A multi-feed co-boresight cylindrical conformal beam switching antenna and a design method thereof

Abstract

The application belongs to the technical field of antennas, and relates to a multi-feed shared-aperture cylindrical conformal beam switching antenna and a design method. The multi-feed shared-aperture cylindrical conformal beam switching antenna comprises a holographic metasurface and feed monopoles. The holographic metasurface is a curved surface structure and comprises a plurality of physical aperture partitions. The number of the physical aperture partitions is the same as the number of target beams, so that each physical aperture partition radiates beams in multiple directions. The number of the feed monopoles is the same as and one-to-one corresponds to the number of the physical aperture partitions, and the feed monopoles are arranged in the corresponding physical aperture partitions. The area ratio of the physical aperture partitions is equal to the gain ratio of the target beams. The application can realize multi-feed shared-aperture beam switching radiation in the case of cylindrical conformality.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and in particular to a multi-feed common-aperture cylindrical conformal beam switching antenna and its design method. Background Technology

[0002] With the development of information and communication technologies in the modern era, more and more aircraft platforms require small-payload, multi-functional antennas. These antennas must be able to meet one-to-many, many-to-one, or many-to-many communication connection requirements. Therefore, conformal integrated antennas on aircraft platforms need to be able to perform multi-beam switching radiation. Holographic impedance-modulated surface antennas have become the first choice for designing conformal antennas due to their advantages of low profile, low cost, small size, and easy feeding.

[0003] In the existing technology, the research on holographic metasurface antennas involves planar structures and curved conformal structures, which can respectively realize planar co-aperture beam switching radiation or single-beam radiation in the conformal case.

[0004] For example, Lv HH disclosed a multi-feed common-aperture holographic metasurface beam-switching antenna in his paper "Holographic Design of Beam-Switchable Leaky-Wave Antenna" (IEEE Antennas and Wireless Propagation Letters, vol.18, no.12, pp.2736-2740, Dec.2019). Four feeds are set on the array surface, and the surface impedance information generated by the interference of the surface wave generated by each feed and the target field is superimposed on the antenna array surface. Only one feed is turned on at a time, which can realize the switching radiation of four beams.

[0005] For example, Chinese patent application publication number CN113991318A, entitled "A conformal surface wave antenna based on a holographic tensor impedance surface and its design method", discloses a conformal surface wave antenna based on a holographic tensor impedance surface and its design method. It realizes a surface wave antenna based on a holographic tensor impedance surface in the case of cylindrical conformal surface, which can radiate a single beam through a single feed and has high aperture efficiency.

[0006] Existing research has achieved the design of metasurface antennas in specific scenarios; however, it only addresses multi-feed co-aperture beam-switching radiation in planar cases or single-beam radiation in cylindrical conformal cases. Due to their respective limitations, they cannot solve the problem of multi-feed co-aperture beam-switching radiation in cylindrical conformal cases. Summary of the Invention

[0007] Therefore, it is necessary to provide a multi-feed common-aperture cylindrical conformal beam switching antenna and its design method to address the above-mentioned technical problems, which can realize multi-feed common-aperture beam switching radiation under cylindrical conformal conditions.

[0008] A multi-feed common-aperture cylindrical conformal beam switching antenna includes: a holographic metasurface and a fed monopole;

[0009] The holographic metasurface has a curved structure and includes multiple physical aperture partitions; the number of physical aperture partitions is the same as the number of target beams, so that each physical aperture partition radiates beams in multiple directions.

[0010] The number of the power supply monopoles is the same as the number of the physical aperture partitions and corresponds one-to-one. The power supply monopoles are located within the corresponding physical aperture partitions.

[0011] In one embodiment, the area ratio of the physical aperture partitions is equal to the gain ratio of the target beam.

[0012] In one embodiment, the physical aperture partition includes: multiple array-distributed impedance modulation units.

