Conformal dual-polarization low-scattering array antenna

Abstract

The invention relates to the field of low-scattering array antennas, in particular to a conformal dual-polarization low-scattering array antenna. According to the scheme, the antenna comprises a dielectric substrate 1, a dipole radiation patch 2, a parasitic patch 3, a wave-absorbing material 4, a feed balun 5 and a metal floor 6, the dielectric substrate 1 and an outer skin of a platform are conformal, the dipole radiation patch 2 subjected to modification and hollowing treatment is printed on the upper surface of the dielectric substrate 1, the parasitic patch 3 is printed on the lower surface of the dielectric substrate 1, and the dielectric substrate 1 is printed on the dielectric substrate 1. The wave-absorbing material 4 is attached to the lower surface of the dielectric substrate 1 and is conformal with the dielectric substrate 1, and the feed balun 5 penetrates through the dielectric substrate 1, the wave-absorbing material 4 and the metal floor 6 and is connected with radiation arms on the two sides of the dipole radiation patch 2 respectively. According to the invention, the antenna scattering can be effectively reduced by shaping and hollowing out the dipole radiation patch, and the standing wave performance can be improved and the scattering can be reduced by loading the parasitic structure and the wave-absorbing material in the space below the dielectric substrate. The method is suitable for the stealth platform.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of low scattering array antenna, in particular to a conformal dual-polarized low scattering array antenna. BACKGROUND

[0002] The concept of stealth platform has been widely concerned since its advent, and the word stealth means invisible, but in the actual military field, it means undetectable by radar. Due to the improvement of survival and penetration combat capability, stealth technology has gradually become a popular development direction of modern combat platform. Stealth is to weaken or suppress the scattered echo signal of the detected target through various technical means.

[0003] With the rapid development of military electronic technology, the survival and combat capability of various platforms are facing more and more challenges, so the stealth performance of modern combat platform is more important. As one of the strong scattering sources of various platforms, the scattering performance of the antenna itself greatly affects the stealth performance of the platform, which requires that in addition to good radiation performance, the array antenna also has good scattering performance. Therefore, modern stealth platform urgently needs low profile, ultra-wideband, large scanning angle, conformal, low scattering and other performance antennas. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a conformal dual-polarized low scattering array antenna, which effectively reduces the scattering of the antenna.

[0005] The present application achieves the above-mentioned purpose by adopting the following technical scheme, and provides a conformal dual-polarized low scattering array antenna, which comprises: a dielectric substrate 1, a dipole radiation patch 2, a parasitic patch 3, a wave-absorbing material 4, a feed balun 5, and a metal floor 6. The dielectric substrate 1 is conformal with the outer skin of the platform, the dipole radiation patch 2 printed on the upper surface of the dielectric substrate 1 is subjected to shaping and hollowing treatment, the parasitic patch 3 is printed on the lower surface of the dielectric substrate 1, the wave-absorbing material 4 is attached to the lower surface of the dielectric substrate 1 and conformal with the dielectric substrate 1, and the feed balun 5 penetrates the dielectric substrate 1, the wave-absorbing material 4 and the metal floor 6 and is connected with the two side radiation arms of the dipole radiation patch 2 respectively for feeding.

[0006] Further, the dipole radiation patch 2 is arrayed by tight coupling, coupling the vertical polarization and the horizontal polarization together, the coupling mode is cross, the ends of the adjacent unit radiation arms and the gap between the units form the coupling place, and the coupling strength between the units is controlled by controlling the size and shaping shape of the gap.

[0007] Further, the parasitic patch 3 is located directly below the coupling center of the dipole radiating patch 2, the parasitic patch 3 is square, circular or elliptical in shape, and the coupling effect of the parasitic patch 3 is the same as the coupling effect of the vertical polarization and horizontal polarization of the adjacent unit of the radiating arm of the dipole radiating patch 2.

[0008] Further, the modification processing of the dipole radiating patch 2 is related to the modification processing of the end or feeding end of the radiating arm of the dipole radiating patch 2, specifically cutting an angle, the cutting angle mode includes straight cutting to form a wedge and a triangle, or using an elliptical, hyperbolic, parabolic, exponential gradient mode.

