitting and receiving components, so as to achieve purposes such as long-distance scanning, tracking, and high-quality communication.

[0003] An array antenna is generally composed of multiple unit antennas according to a certain arrangement rule, and a corresponding feeding network can be configured to achieve specific beam requirements. Usually, in order to achieve higher gain, the unit antennas that make up the array antenna are completely the same, and the radiation amplitude-phase characteristics of each unit antenna are also the same, so as to realize the in-phase superposition of the radiation waves in space to achieve high gain. The same unit antenna generates scattered waves with the same amplitude-phase characteristics due to its completely identical radiator structure, and forms a peak scattered beam by in-phase superposition in space, resulting in a large RCS value of the array antenna and poor stealth performance. Therefore, the application range of traditional array antennas is greatly limited on platforms with high stealth requirements (such as stealth aircraft, stealth ships, etc.). Summary of the Invention

[0004] The embodiments of this application provide a hybrid element low-RCS array antenna, which realizes reducing the RCS value of the array antenna in a wide frequency band range without changing the radiation performance.

[0005] The embodiments of this application provide a hybrid element low-RCS array antenna, including:

[0006] A radiation disk, which is a metal plate of a set specification. An array of grooves is provided on one surface of the radiation disk, and the grooves have the same specification and a shape similar to that of the radiation disk. The other surface of the radiation disk is the feeding network of the array antenna;

[0007] A plurality of microstrip antennas, the number of the microstrip antennas is the same as the number of the grooves, and the size is adapted to the grooves. Any microstrip antenna is embedded in the corresponding groove;

[0008] The outer shapes of the upper radiation metal patches of any microstrip antenna are not completely the same.

[0009] Each upper radiation metal patch of the array antenna in the embodiment of the present application has a different outer shape. Metal patches with different outer shapes will generate scattered waves with different amplitude-phase characteristics and superimpose and cancel each other in space, realizing the reduction of the RCS value of the array antenna within the frequency band without changing the radiation performance.

[0010] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically given below. Description of the Drawings

[0011] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0012] Figure 1 Schematic diagram of the basic structure of the hybrid unit low-RCS array antenna according to the embodiment of the present application;

[0013] Figure 2 Schematic diagram of the specifications of the hybrid unit low-RCS array antenna according to the embodiment of the present application;

[0014] Figure 3 Schematic diagram of an application specification of the hybrid unit low-RCS array antenna according to the embodiment of the present application;

[0015] Figure 4 Simulation results of the return loss (S11) parameters of 4 microstrip antenna units in the application example of the present application;

[0016] Figure 5 Simulation results of the gain pattern of 4 microstrip antenna units at 4.3 GHz in the application example of the present application;

[0017] Figure 6 When the application example of the present application is installed on an analog stealth aircraft carrier, and the radar detection wave frequency irradiates the antenna in the form of grazing incidence at frequencies of 2 GHz, 10 GHz, and 18 GHz respectively, with the azimuth angle being [-90°, +90°] and the elevation angle being 0°, the RCS simulation curve of the antenna;

[0018] Figure 7 Comparison of the gain patterns between the hybrid unit low-RCS array antenna and the conventional 4-element rectangular radiation metal patch in the application example of the present application;

[0019] Figure 8 In the application example of this application, the radar detection wave frequencies irradiate the antenna in the form of grazing incidence with different frequencies, an azimuth angle of 0°, and an elevation angle of 0°. The RCS simulation curves of the hybrid unit low-RCS array antenna and the conventional 4-element rectangular patch array antenna are compared. Specific Embodiments

[0020] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0021] An embodiment of this application provides a hybrid unit low-RCS array antenna, as Figure 1 shown, including:

[0022] A radiation disk 1, which is a metal plate of a set specification. An array of grooves is provided on one surface of the radiation disk 1, and the grooves have the same specification and an outer shape similar to that of the radiation disk 1. The other surface of the radiation disk 1 is the feeding network of the array antenna;

[0023] A plurality of microstrip antennas, the number of the microstrip antennas is the same as the number of the grooves, and the size is adapted to the grooves. Any one of the microstrip antennas is embedded in the corresponding groove;

[0024] The outer shapes of the upper radiation metal patches of any one of the microstrip antennas are not completely the same.

[0025] In some embodiments, the radiation disk 1 is a rhombic metal plate, and the acute interior angle φ of the rhombic metal plate satisfies 70° ≤ φ ≤ 80°;

[0026] The groove is also rhombic, the depth of the groove is h, the length LX satisfies: 0.5λ ≤ LX ≤ 1λ, and the width WX satisfies: 0.5λ ≤ WX ≤ 1λ, where λ is the free space wavelength corresponding to the center frequency point of the antenna operation.

[0027] In some embodiments, the array of grooves is arranged axially symmetrically with respect to the diagonal of the radiation disk (1) and is parallel to the edge. The groove element spacing is D1 and D2, and satisfies 0.5λ ≤ D1 ≤ 1λ, 0.5λ ≤ D2 ≤ 1λ.

[0028] In some embodiments, each microstrip antenna has the same operating frequency band, the same polarization direction, and the same printed circuit board outer dimension.