[0013] In one embodiment, the impedance modulation unit includes: a radiating patch, a dielectric substrate, and a ground plane;

[0014] The radiating patch is disposed on the front side of the dielectric substrate, and the ground plane is disposed on the back side of the dielectric substrate, with both the radiating patch and the ground plane aligned with the center of the dielectric substrate on the same vertical line.

[0015] In one embodiment, the size of the radiating patch is determined based on the impedance distribution of the physical aperture partition.

[0016] In one embodiment, the impedance distribution of the physical aperture partition is obtained based on an interferogram based on the holographic principle, which is formed by the interference of a cylindrical surface wave generated by a fed monopole with a linearly polarized target wave.

[0017]

[0018]

[0019]

[0020] In the formula, Ψ surf For a cylindrical surface wave, x and y are the coordinates of the impedance modulation element in the plane, r is the position vector of the impedance modulation element in the plane, j is the imaginary unit, and k t Let Ψ be the wave number for the propagation of a cylindrical surface wave. obj For a linearly polarized target wave, θ NLet φ be the elevation angle of the emitted beam in spherical coordinates within the Nth physical aperture partition. N Let be the azimuth angle of the emitted beam in spherical coordinates in the Nth physical aperture partition, k0 be the free space wavenumber, and ρ be the radius of curvature of the cylindrical conformal carrier of the antenna.

[0021] In one embodiment, the impedance distribution of the physical aperture partition is obtained by modulating a cylindrical surface wave and a linearly polarized target wave, which generate an interferogram based on holographic principles, using the following modulation method:

[0022]

[0023] In the formula, Z′ represents the modulation method, X represents the average impedance value of all impedance modulation units, M represents the modulation depth, and Re represents the complex number (ψ). obj ·ψ surf * The real part of ) ψ surf * To obtain the surface wave ψ surf . conjugate.

[0024] In one embodiment, all impedance modulation units share a single dielectric substrate;

[0025] The feed monopole is connected to the ground plane and passes through the dielectric substrate and is spaced apart from the radiating patch, with a gap between the feed monopole and the dielectric substrate.

[0026] A design method for a multi-feed common-aperture cylindrical conformal beam switching antenna, as described above, includes:

[0027] Based on the preset generation requirements of the target beam, the number of physical aperture partitions of the holographic metasurface is designed; the number of physical aperture partitions is the same as the number of target beams, so that each physical aperture partition radiates beams in multiple directions.

[0028] The area ratio of the physical aperture partition is determined based on the gain ratio between the target beams;

[0029] The number of the power supply monopoles is the same as the number of the physical aperture partitions and corresponds one-to-one. The power supply monopoles are located within the corresponding physical aperture partitions.

[0030] In one embodiment, it also includes:

[0031] The physical aperture partition includes: multiple impedance modulation units;

[0032] The impedance modulation unit includes: a dielectric substrate, a radiating patch disposed on the front side of the dielectric substrate, and a ground plane disposed on the back side of the dielectric substrate.

[0033] Based on the preset generation requirements of the target beam, an interferogram based on the principle of holography is designed;

[0034] The impedance distribution of the physical aperture partition is obtained by modulating the cylindrical surface wave and the linearly polarized target wave based on the generated interferogram of the holographic principle.

[0035] The surface impedance of the impedance modulation unit is determined based on the impedance distribution of the physical aperture partition.

[0036] The dimensions of the radiating patch are designed based on the surface impedance of the impedance modulation unit.

[0037] The aforementioned multi-feed common-aperture cylindrical conformal beam switching antenna and its design method perform separate beam design for multiple physical aperture zones, enabling each physical aperture zone to radiate beams in different directions. Only one feed monopole in a physical aperture zone is activated at a time, allowing for beam switching among multiple beams. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of a multi-feed common-aperture cylindrical conformal beam switching antenna in one embodiment;

[0039] Figure 2 This is a schematic diagram of the physical aperture partitioning of a holographic metasurface in one embodiment;

[0040] Figure 3 This is a schematic diagram of the impedance modulation unit in one embodiment;

[0041] Figure 4 This is a schematic diagram of the distribution of the fed monopole in one embodiment;

[0042] Figure 5 This is a schematic diagram of a design for each physical aperture partition in one embodiment;

[0043] Figure 6 This is a schematic diagram of the surface impedance distribution of a holographic metasurface in one embodiment;

[0044] Figure 7 This is a surface impedance fitting curve of the impedance modulation unit in one embodiment;

[0045] Figure 8 This is a schematic diagram of the result of exciting only feed 1 in one embodiment, where (a) is the three-dimensional radiation pattern of the beam and (b) is the two-dimensional radiation pattern of the beam.

