Integrated phased array antenna for broadband radar cross section reduction

Abstract

The application discloses an integrated phased array antenna for wideband radar cross section reduction, which is composed of M*N array antenna unit structures arranged periodically; the array antenna unit structure comprises a loss layer and an antenna layer, the loss layer and the antenna layer are separated by an air layer, and the loss layer and the antenna layer are supported by nylon columns. The technical scheme has the characteristics of ultra-wideband radar cross section (RCS) reduction, can effectively reduce the probability of being detected by a radar in a wide frequency band range, has a flexible beam scanning capability of ±45 degrees, can realize wide-range space detection coverage, and has good angle stability, and can still maintain stable and reliable performance in a wide range of incident angles.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of radar antennas, and particularly relates to an integrated phased array antenna for wideband radar cross section reduction. BACKGROUND

[0002] Radar detection technology plays a key role in modern military wars. The radar cross section (RCS) reduction technology developed along with it is indispensable in stealth applications. Metamaterials and metasurfaces have flexible electromagnetic control capabilities and are effective ways to achieve RCS reduction.

[0003] The RCS reduction methods include active cancellation, shaping methods, electromagnetic absorption and passive cancellation. Among them, the electromagnetic absorption method includes converting incident electromagnetic waves into surface waves and absorbing them using resistors. The structure of converting incident electromagnetic waves into surface waves is generally a three-dimensional structure, which is relatively complex. The RCS reduction bandwidth of the traditional electromagnetic absorption method is relatively narrow, the structure is complex, and the angle stability is limited. Passive cancellation methods mainly include coded metasurfaces, phase gradient metasurfaces, chessboard metasurfaces, dartboard metasurfaces, etc. Among them, the RCS reduction bandwidth of coded metasurfaces and phase gradient metasurfaces is limited. Phase cancellation and polarization conversion are the main RCS reduction mechanisms of chessboard metasurfaces. The former principle is to realize backward RCS reduction by making different scattering waves have a phase difference of 180°±37°. The latter principle is to convert the energy of the incident wave to the cross-polarization component, thereby realizing the RCS reduction of co-polarization. However, many existing passive cancellation methods cannot simultaneously achieve ultra-wideband RCS reduction and wide-angle stability.

[0004] In summary, it is relatively difficult to simultaneously achieve wideband RCS reduction, have a flexible beam scanning capability of ±45°, and have good angle stability. SUMMARY

[0005] The technical problem to be solved by the application is to provide an integrated phased array antenna for wideband radar cross section reduction.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows:

[0007] An integrated phased array antenna for wideband radar cross section reduction is composed of MxN array antenna unit structures arranged periodically to form a phased array antenna; the array antenna unit structure comprises a loss layer and an antenna layer, the loss layer and the antenna layer are separated by an air layer, and the loss layer and the antenna layer are supported by nylon columns.

[0008] As preferred, the antenna layer comprises: a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a first metal ground plate, a fourth dielectric substrate, a fifth dielectric substrate and a second metal ground plate connected in sequence; a first radiation layer is arranged between the first dielectric substrate and the second dielectric substrate, a second radiation layer is arranged between the second dielectric substrate and the third dielectric substrate, and an impedance matching network layer is arranged between the fourth dielectric substrate and the fifth dielectric substrate.

[0009] As preferred, the loss layer comprises a sixth dielectric substrate, and a metal wire and four patch resistors are arranged on the sixth dielectric substrate, the metal wire is composed of four square metal rings and an intermediate circular metal ring, and the four patch resistors are arranged on the metal circular ring, the patch resistors are used for matching the wave impedance in free space to realize wideband absorption.

[0010] As preferred, the impedance matching network layer comprises a strip line impedance matching network of a short-circuit line and an open-circuit line, the short-circuit line has a length L s in the range of 3-4 mm and a width W s in the range of 0.1-0.2 mm, and the open-circuit line has a length L o in the range of 2-3 mm and a width W o in the range of 2-3 mm.

[0011] As preferred, the gap width W1 of the connection between the metal square ring and the metal circular ring in the loss layer is in the range of 0.1-0.5 mm, the length L1 is in the range of 1-3 mm, the outer diameter R1 of the metal circular ring is in the range of 3-3.7 mm, the inner diameter R2 is in the range of 2-3 mm, the outer length W2 of the metal square ring is in the range of 3.5-5.5 mm, and the inner length L2 is in the range of 2.5-4.5 mm.

