A full-metal dual-frequency low-profile folded reflect-transmit hybrid array antenna

Abstract

This application discloses an all-metal dual-band low-profile folded transmissive-reflective hybrid array antenna, relating to the field of wireless communication technology. It includes a feed element and sequentially arranged first, second, third, and fourth metal layers. The first and second metal layers form a transmissive module, and the third and fourth metal layers form a reflective module. The feed element is located at the center of the reflective module. This antenna consists of only four metal layers: the first and second metal layers form the transmissive surface, and the third and fourth metal layers form the reflective surface. It has no dielectric substrate structure and achieves a dual-band, independently controllable folded transmissive-reflective hybrid metasurface array through a planar pure metal structure. Compared to pure metal antenna arrays, it improves integration and space utilization; compared to traditional substrate antennas, it significantly reduces cost and improves aperture efficiency and reliability in harsh environments.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to an all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna. Background Technology

[0002] Traditional antennas are typically parabolic antennas, which use geometry to ensure that all points are equidistant from the feed source, guaranteeing the same phase of the electromagnetic waves and thus focusing them. However, their high profile and bulky size make them difficult to integrate. In recent years, metasurface antenna arrays have flourished. These arrays use a surface composed of subwavelength elements for phase modulation, enabling complex functions with simple design, low cost, high integration, and lightweight flexibility. A metasurface antenna array consists of several basic elements. For planar metasurface antenna arrays, because the distance from the feed source to different locations on the antenna surface varies, the phase of the electromagnetic waves also differs. Therefore, the way metasurface antenna arrays focus energy is by changing the shape of each element according to the distance, allowing each element to reasonably compensate for the phase difference caused by the distance, thus focusing the electromagnetic waves.

[0003] Metasurface arrays capable of achieving similar complex functions currently all use traditional PCB structures, which are expensive, unsuitable for deployment in harsh environments, and have low gain and efficiency. Pure metal metasurface arrays currently achieve relatively simple functions; planar pure metal structures are limited to folded reflective and transmissive arrays operating at a single frequency, resulting in low space utilization and insufficient integration. Summary of the Invention

[0004] This application aims to solve one of the aforementioned technical problems in the prior art. To this end, embodiments of this application provide an all-metal dual-band low-profile folded reflective-transmitting hybrid array antenna.

[0005] According to an embodiment of this application, an all-metal dual-band low-profile folded reflective-transmitting hybrid array antenna is provided, including a feed element and a first metal layer, a second metal layer, a third metal layer and a fourth metal layer arranged sequentially, wherein the first metal layer and the second metal layer form a transmission module, the third metal layer and the fourth metal layer form a reflection module, and the feed element is disposed at the center of the reflection module; The first metal layer includes a plurality of arrayed first transmissive surface units, and the first transmissive surface unit includes a first hollow structure; The second metal layer includes a plurality of arrayed second transmission surface units, each of which includes a second cutout structure. The first cutout structure and the second cutout structure cooperate to form a frequency selector. The frequency selector is capable of selectively transmitting low-frequency incident waves and selectively orthogonally converting and phase-compensating high-frequency incident waves before transmitting them. The third metal layer includes a plurality of arrayed first reflective surface units, and the first reflective surface unit includes a third hollow structure; The fourth metal layer is a metal ground layer. The fourth metal layer, in conjunction with the third hollow structure, can convert the incident linearly polarized wave into a linearly polarized wave orthogonal to the incident linear polarization, and can perform phase compensation on the reflected low-frequency incident wave.

[0006] The aforementioned all-metal dual-band low-profile folded reflective-transmitting hybrid array antenna has at least the following advantages: The all-metal dual-band low-profile folded reflective-transmitting hybrid array antenna of this application consists of only four metal layers. The first and second metal layers constitute the transmitting surface, and the third and fourth metal layers constitute the reflecting surface. It has no dielectric substrate structure, achieving a dual-band, independently controllable folded reflective-transmitting hybrid metasurface array through a planar pure metal structure. Compared to existing pure metal antenna arrays, it improves integration and space utilization; compared to existing traditional substrate antennas, it significantly reduces cost and improves aperture efficiency and reliability in harsh environments.

