A low profile phased array antenna and antenna array

Abstract

The application discloses a low-profile phased array antenna and an antenna array, which comprises a reflecting plate, a phase adjuster, a parasitic column, an antenna unit and a radio frequency connector; the reflecting plate is provided with a through hole; the antenna unit comprises two arm-like structures, a feed line and a grounding surface; the two arm-like structures are electrically connected with the grounding surface respectively; the radio frequency connector comprises an inner conductor and an outer conductor; the inner conductor is electrically connected with the feed line through the through hole; the grounding surface and the outer conductor are electrically connected with the reflecting plate; the parasitic column is two, which are located on the two sides of the reflecting plate respectively, and the two arm-like structures are directed to the parasitic columns respectively; the phase adjuster is a pair of conductor rings, which are located at a set height between the reflecting plate and the arm-like structures, and the two conductor rings are distributed between the antenna unit and the parasitic columns and are electrically connected with the parasitic columns and the grounding surface. The application introduces a special-shaped phase adjuster, reduces the profile height of the phased array antenna, and realizes the miniaturization design of the phased array antenna array.

Description

Technical Field

[0001] This invention relates to the field of phased array antenna technology, specifically a low-profile phased array antenna and antenna array. Background Technology

[0002] Antennas are sensors used to radiate or receive electromagnetic waves, and are an important and special component of radar. The regular movement of the beam pointing an antenna to transmit or receive electromagnetic waves is called scanning. Antenna beam scanning methods are divided into mechanical scanning and electronic scanning. A phased array antenna, also known as a phase-scanned antenna, is an antenna that changes the beam direction by controlling the phase of each element or subarray of the array antenna; it is a type of electronically scanned antenna.

[0003] Phased array antennas play a crucial role in radar systems due to their superior performance in beamforming and pointing. The continuous development of phased array antennas has undergone a series of evolutionary processes. Modern radar demands on phased array antennas no longer limited to broadband and wide-angle scanning; they also require low profile, low cost, and simple design. Therefore, research on low-profile phased array antennas is extremely important. Many researchers have conducted in-depth studies on low-profile phased array antennas.

[0004] The paper "Research on Low-Profile Widebandgap Phased Array Antenna" (Xing Weiyi, University of Electronic Science and Technology of China, 2019) proposes a low-profile widebandgap phased array antenna. The advantage of this antenna is that it achieves an impedance bandwidth of 28% over ±60° of E-plane and H-plane scanning when the active VSWR is less than 2.5. The disadvantages include the introduction of a multilayer dielectric substrate, multiple tuning structures and matching layers, and various fixing modules, resulting in a complex structure, high fabrication difficulty, and high precision requirements. The consistency between fabrication test results and simulation results depends on the fabrication accuracy, and the yield rate needs to be considered in engineering implementation. Furthermore, the antenna has a relatively high profile height, which is 0.12 times the low-frequency wavelength, allowing for further low-profile design.

[0005] The paper "Design of an Ultra-Wideband Low-Cross-Polarization Low-Profile Phased Array Antenna Element" (Li Xiaojin et al., Electronic Measurement Technology, 2019) proposes an ultra-wideband low-cross-polarization low-profile phased array antenna element design. The advantage of this antenna is that the active VSWR of ±45° in the E and H planes is less than 3.5 within the 7GHz–16GHz frequency band. The disadvantages include the introduction of 10 dielectric substrates, each with metal patches etched with different patterns, resulting in a complex structure, high fabrication difficulty, and high precision requirements. The consistency between fabrication test results and simulation results depends on the fabrication accuracy, and the yield rate needs to be considered in engineering implementation. Furthermore, the antenna has a very high profile height, which is 0.42 times the low-frequency wavelength.