[0012] As preferred, the length and width P of the unit structure of the loss layer and the antenna layer are both 20 mm, the height of the loss layer is in the range of 1-2 mm, and the height h air of the air layer is in the range of 7-9 mm.

[0013] As preferred, the overall height of the antenna layer is in the range of 6-8 mm, and the height h1 of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate in the antenna layer is 2 mm, and the height h2 of the fourth dielectric substrate and the fifth dielectric substrate is 0.5 mm.

[0014] As preferred, the packaging model of the patch resistor is 0402, the length of the resistor is 1 mm, the width is 0.5 mm, and the resistance of the patch resistor is 100Ω.

[0015] As preferred, the structure of the first radiation layer is that the length and width p1 are in the range of 10-11 mm, and the thickness is 0.018 mm, and the structure of the second radiation layer is that the length and width p2 are in the range of 13-14 mm, and the thickness is 0.018 mm.

[0016] Preferably, the metal material on the loss layer and the antenna layer is copper, and the thickness is 0.018 mm.

[0017] The integrated phased array antenna has excellent performance: first, it has the radar cross section (RCS) reduction characteristic of ultra-wideband, and can effectively reduce the probability of target being detected by radar in a wide frequency band range; second, it has the flexible beam scanning capability of ±45°, and can realize wide range of space detection coverage; third, it has good angle stability, and can still maintain stable and reliable performance in a wide range of incident angles. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0019] Figure 1 The structural schematic diagram of the integrated phased array antenna for wideband radar cross section reduction according to the embodiments of the present application is shown in the figure.

[0020] Figure 2 The structural schematic diagram of the array antenna unit is shown in the figure.

[0021] Figure 3 The structural schematic diagram of the loss layer is shown in the figure.

[0022] Figure 4 The structural schematic diagram of the antenna layer is shown in the figure.

[0023] Figure 5 The structural schematic diagram of the impedance matching network layer is shown in the figure.

[0024] Figure 6 The reflection coefficient of the unit structure of the present application is shown in the figure.

[0025] Figure 7 The transmission coefficient and wave absorption rate of the unit structure of the present application are shown in the figure.

[0026] Figure 8 The single station RCS reduction result schematic diagram of the present application when vertically incident with the metal floor of the same size is shown in the figure, wherein (a) is the RCS reduction result schematic diagram when x polarization, (b) is the RCS reduction result schematic diagram when y polarization,

[0027] Figure 9 The comparative schematic diagram of the 3D scattering pattern of the present application when vertically incident with the metal floor of the same size is shown in the figure.

[0028] Figure 10 This is a schematic diagram of the bistatic RCS reduction results of the present invention with a metal floor of the same size under oblique incidence; wherein, (a) is a schematic diagram of the bistatic RCS reduction results when the incidence angle is 5°, (b) is a schematic diagram of the bistatic RCS reduction results when the incidence angle is 10°, (c) is a schematic diagram of the bistatic RCS reduction results when the incidence angle is 15°, and (d) is a schematic diagram of the bistatic RCS reduction results when the incidence angle is 20°.

[0029] Figure 11 This is a schematic diagram of the gain of the present invention as a function of frequency;

[0030] Figure 12 This is a schematic diagram of beam scanning at 6.5 GHz according to the present invention; wherein, (a) is a schematic diagram of beam scanning in the xoz plane, and (b) is a schematic diagram of beam scanning in the yoz plane. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1:

[0034] like Figure 1 , 2 As shown in Figure 4, this embodiment of the invention provides an integrated phased array antenna for reducing the cross-section of a broadband radar. The phased array antenna is composed of M×N array antenna elements arranged periodically. Each array antenna element includes a loss layer and an antenna layer, separated by an air layer and supported by nylon pillars. The antenna layer includes: a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a first metal ground plane, a fourth dielectric substrate, a fifth dielectric substrate, and a second metal ground plane connected sequentially. A first radiating layer is provided between the first and second dielectric substrates, a second radiating layer is provided between the second and third dielectric substrates, and an impedance matching network layer is provided between the fourth and fifth dielectric substrates. The loss layer includes a sixth dielectric substrate, on which metal lines and four patch resistors are provided. The metal lines consist of four square metal rings connected to a central circular metal ring. The four patch resistors are disposed on the metal rings and are used to match the wave impedance in free space, achieving broadband absorption.

