A Ka-band high-power beam scanning array antenna based on polarization twisting

Abstract

The present invention discloses a Ka-band high-power beam scanning array antenna based on polarization twisting, wherein the array antenna comprises antenna units, wherein the antenna units are composed of a reflecting surface, a square cone horn and a polarization twisting plate, wherein the reflecting surface is a parabolic structure with a horizontal grid, wherein the horizontal grid is arranged on a convex surface of the reflecting surface, and wherein the reflecting surface, the square cone horn and the polarization twisting plate are metal structures; a horizontally polarized wave is fed into the square cone horn, and after being transmitted to the horizontal grid on the reflecting surface, it is reflected back to the polarization twisting plate, and after being twisted, it is changed from a horizontally polarized wave to a vertically polarized wave, and then is reflected back to the reflecting surface, and then radiated to free space through the horizontal grid on the reflecting surface. The array antenna of the present invention has high power capacity, compact feed source volume, and flexible array formation, and realizes the quasi-planarization of the antenna, and can solve the problems of complex structure, difficulty in array formation, inability to beam scan, and insufficient power capacity of polarization twisting antenna of traditional HPM antenna.

Description

Technical Field

[0001] The invention belongs to the technical field of high-power microwaves, and in particular relates to a Ka-band high-power beam scanning array antenna based on polarization twisting. Background Art

[0002] High-power microwave (HPM) refers to electromagnetic waves in the frequency band of 1 to 300 GHz with a peak power higher than 100 MW. At present, high-power technology is developing towards higher frequencies under the guidance of the demand for microwave sources in communication systems, long-range radars and new accelerators. According to published literature, Ka-band high-power microwave sources have reached 500 megawatts. Horn antennas are often used in high-power microwave systems, but their low gain and large size are not conducive to practical application scenarios.

[0003] Traditional HPM antennas, such as Vlasov antennas, COBRA antennas, and large-aperture parabolic antennas, meet the needs of experiments and applications to a certain extent, but their large size, complex configuration, and low radiation efficiency limit their applications. Later, radial helical array antennas, radial slot antennas, and transmission array antennas were developed. These types of antennas have good performance, but they are particularly difficult to handle when the wavelength of high-frequency electromagnetic waves becomes shorter. In addition, the feeding network is complicated, making it difficult to form a large array, and most antennas do not have beam scanning capabilities.

[0004] Traditional polarization twist antennas have good beam scanning performance, but their polarization twist plates and parabolas rely on dielectric plates, which greatly limits their application in high-power fields. In order to improve practicality and broaden the scope of application, it has become an urgent issue to develop miniaturized, beam-scannable Ka-band high-power millimeter-wave antennas. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems of the prior art and disclose a Ka-band high-power beam scanning array antenna based on polarization twisting. Through the structural setting of the array antenna, the problems of complex structure, difficulty in array formation, inability to perform beam scanning and insufficient power capacity of polarization twisted antennas of traditional HPM antennas are solved.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] A Ka-band high-power beam scanning array antenna based on polarization twisting, wherein the array antenna comprises a plurality of antenna units.

[0008] The antenna unit is composed of a reflecting surface, a square cone horn and a polarization twisting plate, wherein the reflecting surface is a parabolic structure with a horizontal grid, and the horizontal grid is arranged on the convex surface of the reflecting surface, and the reflecting surface, the square cone horn and the polarization twisting plate are metal structures;

[0009] The horizontally polarized wave is fed into the square cone horn, transmitted to the horizontal grid on the reflecting surface, and then reflected back to the polarization twisting plate. After being twisted, it is changed from a horizontally polarized wave to a vertically polarized wave, and then reflected back to the reflecting surface, and then radiated into the free space through the horizontal grid on the reflecting surface.

[0010] Compared with the traditional polarization twist antenna, this array antenna improves the structure of the polarization twist plate and the parabola, removes the dielectric plate, realizes the full metallization of the antenna, and greatly improves the power capacity of the antenna.

[0011] According to a preferred embodiment, the concave surface of the reflecting surface is arranged opposite to the polarization twisting plate, and the square cone horn is arranged through the polarization twisting plate.

[0012] According to a preferred embodiment, adjacent antenna units in the array antenna are connected to each other.

[0013] According to a preferred embodiment, the reflecting surface is a square parabola structure, and the reflecting surfaces of adjacent antenna units are connected to each other using the edges of the square parabola as connecting edges.

[0014] The present invention designs the parabola as a square-cut parabola, and adjacent antenna units are connected to each other, thereby converting a large-aperture parabola antenna with a single feed source into a small-aperture array antenna with multiple feed sources, which can significantly reduce the axial height of the antenna. Multiple small-aperture parabolas are connected to each other to form a quasi-planar structure, which is convenient for the planarization of the antenna. The power capacity of a single feed source is equally divided into multiple feed sources, reducing the upper limit of the power capacity required for each feed source, thereby reducing the volume of the feed source, and the array is flexible, and the appropriate number of sub-arrays can be selected according to the power capacity requirements.