[0046] Figure 9 This is a schematic diagram of the result of exciting only feed 2 in one embodiment, where (a) is the three-dimensional radiation pattern of the beam and (b) is the two-dimensional radiation pattern of the beam.

[0047] Figure 10 This is a schematic diagram of the result of exciting only the feed source 3 in one embodiment, where (a) is the three-dimensional radiation pattern of the beam and (b) is the two-dimensional radiation pattern of the beam.

[0048] Figure 11 This is a schematic diagram of the result of exciting only the feed 4 in one embodiment, where (a) is the three-dimensional radiation pattern of the beam and (b) is the two-dimensional radiation pattern of the beam.

[0049] Figure 12 This is a schematic diagram of the result of exciting only the feed source 5 in one embodiment, where (a) is the three-dimensional radiation pattern of the beam and (b) is the two-dimensional radiation pattern of the beam.

[0050] Figure 13 This is a flowchart illustrating the design method of a multi-feed common-aperture cylindrical conformal beam switching antenna in one embodiment.

[0051] Figure label:

[0052] 1 Holographic metasurface, 11 Impedance modulation unit, 111 Dielectric substrate, 112 Radiation patch, 113 Ground plane; 2 Feed monopole, 21 Feed 1, 22 Feed 2, 23 Feed 3, 24 Feed 4, 25 Feed 5. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0054] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0055] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.

[0056] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0057] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0058] This application provides a multi-feed common-aperture cylindrical conformal beam switching antenna, such as Figure 1 As shown, in one embodiment, it includes: a holographic metasurface and a fed monopole.

[0059] The holographic metasurface is a curved structure and includes multiple physical aperture partitions. The number of physical aperture partitions is the same as the number of target beams, so that each physical aperture partition radiates beams in multiple different directions to generate multiple corresponding target beams. The area ratio of the physical aperture partitions is equal to the gain ratio of the target beams. The gain ratio is the proportion of gain magnitude, and the gain magnitude between the target beams can be adjusted by adjusting the area ratio between multiple physical aperture partitions.

[0060] The physical aperture partitioning includes multiple array-distributed impedance modulation units.

[0061] The impedance modulation unit includes a radiating patch, a dielectric substrate, and a ground plane. The radiating patch is located on the front side of the dielectric substrate, and the center of the radiating patch and the center of the dielectric substrate are on the same vertical line, that is, the center of the radiating patch is located on the center normal of the dielectric substrate. The ground plane is located on the back side of the dielectric substrate, and the center of the ground plane and the center of the dielectric substrate are on the same vertical line, that is, the center of the ground plane is located on the center normal of the dielectric substrate. The radiating patch, the dielectric substrate, and the ground plane are all identical in shape and size.

[0062] Preferably, both the radiating patch and the dielectric substrate are square, and the two diagonals of the radiating patch and the dielectric substrate are collinear.

[0063] The size of the radiating patch is obtained based on the impedance distribution of the physical aperture partition. Specifically, the size of the radiating patch is determined based on the surface impedance of the impedance modulation unit, which in turn is determined based on the impedance distribution of the physical aperture partition. More specifically, the size of the radiating patch is obtained based on the side length of the dielectric substrate and the difference between the side length of the radiating patch and the side length of the dielectric substrate. The difference between the side length of the radiating patch and the side length of the dielectric substrate is determined based on the surface impedance of the impedance modulation unit, which in turn is determined based on the impedance distribution of the physical aperture partition.