[0035] The length and width P of the unit structure of the loss layer and the antenna layer are both 20 mm, the height of the loss layer ranges from 1 mm to 2 mm, the height of the air layer ranges from 7 mm to 9 mm, and the overall height of the antenna layer ranges from 6 mm to 8 mm. air The height h1 of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate in the antenna layer is 2 mm, and the height h2 of the fourth dielectric substrate and the fifth dielectric substrate is 0.5 mm. The loss layer adopts a combination of metal and resistance, and the metal shape of the loss layer is a metal square ring and a metal circular ring. The metal material on the loss layer and the antenna layer is copper, and the thickness is 0.018 mm. The loss layer absorbs electromagnetic waves outside the antenna operating frequency band and can transmit electromagnetic waves within the antenna operating frequency band, ensuring that the radiation performance of the antenna does not decrease significantly.

[0036] The packaging model of the chip resistor is 0402, the length of the resistor is 1 mm, the width is 0.5 mm, and the resistance value of the chip resistor is 100 Ω.

[0037] The overall size of the integrated phased array in the transverse direction is 160*160 mm 2 , and the overall thickness is 16.5 mm. Under the condition of vertical incidence of electromagnetic waves, the integrated phased array can realize an average RCS single-station reduction of 14.6 dB in a wideband frequency range of 3.3-9.4 GHz, which covers the in-band operating frequency range and the out-of-band operating frequency range. At the same time, under the condition of oblique incidence of electromagnetic waves, the integrated phased array has angle stability in terms of RCS reduction.

[0038] The specific size of the metal layer and the thickness and relative dielectric constant of the dielectric substrate and the air layer are determined according to the operating frequency and bandwidth. The dielectric substrate material used in the embodiment of the application is F4B, the relative dielectric constant is ε r = 2.2, and the loss tangent is tan δ = 0.001.

[0039] As shown in Figure 3 , the gap width W1 of the connection between the metal square ring and the metal circular ring in the loss layer ranges from 0.1 mm to 0.5 mm, the length L1 ranges from 1 mm to 3 mm, the outer diameter R1 of the metal circular ring ranges from 3 mm to 3.7 mm, the inner diameter R2 ranges from 2 mm to 3 mm, the outer length W2 of the metal square ring ranges from 3.5 mm to 5.5 mm, and the inner length L2 ranges from 2.5 mm to 4.5 mm.

[0040] As shown in Figure 4 , the structure of the first radiation layer is that the length and width p1 both range from 10 mm to 11 mm, and the thickness is 0.018 mm. The structure of the second radiation layer is that the length and width p2 both range from 13 mm to 14 mm, and the thickness is 0.018 mm.

[0041] As shown inFigure 5 As shown, the impedance matching network layer comprises: a strip line impedance matching network of short-circuit lines and open-circuit lines, the long L s of the short-circuit lines ranges from 3 to 4 mm, and the width W s of the open-circuit lines ranges from 0.1 to 0.2 mm, the long L o of the short-circuit lines ranges from 2 to 3 mm, and the width W o of the open-circuit lines ranges from 2 to 3 mm.

[0042] In an embodiment of the present application, as Figure 6 shown, the reflection coefficient of the integrated phased array unit structure, it can be seen that the operating bandwidth of the unit is from 5.5 GHz to 7.5 GHz. As Figure 7 shown, the transmission coefficient and the wave absorption rate of the integrated phased array unit, the unit can achieve better wave absorption in the operating frequency band range of 4 GHz to 4.9 GHz and 7.8 GHz to 9.3 GHz, and can achieve good wave transmission in the operating frequency range of 5.5 GHz to 7.5 GHz, which ensures that the radiation performance of the antenna is not affected.

[0043] In an embodiment of the present application, Figure 8 shown is the simulated single-station RCS reduction of the x-polarization and y-polarization of the integrated phased array under the condition of vertical incidence. It should be pointed out that the RCS reduction is the comparison result of the equal-size integrated phased array and the flat metal floor. It can be seen that for the x-polarized incident wave, wideband RCS reduction can be achieved in the frequency range of 3.3 GHz to 9.4 GHz; for the y-polarized incident wave, the loss layer can still achieve out-of-band wave absorption and thus achieve out-of-band RCS reduction, which is polarization-insensitive, while the impedance matching network can only achieve in-band RCS reduction for the same-polarized incident wave.

[0044] In an embodiment of the present application, Figure 9 shown is the comparison of the three-dimensional scattering patterns of the flat metal floor and the integrated phased array of the same size at 6 GHz and 7 GHz under the condition of vertical incidence. It can be seen that compared with the RCS of the equal-size metal plate, the integrated phased array can achieve a large amount of RCS reduction at different frequencies.