[0009] Further, the hollow processing of the dipole radiating patch 2 is to perform hollow processing at the center of the dipole radiating patch 2, and the hollow opening shape is a shape around the center of the radiating arm, which is trapezoidal, triangular, circular, sector, or square.

[0010] Further, the wave-absorbing material 4 includes two layers, the upper layer is PP or PMI hard foam, and the lower layer is a wave-absorbing adhesive plate, or the two layers are the same kind of wave-absorbing material, and the single wave-absorbing material is a gradient gradient layered structure, which realizes the adjustment of impedance through layering.

[0011] Further, the feeding balun 5 is gradually changed to feed the radiating arms on both sides of the patch.

[0012] The beneficial effects of the present application are: The present application can effectively reduce the antenna scattering by modifying and hollow processing the dipole radiating patch, conform to the outer skin of the platform, which is beneficial to the integration of the platform and realizes the low scattering of the whole platform, the spacing of the composed radiating unit is small, which is beneficial to realize the large-angle wave velocity scanning, the space below the dielectric substrate is loaded with parasitic structure and wave-absorbing material, which can improve the standing wave performance and reduce scattering. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a schematic diagram of a conformal dual-polarized low-scattering array antenna structure provided by the present application; Figure 2 is a schematic diagram of a dipole radiating patch hollow region provided by the present application; Figure 3 is a schematic diagram of the shape of the dipole radiating patch after hollowing provided by the present application; Figure 4 is a schematic diagram of a sector dipole radiating patch hollow region provided by the present application; Figure 5 is a schematic diagram of the shape of the sector dipole radiating patch after hollowing provided by the present application; Figure 6is the top view of the hollowed dipole radiating patch of the conformal dual-polarized low-scattering array antenna provided by the application; Figure 7 is the structural schematic diagram of the structure after removing the dipole radiating patch and the dielectric layer provided by the application; Figure 8 and Figure 9 are the active standing wave ratios of the conformal dual-polarized low-scattering array antenna provided by the application at 0° and 50° scanning of vertical polarization and horizontal polarization respectively; Figure 10 and Figure 11 are the effective gain comparison diagrams of the conformal dual-polarized low-scattering array antenna provided by the application at 0° and 50° scanning of vertical polarization and horizontal polarization at angle θ respectively; Figure 12 and Figure 13 are the radar scattering cross section comparison diagrams of the shaped array and the unshaped array provided by the application at a certain frequency point under vertical polarization and horizontal polarization in the S band; Figure 14 and Figure 15 are the radar scattering cross section comparison diagrams of the shaped array and the unshaped array provided by the application at a certain frequency point under vertical polarization and horizontal polarization in the X band; In the drawings, 1 is a dielectric substrate, 2 is a dipole radiating patch, 3 is a parasitic patch, 4 is a wave-absorbing material, 5 is a feed balun, and 6 is a metal floor. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application.

[0015] The application provides a conformal dual-polarized low-scattering array antenna, as shown in the drawings, which comprises a dielectric substrate 1, a dipole radiating patch 2, a parasitic patch 3, a wave-absorbing material 4, a feed balun 5 and a metal floor 6. Figures 1 to 7

[0016] The dielectric substrate 1 is conformal to the outer skin of the platform, and the material thereof can be a flexible material such as polyimide or polyester.

[0017] The dipole radiating patch 2 after shaping and hollowing is printed on the upper surface of the dielectric substrate 1 and is arranged in an array through tight coupling, i.e. end-to-end close arrangement, specifically including horizontal direction arrangement and vertical polarization direction arrangement, i.e. coupling vertical polarization and horizontal polarization together, the coupling mode is cross mode, there are gaps between adjacent units, the coupling place is formed by the end of the radiating arm of the adjacent unit and the gap between the units, and the coupling strength between the units can be controlled by controlling the size and shaping shape of the gap. ​

[0018] The primary innovation of the present application is to modify the end or feed end of the dipole radiating patch 2, and to remove the central part of the radiation arms on both sides of the array unit, because the edge scattering is relatively strong at these places, or the surface current is strong when radiating and weak when scattering. Through these treatments, the scattering of the antenna can be reduced.

