Novel double-layer pure metal transmission array antenna for beam scanning

Abstract

The utility model discloses a novel double-layer pure metal transmission array antenna used for wave beam scanning, compared with a traditional transmission array, a dielectric substrate which is easily influenced by environmental factors is not used, but a pure metal structure is adopted, so that the dielectric substrate is prevented from being damaged in some extreme environments. Meanwhile, two groups of first double-end cross-shaped slot structures and second double-end cross-shaped slot structures which are different in length and parallel to the y direction are etched on the transmission unit, and the first double-end cross-shaped slot structures and the second double-end cross-shaped slot structures are alternately arranged on the transmission unit. Compared with a Huygens pure metal unit, the unit has the functions of low transmission loss and meeting the 360-degree phase change range, the unit structure is simple, large-scale multi-parameter scanning is not needed, the design difficulty is low, the expandability and universality of the unit are improved, meanwhile, an additional structure such as a metal column is not introduced, and the cost is low. And relatively low processing complexity is maintained, and the processing cost is relatively low.

Description

Technical Field

[0001] The utility model belongs to the technical field of metal transmission antennas, in particular to a novel double-layer pure metal transmission array antenna for beam scanning. Background Art

[0002] As one of the ideal solutions for high-gain antennas, transmission array antennas play an important role in various modern communications and radar systems. The transmission array antenna system consists of a spatial feed that provides a quasi-spherical incident wave and a transmission array plane composed of multiple periodically arranged sub-wavelength units, which can radiate beams in a specific direction. It combines the advantages of lens antennas and phased array antennas. Its planar metasurface array structure is simple and easy to process. At the same time, the spatial feeding structure avoids the influence of complex feeding networks on the complexity of array design and array performance. Compared with reflective array antennas with similar structures, the spatial feed and beam of the transmission array antenna are located on both sides of the array surface, and the gain will not decrease due to the obstruction of the feed source. The beam pointing is also more flexible, and it has received more and more attention in recent years.

[0003] The units of transmission array antennas are usually designed based on dielectric substrates with specific dielectric constants and thicknesses, and are manufactured and processed using printed circuit board technology. However, for transmission beams, dielectric substrates introduce additional insertion losses, resulting in reduced antenna efficiency, and when propagating high-power beams, the heat generated by insertion losses may cause changes in the dielectric constant of the substrate. Under the extremely high temperatures of the space environment, the dielectric substrate may deform and fail to maintain stable and reliable performance to achieve high-quality communications. Pure metal transmission array antennas, due to their characteristics of not using dielectric substrates, overcome the various problems brought about by dielectric substrates. Not only are their performance more stable and their processing complexity is lower, but their manufacturing costs are also reduced, and they have been favored by researchers at home and abroad.

[0004] In related research, pure metal transmission array antennas are designed as structures with at least three layers of metal plates stacked at a certain distance. The more layers of metal plates there are, the easier it is for the transmission unit to obtain a better transmission coefficient while ensuring a 360° phase variation range and meeting the array phase compensation requirements. However, in actual assembly, more metal layers will not only increase the complexity of assembly, but also accumulate errors in the spacing between metal plates and the alignment of the upper and lower structures, thereby affecting the performance of the array. Therefore, reducing the number of metal plate layers while ensuring a 360° phase variation range and a high transmission coefficient is an important criterion for the design of pure metal transmission arrays. Pure metal transmission units and arrays that reduce the number of layers to two have been intensively studied in recent years.

[0005] In the patent document disclosed in China with patent publication number CN115207638A, a double-layer pure metal transmission array based on Huygens metasurface is proposed. During the simulation process of the unit, three independent parameter lists corresponding to different transmission phases were obtained, covering a 360° phase change range with a phase gradient of about 30°. However, this design method requires a large number of parameter scans, which is difficult to expand to different frequency bands, and the discontinuous phase change will produce phase errors and cannot completely compensate for the phase of the incident wave. At the same time, this pure metal Huygens unit will have a very narrow metal structure when the parameters change, with low mechanical strength and prone to bending and deformation.