[0064] The impedance distribution of the physical aperture partition is obtained based on the interferogram based on the holographic principle. The interferogram based on the holographic principle is formed by the interference of the cylindrical surface wave generated by the fed monopole and the linearly polarized target wave.

[0065]

[0066]

[0067]

[0068] In the formula, Ψ surf For a cylindrical surface wave, x and y are the coordinates of the impedance modulation element in the plane, r is the position vector of the impedance modulation element in the plane, j is the imaginary unit, and k t Let Ψ be the wave number for the propagation of a cylindrical surface wave. obj For a linearly polarized target wave of arbitrary orientation, θ N Let φ be the elevation angle of the emitted beam in spherical coordinates within the Nth physical aperture partition. N Let be the azimuth angle of the emitted beam in the spherical coordinate system in the Nth physical aperture partition. The elevation angle and azimuth angle constitute the direction of the target beam. k0 is the free space wavenumber, and ρ is the radius of curvature of the cylindrical conformal carrier of the antenna (i.e., the radius of the cylindrical carrier structure of the conformal antenna).

[0069] The impedance distribution of the physical aperture partition is obtained by modulating a cylindrical surface wave and a linearly polarized target wave using the following method to generate an interferogram based on the holographic principle:

[0070]

[0071] In the formula, Z′ represents the modulation method, X represents the average impedance value of all impedance modulation units, M represents the modulation depth, and Re represents the complex number (ψ). obj ·ψ surf * The real part of ) ψ surf * To obtain the surface wave ψ surf . conjugate.

[0072] The number of feed monopoles corresponds one-to-one with the number of physical aperture zones, and the feed monopoles are located within the corresponding physical aperture zones. All impedance modulation units share a single dielectric substrate; the feed monopoles are connected to the ground plane and pass through the dielectric substrate, then are spaced apart from the radiating patches. There is a gap between the feed monopoles and the dielectric substrate, meaning that the dielectric substrate has through holes with a diameter larger than that of the feed monopoles, and the feed monopoles pass through the through holes without contacting the dielectric substrate.

[0073] In a specific embodiment, the physical aperture partition is determined according to the number B of the required target beams. The number of physical aperture partitions is N, and B = N, where B ≥ 2 and N ≥ 2. The N physical aperture partitions are designed separately, so that each physical aperture partition can independently radiate beams in different directions to obtain N target beams, thereby realizing the switching of beam radiation among the N target beams.

[0074] The gain ratio between different beams can be adjusted, specifically by adjusting the aperture area ratio between different physical aperture zones. That is, different aperture areas S1, S2, ..., S are assigned to N zones. N This allows for adjusting the gain between target beams by varying the aperture area ratio K across different beam segments, where K = S1:S2...:S N .

[0075] Taking a five-feed common-aperture cylindrical conformal beam switching antenna as an example, the operating frequency is 15GHz, and the radius of curvature ρ of the cylindrical conformal structure is 400mm.

[0076] The number of physical aperture partitions, N=5, is determined based on the required number of target beams, B=5. The specific physical aperture partitioning of holographic metasurface 1 is as follows: Figure 2 As shown, there are five physical aperture zones: ①, ②, ③, ④, and ⑤. Each of these zones is designed with its own beam to generate different target beams.

[0077] The gain between the target beams is adjusted by adjusting the aperture area ratio K of the five physical aperture sections. To make the gain between the five target beams close to 1:1:1:1:1, K = S1:S2:S2:S3:S4:S5 = 1:1:1:1:0.6.

[0078] The holographic metasurface includes p×q periodically arranged impedance modulation units 11, where p ≥ 40 and q ≥ 40. The p×q periodically arranged impedance modulation units are distributed across N physical aperture partitions, each physical aperture partition comprising multiple impedance modulation units. Figure 3As shown, the impedance modulation unit 11 includes a dielectric substrate and a radiating patch (made of metal) disposed on the upper surface of the dielectric substrate; the size of the radiating patch is determined according to the impedance of the impedance modulation unit. The impedance modulation unit also includes a metal ground plane printed on the lower surface of the dielectric substrate.

