A broadband circularly polarized metasurface antenna

Abstract

The present invention discloses a broadband circularly polarized metasurface antenna, comprising at least one metasurface antenna unit, the antenna unit comprising a linearly polarized wave receiving patch assembly, a first dielectric layer, a metal floor, a connecting layer, a second dielectric layer and a circularly polarized electromagnetic wave transmitting mechanism, the linearly polarized wave receiving patch assembly and the circularly polarized wave transmitting mechanism are connected through a metal column; the linearly polarized wave receiving patch assembly comprises a first linearly polarized wave receiving patch and a second linearly polarized wave receiving patch with 180-degree rotational symmetry. The antenna can efficiently receive linearly polarized incident waves, and transmit them to a circularly polarized electromagnetic wave transmitting mechanism of a double-arm helical structure through a metal column. The above layout enables the metal column to generate a reverse current, forming a balanced differential feeding mechanism, providing efficient differential feeding, and the linearly polarized electromagnetic wave is converted into broadband circularly polarized electromagnetic wave radiation. The bandwidth range of the metasurface antenna can reach 15.3~28.4 GHz, and the transmission amplitude is higher than ‑1.2dB, achieving the effects of broadband, low loss and high transmission efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas and relates to a super-surface antenna, in particular to a broadband circularly polarized super-surface antenna. Background Art

[0002] With the rapid development of wireless communication technology, the requirements for antenna performance are becoming higher and higher. In order to meet the urgent needs of modern wireless communication systems for high bandwidth, high gain and high stability, metasurface antennas have attracted much attention in recent years. A metasurface antenna is an antenna composed of multiple unit electromagnetic components. Each unit electromagnetic component is a tiny conductor sheet. The shape and arrangement of these conductor sheets can be optimized according to specific needs. When electromagnetic waves pass through these conductor sheets, they are reflected, transmitted and diffracted, thus forming a specific electromagnetic wave radiation pattern.

[0003] Metasurface antennas mainly include transmission array antennas and reflection array antennas, which are similar in function to lens antennas and reflector antennas. They can accurately compensate for the phase of the quasi-spherical wave from the feed source and convert it into a plane wave, thereby forming a high-gain unidirectional pencil beam. This feature is crucial in the wireless transmission of signals. It not only helps to overcome the path loss problem in long-distance signal transmission, but also significantly improves the channel quality. At the same time, compared with traditional lens antennas and reflector antennas, transmission array antennas and reflection array antennas also have the advantage of compact structure. By adopting a planar design, they also greatly reduce weight, reduce space occupied, and reduce overall manufacturing costs.

[0004] Compared with reflector array antennas, transmission array antennas have the advantage of no feed blockage problem, which makes the design of their radiation patterns more flexible and not restricted by specific directions. In addition, compared with traditional linearly polarized antennas, circularly polarized antennas have the advantage of being able to effectively reduce multipath interference and signal fading problems, resist the Faraday rotation effect, and reduce the performance loss caused by polarization misalignment between the transmitting and receiving antennas. Therefore, in wireless communication systems, especially satellite communication systems, circularly polarized transmission array antennas have more superior performance. However, in the prior art, conventional circularly polarized transmission array antennas have the problems of narrow bandwidth (<40%) and poor transmission efficiency, which limits their application. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is that the existing circularly polarized metasurface antenna has a narrow bandwidth and low transmission efficiency, and thus a broadband circularly polarized metasurface antenna with high transmission efficiency is proposed.

[0006] In order to solve the above technical problems, the technical solution of the present invention is:

[0007] The present invention provides a broadband circularly polarized metasurface antenna, which comprises at least one metasurface antenna unit; each of the metasurface antenna units comprises a linearly polarized wave receiving patch assembly, a first dielectric layer, a metal floor, a connecting layer, a second dielectric layer and a circularly polarized electromagnetic wave transmitting mechanism which are connected in sequence; the receiving patch assembly is connected to the circularly polarized electromagnetic wave transmitting mechanism via a metal column which penetrates the first dielectric layer, the metal floor, the connecting layer and the second dielectric layer; wherein the linearly polarized wave receiving patch assembly comprises a first linearly polarized wave receiving patch and a second linearly polarized wave receiving patch which are arranged with 180-degree rotational symmetry, and the circularly polarized electromagnetic wave transmitting mechanism is a double-arm helical structure.

[0008] Preferably, the circularly polarized electromagnetic wave transmitting mechanism is a two-arm Archimedean spiral structure, which includes a first Archimedean spiral arm and a second Archimedean spiral arm, wherein the second Archimedean spiral arm is spaced apart from the first Archimedean spiral arm, and the second Archimedean spiral arm is rotationally symmetric relative to the first Archimedean spiral arm.