[0006] In the patent document with Chinese patent publication number CN112421227A, a double-layer pure metal transmission unit based on a receiving and transmitting structure is disclosed. Two U-shaped grooves of different sizes are etched on the two metal layers of the unit, and a metal column is designed in the center of the unit to connect the two metal plates. The groove structures of the upper and lower layers are orthogonal to each other. By rotating the lower groove structure and changing the size of the U-shaped groove, a 360° phase change range and a transmission loss of less than 2dB are achieved. The groove structure complexity of this unit is relatively low, but the metal column structure greatly increases the complexity of processing and manufacturing, and the diameter of the metal column is only 0.8mm, which is easy to bend and deform in actual use. Its upper and lower orthogonal structure inevitably deflects the polarization of the beam.

[0007] Transmission array antennas with beam scanning capability are an important area of ​​antenna research due to their diverse functions and high system efficiency. Beam scanning antennas have the ability to flexibly adjust the beam direction in wireless communications, are suitable for signal transmission and reception, and play an important role in target search and tracking applications. Transmission array antenna systems usually use two schemes: electrical control and mechanical control to achieve beam scanning.

[0008] The electrical control method mainly includes integrating RF devices such as PIN diodes, varactor diodes and MEMS switches into the transmission unit, and designing a DC feeding network to control it, thereby achieving beam scanning. However, due to the inherent power limitations of RF devices, the transmission array is not suitable for applications that require high-power beams, such as military radars. In addition, RF devices are not only expensive, but also introduce additional ohmic losses. The complex feeding network designed for them will also significantly affect the antenna efficiency. Utility Model Content

[0009] The utility model provides a novel double-layer pure metal transmission array antenna for beam scanning, which solves the problems of high loss and complex structure of the existing transmission array antenna.

[0010] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0011] A novel double-layer pure metal transmission array antenna for beam scanning comprises a pyramidal horn antenna and a transmission array, wherein the pyramidal horn antenna is a feed source of the transmission array, and the transmission array comprises two layers of metal plates, an air layer is arranged between the two layers of the metal plates, and a plurality of transmission units are arranged on each of the metal plates, and two groups of first double-headed cross-shaped slot structures and second double-headed cross-shaped slot structures of different lengths parallel to the y direction are etched on the transmission units, and the first double-headed cross-shaped slot structures and the second double-headed cross-shaped slot structures are alternately arranged on the transmission units.

[0012] Preferably, the two groups of double-headed cross-slot structures include: the geometric centers of the first double-headed cross-slot structure and the double-headed cross-slot structure are P / 4 apart in the x-direction and P / 2 apart in the y-direction, and P is a period.

[0013] Preferably, the distance between two adjacent first double-headed cross-shaped gap structures in the x direction is P / 2.

[0014] Preferably, the distance between two adjacent second double-headed cross-shaped gap structures in the x direction is also P / 2.

[0015] Preferably, the length of the main rod of the first double-headed cross-shaped gap structure ranges from 15.2 mm to 16 mm.

[0016] Preferably, the length of the orthogonal branches of the first double-headed cross-shaped gap structure ranges from 1 mm to 5.8 mm.

[0017] Preferably, the length of the trunk of the second double-headed cross-shaped slit structure ranges from 11.4 mm to 13 mm.

[0018] Preferably, the length of the orthogonal branches of the second double-headed cross-shaped gap structure ranges from 1 mm to 3.2 mm.

[0019] Preferably, the total length relationship between the first double-ended cross-shaped gap structure and the second double-ended cross-shaped gap structure is:

[0020] L2=0.67*L1+1.67

[0021] Wherein, L2 is the total length of the second double-headed cross-shaped gap structure, and L1 is the total length of the first double-headed cross-shaped gap structure.

[0022] Preferably, the transmission array comprises 24×24 transmission units arranged in a periodic pattern.

[0023] Compared with the prior art, the utility model has the following beneficial effects: the utility model provides a new double-layer pure metal transmission array antenna for beam scanning. Compared with the traditional transmission array, it does not use a dielectric substrate that is easily affected by environmental factors, but adopts a pure metal structure, avoiding the problem of unstable dielectric constant or even deformation and inability to work caused by temperature changes in some extreme environments such as space environments. At the same time, when transmitting high-power beams, the pure metal transmission array also avoids the large amount of heat generated by the dielectric loss of the dielectric substrate. The performance of the array unit is more stable and reliable, and it is not easy to be penetrated by high-power beams. At the same time, by etching two sets of first double-headed cross-shaped slot structures and second double-headed cross-shaped slot structures with different lengths parallel to the y direction on the transmission unit, the first double-headed cross-shaped slot structure and the second double-headed cross-shaped slot structure are alternately arranged on the transmission unit. Compared with the existing double-layer pure metal transmission array antenna, it has low transmission loss and meets the function of 360° phase change range, and the unit structure is relatively simple. Compared with the Huygens pure metal unit, there is no need for large-scale multi-parameter scanning, and the design difficulty is relatively low, which greatly increases the scalability and universality of the unit. At the same time, no additional structures such as metal columns are introduced, which maintains a low processing complexity and low processing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The utility model is a schematic diagram of a novel double-layer pure metal transmission array antenna for beam scanning.