[0006] Chinese invention patent CN112259959A, entitled "Low-profile Wideband Scanning Phased Array Antenna Element," discloses a low-profile wideband scanning phased array antenna element. The advantage of this antenna is that within the 8GHz–12GHz frequency band, the active standing wave ratio (VSWR) is less than 3 for azimuth scanning ±45° and elevation scanning ±30°. The disadvantages include the introduction of three dielectric substrates and one metal cavity. Each dielectric substrate has metal patches etched with different patterns, and a blind cavity is cut out in the middle of the metal cavity. The multi-layer dielectric substrates need to be mixed and bonded to the metal cavity, resulting in a complex structure, high manufacturing difficulty, and high precision requirements. The consistency between the manufacturing test results and simulation results depends on the manufacturing precision, and the yield rate needs to be considered in engineering implementation. Furthermore, the antenna has a relatively high profile height, which is 0.12 times the low-frequency wavelength, allowing for further low-profile design.

[0007] In summary, existing literature demonstrates how introducing multi-layer resonant structures and multi-layer matching layers can achieve broadband and wide-angle scanning capabilities in phased array antennas, while also enabling low-profile designs to some extent. However, the complex design of multi-layer resonant structures and multi-layer matching layers places high demands on manufacturing precision, making fabrication extremely difficult and requiring consideration of yield rates. Furthermore, the introduction of multi-layer resonant structures and multi-layer matching layers inevitably increases the profile height of the phased array antenna, leaving significant room for improvement in low-profile design. Summary of the Invention

[0008] The technical problem to be solved by this invention is how to design a phased array antenna with simple structure, low cost, low design complexity, and low profile.

[0009] The present invention solves the above-mentioned technical problems through the following technical means:

[0010] A low-profile phased array antenna includes a reflector 10, a phase adjuster 20, a parasitic post 30, an antenna element 40, and an RF connector 50.

[0011] The reflector 10 has an opening; the antenna unit 40 includes two arm-like structures 401, a feed line 402, and a ground surface 403; the two arm-like structures 401 are electrically connected to the ground surface 403 respectively; the RF connector 50 includes an inner conductor 501 and an outer conductor 502; the inner conductor passes through the opening and is electrically connected to the feed line 402; both the ground surface 403 and the outer conductor 502 are electrically connected to the reflector 10;

[0012] There are two parasitic columns 30, located on both sides of the emission plate 10, and the two arm-like structures 401 point towards the parasitic column 30 respectively;

[0013] The phase adjuster 20 is a pair of conductor rings located at a set height between the reflector 10 and the arm-like structure 401. The two conductor rings are respectively distributed between the antenna element 40 and the parasitic post 30, and are electrically connected to the parasitic post 30 and the ground surface 403.

[0014] Furthermore, the through hole is located at the center of the reflector 10.

[0015] Furthermore, the parasitic column 30 is located on the edges of two opposite sides of the reflector 10.

[0016] Furthermore, the antenna element 40 can be one of the following: a metal dipole, a microstrip dipole, an air plate wire dipole, a banyan tree antenna, a Vivaldi antenna, or a folded dipole.

[0017] Furthermore, the conductor ring is supported on the reflector plate 10 by a support column.

[0018] Furthermore, the conductor ring is a square ring.

[0019] Furthermore, the parasitic column 30 is one of a semi-cylinder, a cylinder, or a square column; the parasitic column 30 can be a solid column or a hollow column.

[0020] Furthermore, the reflector 10, phase adjuster 20, parasitic post 30, antenna unit 40, and radio frequency connector 50 are made of metal, or are made of materials that have metallic electrical properties after metallization treatment of carbon fiber, graphene, foam, PTFE, hydrocarbon materials, or thermosetting resin.

[0021] The present invention also provides a low-profile phased array antenna array, wherein the aforementioned low-profile phased array antennas are arranged in a two-dimensional square grid according to an n*m grid, and adjacent low-profile phased array antennas are seamlessly connected.

[0022] The advantages of this invention are:

[0023] This invention reduces the profile height of the phased array antenna by introducing a phase adjuster with a special shape, so that the overall profile height of the array composed of phased array antennas is reduced to less than 0.1 times the low frequency wavelength, thereby realizing the miniaturization design of the phased array antenna array.