[0045] In an embodiment of the present application, Figure 10 shown is the RCS reduction of the integrated phased array in the mirror direction of the TE polarization under the condition of oblique incidence. Under the condition of oblique incidence, the xoz plane is selected as the incidence plane (azimuth angle φ i = 0), and the different elevation angles of the incidence angle are θ i = 5°, 10°, 15°, and 20°. Under the TE polarization, the integrated phased array can achieve wideband RCS reduction at different incidence angles, which has angle stability.

[0046] In one embodiment of the present application, Figure 11 The gain-frequency curve of the integrated phased array with lossy layer and the phased array without lossy layer is shown. It can be seen that the two curves almost coincide, which indicates that the integrated phased array can work normally in the working frequency band, and the lossy layer does not cause obvious influence on the antenna. Figure 12 The beam scanning performance of the integrated phased array in the xoz plane and the yoz plane is shown. It can be seen that the integrated phased array can realize beam scanning in the range of ±45° in the xoz plane and the yoz plane, and the mainboard gain attenuation is not more than 3 dB, and the maximum sidelobe level is lower than -10 dB.

[0047] The above-described embodiments are only descriptions of the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. An integrated phased array antenna for wideband radar cross section reduction, characterized in that, The phased array antenna is composed of M*N array antenna unit structures arranged periodically; The array antenna unit structure comprises a loss layer and an antenna layer, the loss layer and the antenna layer are separated by an air layer, and the loss layer and the antenna layer are supported by nylon columns; The antenna layer comprises a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a first metal ground plate, a fourth dielectric substrate, a fifth dielectric substrate and a second metal ground plate connected in sequence; a first radiation layer is arranged between the first dielectric substrate and the second dielectric substrate, a second radiation layer is arranged between the second dielectric substrate and the third dielectric substrate, and an impedance matching network layer is arranged between the fourth dielectric substrate and the fifth dielectric substrate; The loss layer comprises a sixth dielectric substrate, and the sixth dielectric substrate is provided with a metal wire and four patch resistors; the metal wire is composed of four square metal rings and one circular metal ring in the middle; the four patch resistors are arranged on the metal circular ring, and the patch resistors are used for matching the wave impedance in free space to realize wideband absorption. The impedance matching network layer comprises a strip line impedance matching network of shorted lines and open lines, the shorted lines having a length L s in the range 3-4 mm, a width W s in the range 0.1-0.2 mm, the open lines having a length L o in the range 2-3 mm, a width W o in the range 2-3 mm; The gap width W1 of the connection between the metal square ring and the metal circular ring in the loss layer ranges from 0.1mm to 0.5mm, the length L1 ranges from 1mm to 3mm, the outer diameter R1 of the metal circular ring ranges from 3mm to 3.7mm, the inner diameter R2 ranges from 2mm to 3mm, the outer length W2 of the metal square ring ranges from 3.5mm to 5.5mm, and the inner length L2 ranges from 2.5mm to 4.5mm.

2. The integrated phased array antenna for wideband radar cross section reduction of claim 1, wherein, The length and width P of the unit structure of the loss layer and the antenna layer are both 20 mm, the height of the loss layer ranges from 1 mm to 2 mm, and the height h of the air layer ranges from 7 mm to 9 mm. air ranges from 7 mm to 9 mm.

3. The integrated phased array antenna for wideband radar cross section reduction of claim 2, wherein, The overall height of the antenna layer ranges from 6mm to 8mm; the height h1 of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate in the antenna layer is 2mm, and the height h2 of the fourth dielectric substrate and the fifth dielectric substrate is 0.5mm.

4. The integrated phased array antenna for wideband radar cross section reduction of claim 3, wherein, The packaging model of the patch resistor is 0402, the resistance length is 1mm, the resistance width is 0.5mm, and the patch resistor resistance is 100Ω.

5. The integrated phased array antenna for wideband radar cross section reduction of claim 4, wherein, The structure of the first radiation layer is that the length and the width p1 both range from 10mm to 11mm, and the thickness is 0.018mm; the structure of the second radiation layer is that the length and the width p2 both range from 13mm to 14mm, and the thickness is 0.018mm.

6. The integrated phased array antenna for wideband radar cross section reduction of claim 5, wherein, The metal materials on the loss layer and the antenna layer are both copper, and the thicknesses are both 0.018mm.

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