[0015] According to a preferred embodiment, adjacent antenna units share the same polarization twisting plate.

[0016] According to a preferred embodiment, the beam scanning of the array antenna is achieved by rotating the polarization twisting plate.

[0017] Taking the 2×2 array as an example, by rotating the entire polarization twisting plate, wide-angle two-dimensional beam scanning of the antenna can be achieved. The scanning angle is twice the rotation angle, and the rotation of the entire plate avoids phase compensation between each unit.

[0018] According to a preferred embodiment, the grid bar spacing d1 and grid bar width w1 of the horizontal grid on the reflection surface are determined based on the reflection and transmission performance and power capacity of the antenna unit.

[0019] According to a preferred embodiment, the grid bar height h2 of the polarization twisting plate is approximately equal to one quarter of the wavelength of the horizontal polarization wave.

[0020] The aforementioned main scheme of the present invention and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection by the present invention. After understanding the scheme of the present invention, those skilled in the art can understand that there are multiple combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present invention, and they are not exhaustively listed here.

[0021] Beneficial effects of the present invention:

[0022] 1. The present invention improves the structure of the polarization twisting plate and the reflecting surface, removes the dielectric plate, and realizes full metallization of the antenna. Compared with the traditional polarization twisting antenna, the power capacity of the antenna is greatly improved.

[0023] 2. The present invention designs the reflective surface as a square cut parabola, and adjacent units are connected to each other, thereby converting a single-feed large-aperture parabola antenna into a multi-feed small-aperture array antenna, which can significantly reduce the axial height of the antenna. Multiple small-aperture parabolas are connected to each other to form a quasi-planar structure, which is convenient for the planarization of the antenna. The power capacity of a single feed source is equally divided into multiple feed sources, reducing the upper limit of the power capacity required for each feed source, thereby reducing the volume of the feed source, and the array is flexible, and the appropriate number of sub-arrays can be selected according to the power capacity requirements.

[0024] 3. In the present invention, multiple antenna units share the same polarization twist plate, and two-dimensional beam scanning is achieved by rotating the entire plate, which avoids the phase difference caused by rotation when the polarization twist plate is not shared, thereby simplifying the antenna structure and facilitating process implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of a certain antenna unit in the array antenna of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of the 2×2 array antenna of the present invention;

[0027] Figure 3 It is a schematic structural diagram of the horizontal grid of the present invention.

[0028] Figure 4 yes Figure 3 The result graph of the reflectivity variation with frequency for horizontally polarized waves at different incident angles.

[0029] Figure 5 yes Figure 3 The results of the transmission rate of vertically polarized waves changing with frequency at different incident angles.

[0030] Figure 6 It is a schematic diagram of the structure of the grid on the polarization twisting plate of the present invention.

[0031] Figure 7 yes Figure 6The results of polarization twisting efficiency changing with frequency at different incident angles.

[0032] Figure 8 It is a reflection coefficient simulation result diagram of the present invention.

[0033] Fig. 9 It is a diagram of the radiation directivity simulation result of the present invention.

[0034] Fig.10 This is a graph showing the change in antenna performance at different rotation angles of the polarization twisting plate of the present invention.

[0035] Fig.11 It is the three-dimensional radiation pattern of the antenna of the polarization twisting plate of the present invention at different rotation angles.

[0036] Fig.12 It is the field intensity distribution diagram of the antenna of the polarization twisting plate of the present invention at different rotation angles.

[0037] Fig.13 It is a reflection coefficient simulation result diagram of the 2×2 array form of the present invention.

[0038] Fig.14 It is a diagram of the radiation directivity simulation result of the 2×2 array form of the present invention.

[0039] Fig.15 It is a result diagram of the change of antenna performance of the polarization twisting plate in the form of a 2×2 array of the present invention at different rotation angles.

[0040] Fig.16 It is the three-dimensional radiation pattern of the antenna of the polarization twisting plate in the form of 2×2 array of the present invention at different rotation angles.

[0041] Fig.17 It is the field strength distribution diagram of the antenna of the polarization twisting plate in the form of 2×2 array of the present invention at different rotation angles.

[0042] Among them, 1-reflection surface, 2-square cone horn, 3-polarization twisting plate. DETAILED DESCRIPTION

[0043] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0044] 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.