[0009] Preferably, the metal column is a metallized via, the metallized via includes a first metallized via and a second metallized via arranged at intervals, the first Archimedean spiral arm includes a first connecting portion, the first connecting portion is connected to a first linearly polarized wave receiving patch through the first metallized via, and the first Archimedean spiral arm extends spirally outward with the first connecting portion as the axis; the second Archimedean spiral arm includes a second connecting portion, the second connecting portion is connected to the second linearly polarized wave receiving patch through the second metallized via, and the second Archimedean spiral arm extends spirally outward with the second connecting portion as the axis.

[0010] Preferably, the center distance between the first connecting portion and the second connecting portion is 0.025λ-0.08λ, where λ is the wavelength corresponding to the working center frequency of the antenna.

[0011] Preferably, the equations of the first Archimedean spiral arm and the second Archimedean spiral arm in the rectangular coordinate system are:

[0012] X(t)=(r 0 +α 1 ·t)·cos(t);

[0013] Y(t)=(r 0 +α 1 ·t)·sin(t);

[0014] Where X(t) is the x-axis coordinate of the helical arm in the rectangular coordinate system, and Y(t) is the y-axis coordinate of the helical arm in the rectangular coordinate system; 0 is the starting radius; t is the winding angle, 0≤t≤2π·n1 , n1 is the number of revolutions of the spiral arm, and its value range is 0.9-2; α 1 is the spiral expansion rate, and its value range is 0.01-0.04λ;

[0015] Alternatively, the equations of the first Archimedean spiral arm and the second Archimedean spiral arm in the polar coordinate system are:

[0016] ρ = ρ 0 + α 1 ·Φ 1 ;

[0017] 0 ≤ Φ1 ≤ 2π·n 1 ;

[0018] where ρ is the radial distance from the center to a point on the spiral arm; 0 is the starting radius of the spiral arm, and its value range is 0.025λ-0.08λ; α 1 is the spiral expansion rate, and its value range is 0.01λ-0.04λ, Φ 1 Indicates the winding angle, n 1 is the number of revolutions of the spiral arm, and its value range is 0.9-2.

[0019] Preferably, the first linear polarized wave receiving patch and the second linear polarized wave receiving patch are both one of a semi-U-shaped slot patch, a U-shaped slot patch, a semi-E-shaped patch, and an E-shaped patch.

[0020] Preferably, the first linear polarization wave receiving patch and the second linear polarization wave receiving patch are half U-shaped slot patches, and the first linear polarization wave receiving patch and the second linear polarization wave receiving patch are rotationally symmetric; the lengths of the first linear polarization wave receiving patch and the second linear polarization wave receiving patch are both 0.4λ g -0.5λ g , the width is 0.2λ g -0.3λ g , where λ g It is the waveguide wavelength corresponding to the antenna operating center frequency.

[0021] Preferably, the first dielectric layer and the second dielectric layer are both rectangular dielectric plates, the length of the first dielectric layer is 0.35λ-0.5λ, the width is 0.35λ-0.5λ, and the thickness is 0.18λ-0.28λ; the length of the second dielectric layer is 0.35λ-0.5λ, the width is 0.35λ-0.5λ, and the thickness is 0.18λ-0.28λ; the connecting layer is a rectangular bonding layer, the length of the connecting layer is 0.35λ-0.5λ, the width is 0.35λ-0. .5λ, and a thickness of 0.08-0.2mm; the metal floor is a rectangular plate, the length of the metal floor is 0.35λ-0.5λ, and the width is 0.35λ-0.5λ, the metal floor is also provided with an avoidance groove for avoiding the metallized via, the diameter of the metallized via is 0.01λ-0.05λ, the avoidance groove is a circular groove or a square groove, and the diameter or side length of the avoidance groove is 0.1λ-0.25λ, wherein λ is the wavelength corresponding to the working center frequency of the antenna.

[0022] Preferably, it comprises 6 said super-surface antenna units connected in sequence along the horizontal direction, and the circularly polarized electromagnetic wave transmitting mechanisms of adjacent said super-surface antenna units have a phase difference of 60°.

[0023] Preferably, the six sequentially connected metasurface antenna units are respectively the first metasurface antenna unit, the second metasurface antenna unit, the third metasurface antenna unit, the fourth metasurface antenna unit, the fifth metasurface antenna unit and the sixth metasurface antenna unit; wherein, the linear polarized wave receiving patch assembly in the first metasurface antenna unit, the linear polarized wave receiving patch assembly in the second metasurface antenna unit and the linear polarized wave receiving patch assembly in the sixth metasurface antenna unit are flipped 180 degrees relative to the linear polarized wave receiving patch assembly in the third metasurface antenna unit, the linear polarized wave receiving patch assembly in the fourth metasurface antenna unit and the linear polarized wave receiving patch assembly in the fifth metasurface antenna unit.