[0079] The number of the fed monopoles is 5, and they are located in 5 physical aperture partitions. The 5 physical aperture partitions include four outer regions corresponding to the four sides of the array, and an intermediate region formed by the middle of the four outer regions. Figure 4 As shown, the five feed monopoles are feed source 1, feed source 2, feed source 3, and feed source 4, located at the midpoint of the cutout on each side of the array. Feed source 5 is located at the cutout at the geometric center of the entire array. The coordinate formulas of the five feed monopoles are as follows:

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] Among them, X N (i,t) and Y N (i,t) represents the coordinates of the Nth fed monopole 2, where N = 1, 2, 3, 4, 5.

[0086] Given p = 80° and q = 80°, the structure of the impedance modulation unit is as follows: Figure 3 As shown, the dielectric substrate has a side length *a* of 3 mm, a relative permittivity of 4.10, a relative permeability of 1, and a thickness *h* of 1.27 mm. The center of the radiating patch is located on the center normal of the dielectric substrate, and the two diagonals of the radiating patch coincide with the two diagonals of the surface of the dielectric substrate. *g* is the difference between the side length of the dielectric substrate and the side length of the radiating patch. Therefore, the distance between the side length of the radiating patch and the side length of the dielectric substrate is *g / 2*.

[0087] The difference g between the side length of the dielectric substrate and the side length of the radiating patch can be determined based on the impedance Z of the impedance modulation unit. Then, the size of the radiating patch can be calculated based on the length of the dielectric substrate and the difference g. Specifically, the side length (size) of the radiating patch is the side length a of the dielectric substrate minus the difference g between the side length of the dielectric substrate and the side length of the radiating patch.

[0088] Individual beam design is performed for the five physical aperture zones, such as Figure 5 As shown, the directions of the five target beams are respectively... For each physical aperture partition, a separate interferogram based on the holographic principle is designed.

[0089] The calculated surface impedance distribution of the holographic metasurface is as follows: Figure 6 As shown. Among them, Figure 6 The X-coordinate in the figure is the coordinate on the X-axis corresponding to each impedance modulation unit in the rectangular coordinate system, and its unit is meters (m); the Y-coordinate is the coordinate on the Y-axis corresponding to each impedance modulation unit, and its unit is meters (m); the surface impedance is the surface impedance of each impedance modulation unit, and its unit is ohms (Ω).

[0090] The formula for calculating the surface impedance of any impedance modulation unit is:

[0091]

[0092] in, and Let ω be the phase difference of the impedance modulation unit in the x and y directions, and ω be the angular frequency corresponding to the operating frequency. Considering that this impedance modulation unit is a scalar unit, its surface impedance is not affected by the direction of surface wave propagation, therefore, it is set as follows:

[0093] like Figure 7 The figure shows the surface impedance fitting curve of the impedance modulation unit; where the horizontal axis "gap" represents the difference "g" between the side length of the dielectric substrate and the side length of the radiating patch, in millimeters (mm); and the vertical axis "impedance" represents the surface impedance of the impedance modulation unit, in ohms (Ω). (Refer to...) Figure 7 Changing the size of the radiation patch, i.e., changing g (i.e. Figure 7 The size of the gap corresponds to a different surface impedance of the impedance modulation unit. The relationship between the surface impedance Z of the impedance modulation unit and g is obtained through curve fitting:

[0094] Z = -429 * g 5 +1475*g 4 -2009*g 3 +1577*g 2 -929.8*g 1 +550.2

[0095] Given the distribution of surface impedance Z′ in the five physical aperture partitions of a five-feed common-aperture cylindrical conformal beam-switching antenna, the surface impedance Z of each impedance modulation unit can be obtained, and the size of the surface metal patch of each impedance modulation unit can be obtained by inversion.