[0029] In some embodiments, the printed circuit board dielectric constant ε of each microstrip antenna is the same and satisfies 2.2 ≤ ε ≤ 16, and the thickness h is the same as the groove depth and satisfies 0.01λ ≤ h ≤ 0.05λ.

[0030] In some embodiments, the upper-layer radiation metal patches of each microstrip antenna are randomly arranged.

[0031] In some embodiments, the shapes of the upper-layer radiation metal patches of any microstrip antenna are all different.

[0032] In a specific example, the shapes of the radiation metal patches of the unit antennas that make up the microstrip array antenna of the embodiments of the present application are not one kind, but two kinds, three kinds or more kinds of shapes. The unit antennas with different-shaped radiators still maintain the same radiation characteristics, that is, the antenna gain and beam width are the same. In this way, after the unit antennas with different-shaped radiators form an array antenna, the radiation performance is basically equivalent to that of the array antenna composed of the same unit antennas, but the scattering performance is completely different. Since the scattering wave amplitude-phase characteristics generated by different radiators are completely different, they cannot be in-phase superimposed to form a scattering peak in space, but produce a superimposed cancellation effect of the scattering waves, similar to the "diffuse reflection" phenomenon, thereby effectively reducing the RCS value of the array antenna.

[0033] The embodiments of the present application also propose an implementation case of a hybrid unit low-RCS array antenna, including a radiation disk 1 and four microstrip antenna units Figure 1 in 2 - 5.

[0034] As Figure 2 shown, the radiation disk 1 is a rhombic metal plate with a thickness of H, a length of LD (LD ≥ m × D1), and a width of WD (WD ≥ m × D2). The acute interior angle of the rhombic metal plate is φ, (70° ≤ φ ≤ 80°). There are m × m rhombic grooves on one side of the radiation disk. The shape of each rhombic groove is similar to that of the radiation disk 1, with a depth of h, a length of LX (0.5λ ≤ LX ≤ 1λ), and a width of WX (0.5λ ≤ WX ≤ 1λ), where λ is the free space wavelength corresponding to the center frequency point of the antenna operation. The other side of the radiation disk is the array antenna feeding network.

[0035] Each rhombic groove is embedded with a rhombic microstrip antenna. The microstrip antenna has the same shape and size as the groove. The other side of the radiation disk is the feeding network. The m × m rhombic grooves are arranged axially symmetrically along the diagonal of the radiation disk 1 and the edges are parallel. The element spacing is D1 and D2 (0.5λ ≤ D1 ≤ 1λ, 0.5λ ≤ D2 ≤ 1λ).

[0036] Each microstrip antenna unit has the same operating frequency band, the same polarization direction, and the same printed circuit board (PCB) outer dimensions. Each microstrip antenna unit is composed of a PCB with an upper radiation metal patch and a lower metal ground plane. The dielectric constant ε of the PCB is the same and satisfies 2.2 ≤ ε ≤ 16, and the thickness h is the same as the groove depth and satisfies 0.01λ ≤ h ≤ 0.05λ.

[0037] The outer shapes of the upper radiation metal patches of each microstrip antenna are all different, and the number of outer shape types is m×m. The microstrip antennas with different upper radiation metal patch shapes are randomly arranged.

[0038] In a more specific embodiment, as Figure 3 shown in the hybrid unit low RCS array antenna, including: a radiation disk 1, a first microstrip antenna unit 2, a second microstrip antenna unit 3, a third microstrip antenna unit 4, and a fourth microstrip antenna unit 5.

[0039] The radiation disk 1 is a diamond-shaped aluminum plate with a thickness of H = 5.8 mm. The diagonal length WD of the aluminum plate is 97.5 mm, and the width LD is 88.5 mm. There are 4 diamond-shaped grooves on one side of the aluminum plate, which are arranged symmetrically about the diagonal of the radiation disk 1 and are parallel to the edges. The element spacings D1 and D2 are 54 mm and 52 mm, respectively. The depths of the 4 grooves are all h = 1.5 mm. 4 microstrip antenna units are welded in each groove by reflow soldering. The outer dimensions of the groove are the same as those of the microstrip antenna unit, and the diagonal length WX and width LX are 40.5 mm and 34 mm, respectively.

[0040] The outer shapes of the upper radiation metal patches of the 4 microstrip antenna units are all different. Among them, the upper radiation metal patch of the microstrip antenna unit 1 is in the shape of a double-headed arrow, with a length L1 = 21.2 mm and a width W1 = 19.5 mm; the upper radiation metal patch of the microstrip antenna unit 2 is diamond-shaped, with a length L2 = 29.8 mm and a width W2 = 25.8 mm; the upper radiation metal patch of the microstrip antenna unit 3 is rectangular, with a length L3 = 19.2 mm and a width W3 = 9.8 mm; the upper radiation metal patch of the microstrip antenna unit 4 is in the shape of a capital letter H in English, with a length L1 = 21.2 mm and a width W1 = 8 mm

[0041] Figure 4 The simulation results of the return loss (S11) parameters of the 4 microstrip antenna units of the hybrid unit low RCS array antenna in this example are shown. The horizontal axis is the frequency, and the vertical axis is S11. It can be seen that S11 of the 4 microstrip antennas is basically the same in the frequency range of 4.28 GHz to 4.32 GHz of the operating frequency band.