[0007] According to the embodiment of this application, the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna has a first hollow structure comprising a first arc groove and a second arc groove arranged concentrically. The opening direction of the first arc groove is perpendicular to the opening direction of the second arc groove, and the radius of the first arc groove is greater than the radius of the second arc groove.

[0008] According to the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna described in the embodiments of this application, the opening angle of the first circular arc slot is smaller than the opening angle of the second circular arc slot.

[0009] According to the embodiments of this application, the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna, the second hollow structure includes a third circular arc groove and a fourth circular arc groove arranged concentrically, the opening direction of the third circular arc groove is the same as the opening direction of the fourth circular arc groove, and the radius of the third circular arc groove is greater than the radius of the fourth circular arc groove.

[0010] According to the embodiments of this application, the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna has the third arc groove concentric with the first arc groove and has the same opening orientation and radius. The opening orientation of the fourth arc groove is perpendicular to the opening orientation of the second arc groove, and the opening size and radius of the fourth arc groove are the same as those of the second arc groove.

[0011] According to the embodiments of this application, the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna includes a third hollow structure comprising a first channel and a second channel intersecting at the center of the first reflective surface unit. The first channel is perpendicular to the second channel, and the width of the first channel is greater than the width of the second channel.

[0012] According to the embodiment of this application, the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna has a fifth arc groove at both ends of the first channel and at both ends of the second channel, with the inner side of the fifth arc groove facing the center of the first reflective surface unit.

[0013] According to the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna described in the embodiments of this application, the third hollow structure further includes a first slot structure and a second slot structure orthogonal to the center of the first reflective surface unit. The first slot structure includes two third channels, one end of which faces the center of the first reflective surface unit, and the other end of which extends to the edge of the first reflective surface unit and is open. The second slot structure includes two fourth channels, one end of which faces the center of the first reflective surface unit, and the other end of which extends to the edge of the first reflective surface unit and is open. The slot width of the third channel is greater than the slot width of the fourth channel.

[0014] According to the embodiment of this application, the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna has a sixth arc groove at one end of the third and fourth channels facing the center of the first reflective surface unit. The outer side of the sixth arc groove faces the center of the first reflective surface unit. The third channel is perpendicular to the first channel or the second channel. The first reflective surface unit is rectangular in shape. The third and fourth channels are both located at the corners of the first reflective surface unit.

[0015] According to the embodiments of this application, the thickness of all metal layers is set to 0.2-0.5 mm, there is an air gap layer between the first metal layer and the second metal layer, and there is an air gap layer between the third metal layer and the fourth metal layer.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The present application will be further described below with reference to the accompanying drawings and embodiments; Figure 1This is a schematic diagram of the structure of the all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna according to an embodiment of this application; Figure 2 This is a schematic diagram of the cross-sectional principle of an all-metal dual-frequency low-profile folded reflective-transmitting hybrid array antenna in an embodiment of this application; Figure 3 This is a schematic diagram of the frequency selector in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the first transmissive surface unit in an embodiment of this application. Figure 1 ; Figure 5 This is a schematic diagram of the structure of the first transmissive surface unit in an embodiment of this application. Figure 2 ; Figure 6 This is a schematic diagram of the structure of the second transmission surface unit in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of the first reflective surface unit in an embodiment of this application. Figure 1 ; Figure 8 This is a schematic diagram of the structure of the first reflective surface unit in an embodiment of this application. Figure 2 ; Figure 9 This is a schematic diagram of the structure of the first reflective surface unit in an embodiment of this application. Figure 3 ; Figure 10 This is a schematic diagram of the structure of the first metal layer in an embodiment of this application; Figure 11 yes Figure 10 Enlarged view of point A in the middle; Figure 12 This is a schematic diagram of the structure of the second metal layer in an embodiment of this application; Figure 13 yes Figure 12 Enlarged view of point B in the middle; Figure 14 This is a schematic diagram of the structure of the third metal layer in an embodiment of this application; Figure 15 yes Figure 14 Enlarged view of point C in the middle; Figure 16 This is a schematic diagram of the structure of the fourth metal layer in an embodiment of this application; Figure 17 This is a schematic diagram of the low-frequency phase distribution in an embodiment of this application; Figure 18 This is a schematic diagram of the high-frequency phase distribution in an embodiment of this application; Figure 19 This is the array normalized radiation pattern (E-plane, H-plane) at a low frequency of 26 GHz in this embodiment of the application. Figure 20 This is the array normalized radiation pattern (E-plane, H-plane) at a high frequency of 36 GHz in this embodiment of the application. Figure 21 In the embodiments of this application, the antenna array gain and aperture efficiency are described.

