Metasurface unit and metasurface reflective array antenna

Abstract

The invention relates to the technical field of microwaves and antennas, and discloses a metasurface unit and a metasurface reflective array antenna, the metasurface unit comprises a dielectric substrate and a conductive structure layer arranged on the surface of the dielectric substrate; the conductive structure layer comprises a first resonant structure, a second resonant structure, a third resonant structure and a fourth resonant structure which are respectively used for modulating electromagnetic wave reflection phases of a first frequency band, a second frequency band, a third frequency band and a fourth frequency band; the first resonant structure, the second resonant structure, the third resonant structure and the fourth resonant structure are arranged on the same surface of the dielectric substrate in a coplanar manner; the first resonant structure is located in the middle of the surface of the dielectric substrate; the second resonant structure is located at the corner position of the surface of the dielectric substrate; the third resonant structure is located in the extension line direction of the first resonant structure; the fourth resonant structure is located in the non-extension line direction of the first resonant structure. According to the invention, multi-band independent phase modulation can be realized, and the multi-band working performance of the antenna is improved.

Description

Technical Field

[0001] This invention relates to the field of microwave and antenna technology, and in particular to a metasurface element and a metasurface reflective array antenna. Background Technology

[0002] With the continuous development of communication technology, metasurface array antennas, as an artificially designed planar structure, are composed of a series of subwavelength elements arranged in a specific manner. They possess unique electromagnetic properties and are not only a material form but also a design concept. Based on the generalized Snell's law, metasurface antennas can flexibly manipulate electromagnetic waves to achieve functions such as anomalous reflection and refraction, signal enhancement, and beam scanning, providing new ideas and revolutions for scientific research, engineering design, and methods.

[0003] With the development of electromagnetic integration technology, multi-band metasurface array antennas need to simultaneously achieve reflection phase modulation in multiple different frequency bands to meet the requirements of multi-band communication. However, existing metasurface unit structures often struggle to independently modulate the reflection phase of each frequency band when achieving multi-band operation, resulting in phase coupling interference between the bands. This limits the multi-band independent control capability and integration capability of metasurface antennas.

[0004] Therefore, it is urgent to propose a metasurface element and a metasurface reflective array antenna to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to propose a metasurface element and a metasurface reflective array antenna that can achieve multi-band independent phase modulation and improve the multi-band performance of the antenna.

[0006] To solve the above-mentioned technical problems, the present invention provides a metasurface unit, including a dielectric substrate and a conductive structure layer disposed on the surface of the dielectric substrate; The conductive structure layer includes a first resonant structure, a second resonant structure, a third resonant structure, and a fourth resonant structure, which are used to modulate the electromagnetic wave reflection phase of the first frequency band, the second frequency band, the third frequency band, and the fourth frequency band, respectively. The first resonant structure, the second resonant structure, the third resonant structure, and the fourth resonant structure are coplanarly disposed on the same surface of the dielectric substrate. The first resonant structure is located at the center of the surface of the dielectric substrate. The second resonant structure is located at a corner of the surface of the dielectric substrate. The third resonant structure is located in the extension direction of the first resonant structure. The fourth resonant structure is located in the non-extension direction of the first resonant structure.

[0007] Furthermore, the first resonant structure is cross-shaped and located at the center of the surface of the dielectric substrate.

[0008] Furthermore, the second resonant structure includes an L-shaped angular dipole structure.

[0009] Furthermore, there are multiple L-shaped angular dipole structures; the multiple L-shaped angular dipole structures are respectively located at the four corner positions of the surface of the dielectric substrate, with their opening directions all facing the first resonant structure, and are symmetrically distributed around the first resonant structure.

[0010] Furthermore, the third resonant structure includes multiple arc-shaped dipole structures; each arc-shaped dipole structure is arranged at equal angular intervals along the circumference with the geometric center of the first resonant structure as the center of symmetry, forming a uniform and symmetrical distribution.