[0042] Figure 5The simulation results of the gain patterns of 4 microstrip antenna elements of the hybrid unit low-RCS array antenna of this example are shown. The horizontal axis is the azimuth angle, and the vertical axis is the gain. It can be seen that the gain patterns of the 4 microstrip antenna elements are basically the same.

[0043] Figure 6 It shows that the hybrid unit low-RCS array antenna of this example is installed on an analog stealth aircraft carrier. When the radar detection wave irradiates the antenna in the form of grazing incidence with frequencies of 2 GHz, 10 GHz, and 18 GHz respectively, an azimuth angle of [-90°, +90°], and an elevation angle of 0°, the RCS simulation curve of the antenna is shown. The horizontal axis is the azimuth angle, and the vertical axis is the RCS value.

[0044] Figure 7 It shows the comparison of the gain patterns between the hybrid unit low-RCS array antenna of this example and a conventional 4-element rectangular radiation metal patch.

[0045] Figure 8 It shows the comparison of the RCS simulation curves between the hybrid unit low-RCS array antenna of this embodiment and a conventional 4-element rectangular patch array antenna when the radar detection wave irradiates the antenna in the form of grazing incidence with different frequencies, an azimuth angle of 0°, and an elevation angle of 0°. The horizontal axis is the frequency, and the vertical axis is the RCS value.

[0046] Each component unit of the array antenna of this application has a different shape, but has the same radiation performance. The radiation units with different shapes will generate scattered waves with different amplitude-phase characteristics and superimpose and cancel each other in space, forming an effect similar to "diffuse reflection", thereby reducing the RCS value of the array antenna within the frequency band. At the same time, since each radiation unit has the same radiation performance, the radiation performance remains unchanged after forming the array antenna. Under the premise of consistent radiation performance, within the range of azimuth angle ±45°, the RCS value of the array antenna of this application is lower than -28.2 dBsm. Under the premise of consistent radiation performance, within the frequency range of 2 GHz to 18 GHz, the RCS value of the array antenna of this application is reduced by up to 16.6 dB compared with that of the conventional array antenna.

[0047] It should be noted that in each embodiment of this application, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including that element.

[0048] The serial numbers of the embodiments of the present application above are only for description and do not represent the superiority or inferiority of the embodiments.

[0049] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific implementation manners. The above specific implementation manners are merely illustrative rather than restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims. All of these are within the protection scope of the present application.

Claims

1. A hybrid unit low RCS array antenna, characterized in that, Comprising: A radiation disk (1), which is a metal plate of a set specification. An array of grooves is provided on one side surface of the radiation disk (1), and the grooves have the same specification and a shape similar to that of the radiation disk (1). The other side surface of the radiation disk (1) is a feeding network of an array antenna; A plurality of microstrip antennas, the number of the microstrip antennas being the same as the number of the grooves and the size being adapted to the grooves, and any one of the microstrip antennas being embedded in the corresponding groove; The outer shapes of the upper-layer radiation metal patches of any one of the microstrip antennas are not completely the same.

2. The hybrid unit low RCS array antenna according to claim 1, characterized in that The radiation disk (1) is a rhombic metal plate, and the acute inner angle φ of the rhombic metal plate satisfies 70° ≤ φ ≤ 80°; The groove is also rhombic, the depth of the groove is h, the length LX satisfies: 0.5λ ≤ LX ≤ 1λ, and the width WX satisfies: 0.5λ ≤ WX ≤ 1λ, where λ is the free space wavelength corresponding to the center frequency point of the antenna operation.

3. The hybrid unit low RCS array antenna according to claim 2, characterized in that, The array of grooves is arranged axially symmetrically with respect to the diagonal of the radiation disk (1) and is parallel to the edge. The groove element spacings are D1 and D2, satisfying 0.5λ ≤ D1 ≤ 1λ, 0.5λ ≤ D2 ≤ 1λ.

4. The hybrid unit low RCS array antenna according to claim 2, wherein Each microstrip antenna has the same operating frequency band, the same polarization direction, and the same printed board external dimension.

5. The hybrid unit low RCS array antenna according to claim 4, characterized in that, The printed board dielectric constants ε of each microstrip antenna are the same and satisfy 2.2 ≤ ε ≤ 16, and the thickness h is the same as the groove depth and satisfies 0.01λ ≤ h ≤ 0.05λ.

6. The hybrid unit low RCS array antenna according to claim 1, wherein The upper-layer radiation metal patches of each microstrip antenna are randomly arranged.

7. The hybrid unit low RCS array antenna according to claim 1, characterized in that The outer shapes of the upper-layer radiation metal patches of any one of the microstrip antennas are different.

8. A communication device, characterized in that, Including the hybrid unit low RCS array antenna according to any one of claims 1-7.

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