[0024] The above technical solution of the present invention has the following advantages compared with the prior art:

[0025] The broadband circularly polarized metasurface antenna provided by the present invention comprises at least one metasurface antenna unit, each of which comprises a linearly polarized wave receiving patch assembly, a first dielectric layer, a metal floor, a connection layer, a second dielectric layer and a circularly polarized electromagnetic wave transmitting mechanism connected in sequence, and the linearly polarized wave receiving patch assembly is connected to the circularly polarized wave transmitting mechanism through a metal column; wherein the linearly polarized wave receiving patch assembly comprises a first linearly polarized wave receiving patch and a second linearly polarized wave receiving patch which are arranged 180 degrees rotationally symmetrically. By adopting the first linear polarization wave receiving patch and the second linear polarization wave receiving patch arranged with 180-degree rotational symmetry, the linear polarization incident wave of space feeding can be efficiently received, and the linear polarization incident wave is transmitted to the circularly polarized electromagnetic wave transmitting mechanism of the double-arm spiral structure through the metal column. The above-mentioned 180-degree rotational symmetry layout enables the metal column to generate reverse current, forming a balanced differential feeding mechanism, providing efficient differential feeding for the circularly polarized electromagnetic wave transmitting mechanism, and the linear polarization electromagnetic wave is converted into broadband circularly polarized electromagnetic wave radiation. The bandwidth range of the metasurface antenna can reach 15.3~28.4 GHz, and the transmission amplitude is higher than -1.2dB, achieving the technical effects of broadband, low loss and high transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0027] Figure 1 is a schematic diagram of an exploded view of a metasurface antenna unit in a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0028] Figure 2 is a perspective schematic diagram of a metasurface antenna unit in a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0029] Figure 3 is another exploded schematic diagram of a metasurface antenna unit in a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0030] Figure 4 It is a schematic structural diagram of a metasurface antenna unit in a broadband circularly polarized metasurface antenna provided in an embodiment of the present invention;

[0031] Figure 5 is a side view of a metasurface antenna unit in a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0032] Figure 6 It is a schematic diagram of the top surface structure of a metasurface antenna unit in a broadband circularly polarized metasurface antenna provided in an embodiment of the present invention;

[0033] Figure 7It is a schematic diagram of the bottom structure of a metasurface antenna unit in a broadband circularly polarized metasurface antenna provided in an embodiment of the present invention;

[0034] Figure 8 It is a structural schematic diagram of another implementation of a linearly polarized wave receiving patch component in a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0035] Fig. 9 It is a structural schematic diagram of another implementation of a linearly polarized wave receiving patch component in a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0036] Fig.10 It is a structural schematic diagram of another implementation of a linearly polarized wave receiving patch component in a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0037] Fig.11 is a schematic diagram of the top surface structure of a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0038] Fig.12 It is a schematic diagram of the bottom structure of a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0039] Fig.13 is an unwinding phase curve diagram of a broadband circularly polarized metasurface antenna provided by an embodiment of the present invention;

[0040] Fig.14 It is a transmission amplitude curve diagram of the broadband circularly polarized metasurface antenna provided by an embodiment of the present invention.

[0041] The reference numerals in the figure are represented as follows: 100-supersurface antenna unit; 1-linearly polarized wave receiving patch assembly; 11-first linearly polarized wave receiving patch; 12-second linearly polarized wave receiving patch; 2-first dielectric layer; 3-metal floor; 4-connecting layer; 5-second dielectric layer; 6-circularly polarized electromagnetic wave transmitting mechanism; 61-first Archimedean spiral arm; 611-first connecting part; 62-second Archimedean spiral arm; 621-second connecting part; 7-metal column; 71-first metallized via; 72-second metallized via. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0043] In the description of the present invention, it should be understood that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the present invention are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. These are merely 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 orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] The terms “first”, “second”, etc. in the present invention are only used to distinguish between the two in the description and have no special meaning.

[0045] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting" and "installation" 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 direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Example

[0047] This embodiment provides a broadband circularly polarized metasurface antenna. Figure 1-Figure 7 The broadband circularly polarized metasurface antenna includes at least one metasurface antenna unit 100, each metasurface antenna unit 100 includes a linear polarized wave receiving patch assembly 1, a first dielectric layer 2, a metal floor 3, a connection layer 4, a second dielectric layer 5 and a circular polarized electromagnetic wave transmitting mechanism 6 connected in sequence from bottom to top, and the linear polarized wave receiving patch assembly 1 is connected to the circular polarized electromagnetic wave transmitting mechanism 6 through a metal column 7 that penetrates the first dielectric layer 2, the metal floor 3, the connection layer 4, and the second dielectric layer 5. Among them, the linear polarized wave receiving patch assembly 1 includes a first linear polarized wave receiving patch 11 and a second linear polarized wave receiving patch 12 that are arranged 180 degrees rotationally symmetrically.