[0011] Furthermore, the arc-shaped dipole structure is located in the edge region of the dielectric substrate surface.

[0012] Furthermore, the fourth resonant structure includes multiple linear dipole structures; each linear dipole structure is arranged at equal angular intervals along the circumference with the geometric center of the first resonant structure as the center of symmetry, forming a uniform symmetrical distribution; the linear dipole structures are arranged adjacent to the first resonant structure.

[0013] Furthermore, the radial distance of the third resonant structure relative to the center of the first resonant structure is greater than the radial distance of the fourth resonant structure relative to the center of the first resonant structure.

[0014] Furthermore, the present invention also proposes a metasurface reflective array antenna, including a feed source, a reflector, and a plurality of metasurface elements as described above, wherein the plurality of metasurface elements are arranged in an array to form a reflective surface array; the feed source is used to radiate electromagnetic waves to the reflective surface array; the reflector is disposed on the side of the dielectric substrate away from the conductive structure layer.

[0015] Furthermore, the metasurface units at different positions in the reflective array have different resonant structure geometric parameters to form phase gradient distributions for each frequency band.

[0016] Through the above technical solution, the present invention has the following beneficial effects: By setting a first resonant structure, a second resonant structure, a third resonant structure, and a fourth resonant structure in the conductive structure layer, respectively, for modulating the electromagnetic wave reflection phase of the first, second, third, and fourth frequency bands, and by setting the first, second, third, and fourth resonant structures coplanarly on the same surface of the dielectric substrate; the first resonant structure is located at the center of the dielectric substrate surface; the second resonant structure is located at a corner of the dielectric substrate surface; the third resonant structure is located along the extension direction of the first resonant structure; and the fourth resonant structure is located along the non-extension direction of the first resonant structure, the geometric parameters of each resonant structure can be set independently, thereby realizing independent phase modulation of multiple frequency bands, avoiding phase coupling interference between different frequency bands, improving the phase modulation accuracy and flexibility of the metasurface unit when operating in multiple frequency bands, and also enhancing the multi-band operating performance of the metasurface reflective array antenna.

[0017] Furthermore, by setting the first resonant structure as a cross-shaped structure located at the center of the dielectric substrate surface, setting multiple L-shaped angular dipole structures of the second resonant structure at the four corner positions and symmetrically distributed around the first resonant structure, and arranging multiple arc-shaped dipole structures of the third resonant structure and multiple linear dipole structures of the fourth resonant structure at equal angular intervals along the circumference with the geometric center of the first resonant structure as the center of symmetry, a compact and symmetrical multi-resonant structure layout can be formed, improving the space utilization of the unit, enhancing the symmetry and stability of the resonance in each frequency band, thereby improving the polarization and radiation characteristics of the metasurface unit, and improving the beam quality and radiation efficiency of the metasurface reflective array antenna. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a metasurface unit in one embodiment of the present invention; Figure 2 This is a side view of a metasurface unit in one embodiment of the present invention; Figure 3 This is a schematic diagram of the composition and structure of the metasurface unit in the first frequency band and the corresponding phase shift structure in a metasurface reflective array antenna according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the composition and structure of the metasurface unit in the second frequency band and the corresponding phase shift structure in a metasurface reflective array antenna according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the composition and structure of the metasurface unit in the third frequency band and the corresponding phase shift structure in a metasurface reflective array antenna according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the composition and structure of the metasurface unit in the fourth frequency band and the corresponding phase shift structure in a metasurface reflective array antenna according to an embodiment of the present invention; Figure 7 This is a far-field diagram of a metasurface reflective array antenna in the first frequency band according to an embodiment of the present invention; Figure 8 This is a far-field diagram of a metasurface reflective array antenna in the second frequency band according to an embodiment of the present invention; Figure 9 This is a far-field diagram of a metasurface reflective array antenna in the third frequency band according to an embodiment of the present invention; Figure 10 This is a far-field diagram of a metasurface reflective array antenna in the fourth frequency band according to an embodiment of the present invention.