[0045] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0046] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0047] In the description of the present invention, 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 elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In addition, the present invention should be pointed out that, in the present invention, unless the specific structure, connection relationship, positional relationship, power source relationship, etc. are specifically written out, the structure, connection relationship, positional relationship, power source relationship, etc. involved in the present invention are all known by those skilled in the art on the basis of the prior art without creative work.

[0049] Embodiment 1:

[0050] refer to Figure 1 and Figure 2 As shown, the figure shows a Ka-band high-power beam scanning array antenna based on polarization twisting, and the array antenna includes a number of antenna units.

[0051] Each antenna unit consists of a reflecting surface 1, a square cone horn 2 and a polarization twisting plate 3. The reflecting surface 1 is a parabolic structure with a horizontal grid. The horizontal grid is arranged on the convex surface of the reflecting surface 1. The reflecting surface 1, the square cone horn 2 and the polarization twisting plate 3 are metal structures.

[0052] The concave surface of the reflective surface 1 is arranged opposite to the polarization twisting plate 3 , and the square cone horn 2 is arranged to penetrate the polarization twisting plate 3 .

[0053] The horizontally polarized wave is fed into the square cone horn 2, transmitted to the horizontal grid on the reflecting surface 1, and then reflected back to the polarization twisting plate 3. After being twisted, it is changed from a horizontally polarized wave to a vertically polarized wave and then reflected back to the reflecting surface 1, and then radiated to the free space through the horizontal grid of the reflecting surface 1.

[0054] Compared with the traditional polarization twist antenna, the array antenna improves the structure of the polarization twist plate 3 and the parabola, removes the dielectric plate, realizes the full metallization of the antenna, and greatly improves the power capacity of the antenna.

[0055] Preferably, adjacent antenna units in the array antenna are connected to each other.

[0056] Furthermore, the reflecting surface 1 is a square parabola structure, and the reflecting surfaces 1 of adjacent antenna units are connected to each other using the edges of the square parabola as connecting edges.

[0057] The present invention designs the reflecting surface 1 as a square-cut parabola, and adjacent antenna units are connected to each other, thereby converting a single-feed large-aperture parabolic antenna into a multi-feed small-aperture array antenna, which can significantly reduce the axial height of the antenna. Multiple small-aperture parabolas are connected to each other to form a quasi-planar structure, which is convenient for the planarization of the antenna.

[0058] The power capacity of a single feed is equally divided among multiple feeds, which reduces the upper limit of the power capacity required for each feed, thereby reducing the volume of the feed. The array is flexible and the appropriate number of sub-arrays can be selected according to the power capacity requirements.

[0059] Preferably, adjacent antenna units share the same polarization twisting plate 3. The beam scanning of the array antenna is achieved by rotating the polarization twisting plate 3.

[0060] like Figure 2 As shown, taking a 2×2 array as an example, multiple antenna units share the same polarization twist plate 3. By rotating the entire polarization twist plate 3, wide-angle two-dimensional beam scanning of the antenna can be achieved. The scanning angle is twice the rotation angle, and the rotation of the entire plate avoids phase compensation between the units, thereby simplifying the antenna structure and facilitating process implementation.

[0061] Figure 3The horizontal grid structure diagram of the present invention is shown in FIG. The grid bar spacing d1 and the grid bar width w1 are determined based on the reflection and transmission performance and power capacity of the antenna unit.

[0062] Figure 4 yes Figure 3 The reflectivity of horizontally polarized waves varies with frequency at different incident angles. When the incident angle varies from 0° to 30°, the reflectivity of horizontally polarized waves is always higher than 99% within 30–31 GHz.

[0063] Figure 5 yes Figure 3 The transmittance of vertically polarized waves varies with frequency at different incident angles. When the incident angle varies from 0° to 30°, the transmittance of vertically polarized waves is always higher than 95% within 30–31 GHz.

[0064] Figure 6 The figure is a schematic diagram of the structure of the grid on the polarization twisting plate of the present invention. The conventional polarization twisting plate is improved and designed by removing the dielectric plate and raising the height of the grid bars (the grid bar height h2 is approximately equal to a quarter wavelength), so as to achieve full metallization of the polarization twisting plate 3, thereby improving the power capacity of the antenna. Through simulation optimization, the polarization twisting performance and power capacity of the unit are comprehensively considered to determine the grid spacing d2, grid bar width w2 and grid bar height h2.

[0065] Figure 7 yes Figure 6 The result diagram of polarization twist efficiency changing with frequency at different incident angles. When the incident angle changes from 0° to 15°, the polarization twist rate is always higher than 95% within 30–31GHz, and the polarization twist performance is good.

[0066] Figure 8 This is a reflection coefficient simulation result diagram of the present invention. In the 30-31 GHz frequency band, the antenna reflection coefficient is less than -14 dB, and the transmission efficiency is greater than 95%.