[0048] The broadband circularly polarized patch antenna adopts a first linearly polarized wave receiving patch 11 and a second linearly polarized wave receiving patch 12 that are rotationally symmetrically arranged, and a circularly polarized electromagnetic wave transmitting mechanism 6 with a double-arm spiral structure that is connected to the first linearly polarized wave receiving patch 11 and the second linearly polarized wave receiving patch 12 through a metal column 7. The first linearly polarized wave receiving patch 11 and the second linearly polarized wave receiving patch 12 can efficiently receive a linearly polarized incident wave fed by space. When the linearly polarized incident wave is incident, an induced current is generated on the surface of the first linearly polarized wave receiving patch 11 and the second linearly polarized wave receiving patch 12. The induced current is transmitted to the circularly polarized electromagnetic wave transmitting mechanism 6 with a double-arm spiral structure through the metal column 7. In this process, a free space wave is converted into a guided wave, and then the guided wave is converted into a free space wave, thereby achieving an effect of converting a linearly polarized wave into a circularly polarized wave. At the same time, the first linear polarization wave receiving patch 11 and the second linear polarization wave receiving patch 12, which are arranged with 180-degree rotational symmetry, can cause the metal column 7 to generate a reverse current. The metal column 7 carrying the reverse current then forms a balanced differential feeding structure, providing efficient differential feeding for the circularly polarized electromagnetic wave transmitting mechanism 6 of the double-arm spiral structure, thereby realizing broadband circularly polarized radiation. It is a broadband circularly polarized metasurface transmission array antenna with a bandwidth range of up to 15.3~28.4 GHz and a transmission amplitude higher than -1.2dB, achieving the technical effects of broadband, low loss and high transmission efficiency.

[0049] like Figure 1-Figure 4 , Figure 6 As shown, the circularly polarized electromagnetic wave transmitting mechanism 6 in the metasurface antenna unit 100 adopts a two-arm spiral structure: such as a two-arm Archimedean spiral structure or a two-arm equiangular spiral structure. Specifically in this embodiment, the circularly polarized electromagnetic wave transmitting mechanism 6 is a two-arm Archimedean spiral structure, which includes a first Archimedean spiral arm 61 and a second Archimedean spiral arm 62, the first Archimedean spiral arm 61 and the second Archimedean spiral arm 62 are arranged at intervals, and the second Archimedean spiral arm 62 is in a 180° rotationally symmetrical relationship with respect to the first Archimedean spiral arm 61, that is, the second Archimedean spiral arm 62 can overlap with the first Archimedean spiral arm 61 after rotating 180 degrees around a certain point on the plane.

[0050] In order to realize that the first linear polarized wave receiving patch 11 and the second linear polarized wave receiving patch 12 are respectively connected to the first Archimedean spiral arm 61 and the second Archimedean spiral arm 62 through the metal column 7, in this embodiment, the metal column 7 is specifically a metallized via that penetrates the first dielectric layer 2, the metal floor 3, the connection layer 4, and the second dielectric layer 5, and the metallized via specifically includes a first metallized via 71 and a second metallized via 72 that are arranged at intervals. The first Archimedean spiral arm 61 includes a first connecting portion 611, the first connecting portion 611 is connected to the first linear polarized wave receiving patch 11 through the first metallized via 71, and the first Archimedean spiral arm 61 extends outwardly in a spiral with the first connecting portion 611 as the axis. The second Archimedean spiral arm 62 includes a second connecting portion 621, the second connecting portion 621 is connected to the second linear polarized wave receiving patch 12 through the second metallized via 72, and the second Archimedean spiral arm 62 extends outwardly in a spiral with the second connecting portion 621 as the axis.

[0051] Among them, the center distance between the first connecting part 611 and the second connecting part 621 is 0.025λ-0.08λ. In this embodiment, λ is the wavelength corresponding to the working center frequency of the antenna. In this embodiment, preferably, the center distance between the first connecting part 611 and the second connecting part 621 is 0.055λ.

[0052] In the double-arm Archimedean spiral structure provided in this embodiment, the first Archimedean spiral arm 61 and the second Archimedean spiral arm 62 have the same equation due to their 180° rotational symmetry. In the rectangular coordinate system, the equations of the first Archimedean spiral arm 61 and the second Archimedean spiral arm 62 are both:

[0053] X(t)=(r 0 +α 1 ·t)·cos(t);

[0054] Y(t)=(r 0 +α 1 ·t)·sin(t);

[0055] Where X(t) is the x-axis coordinate of the helical arm in the rectangular coordinate system, and Y(t) is the y-axis coordinate of the helical arm in the rectangular coordinate system; 0 is the starting radius of the spiral arm, and its value range is 0.025λ-0.08λ; t is the winding angle, 0≤t≤2π·n 1 , n1 is the number of revolutions of the spiral arm, and its value range is 0.9-2; α 1 is the spiral expansion rate, and its value range is 0.01-0.04λ.

[0056] Alternatively, in the polar coordinate system, the equations of the first Archimedean spiral arm 61 and the second Archimedean spiral arm 62 are both:

[0057] ρ = ρ 0 + α 1 ·Φ 1 ;

[0058] 0 ≤ Φ1 ≤ 2π·n 1 ;

[0059] Where ρ is the radial distance from the center to a point on the spiral arm, and the center refers to the coordinate origin of the x-axis and y-axis of the double-arm spiral line; ρ 0 is the starting radius of the spiral arm, and its value range is 0.025λ-0.08λ; α 1 is the spiral expansion rate, and its value range is 0.01λ-0.04λ, Φ 1 Indicates the winding angle, n 1 is the number of revolutions of the spiral arm, and its value range is 0.9-2.