[0018] Reference numerals: First metal layer 100, first transmissive surface unit 101, first arc groove 110, second arc groove 120, second metal layer 200, second transmissive surface unit 201, third arc groove 210, fourth arc groove 220, third metal layer 300, first reflective surface unit 301, first channel 310, fifth arc groove 311, second channel 320, third channel 330, sixth arc groove 331, fourth channel 340, fourth metal layer 400, placement groove 401. Detailed Implementation

[0019] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.

[0020] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0023] Reference Figure 1 and Figure 2The all-metal dual-band low-profile folded reflective-transmitting hybrid array antenna provided in this application includes a feed unit and a first metal layer 100, a second metal layer 200, a third metal layer 300 and a fourth metal layer 400 arranged sequentially. The first metal layer 100 and the second metal layer 200 form a transmission module, and the third metal layer 300 and the fourth metal layer 400 form a reflection module. The feed unit is disposed at the center of the reflection module.

[0024] Specifically, such as Figure 10 and Figure 11 As shown, the first metal layer 100 includes a plurality of arrayed first transmissive surface units 101, and each first transmissive surface unit 101 includes a first perforated structure; as shown Figure 12 and Figure 13 As shown, the second metal layer 200 includes a plurality of arrayed second transmission surface units 201. Each second transmission surface unit 201 includes a second hollow structure. The first hollow structure and the second hollow structure cooperate to form a frequency selector. The frequency selector can selectively transmit low-frequency incident waves and selectively polarize orthogonally convert and phase-compensate high-frequency incident waves before transmitting them.

[0025] like Figure 14 and Figure 15 As shown, the third metal layer 300 includes a plurality of arrayed first reflective surface units 301, and each first reflective surface unit 301 includes a third hollow structure; as Figure 16 As shown, the fourth metal layer 400 is a metal ground layer. The fourth metal layer 400, in conjunction with the third hollow structure, can convert the incident linearly polarized wave into a linearly polarized wave orthogonal to the incident linear polarization, and can perform phase compensation for the reflected low-frequency incident wave.

[0026] The thickness of all metal layers is set to 0.2-0.5 mm. There is an air gap between the first metal layer 100 and the second metal layer 200, and there is an air gap between the third metal layer 300 and the fourth metal layer 400.

[0027] In some of the illustrated embodiments, the all-metal dual-band low-profile folded reflective-transmittive hybrid array antenna provided in this application consists of only four metal layers, referred to as layers ABCD from top to bottom. Layer AB constitutes the upper transmitting surface, and layer CD constitutes the lower reflecting surface, with each layer having a thickness of 0.3 mm. The entire antenna structure has no dielectric substrate structure, and the feed element uses a waveguide horn feed. The center of the bottom layer (layer CD) is hollowed out to accommodate the horn feed. The all-metal dual-band low-profile folded reflective-transmittive hybrid array antenna of this application operates in the millimeter-wave Ka-band (26 GHz-40 GHz). The low-frequency operation at 26 GHz is a commonly used band for 5G communication; the high-frequency operation at 36 GHz is a commonly used band for meteorological satellite antennas, and the feed waveguide is WR28.

[0028] At a low frequency of 26 GHz, the all-metal dual-frequency low-profile folded reflection-transmission hybrid array antenna of this application is an overall folded reflection array. The linearly polarized wave is incident from the feed source and is totally reflected when it reaches the lower surface of the second metal layer 200. It then reaches the upper surface of the third metal layer 300. The third metal layer 300 and the fourth metal layer 400 perform polarization conversion and phase compensation on the incident wave and then reflect it. At this time, the wave is a plane wave with concentrated energy and can be directly emitted into free space through the first metal layer 100 and the second metal layer 200. The wave folds twice in the array, and the profile height H is reduced to 1 / 2 of the focal length F.