[0067] Fig. 9 This is the radiation directivity simulation result diagram of the antenna unit of the present invention. At 30.5GHz, the antenna gain is 32.7dB and the aperture efficiency is 63.7%

[0068] Fig.10The polarization twisting plate of the antenna unit of the present invention shows the change in antenna performance at different rotation angles. When rotating along the E plane by 0°, 5°, 10° and 15°, the corresponding E plane radiation pattern deflects by 0°, 10°, 20° and 30°, and the corresponding gains are 32.7dB, 32.5dB, 32.3dB and 32dB respectively. The aperture efficiency is reduced from 63.7% to 54.2%, and the reflection coefficient is always below -10dB, with good transmission performance. When rotating along the H plane, the corresponding antenna performance is similar to that of the E plane.

[0069] Fig.11 The three-dimensional radiation pattern of the polarization twisting plate of the antenna unit of the present invention at different rotation angles. It can be seen that the antenna can realize two-dimensional beam scanning as the twisting plate rotates, and the scanning angle is twice the rotation angle.

[0070] Fig.12 This is the field strength distribution diagram of the polarization twisting plate of the antenna unit of the present invention at different rotation angles. It can be seen that the maximum field strength is at the horn antenna feed end, with a maximum of 4600V / m, and a power capacity of about 133MW in vacuum. The maximum field strength on the polarization twisting plate and the reflector is about 400V / m.

[0071] Fig.13 This is a simulation result diagram of the reflection coefficient of the 2×2 array of the present invention. In the 30-31 GHz frequency band, the antenna reflection coefficient is less than -10 dB and the transmission efficiency is greater than 90%.

[0072] Fig.14 This is a simulation result diagram of the radiation directivity of the 2×2 array form of the present invention. At 30.5GHz, the antenna gain is 38.8dB and the aperture efficiency is 64.9%.

[0073] Fig.15 This is a result diagram of the change in antenna performance of the polarization twisting plate in the form of a 2×2 array of the present invention at different rotation angles. When rotating along the E plane by 0°, 5°, 10° and 15°, the corresponding E plane radiation pattern deflects by 0°, 10°, 20°, and 30°, and the reflection coefficient is always below -10dB, with good transmission performance. When rotating along the H plane, the corresponding antenna performance is similar to that of the E plane.

[0074] Fig.16 The three-dimensional radiation pattern of the antenna of the 2×2 array polarization twisting plate of the present invention at different rotation angles. It can be seen that the antenna can realize two-dimensional beam scanning as the twisting plate rotates, and the scanning angle is always twice the rotation angle.

[0075] Fig.17This is the field strength distribution diagram of the antenna of the 2×2 array form of the polarization twisting plate of the present invention at different rotation angles. The maximum field strength of the antenna of the 2×2 array form of the polarization twisting plate at different rotation angles is at the horn antenna feed end, with a maximum of 4600V / m, and a power capacity of about 133MW in a vacuum. The maximum field strength on the polarization twisting plate and the reflector is about 400V / m. Compared with the antenna unit, the antenna array after arraying has no obvious field enhancement, and the maximum field strength is consistent with the antenna unit.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A Ka-band high-power beam scanning array antenna based on polarization twisting, characterized in that: The array antenna comprises antenna units. The antenna unit is composed of a reflecting surface (1), a square cone horn (2) and a polarization twisting plate (3); the reflecting surface (1) is a parabolic structure with a horizontal grid, the horizontal grid is arranged on a convex surface of the reflecting surface (1); the reflecting surface (1), the square cone horn (2) and the polarization twisting plate (3) are metal structures; The horizontally polarized wave is fed into the square cone horn (2), transmitted to the horizontal grid on the reflecting surface (1), and then reflected back to the polarization twisting plate (3). After being twisted, the horizontally polarized wave is transformed into a vertically polarized wave, and then reflected back to the reflecting surface (1), and then radiated to the free space through the horizontal grid on the reflecting surface (1); The concave surface of the reflection surface (1) is arranged opposite to the polarization twisting plate (3), and the square cone horn (2) is arranged to penetrate the polarization twisting plate (3); Adjacent antenna units in the array antenna are connected to each other; The reflecting surface (1) is a square parabolic structure. The reflection surfaces (1) of adjacent antenna units are connected to each other using the edges of the square paraboloid as connecting edges; Adjacent antenna units share the same polarization twist plate (3); beam scanning of the array antenna is achieved by rotating the polarization twist plate (3); The grid bar height h2 of the polarization twisting plate (3) is equal to one quarter of the wavelength of the horizontal polarization wave; The grid bar spacing d1 and grid bar width w1 of the horizontal grid on the reflection surface (1) are determined based on the reflection and transmission performance and power capacity of the antenna unit.

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