[0024] The antenna unit structure of this invention is simple, easy to manufacture, and has low engineering implementation requirements. The measured results from the fabrication process match the simulation results, eliminating the need for multiple debugging or repeated design improvements. The entire antenna is made of metal, making it easy to manufacture. Its simple structure and low design complexity significantly reduce design and development risks, improve design and engineering implementation efficiency, and lower design and engineering costs. Attached Figure Description

[0025] Figure 1 This is an overall structural diagram of the low-profile phased array antenna disclosed in Embodiment 1 of the present invention;

[0026] Figure 2 This is a front view of the low-profile phased array antenna disclosed in Embodiment 1 of the present invention;

[0027] Figure 3 This is a top view of the low-profile phased array antenna disclosed in Embodiment 1 of the present invention;

[0028] Figure 4 This is a partial enlarged view of the low-profile phased array antenna disclosed in Embodiment 1 of the present invention;

[0029] Figure 5 This is an overall structural diagram of the low-profile phased array antenna disclosed in Embodiment 2 of the present invention;

[0030] Figure 6 This is a front view of the low-profile phased array antenna disclosed in Embodiment 2 of the present invention;

[0031] Figure 7 This is a partial enlarged view of the low-profile phased array antenna disclosed in Embodiment 2 of the present invention;

[0032] Figure 8 This is a rear view of the low-profile phased array antenna disclosed in Embodiment 2 of the present invention;

[0033] Figure 9 This is an overall structural diagram of the 10×10 antenna array disclosed in Embodiment 3 of the present invention;

[0034] Figure 10 This is a front view of the 10×10 antenna array disclosed in Embodiment 3 of the present invention;

[0035] Figure 11 This is an overall structural diagram of the 10×10 antenna array disclosed in Embodiment 4 of the present invention;

[0036] Figure 12 This is a front view of the 10×10 antenna array disclosed in Embodiment 4 of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0038] Example 1

[0039] Comprehensive reference Figures 1 to 4 The low-profile phased array antenna includes a reflector 10, an RF connector 50, a phase adjuster 20, a parasitic post 30, and an antenna element 40.

[0040] like Figure 3 , Figure 4 As shown, the reflector 10 is rectangular in shape, with a through hole located at the center of the reflector 10. The material of the reflector 10 can be metal, or it can be a material that has been metallized to have metallic electrical properties, including but not limited to carbon fiber, graphene, foam, PTFE, hydrocarbon materials, thermosetting resins, etc. The above materials can be used alone or in combination, as long as they can meet the electrical performance requirements after metallization.

[0041] like Figure 2 , Figure 4 As shown, the inner conductor 501 of the RF connector 50 is directly and physically connected to the feed line 402 of the antenna unit 40 through a through-hole on the reflector 10. In this embodiment, the physical connection can be welding, integral metal forming, or overlapping while ensuring structural strength. The inner conductor 501 of the RF connector 50 is not allowed to be directly and physically connected to the reflector 10. The outer conductor 502 of the RF connector 50 must have good electrical connectivity with the reflector 10.

[0042] like Figure 1 , Figure 3 As shown, there are two parasitic pillars 30, fixed to the left and right edges of the reflector 10 respectively. The material of the parasitic pillars 30 can be metal, or materials including but not limited to those that have undergone metallization treatment to acquire metallic electrical properties, such as carbon fiber, graphene, foam, PTFE, hydrocarbon materials, and thermosetting resins. The shape of the parasitic pillars 30 is cylindrical. The parasitic pillars 30 can be solid, or they can be solid bodies with a hollowed-out interior, retaining a certain thickness to form a closed shell. The parasitic pillars 30 and the reflector 10 must have good electrical connection. The dimensions of the three dimensions of the parasitic pillars 30 and their distance from the center of the reflector 10 need to be optimized using the full-wave electromagnetic simulation software HFSS according to the phased array antenna specifications. This invention does not describe the optimization strategy of the full-wave electromagnetic simulation software HFSS.

[0043] like Figure 1 , Figure 3 As shown, antenna element 40 is fixed at the center of reflector 10. The grounding surface 403 of antenna element 40 must have good electrical connection with reflector 10, and feed line 402 of antenna element 40 is not allowed to be directly physically connected to reflector 10.