[0029] At a high frequency of 36 GHz, the all-metal dual-band low-profile folded reflection-transmission hybrid array antenna array of this application is an overall folded transmission array. When the wave is incident from the feed, it is totally reflected when it reaches the lower surface of the second metal layer 200, and then to the upper surface of the third metal layer 300. The third metal layer 300 and the second metal layer 200 perform polarization conversion on the high-frequency incident wave and then reflect it without phase compensation. When the wave reaches the lower surface of the second metal layer 200 again, it undergoes phase compensation under the action of the first metal layer 100 and the second metal layer 200 and is transmitted into free space. The wave folds three times in the array, and the profile height H is reduced to 1 / 3 of the focal length F.

[0030] In some embodiments, such as Figures 3 to 5 As shown, the first hollow structure includes a first arc groove 110 and a second arc groove 120 arranged concentrically. The opening direction of the first arc groove 110 is perpendicular to the opening direction of the second arc groove 120. The radius of the first arc groove 110 is larger than the radius of the second arc groove 120. The opening angle of the first arc groove 110 is smaller than the opening angle of the second arc groove 120.

[0031] like Figure 6 As shown, the second hollow structure includes a third arc groove 210 and a fourth arc groove 220 arranged concentrically. The opening direction of the third arc groove 210 is the same as that of the fourth arc groove 220, and the radius of the third arc groove 210 is larger than that of the fourth arc groove 220. The third arc groove 210 is concentric with the first arc groove 110 and has the same opening direction and radius. The opening direction of the fourth arc groove 220 is perpendicular to the opening direction of the second arc groove 120, and the opening size and radius of the fourth arc groove 220 are the same as those of the second arc groove 120.

[0032] like Figure 6 As shown, the side length of the transmission surface unit The thickness is 4.5mm (corresponding to a high frequency of 0.54λ, where λ is the free space wavelength corresponding to the design frequency). The second metal layer 200 (bottom layer) is etched with two concentric arc grooves with the same opening direction. The third arc groove 210 operates at a low frequency of 26GHz, and the fourth arc groove 220 operates at a high frequency of 36GHz. Both of them will totally reflect linearly polarized waves parallel to the arc direction at their respective frequencies, and at the same time completely transmit linearly polarized waves orthogonal to the arc direction.

[0033] The first metal layer 100 (Top layer) also has two concentric arc grooves, but their directions are orthogonal. The first arc groove 110 is parallel to the third arc groove 210 and has the same parameter direction, while the second arc groove 120 is orthogonal to the fourth arc groove 220 and has the same parameter direction. The first arc groove 110 and the third arc groove 210 work together to form a polarization-selective transmission structure for low-frequency incident waves, that is, linearly polarized waves parallel to the direction of the arc groove in the low-frequency band will be totally reflected, while linearly polarized waves orthogonal to them will be totally transmitted.

[0034] Simultaneously, the second circular arc groove 120 and the fourth circular arc groove 220 act at high frequencies, jointly forming a structure similar to an FP cavity (Fabry-Perot resonator). That is, linearly polarized waves parallel to the direction of the arc grooves in the high-frequency band will be totally reflected, while linearly polarized waves orthogonal to them will undergo polarization orthogonal conversion and phase compensation before transmission. This can be achieved by changing the opening angle of the fourth circular arc groove 220. Phase compensation is performed on the high-frequency transmitted waves. For the phase range of 0-180°, state 0 is used, and the opening angles of the second circular arc groove 120 and the fourth circular arc groove 220 are changed to adjust the phase. For the range of 180-360°, the second circular arc groove 120 of the first metal layer 100 is mirrored before the arc angle is changed for phase adjustment. The isolation between high and low frequencies is high, meaning that the low-frequency performance is basically not affected during high-frequency phase adjustment.