[0096] Full-wave simulation of the above embodiments was performed using the electromagnetic simulation software ANSYS HFSS. The beam-switching radiation capability was observed by exciting different fed monopoles, such as... Figures 8 to 12 As shown, GainTotal represents the gain of the target beam, and Theta(deg) represents the angle of the target beam.

[0097] Only feed source 1 is excited; other fed monopoles are not excited. When viewed from a plane, the three-dimensional beam pattern is obtained as follows: Figure 8 As shown in (a), the two-dimensional radiation pattern is as follows: Figure 8 As shown in (b), the beam gain at the feed is 14.36 dB, and the direction is (60°, 0°).

[0098] Only feed source 2 is excited; other fed monopoles are not excited. When viewed from a plane, the three-dimensional beam pattern is obtained as follows: Figure 9 As shown in (a), the two-dimensional radiation pattern is as follows: Figure 9 As shown in (b), the beam gain at feed 2 is 13.79 dB, and the direction is (62°, 90°).

[0099] Only feed source 3 is excited; other fed monopoles are not excited. When viewed from a plane, the three-dimensional beam pattern is obtained as follows: Figure 10 As shown in (a), the two-dimensional radiation pattern is as follows: Figure 10 As shown in (b), the beam gain at feed 3 is 14.36 dB, and the direction is (58°, 180°).

[0100] Only feed source 4 is excited; other fed monopoles are not excited. When viewed from a plane, the three-dimensional beam pattern is obtained as follows: Figure 11 As shown in (a), the two-dimensional radiation pattern is as follows: Figure 11 As shown in (b), the beam gain at feed 4 is 14.10 dB, and the direction is (60°, 270°).

[0101] Only feed source 5 is excited; other fed monopoles are not excited. When viewed from a plane, the three-dimensional beam pattern is obtained as follows: Figure 12 As shown in (a), the two-dimensional radiation pattern is as follows: Figure 12 As shown in (b), the beam gain at feed 5 is 13.08 dB, and the direction is (0°, 0°).

[0102] The multi-feed common-aperture cylindrical conformal beam-switching antenna, which achieves beam-switching radiation in a common-aperture cylindrical conformal configuration through physical aperture partitioning, can control the gain ratio between beams by adjusting the area ratio of the physical aperture partitioning.

[0103] The aforementioned multi-feed common-aperture cylindrical conformal beam switching antenna uses a holographic metasurface to achieve cylindrical conformality, and utilizes multiple physical aperture partitions for individual beam design, so that each physical aperture partition can radiate beams in different directions. Only the feed monopole in one physical aperture partition is turned on at a time, thereby enabling switching of beam radiation between multiple beams.

[0104] This application also provides a design method for a multi-feed common-aperture cylindrical conformal beam switching antenna, such as... Figure 13 As shown, in one embodiment, the following steps are included:

[0105] Step 1302: Design the number of physical aperture partitions of the holographic metasurface according to the preset generation requirements of the target beam; the number of physical aperture partitions is the same as the number of target beams, so that each physical aperture partition radiates beams in multiple directions to generate multiple corresponding target beams.

[0106] Step 1304: Determine the area ratio of the physical aperture partition based on the gain ratio between the target beams.

[0107] Step 1306: The number of power supply monopoles is the same as the number of physical aperture partitions and corresponds one-to-one. The power supply monopoles are set in the corresponding physical aperture partitions.

[0108] Step 1308: Physical aperture partitioning includes: multiple impedance modulation units.

[0109] Step 1310: The impedance modulation unit includes: a dielectric substrate, a radiating patch disposed on the front side of the dielectric substrate, and a ground plane disposed on the back side of the dielectric substrate.