[0019] Specifically, the end or feed end of the radiation arm of the dipole radiating patch 2 that has been modified and hollowed out can be modified in a related manner, specifically by cutting an angle, and the cutting angle method includes straight cutting to form a wedge, a triangle, but can also adopt an elliptical, hyperbolic, parabolic, exponential gradient, etc. Through the modification method of cutting an angle, under the condition of not affecting the radiation performance and coupling characteristics, by optimizing the removed metal part, adjusting the remaining metal or even the dielectric boundary, it is beneficial to reduce the electromagnetic scattering of the antenna.

[0020] The two sides of the radiation arm of each dipole radiating patch 2 array unit that has been modified and hollowed out have metal hollowing treatment at the center position, and the surface current is weak when radiating and strong when scattering at the center of the radiation arm. Through the hollowing treatment, the purpose of reducing the surface area of the metal patch can be achieved with little impact on radiation, thereby reducing the radar scattering cross section of the antenna. The shape of the hollowing opening is around the center of the radiation arm, including but not limited to trapezoidal, triangular, circular, sector, or square, etc. The hollowing area of the dipole radiating patch is shown in Figure 2 , the shape of the dipole radiating patch after hollowing is shown in Figure 3 , the hollowing area of the sector dipole radiating patch is shown in Figure 4 , the shape of the sector dipole radiating patch after hollowing is shown in Figure 5 .

[0021] The parasitic patch 3 is printed on the lower surface of the dielectric substrate 1, and is also located directly below the center of the coupling of the dipole radiating patch 2 that has been modified and hollowed out. The shape of the parasitic patch 3 can be square, circular, elliptical, etc. It has the same coupling effect as the radiation arm of the adjacent unit with vertical polarization and horizontal polarization, and its function is to widen the low frequency bandwidth by enhancing the coupling effect. In order to further expand the performance of the antenna, the dielectric substrate 1 can be single-layer, double-layer or multi-layer, and when it is multi-layer, the parasitic patch 3 is in the middle layer or the lower surface of the multi-layer. The top view of the dipole radiating patch after hollowing of the conformal dual-polarized low-scattering array antenna is shown in Figure 6 , the structure after removing the dipole radiating patch and the dielectric layer is shown in Figure 7 .

[0022] The wave-absorbing material 4 is located on the upper surface of the metal floor 6 and conforms to the metal floor 6, or is located on the lower surface of the dielectric substrate 1 and conforms to the dielectric substrate 1. The wave-absorbing material can be of various types, such as foam, adhesive plate, honeycomb, etc. or a combination thereof. For example, the wave-absorbing material can be two layers, the upper layer being PP or PMI hard foam, which has a relatively low relative dielectric constant, is relatively light in weight and has a slightly weak wave-absorbing effect, and the lower layer being a wave-absorbing adhesive plate, which has a relatively high relative dielectric constant and magnetic permeability, has a good wave-absorbing effect but is relatively heavy in weight, so that the two types of wave-absorbing materials are used in combination to strike a balance between the weight and the wave-absorbing effect. Meanwhile, a single type of wave-absorbing material can also be a gradiently graded layered structure, and through layering, impedance adjustment is realized, which is more conducive to matching with the air impedance.

[0023] The feed balun 5 penetrates through the dielectric substrate 1, the wave-absorbing material 4 and the metal floor 6 and is connected with the two side radiation arms of the dipole radiation patch 2 respectively to perform feeding.

[0024] Specifically, the feed balun is a gradually changing feed line printed on the dielectric plate, and there are openings on the dielectric substrate, the wave-absorbing material and the metal floor, and the balun penetrates through them to feed the two side radiation arms of the dipole and also realizes the function of impedance transformation. In addition, the good standing wave performance of the feed balun can also optimize the standing wave performance of the antenna to a certain extent.

[0025] Figure 8 and Figure 9 are respectively the comparison diagrams of the active standing wave ratios of the conformal dual-polarized low-scattering array antenna of the application in the cases of vertical polarization scanning 0 degrees and horizontal polarization scanning 50 degrees. It can be seen that the active standing wave ratios are all less than 3, and most of the frequency bands in the band are less than 2.5, so that the array antenna has good standing wave performance.

[0026] Figure 10 are respectively the radiation patterns of the conformal dual-polarized low-scattering array antenna of the application in the cases of vertical polarization scanning 0 degrees and horizontal polarization scanning 50 degrees at 4 f 0. The maximum achievable gain when scanning 0 degrees is 10.70 dBi, and the maximum achievable gain when scanning 50 degrees is 5.84 dBi.