[0025] Figure 2 The utility model is a novel double-layer pure metal transmission array antenna for beam scanning, wherein b is an enlarged view of the transmission unit and a is a schematic diagram of the plane structure of the pure metal transmission unit.

[0026] Figure 3 The utility model is a three-dimensional structural schematic diagram of a transmission unit of a novel double-layer pure metal transmission array antenna for beam scanning.

[0027] Figure 4 The utility model is a new double-layer pure metal transmission array antenna for beam scanning. The transmission amplitude and phase of the antenna vary with the parameter L1 at the design frequency of 10 GHz.

[0028] Figure 5 The utility model is a radiation pattern of a novel double-layer pure metal transmission array antenna for beam scanning measured at 10GHz.

[0029] In the figure: 1- pyramidal horn antenna; 2- transmission array; 3- transmission unit; 4- first double-ended cross-shaped slot; 5- second double-ended cross-shaped slot; 6- metal plate. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In the description of the embodiments of the present utility model, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use, it is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0034] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0035] In the description of the embodiments of the present utility model, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0037] like Figures 1 to 3 The utility model shown provides a novel double-layer pure metal transmission array antenna for beam scanning, including a linearly polarized pyramidal horn antenna 1 and a transmission array 2, wherein the pyramidal horn antenna 1 is a feed source of the transmission array 2, and the transmission array 2 includes two layers of metal plates 6, an air layer is arranged between the two layers of the metal plates 6, and a plurality of transmission units 3 are arranged on each of the metal plates 6, and two groups of first double-headed cross-shaped slot structures 4 and second double-headed cross-shaped slot structures 5 with different lengths and parallel to the y direction are etched on the transmission unit 3, and the first double-headed cross-shaped slot structure 4 and the second double-headed cross-shaped slot structure 5 are alternately arranged on the transmission unit 3.

[0038] The pyramid horn antenna 1 is used as a feed source to provide an x-polarized quasi-spherical incident wave and is located at the focal position of the transmission array 2 .

[0039] The distance from the phase center of the pyramid horn to the pure metal transmission array antenna surface is 246.7mm. The aperture size of the transmission array 2 is 432mm×432mm, and it contains 24×24 periodically arranged transmission units. Each pure metal transmission unit consists of two layers of thin metal plates with the same structure.

[0040] The unit's operating frequency is 10 GHz, with a period of P = 18 mm. The air gap thickness H1 of the two metal plates is 5 mm, the thickness H2 of the metal plates is 0.5 mm, and the total thickness of the unit is 5.1 mm. Two sets of double-headed cross-slit structures parallel to the y-axis and with different lengths are alternately etched on the metal plates to jointly achieve phase control of the incident wave. These two sets of double-headed cross-slit structures are periodically arranged on the array surface with the unit, and can control x-polarized electromagnetic waves.

[0041] The geometric centers of the first double-headed cross-shaped slot structure 4 and the second double-headed cross-shaped slot structure 5 are P / 4 apart in the x direction and P / 2 apart in the y direction. The distance between two adjacent first double-headed cross-shaped slot structures 4 in the x direction is P / 2, and the distance between two adjacent second double-headed cross-shaped slot structures 5 in the x direction is also P / 2.

[0042] The parameters of the first double-headed cross-shaped gap structure 4 include the length L11 of the trunk and the length L12 of the orthogonal branches, and the parameter L1=L11+L12. The parameters of the second double-headed cross-shaped gap structure 5 include the length L21 of the trunk and the length L22 of the orthogonal branches, and the parameter L2=L21+L22. The length variation range of L11 is between 15.2 and 16 mm, and the length variation range of L12 is between 1 and 5.8 mm. The length variation range of L21 is between 11.4 and 13 mm, and the length variation range of L22 is between 1 and 3.2 mm. As the value of L1 increases, the trunk length L11 of the first double-headed cross-shaped gap structure 4 gradually increases, and L12 first maintains the minimum value unchanged until L11 gradually increases to the maximum value, and then the value of L12 begins to increase. The variation relationship between the parameters L2, L21 and L22 of the second double-headed cross-shaped gap structure 5 is the same.