[0035] For the transmission surface composed of the first metal layer 100 and the second metal layer 200, the metal material parameters are copper, with a thickness of 0.3 mm and an electrical conductivity of 5.8 × 10⁷ S / m; the unit period is... =4.5mm, corresponding to 0.4 times the wavelength for low frequency and 0.54 times the wavelength for high frequency. The parameters and directions of the two outer grooves (i.e., the first arc-shaped groove and the third arc-shaped groove) are exactly the same, and the outer radius is 4.5mm. It is 2.15mm, inner radius It is 1.8mm, and the arc angle is... The angle is 168°; the two inner grooves (the second and fourth arc-shaped grooves) have the same parameters, but their directions are orthogonal, and their outer radii are... It is 1.5mm, inner radius The height of the air cavity between the two layers is 1mm. It is 1mm. By adjusting the inner arc angle High-frequency phase compensation, adjusted to an angle of 148-178°, can achieve 180° phase coverage. Mirroring the two states allows for 360° phase coverage, while the cross-polarized transmission insertion loss is better than -1.8dB. It is important to note that if an x-polarized feed is used, the inner and outer arcs (the third and fourth arc slots) of the second metal layer 200 should be parallel to the x-axis, and conversely, parallel to the y-axis.

[0036] like Figures 7 to 9 The third hollow structure includes a first channel 310 and a second channel 320 intersecting the center of the first reflective surface unit 301. The first channel 310 and the second channel 320 are perpendicular, and the width of the first channel 310 is greater than the width of the second channel 320. A fifth arc groove 311 is provided at both ends of the first channel 310 and both ends of the second channel 320, and the inner side of the fifth arc groove 311 faces the center of the first reflective surface unit 301.

[0037] In some other embodiments, the third hollow structure also includes a first groove structure and a second groove structure orthogonal to the center of the first reflective surface unit 301. The first groove structure includes two third channels 330, one end of which faces the center of the first reflective surface unit 301 and the other end of which extends to the edge of the first reflective surface unit 301 and is open. The second groove structure includes two fourth channels 340, one end of which faces the center of the first reflective surface unit 301 and the other end of which extends to the edge of the first reflective surface unit 301 and is open. The width of the third channel 330 is greater than the width of the fourth channel 340.

[0038] The third channel 330 and the fourth channel 340 are provided with a sixth arc groove 331 at one end facing the center of the first reflective surface unit 301. The outer side of the sixth arc groove 331 faces the center of the first reflective surface unit 301. The third channel 330 is perpendicular to the first channel 310 or the second channel 320. The first reflective surface unit 301 is rectangular in shape. The third channel 330 and the fourth channel 340 are both located at the corners of the first reflective surface unit 301.

[0039] like Figure 8 As shown, the side length of the reflective surface unit The thickness is 5mm (corresponding to a high frequency of 0.6λ). The fourth metal layer 400 is a metal ground layer with a hollowed-out slot 401 for placing the feed speaker in the middle; the third metal layer 300 is composed of staggered cross-shaped units (i.e., the third hollowed-out structure). Each cross-shaped unit consists of two orthogonal rectangular slots (the first slot 310 and the second slot 320) with different widths and an arc structure at its end (the fifth arc slot 311). The overall structure parameters are completely consistent except for the different widths of the rectangular slots. The direction of the rectangular slots is 45 degrees.

[0040] The larger cross-shaped structure (i.e., the cross-shaped structure formed by the first channel 310 and the second channel 320) operates at a low frequency of 26 GHz and has two functions: 1. Efficiently converting the incident linearly polarized wave into its orthogonal linearly polarized wave (x-polarized wave to y-polarized wave, y-polarized wave to x-polarized wave); 2. By changing the arc aperture degree... Phase compensation of the reflected wave can be achieved by changing the aperture angle within the 0-180° range. Within the 180-360° range, the entire unit must be mirror-symmetrical before changing the aperture angle (corresponding to two states) to achieve a 360° phase compensation range. Smaller cross-shaped structures (combined with...) Figure 15 To understand this, the third and fourth slots (330 and 340) operate at a high frequency of 36 GHz. Their structure is consistent with larger cross-shaped structures, but they only perform polarization conversion for high-frequency waves and do not require changing the opening angle of the arc slot (i.e., the sixth arc slot 331) for phase compensation. The isolation between high and low frequencies is high, and the high-frequency performance is basically unaffected during low-frequency phase modulation.