[0027] Figure 11 are respectively the radiation patterns of the conformal dual-polarized low-scattering array antenna of the application in the cases of vertical polarization scanning 0 degrees and horizontal polarization scanning 50 degrees at 4 f 0. The maximum achievable gain when scanning 0 degrees is 10.34 dBi, and the maximum achievable gain when scanning 50 degrees is 6.46 dBi.

[0028] Figure 12 and Figure 13The figures show a comparison of the monostatic radar cross sections (RCS) of the modified and unmodified arrays illuminated by vertically and horizontally polarized radar waves at a specific frequency in the S-band. Under VV polarization, the modified array shows a 1.02 dBsm reduction in RCS compared to the unmodified array, while under HH polarization, the modified array shows a 2.51 dBsm reduction in RCS compared to the unmodified array.

[0029] Figure 14 and Figure 15 The figures show a comparison of the monostatic radar cross sections (RCS) of the modified and unmodified arrays illuminated by vertically and horizontally polarized radar waves at a specific frequency in the X-band. Under VV polarization, the modified array exhibits a 5.13 dBsm reduction in RCS compared to the unmodified array, while under HH polarization, the modified array exhibits a 2.16 dBsm reduction in RCS compared to the unmodified array.

[0030] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A conformal dual-polarized low-scattering array antenna, characterized in that, include: The dielectric substrate (1), dipole radiating patch (2), parasitic patch (3), absorbing material (4), feeding balun (5), and metal ground plane (6) are provided. The dielectric substrate (1) conforms to the outer skin of the platform. The dipole radiating patch (2), which has been modified and hollowed out, is printed on the upper surface of the dielectric substrate (1). The parasitic patch (3) is printed on the lower surface of the dielectric substrate (1). The absorbing material (4) is attached to the lower surface of the dielectric substrate (1) and conforms to the dielectric substrate (1). The feeding balun (5) passes through the dielectric substrate (1), the absorbing material (4), and the metal ground plane (6) and is connected to the two radiating arms of the dipole radiating patch (2) respectively for feeding.

2. The conformal dual-polarized low-scattering array antenna according to claim 1, characterized in that, The dipole radiation patch (2) is arrayed in a tight coupling manner, which couples the vertical polarization and the horizontal polarization together. The coupling method is cross-shaped, and the ends of the radiation arms of adjacent units and the gaps between units form coupling points. The coupling strength between units is controlled by controlling the size of the gaps and the shape of the modified gaps.

3. The conformal dual-polarized low-scattering array antenna according to claim 2, characterized in that, The parasitic patch (3) is located directly below the coupling center of the dipole radiation patch (2). The shape of the parasitic patch (3) is square, circular or elliptical. The coupling effect of the parasitic patch (3) is the same as the coupling effect of the radiation arms of the adjacent units of the vertically polarized and horizontally polarized dipole radiation patch (2).

4. The conformal dual-polarized low-scattering array antenna according to claim 1, characterized in that, The shaping process of the dipole radiating patch (2) is to perform relevant shaping processes on the end of the radiating arm or the feeding end of the dipole radiating patch (2), specifically, the corner cutting. The corner cutting methods include oblique straight cutting to form wedges and triangles, or using elliptical, hyperbolic, parabolic, or exponentially gradual methods.

5. The conformal dual-polarized low-scattering array antenna according to claim 1, characterized in that, The cutout treatment of the dipole radiation patch (2) is to cut out the center of the dipole radiation patch (2), and the shape of the cutout opening is the shape around the center of the radiation arm, which can be trapezoidal, triangular, circular, fan-shaped or square.

6. The conformal dual-polarized low-scattering array antenna according to claim 1, characterized in that, The absorbing material (4) consists of two layers: the upper layer is PP or PMI rigid foam and the lower layer is absorbing adhesive board, or the upper and lower layers are the same absorbing material. The single absorbing material has a gradient layered structure, and the impedance can be adjusted by layering.

7. The conformal dual-polarized low-scattering array antenna according to claim 1, characterized in that, The feeding balun (5) uses a gradient type with two sides of the patch-type radial arms for feeding.

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