[0060] The circularly polarized electromagnetic wave transmitting mechanism 6 formed by the first Archimedean spiral arm 61 and the second Archimedean spiral arm 62 under the above equation has good circular polarization effect and wide bandwidth.

[0061] In order to achieve a high-efficiency linear polarization wave receiving effect, the first linear polarization wave receiving patch 11 and the second linear polarization wave receiving patch 12 in the linear polarization wave receiving patch assembly 1 can adopt the following shapes: a half-U-shaped slot patch (such as Figure 7 As shown), U-groove patch (as Figure 8 As shown), semi-E-type patch (such as Fig. 9 As shown), E-type patch (as Fig.10 Specifically, a U-shaped slot patch refers to a patch structure obtained by opening a U-shaped slot in the center of the patch; a semi-U-shaped slot patch is a patch structure obtained by cutting off half of the U-shaped slot patch in 8 along its y-direction midline, and it has a half-edge structure of a U-shaped slot. An E-shaped patch is a patch structure with an E-shaped cross-section, and the patch has two parallel rectangular slots to form an E-shaped structure; a semi-E-shaped patch is a patch structure with a U-shaped slot in the middle of the patch. Fig.10 The patch structure obtained by cutting half of the E-type patch along the y-direction midline has a half-edge structure of the E-type patch.

[0062] In this embodiment, preferably, the first linear polarization wave receiving patch 11 and the second linear polarization wave receiving patch 12 are both half-U-shaped slot patches, which can be obtained by cutting a U-shaped slot patch in half or opening an L-shaped through slot in a rectangular patch. That is, the first linear polarization wave receiving patch 11 and the second linear polarization wave receiving patch 12 both have half of a U-shaped through slot. Since the first linear polarization wave receiving patch 11 and the second linear polarization wave receiving patch 12 are in a 180-degree rotational symmetric relationship, the half-U-shaped slots in the first linear polarization wave receiving patch 11 and the second linear polarization wave receiving patch 12 also have a 180-degree rotational symmetric relationship. The half-U-shaped slot patch can excite four resonance point modes, thereby efficiently receiving y-polarized electromagnetic waves in a wide frequency band.

[0063] In this embodiment, the lengths of the first linear polarization wave receiving patch 11 and the second linear polarization wave receiving patch 12 are both 0.4λ g -0.5λ g , the width is 0.2λ g -0.3λ g , where λ g is the waveguide wavelength corresponding to the antenna working center frequency. In this embodiment, preferably, the lengths of the first linear polarized wave receiving patch 11 and the second linear polarized wave receiving patch 12 are both 0.45λ g , the width is 0.25λ g .

[0064] To further optimize the antenna performance, in this embodiment, the first dielectric layer 2 and the second dielectric layer 5 are both rectangular dielectric substrates, and can be made of Rogers RO3003, Rogers 5880, Rogers 5870 or Rogers 4350B materials, wherein the length of the first dielectric layer 2 is 0.35λ-0.5λ, preferably 0.4λ in this embodiment, the width is 0.35λ-0.5λ, preferably 0.4λ in this embodiment, and the thickness is 0.18λ-0.28λ, preferably 0.23λ in this embodiment. The size of the second dielectric layer 5 is the same as that of the first dielectric layer 2, the length is also 0.35λ-0.5λ, preferably 0.4λ in this embodiment, the width is 0.35λ-0.5λ, preferably 0.4λ in this embodiment, and the thickness is 0.18λ-0.28λ, preferably 0.23λ in this embodiment. The connection layer 4 is a rectangular plate-shaped adhesive layer, and its material can be Rogers 4450F, Rogers 4450D plate, which is xx, the length of the connection layer is 0.35λ-0.5λ, preferably 0.4λ in this embodiment, the width is 0.35λ-0.5λ, preferably 0.4λ in this embodiment, the thickness is 0.08-0.2mm, preferably 0.14mm in this embodiment, and it is used to bond the first dielectric layer 2 and the second dielectric layer 5. The metal floor is a rectangular PCB board, which has a metal copper layer, the length of the metal floor is 0.35λ-0.5λ, preferably 0.4λ in this embodiment, the width is 0.35λ-0.5λ, preferably 0.4λ in this embodiment, wherein the thickness of the metal floor is a standard size, 0.035mm or 0.018mm, and the metal floor serves as a common reflection floor for the linear polarization wave receiving patch assembly 1 and the circular polarization electromagnetic wave transmitting mechanism 6. The circularly polarized electromagnetic wave transmitting mechanism 6 and the linearly polarized wave receiving patch assembly 1 can be made of metals such as copper or aluminum.