[0041] The reflective surface, composed of the third metal layer 300 and the fourth metal layer 400, is also made of copper, with a unit period... =5mm, corresponding to 0.44 times the wavelength at low frequencies and 0.59 times the wavelength at high frequencies. For larger cross-shaped slots (composed of the first slot 310 and the second slot 320), such as Figure 8 As shown, outer radius It is 1.9mm, inner radius The width of the connecting groove is 1.5mm. The width of the finer connecting groove is 0.35mm. The outer diameter is 0.2mm; for smaller cross-grooves, the outer diameter is... It is 1.45mm, inner radius The width of the connecting groove is 1.05mm. The width of the narrower connecting groove is 0.48mm. It is 0.35mm, and the end arc angle is The angle is 70°. The height of the air cavity between the two layers is... The diameter is 1.7mm, achieved by adjusting the arc angle of the end arc groove of the larger cross-shaped groove (third hollow structure). Low-frequency phase compensation is performed, with an adjustment range of 19-43°, to achieve 180° phase coverage. After mirroring the two states, 360° phase coverage can be achieved, while the cross-polarization reflection insertion loss is better than -1.5dB.

[0042] For the overall antenna array, a standard gain horn feed is placed between the third metal layer 300 and the fourth metal layer 400 through a hole. The first metal layer 100 and the second metal layer 200 each consist of 20*20=400 elements (90mm*90mm), and the third metal layer 300 consists of 18*18=324 elements (90mm*90mm). The fourth metal layer 400 serves as the metal ground. A metal frame with holes is added around the array for fixation. The distance H between the third metal layer 300 and the second metal layer 200 is set to 31mm. For a low frequency of 26GHz, the focal length... The focal length is 62mm (2H), corresponding to an F / D of 0.69; for a high frequency of 36GHz, the focal length is... It is 93mm (3H), corresponding to an F / D of 1.

[0043] in, Figure 17 and Figure 18 This is a calculation of the element phase distribution using MATLAB, based on the known operating frequency and focal length, by substituting these parameters into the calculation formula. By using parameters such as focal length, array size, and frequency, combined with relevant calculation formulas, the required compensation phase for each element in the array can be calculated. Figure 17 and Figure 18 The phase diagram shown should be used to arrange the cells into an array.

[0044] like Figure 19 The normalized radiation pattern of the array at a low frequency of 26 GHz on the two principal planes (E plane and H plane) shows that there is a distinct pencil beam at the expected θ=0°, the sidelobe level is better than -14dB, the back lobe is better than -28dB, and the cross-polarization level is better than -22dB, indicating excellent radiation performance at low frequency.

[0045] like Figure 20 The array normalized radiation pattern at 36 GHz on the two principal planes (E plane and H plane) shows that there is a distinct pencil beam at the expected θ=0°, the sidelobe level is better than -14 dB, the back lobe is better than -28 dB, and the cross-polarization level is better than -22 dB, indicating excellent radiation performance at high frequencies.

[0046] like Figure 21 The diagram shows the overall gain and aperture efficiency of the antenna. In the low-frequency band, the maximum gain is 25.1 dBi, corresponding to a maximum aperture efficiency of 42.6%, and a 3-dB bandwidth gain of 8%. In the high-frequency band, the maximum gain is 28.2 dBi, corresponding to a maximum aperture efficiency of 45.9%, and a 3-dB bandwidth gain of 8%. This demonstrates that the antenna has the advantages of high gain and high efficiency.

[0047] In summary, the main beneficial effects of this application are as follows: 1. A dual-frequency, independently controllable folded transmission and reflection hybrid metasurface array is achieved through a planar pure metal structure.

[0048] 2. For the two pure metal units, the first metal layer 100 and the second metal layer 200, polarization selectivity and frequency selectivity are achieved simultaneously by etching the inner and outer double arc structures, so as to achieve phase compensation for high frequency without affecting low frequency transmission.

[0049] 3. For the two pure metal units, the third metal layer 300 and the fourth metal layer 400, the polarization conversion function of high and low frequencies is realized by etching a cross-shaped structure in an alternating arrangement, and the phase compensation of low frequencies is realized without affecting the high frequency reflection.

[0050] Compared to existing pure metal antenna arrays, it improves integration and space utilization, and enables more complex functions. Compared to existing traditional substrate antennas, it significantly reduces costs, improves aperture efficiency, and enhances reliability in harsh environments.