[0044] The antenna element 40 can take many forms, including but not limited to metallic dipoles, microstrip dipoles, air-plate wire dipoles, banyan tree antennas, Vivaldi antennas, folded dipoles, and other dipole-like antennas. The antenna element 40 generally has two arm-like structures 401, which point to the two parasitic pillars 30 respectively. The specific dimensions of the antenna element 40 need to be optimized using the full-wave electromagnetic simulation software HFSS according to the phased array antenna specifications. This invention does not describe the optimization strategy of the full-wave electromagnetic simulation software HFSS.

[0045] like Figure 1 , Figure 4 As shown, the phase adjuster 20 is fixed to the ground surface 403 of the antenna element 40 and the surface of the parasitic post 30. The phase adjuster 20 is directly and physically connected to the ground surface 403 of the antenna element 40, and the phase adjuster 20 is directly and physically connected to the surface of the parasitic post 30. The phase adjuster 20 and the ground surface 403 of the antenna element 40 must have good electrical connection, and the phase adjuster 20 and the surface of the parasitic post 30 must have good electrical connection.

[0046] The phase adjuster 20 is a pair of sheet-like rectangular metal rings, supported on the reflector 10 by foam, dielectric pillars, or metal pillars. The phase adjuster 20 is located above the reflector 10 at a certain height. The phase adjuster 20 is also located below the arm-like structure 401 of the antenna element 40 at a certain height. The specific dimensions of the phase adjuster 20, its height from the arm-like structure 401 of the antenna element 40, and its height from the reflector 10 need to be optimized using the full-wave electromagnetic simulation software HFSS according to the phased array antenna specifications. This invention does not describe the optimization strategy of the full-wave electromagnetic simulation software HFSS.

[0047] The phase modulator 20 can be made of metal, or it can be made of materials that have metallic electrical properties after metallization treatment of carbon fiber, graphene, foam, PTFE, hydrocarbon materials, thermosetting resins, etc.

[0048] Simulation results show that the profile height of the low-profile phased array antenna in this embodiment is 0.095 times the low-frequency wavelength.

[0049] Example 2

[0050] Comprehensive reference Figures 5 to 8The low-profile phased array antenna disclosed in this embodiment two replaces some of the structures of the low-profile phased array antenna disclosed in embodiment one. The antenna element 40 of the low-profile phased array antenna disclosed in embodiment one is replaced with a microstrip dipole instead of the original metal dipole. The shape of the parasitic column 30 of the low-profile phased array antenna disclosed in embodiment one is replaced with a quadrilateral column instead of the original cylinder.

[0051] Simulation results show that the profile height of the low-profile phased array antenna in this embodiment is 0.091 times the low-frequency wavelength.

[0052] Example 3

[0053] like Figure 9 , Figure 10 As shown, the low-profile phased array antennas disclosed in Embodiment 1 are arranged in a 10×10 rectangular grid along the horizontal and vertical directions to form a 10×10 low-profile phased array antenna array 88. Adjacent low-profile phased array antennas in the low-profile phased array antenna array 88 are seamlessly connected. The profile height of the low-profile phased array antenna array 88 is 0.095 times the low-frequency wavelength.

[0054] Example 4

[0055] like Figure 11 , Figure 12 As shown, the low-profile phased array antennas disclosed in Embodiment 2 are arranged in a 10×10 rectangular grid along the horizontal and vertical directions to form a 10×10 low-profile phased array antenna array 99. Adjacent low-profile phased array antennas in the low-profile phased array antenna array 99 are seamlessly connected. The profile height of the low-profile phased array antenna array 99 is 0.091 times the low-frequency wavelength.