[0065] In order to prevent the metal copper layer from affecting the metal column 7, the metal floor 3 is also provided with an avoidance groove 31 for avoiding the metallized via. The avoidance groove 31 can be a circular groove or a rectangular groove, as long as it can avoid being set on the outside of the two metal columns 7. The diameter of the metal column 7 is 0.01λ-0.05λ, and preferably 0.03λ in this embodiment. In this embodiment, the avoidance groove adopts a circular groove, and its diameter is 0.1λ-0.25λ, and preferably 0.2λ in this embodiment.

[0066] In order to achieve a beneficial broadband circularly polarized radiation effect and further achieve a better beam control effect, different transmission phases are formed on the surface of the metasurface antenna to achieve phase compensation, such as Figure 11-Figure 12 As shown, in this embodiment, the broadband circularly polarized metasurface antenna includes six of the above-mentioned metasurface antenna units 100. The six metasurface antenna units 100 are sequentially connected in the horizontal direction, and the phases of the circularly polarized electromagnetic wave transmitting mechanisms 6 in two adjacent metasurface antenna units 100 are sequentially different by 60°, as shown in FIG. Fig.11As shown, the six supersurface antenna units 100 are, from left to right, the first supersurface antenna unit, the second supersurface antenna unit, the third supersurface antenna unit, the fourth supersurface antenna unit, the fifth supersurface antenna unit and the sixth supersurface antenna unit, wherein the phase of the first supersurface antenna unit is 0°, the phase of the second supersurface antenna unit is 60°, the phase of the third supersurface antenna unit is 120°, the phase of the fourth supersurface antenna unit is 180°, the phase of the fifth supersurface antenna unit is 240°, and the phase of the sixth supersurface antenna unit is 300°.

[0067] In order to achieve the above-mentioned phase difference of 60° in sequence, the circularly polarized electromagnetic wave transmitting mechanisms in the second to sixth metasurface antenna units are rotated by a certain angle relative to the circularly polarized electromagnetic wave transmitting mechanism in the first metasurface antenna unit, such as Fig.11 As shown, the circularly polarized electromagnetic wave transmitting mechanism in the second super-surface antenna unit is rotated 65° relative to the circularly polarized electromagnetic wave transmitting mechanism in the first super-surface antenna unit (i.e., rotated 65° clockwise), the circularly polarized electromagnetic wave transmitting mechanism in the third super-surface antenna unit is rotated -65° relative to the circularly polarized electromagnetic wave transmitting mechanism in the first super-surface antenna unit (i.e., rotated 65° counterclockwise), the circularly polarized electromagnetic wave transmitting mechanism in the fourth super-surface antenna unit is rotated 0° relative to the circularly polarized electromagnetic wave transmitting mechanism in the first super-surface antenna unit (i.e., no rotation), the circularly polarized electromagnetic wave transmitting mechanism in the fifth super-surface antenna unit is rotated 65° relative to the circularly polarized electromagnetic wave transmitting mechanism in the first super-surface antenna unit, and the circularly polarized electromagnetic wave transmitting mechanism in the sixth super-surface antenna unit is rotated -65° relative to the circularly polarized electromagnetic wave transmitting mechanism in the first super-surface antenna unit. The above rotation angle is set to make the phases between the metasurface antenna units differ by as much as 60°, thereby optimizing the phase distribution and improving the overall performance. The above phase distribution and the design of the first linear polarized wave receiving patch 11 and the second linear polarized wave receiving patch 12, which are set 180 degrees rotationally symmetrically, can accurately achieve the required transmission phase, thereby achieving more flexible and efficient beam control. The broadband circularly polarized metasurface antenna provided in this embodiment adopts the above 6 metasurface antenna units, which not only maintains the simplicity of the design, but also facilitates the use of planar PCB processing technology, and can achieve efficient electromagnetic wave manipulation, providing a more accurate and flexible solution for electromagnetic wave applications.

[0068] In order to cooperate with the circularly polarized electromagnetic wave transmitting mechanism in each metasurface antenna unit to achieve different transmission phases, such as Fig.12As shown, the linear polarized wave receiving patch assembly 1 in each metasurface antenna unit is arranged in the following manner: the linear polarized wave receiving patch assembly in the first metasurface antenna unit, the linear polarized wave receiving patch assembly in the second metasurface antenna unit, and the linear polarized wave receiving patch assembly in the sixth metasurface antenna unit are flipped 180 degrees relative to the linear polarized wave receiving patch assembly in the third metasurface antenna unit, the linear polarized wave receiving patch assembly in the fourth metasurface antenna unit, and the linear polarized wave receiving patch assembly in the fifth metasurface antenna unit. That is, the opening directions of the semi-U-shaped grooves in the linear polarized wave receiving patch assembly in the first metasurface antenna unit, the linear polarized wave receiving patch assembly in the second metasurface antenna unit, and the linear polarized wave receiving patch assembly in the sixth metasurface antenna unit are consistent, and the opening directions of the semi-U-shaped grooves in the linear polarized wave receiving patch assembly in the third metasurface antenna unit, the linear polarized wave receiving patch assembly in the fourth metasurface antenna unit, and the linear polarized wave receiving patch assembly in the fifth metasurface antenna unit are consistent. The linear polarization wave receiving patch components in the third metasurface antenna unit, the fourth metasurface antenna unit, and the fifth metasurface antenna unit are flipped up and down by 180 degrees, so that the semi-U-shaped grooves in the linear polarization wave receiving patch components in the third metasurface antenna unit, the fourth metasurface antenna unit, and the fifth metasurface antenna unit are flipped up and down by 180 degrees relative to the semi-U-shaped grooves in the linear polarization wave receiving patch components in the first metasurface antenna unit, the second metasurface antenna unit, and the sixth metasurface antenna unit. The above design is to produce a phase difference of 180 degrees so that each circularly polarized electromagnetic wave transmitting mechanism can achieve different phase transmission. Fig.12 In the figure, the deviation between the upper and lower positions of the linear polarization wave receiving patch components in each metasurface antenna unit is an adjustment based on the need to avoid the metal column 7.