[0051] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A full metal dual-band low-profile folded reflect-transmit hybrid array antenna, characterized in that: It includes a feed unit and a first metal layer, a second metal layer, a third metal layer and a fourth metal layer arranged sequentially, wherein the first metal layer and the second metal layer form a transmission module, the third metal layer and the fourth metal layer form a reflection module, and the feed unit is disposed at the center of the reflection module; The first metal layer includes a plurality of arrayed first transmissive surface units, and the first transmissive surface unit includes a first hollow structure; The second metal layer includes a plurality of arrayed second transmission surface units, each of which includes a second cutout structure. The first cutout structure and the second cutout structure cooperate to form a frequency selector. The frequency selector is capable of selectively transmitting low-frequency incident waves and selectively orthogonally converting and phase-compensating high-frequency incident waves before transmitting them. The third metal layer includes a plurality of arrayed first reflective surface units, and the first reflective surface unit includes a third hollow structure; The fourth metal layer is a metal ground layer. The fourth metal layer, in conjunction with the third hollow structure, can convert the incident linearly polarized wave into a linearly polarized wave orthogonal to the incident linear polarization, and can perform phase compensation on the reflected low-frequency incident wave.

2. The all-metal dual-band low-profile folded reflect-transmit array antenna according to claim 1, characterized in that: The first hollow structure includes a first arc groove and a second arc groove arranged concentrically. The opening direction of the first arc groove is perpendicular to the opening direction of the second arc groove, and the radius of the first arc groove is greater than the radius of the second arc groove.

3. The all-metal dual-band low-profile folded reflect-transmit array antenna according to claim 2, characterized in that: The opening angle of the first arc groove is smaller than the opening angle of the second arc groove.

4. The all-metal dual-band low-profile folded reflect-transmit mixed array antenna according to claim 2 or 3, characterized in that: The second hollow structure includes a third arc groove and a fourth arc groove arranged concentrically. The opening direction of the third arc groove is the same as that of the fourth arc groove, and the radius of the third arc groove is greater than that of the fourth arc groove.

5. The all-metal dual-band low-profile folded reflect-transmit-hybrid array antenna according to claim 4, characterized in that: The third arc groove is concentric with the first arc groove and has the same opening orientation and radius. The opening orientation of the fourth arc groove is perpendicular to the opening orientation of the second arc groove. The opening size and radius of the fourth arc groove are the same as those of the second arc groove.

6. The all-metal dual-band low-profile folded reflect-transmit-hybrid array antenna according to claim 1, characterized in that: The third hollow structure includes a first channel and a second channel intersecting at the center of the first reflective surface unit. The first channel is perpendicular to the second channel, and the width of the first channel is greater than the width of the second channel.

7. The all-metal dual-band low-profile folded reflect-transmit-hybrid array antenna according to claim 6, characterized in that: Both ends of the first channel and both ends of the second channel are provided with a fifth arc groove, and the inner side of the fifth arc groove faces the center of the first reflective surface unit.

8. The all-metal dual-band low-profile folded reflect-transmit-hybrid array antenna according to claim 6, characterized in that: The third hollow structure further includes a first groove structure and a second groove structure orthogonal to the center of the first reflective surface unit. The first groove structure includes two third channels, one end of which faces the center of the first reflective surface unit and the other end of which extends to the edge of the first reflective surface unit and is open. The second groove structure includes two fourth channels, one end of which faces the center of the first reflective surface unit and the other end of which extends to the edge of the first reflective surface unit and is open. The width of the third channel is greater than the width of the fourth channel.

9. The all-metal dual-band low-profile folded reflect-transmit-hybrid array antenna according to claim 8, characterized in that: The third channel and the fourth channel are provided with a sixth arc groove at one end facing the center of the first reflective surface unit. The outer side of the sixth arc groove faces the center of the first reflective surface unit. The third channel is perpendicular to the first channel or the second channel. The first reflective surface unit is rectangular in shape. The third channel and the fourth channel are both located at the corners of the first reflective surface unit.

10. The all-metal dual-band low-profile folded reflective-transmissive hybrid array antenna of claim 1, wherein: The thickness of all metal layers is set to 0.2-0.5 mm. There is an air gap layer between the first metal layer and the second metal layer, and there is an air gap layer between the third metal layer and the fourth metal layer.

Images