[0056] The working process and working principle of this invention are as follows:

[0057] Antenna element 40 radiates electromagnetic waves into free space. The direction in which the electromagnetic waves propagate toward reflector 10 is defined as backward, and the opposite direction is defined as forward. In the radar system, it is desirable for antenna element 40 to radiate electromagnetic waves only in the forward direction, and for reflector 10 to reflect the backward-radiated electromagnetic waves back to propagate in the forward direction. When the distance from the arm-like structure (401) of antenna element 40 to reflector 10 is 0.25 times the wavelength, the forward electromagnetic waves and the reflected waves of the backward electromagnetic waves can be superimposed in phase in the far field, increasing the gain and radiation impedance. Therefore, the profile height of antenna element 40 is required to be 0.25 times the wavelength. When a phase adjuster 20 is introduced between the antenna element 40 and the reflector 10, the distance from the arm structure (401) of the antenna element 40 to the reflector 10, i.e. the profile height of the antenna element 40, is reduced. Then, by changing the size of the phase adjuster 20 and its height from the reflector 10, the phase of the reflected wave of the backward electromagnetic wave is adjusted, so that the forward electromagnetic wave and the reflected wave of the backward electromagnetic wave can be superimposed in phase in the far field, thereby increasing the gain and radiation impedance.

[0058] The advantages of the present invention through the above technical solutions are as follows:

[0059] 1. This invention reduces the profile height of the phased array antenna by introducing a phase adjuster with a special shape, so that the overall profile height of the array composed of phased array antennas is reduced to less than 0.1 times the low frequency wavelength, thereby realizing the miniaturization design of the phased array antenna array.

[0060] 2. The present invention has a simple structure and low design complexity, which can greatly reduce design and development risks, improve the efficiency of design and engineering implementation, and reduce design and engineering implementation costs.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low profile phased array antenna, characterized by, The antenna comprises a reflecting plate (10), a phase adjuster (20), a parasitic column (30), an antenna unit (40) and a radio frequency connector (50). The reflecting plate (10) is provided with a through hole; the antenna unit (40) comprises two arm-like structures (401), a feed line (402) and a grounding surface (403); the two arm-like structures (401) are electrically connected to the grounding surface (403) respectively; the radio frequency connector (50) comprises an inner conductor (501) and an outer conductor (502); the inner conductor (501) is electrically connected to the feed line (402) through the through hole; the grounding surface (403) and the outer conductor (502) are electrically connected to the reflecting plate (10). The parasitic column (30) is two, which are located on the two sides of the reflecting plate (10) and electrically connected to the reflecting plate (10), and the two arm-like structures (401) point to the parasitic column (30) respectively. The phase adjuster (20) is a pair of conductor rings, which are located at a set height between the reflecting plate (10) and the arm-like structure (401), and are distributed between the antenna unit (40) and the parasitic column (30) respectively and electrically connected to the parasitic column (30) and the grounding surface (403).

2. A low profile phased array antenna according to claim 1, wherein, The through hole is located at the center of the reflecting plate (10).

3. The low profile phased array antenna of claim 1, wherein, The parasitic column (30) is located at the edge of the two opposite sides of the reflecting plate (10).

4. A low profile phased array antenna according to any one of claims 1 to 3, wherein, The antenna unit (40) can be one of a metal dipole, a microstrip dipole, an air plate line dipole, a banyan tree antenna, a Vivaldi antenna and a folded oscillator.

5. A low profile phased array antenna according to any one of claims 1 to 3, wherein, The conductor ring is supported on the reflecting plate (10) by a support column.

6. A low profile phased array antenna according to any one of claims 1 to 3, wherein, The conductor ring is a square ring.

7. A low profile phased array antenna according to any one of claims 1 to 3, wherein, The parasitic column (30) can be one of a semi-cylindrical body, a cylindrical body and a square column; the parasitic column (30) can be a solid column or a hollow column.

8. A low profile phased array antenna according to any one of claims 1 to 3, wherein, The reflecting plate (10), the phase adjuster (20), the parasitic column (30), the antenna unit (40) and the radio frequency connector (50) are made of metal, or are made of materials with metal electrical properties after carbon fiber, graphene, foam, PTFE, hydrocarbon material and thermosetting resin are subjected to metalization treatment.

9. A low profile phased array antenna array, characterized by, The low-profile phased array antenna according to any one of claims 1 to 8 is arranged in a two-dimensional square grid with n m, and adjacent two low-profile phased array antennas are seamlessly connected.

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