[0069] The broadband circularly polarized metasurface antenna also includes a feeding structure, which radiates electromagnetic waves to the bottom surface of the metasurface antenna (i.e., the surface of the linearly polarized wave receiving patch component 1) through space feeding. The feeding structure can adopt a horn antenna feeding mechanism, a patch antenna feeding mechanism or a dipole antenna feeding mechanism, as long as space feeding can be achieved.

[0070] Experimental example

[0071] 1. The unwinding phase curve of the broadband circularly polarized metasurface antenna provided in the test embodiment is tested. The test results are as follows: Fig.13 shown.

[0072] Among them, the six antenna units at phases of 0°, 60°, 120°, 180°, 240°, and 300° correspond to the state 0, state 1, state 2, state 3, state 4, and state 5 curves respectively. The test results show that above the 14.5-29.3 GHz frequency band, the six unwrapped phase curves are almost parallel and the interval is stable at about 60°, proving that each metasurface antenna unit in the metasurface antenna has excellent broadband phase compensation capability.

[0073] 2. Test the transmission amplitude curve of the broadband circularly polarized metasurface antenna provided in the embodiment. The test results are as follows: Fig.14 shown.

[0074] Among them, the six antenna units at phases of 0°, 60°, 120°, 180°, 240°, and 300° correspond to the state 0, state 1, state 2, state 3, state 4, and state 5 curves respectively. The test results show that in the six states, in the process of converting the y-polarized wave into the right-hand circularly polarized wave, the transmission amplitude is higher than -1.2dB. This high performance covers a bandwidth range of up to 15.3-28.4GHz, accounting for 60% of the entire frequency band, fully demonstrating the broadband and low-loss transmission characteristics of each antenna unit.

[0075] In particular, at 15.7 GHz, the transmission level can reach about 0.09 dB. This outstanding performance confirms that the antenna unit has excellent performance in the field of electromagnetic wave manipulation.

[0076] In summary, in the broadband circularly polarized metasurface antenna provided by the present invention, the antenna unit achieves a transmission bandwidth coverage range of more than 60%, significantly reducing the structural complexity of the metasurface antenna, improving the flexibility and convenience of feed selection, and the antenna unit also reaches a high level in the purity of circularly polarized radiation, effectively enhancing the anti-interference ability of the antenna, and significantly improving the quality of signal transmission. The broadband circularly polarized metasurface antenna also has the advantages of simple structural design and phase compensation without blind hole processing, reducing the cost of PCB processing. At the same time, the period of the antenna unit is only 0.4 wavelengths. This feature can effectively reduce the sidelobe level of the antenna beam and expand the scanning angle of the beam. The antenna unit also has excellent frequency adaptability, and its operating frequency can be flexibly adjusted to meet the needs of different application scenarios.

[0077] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A broadband circularly polarized metasurface antenna, characterized in that: The invention comprises at least one metasurface antenna unit; each of the metasurface antenna units comprises a linearly polarized wave receiving patch assembly, a first dielectric layer, a metal floor, a connecting layer, a second dielectric layer and a circularly polarized electromagnetic wave transmitting mechanism connected in sequence, and the receiving patch assembly is connected to the circularly polarized electromagnetic wave transmitting mechanism through a metal column penetrating the first dielectric layer, the metal floor, the connecting layer and the second dielectric layer; wherein the linearly polarized wave receiving patch assembly comprises a first linearly polarized wave receiving patch and a second linearly polarized wave receiving patch arranged with 180-degree rotational symmetry, and the circularly polarized electromagnetic wave transmitting mechanism is a double-arm Archimedean spiral structure, and the double-arm Archimedean spiral structure comprises a first Archimedean spiral arm and a second Archimedean spiral arm, and the second Archimedean spiral arm is arranged at an interval from the first ... The spiral arm is rotationally symmetric with respect to the first Archimedean spiral arm; the first linear polarized wave receiving patch and the second linear polarized wave receiving patch are both one of a semi-U-shaped slot patch, a U-shaped slot patch, a semi-E-shaped patch, and an E-shaped patch; the metal column is a metallized via, and the metallized via includes a first metallized via and a second metallized via arranged at intervals; the first Archimedean spiral arm includes a first connecting portion, the first connecting portion is connected to the first linear polarized wave receiving patch through the first metallized via, and the first Archimedean spiral arm extends spirally outward with the first connecting portion as the axis; the second Archimedean spiral arm includes a second connecting portion, the second connecting portion is connected to the second linear polarized wave receiving patch through the second metallized via, and the second Archimedean spiral arm extends spirally outward with the second connecting portion as the axis.