[0110] Step 1312: Design an interferogram based on the holographic principle according to the preset generation requirements of the target beam; obtain the impedance distribution of the physical aperture partition by generating the cylindrical surface wave and linearly polarized target wave based on the holographic interferogram; determine the surface impedance of the impedance modulation unit according to the impedance distribution of the physical aperture partition; design the size of the radiating patch according to the surface impedance of the impedance modulation unit.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A multi-feed common-aperture cylindrical conformal beam switching antenna, characterized in that, include: Holographic metasurfaces and fed monopoles; The holographic metasurface has a curved structure and includes multiple physical aperture partitions; The number of physical aperture partitions is the same as the number of target beams, so that each physical aperture partition radiates beams in multiple directions; The number of the power supply monopole is the same as the number of the physical aperture partitions and corresponds one-to-one. The power supply monopole is located in the corresponding physical aperture partition. The physical aperture partition includes: multiple array-distributed impedance modulation units; the impedance modulation unit includes: a radiating patch, a dielectric substrate, and a ground plane; The radiating patch is disposed on the front side of the dielectric substrate, and the ground plane is disposed on the back side of the dielectric substrate, and both the radiating patch and the ground plane are disposed on the same vertical line as the center of the dielectric substrate. The impedance distribution of the physical aperture partition is obtained based on the interferogram based on the holographic principle. The interferogram based on the holographic principle is formed by the interference of the cylindrical surface wave generated by the fed monopole and the linearly polarized target wave. In the formula, It is a cylindrical surface wave. and The coordinates of the impedance modulation unit in the plane are... The position vector of the impedance modulation unit in the plane. The imaginary unit, The wave number for surface wave propagation on a cylindrical surface. For linearly polarized target waves, For the first The elevation angle of the emitted beam in spherical coordinates within each physical aperture zone. For the first The azimuth angle of the emitted beam in spherical coordinates within each physical aperture zone. For free space wavenumber, Let be the radius of curvature of the cylindrical conformal carrier of the antenna; The impedance distribution of the physical aperture partition is obtained by modulating the cylindrical surface wave and the linearly polarized target wave, which generate an interferogram based on the holographic principle, using the following modulation method: In the formula, Modulation method, The average impedance value of all impedance modulation units. For modulation depth, To take complex numbers The real part, To obtain surface waves . conjugate.

2. The multi-feed common-aperture cylindrical conformal beam switching antenna according to claim 1, characterized in that, The area ratio of the physical aperture partitions is equal to the gain ratio of the target beam.

3. The multi-feed common-aperture cylindrical conformal beam switching antenna according to claim 2, characterized in that, The size of the radiating patch is determined based on the impedance distribution of the physical aperture partition.

4. The multi-feed common-aperture cylindrical conformal beam switching antenna according to any one of claims 1 to 3, characterized in that, All impedance modulation units share a single dielectric substrate; The feed monopole is connected to the ground plane and passes through the dielectric substrate and is spaced apart from the radiating patch, with a gap between the feed monopole and the dielectric substrate.

5. A design method for a multi-feed common-aperture cylindrical conformal beam switching antenna, characterized in that, The multi-feed common-aperture cylindrical conformal beam switching antenna as described in any one of claims 1 to 4 comprises: Based on the preset generation requirements of the target beam, the number of physical aperture partitions of the holographic metasurface is designed; the number of physical aperture partitions is the same as the number of target beams, so that each physical aperture partition radiates beams in multiple directions. The area ratio of the physical aperture partition is determined based on the gain ratio between the target beams; The number of the power supply monopoles is the same as the number of the physical aperture partitions and corresponds one-to-one. The power supply monopoles are located within the corresponding physical aperture partitions.

6. The design method of the multi-feed common-aperture cylindrical conformal beam switching antenna according to claim 5, characterized in that, Also includes: The physical aperture partition includes: multiple impedance modulation units; The impedance modulation unit includes: a dielectric substrate, a radiating patch disposed on the front side of the dielectric substrate, and a ground plane disposed on the back side of the dielectric substrate. Based on the preset generation requirements of the target beam, an interferogram based on the principle of holography is designed; The impedance distribution of the physical aperture partition is obtained by modulating the cylindrical surface wave and the linearly polarized target wave based on the generated interferogram of the holographic principle. The surface impedance of the impedance modulation unit is determined based on the impedance distribution of the physical aperture partition. The dimensions of the radiating patch are designed based on the surface impedance of the impedance modulation unit.

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