[0043] In the process of adjusting parameters, the relationship between the total lengths L1 and L2 of the two double-headed cross-shaped gap structures was established, so that continuous phase shift can be obtained only through a single parameter scan, which significantly improves the simulation efficiency. The relationship can be expressed as L2=0.67*L1+1.67 (mm).

[0044] The frequency response of the unit changes with the change of L1 value, and the required continuous 360° phase change range can be achieved near the operating frequency of 10GHz, while the transmission loss is less than 1.6dB. The amplitude and phase characteristics of the unit are plotted in Figure 4 middle.

[0045] Experimental data:

[0046] The far-field radiation pattern of the pure metal transmission array was experimentally measured in a microwave darkroom. The results are as follows: Figure 5 As shown. When the feed moves outward from the center of the array aperture along the x-axis direction by 0mm, 31mm, 62mm, 93mm, 124mm and 170.5mm, its beam direction angle θ, that is, the angle between the direction of the transmission beam passing through the transmission array and the normal of the vertical array plane, is about 0°, 4°, 9°, 14°, 19° and 25° respectively. When θ=0°, the maximum gain of the prototype is 25.82dBi, which is only 0.94dBi lower than the simulation data. The measurement results are completely consistent with the simulation results in the beam direction, but the gain is slightly lower than the simulation results. When the beam direction θ changes from -25° to +25°, the beam sidelobes are all more than 10dB smaller than the main lobe, and the gain change during the scanning process is less than 2.5dBi. In general, the experimental measurement results are basically consistent with the simulation data, indicating that the pure metal transmission array antenna has good beam scanning capability within the angle coverage range of ±25°.

[0047] Although the embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields, and the above-mentioned specific embodiments are merely illustrative and instructive, rather than restrictive. Under the guidance of the specification, a person skilled in the art can make many forms without departing from the scope of protection of the claims of the present invention, all of which belong to the scope of protection of the present invention.

Claims

1. A novel double-layer pure metal transmission array antenna for beam scanning, characterized in that: The invention comprises a pyramidal horn antenna (1) and a transmission array (2), wherein the pyramidal horn antenna (1) is a feed source of the transmission array (2), and the transmission array (2) comprises two layers of metal plates (6), an air layer is arranged between the two layers of the metal plates (6), and a plurality of transmission units (3) are arranged on each of the metal plates (6), and two groups of first double-headed cross-shaped slot structures (4) and second double-headed cross-shaped slot structures (5) of different lengths and parallel to the y direction are etched on the transmission units (3), and the first double-headed cross-shaped slot structures (4) and the second double-headed cross-shaped slot structures (5) are alternately arranged on the transmission units (3).

2. A novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The two groups of double-headed cross-slit structures include: the geometric centers of the first double-headed cross-shaped slot structure (4) and the double-headed cross-shaped slot structure (5) are P / 4 apart in the x direction and P / 2 apart in the y direction, and P is a period.

3. The novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The distance between two adjacent first double-headed cross-shaped gap structures (4) in the x direction is P / 2.

4. The novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The distance between two adjacent second double-headed cross-shaped gap structures (5) in the x direction is also P / 2.

5. The novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The length of the main rod of the first double-headed cross-shaped gap structure (4) ranges from 15.2 mm to 16 mm.

6. The novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The length of the orthogonal branches of the first double-headed cross-shaped gap structure (4) ranges from 1 mm to 5.8 mm.

7. The novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The length of the main trunk of the second double-headed cross-shaped gap structure (5) ranges from 11.4 mm to 13 mm.

8. The novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The length of the orthogonal branches of the second double-headed cross-shaped gap structure (5) ranges from 1 mm to 3.2 mm.

9. The novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The total length relationship between the first double-ended cross-shaped gap structure (4) and the second double-ended cross-shaped gap structure (5) is: L2=0.67*L1+1.67 Wherein, L2 is the total length of the second double-headed cross-shaped gap structure (5), and L1 is the total length of the first double-headed cross-shaped gap structure (4).

10. The novel double-layer pure metal transmission array antenna for beam scanning according to claim 1, characterized in that: The transmission array (2) comprises 24×24 transmission units (3) arranged in a periodic manner.

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