2. The broadband circularly polarized metasurface antenna according to claim 1, characterized in that: The center distance between the first connecting portion and the second connecting portion is 0.025λ-0.08λ, where λ is the wavelength corresponding to the working center frequency of the antenna.

3. The broadband circularly polarized metasurface antenna according to claim 2, characterized in that: The equations of the first Archimedean spiral arm and the second Archimedean spiral arm in the rectangular coordinate system are: X(t)=(r0+α1·t)·cos(t); Y(t)=(r0+α1·t)·sin(t); Wherein, X(t) is the x-axis coordinate of the helical arm in the rectangular coordinate system, Y(t) is the y-axis coordinate of the helical arm in the rectangular coordinate system; r0 is the starting radius; t is the winding angle, 0≤t≤2π·n1, n1 is the number of rotations of the helical arm, and its value range is 0.9-2; α1 is the helical expansion rate, and its value range is 0.01-0.04λ; Alternatively, the equations of the first Archimedean spiral arm and the second Archimedean spiral arm in the polar coordinate system are: ρ = ρ0+ α1·Φ1; 0 ≤ Φ1 ≤ 2π·n1; Among them, ρ is the radial distance from the center to a point on the spiral arm; ρ0 is the starting radius of the spiral arm, and its value range is 0.025λ-0.08λ; α1 is the spiral expansion rate, and its value range is 0.01λ-0.04λ, Φ1 represents the winding angle, and n1 is the number of rotations of the spiral arm, and its value range is 0.9-2.

4. The broadband circularly polarized metasurface antenna according to claim 3, characterized in that: The first linear polarization wave receiving patch and the second linear polarization wave receiving patch are semi-U-shaped slot patches, and the first linear polarization wave receiving patch and the second linear polarization wave receiving patch are rotationally symmetric; the lengths of the first linear polarization wave receiving patch and the second linear polarization wave receiving patch are both 0.4λ g -0.5λ g , the width is 0.2λ g -0.3λ g , where λ g It is the waveguide wavelength corresponding to the antenna operating center frequency.

5. The broadband circularly polarized metasurface antenna according to claim 4, characterized in that: The first dielectric layer and the second dielectric layer are both rectangular dielectric plates, the length of the first dielectric layer is 0.35λ-0.5λ, the width is 0.35λ-0.5λ, and the thickness is 0.18λ-0.28λ; the length of the second dielectric layer is 0.35λ-0.5λ, the width is 0.35λ-0.5λ, and the thickness is 0.18λ-0.28λ; the connecting layer is a rectangular bonding layer, the length of the connecting layer is 0.35λ-0.5λ, the width is 0.35λ-0.5 λ, thickness is 0.08-0.2mm; the metal floor is a rectangular plate, the length of the metal floor is 0.35λ-0.5λ, the width is 0.35λ-0.5λ, the metal floor is also provided with a avoidance groove for avoiding the metallized via, the diameter of the metallized via is 0.01λ-0.05λ, the avoidance groove is a circular groove or a square groove, the diameter or side length of the avoidance groove is 0.1λ-0.25λ, wherein λ is the wavelength corresponding to the working center frequency of the antenna.

6. The broadband circularly polarized metasurface antenna according to claim 5, characterized in that: It comprises six metasurface antenna units connected in sequence along the horizontal direction, and the circularly polarized electromagnetic wave transmitting mechanisms of adjacent metasurface antenna units have a phase difference of 60°.

7. The broadband circularly polarized metasurface antenna according to claim 6, characterized in that: The six sequentially connected metasurface antenna units are respectively the first metasurface antenna unit, the second metasurface antenna unit, the third metasurface antenna unit, the fourth metasurface antenna unit, the fifth metasurface antenna unit and the sixth metasurface antenna unit; wherein, the linear polarized wave receiving patch assembly in the first metasurface antenna unit, the linear polarized wave receiving patch assembly in the second metasurface antenna unit and the linear polarized wave receiving patch assembly in the sixth metasurface antenna unit are flipped 180 degrees relative to the linear polarized wave receiving patch assembly in the third metasurface antenna unit, the linear polarized wave receiving patch assembly in the fourth metasurface antenna unit and the linear polarized wave receiving patch assembly in the fifth metasurface antenna unit.

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