[0019] In the figure, 1 is the dielectric substrate; 2 is the conductive structure layer; 21 is the first resonant structure; 22 is the second resonant structure; 23 is the third resonant structure; 24 is the fourth resonant structure; and 3 is the reflector. Detailed Implementation

[0020] Based on the teachings of this specification, those skilled in the art can form new technical solutions through cross-combination of different implementation methods without creating technical contradictions. Such variations should all be considered to fall within the protection scope of this invention.

[0021] The present invention will now be described in more detail with reference to the accompanying drawings, which illustrate preferred embodiments of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.

[0022] The invention is described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0023] like Figures 1-2 As shown, an embodiment of the present invention proposes a metasurface unit, including a dielectric substrate 1 and a conductive structure layer disposed on the surface of the dielectric substrate 1.

[0024] Specifically, the conductive structure layer includes a first resonant structure 21, a second resonant structure 22, a third resonant structure 23, and a fourth resonant structure 24, which are used to modulate the electromagnetic wave reflection phase of the first, second, third, and fourth frequency bands, respectively. The first resonant structure 21 is located at the center of the surface of the dielectric substrate 1; the second resonant structure 22 is located at a corner of the surface of the dielectric substrate 1; the third resonant structure 23 is located along the extension line of the first resonant structure 21; and the fourth resonant structure 24 is located along the non-extension line of the first resonant structure 21. The first resonant structure 21, the second resonant structure 22, the third resonant structure 23, and the fourth resonant structure 24 are coplanarly disposed on the same surface of the dielectric substrate 1. In this embodiment, a shared aperture is used to integrate the four resonant structures on the same plane, so that the geometric parameters of the first resonant structure 21, the second resonant structure 22, the third resonant structure 23, and the fourth resonant structure 24 are set independently to independently modulate the reflection phase of each frequency band. This embodiment integrates four different resonant structures in a single metasurface unit, enabling independent modulation of the reflected phase of electromagnetic waves in four different frequency bands. This avoids phase coupling interference between frequency bands, thereby improving the multi-band integration capability and electromagnetic wave control capability of the metasurface antenna.

[0025] In this embodiment, the first resonant structure 21 is cross-shaped and located at the center of the surface of the dielectric substrate 1. In a specific example, the cross-shaped structure consists of two mutually perpendicular straight arms, the lengths of which may be the same or different. The first resonant structure 21 is used to modulate the reflected phase of electromagnetic waves in the first frequency band. By adjusting the geometric parameters such as the arm length and arm width of the cross-shaped structure, modulation of the reflected phase of the first frequency band (e.g., the 6GHz band) can be achieved. The cross-shaped structure being located at the center of the surface of the dielectric substrate 1 is beneficial for forming a symmetrical electromagnetic field distribution, improving the radiation performance and polarization purity of the antenna. As those skilled in the art will know, the specific geometric parameters of the first resonant structure 21 can be set according to actual needs. In one embodiment, the second resonant structure 22 includes a plurality of L-shaped angular dipole structures; the plurality of L-shaped angular dipole structures are respectively located at the four corner positions of the surface of the dielectric substrate 1, with their openings all facing the first resonant structure 21, and are symmetrically distributed around the first resonant structure 21. Those skilled in the art will know that the specific geometric parameters of the L-shaped angular dipole structures can be set according to actual needs.

[0026] In this embodiment, each L-shaped angular dipole structure consists of two mutually perpendicular straight arms, forming an L-shape. The opening of the L-shaped angular dipole structure faces the first resonant structure 21, which helps to reduce coupling interference with the first resonant structure 21 and avoid strong coupling. The four L-shaped angular dipole structures are symmetrically distributed about the geometric center of the first resonant structure 21, which helps to form a uniform electromagnetic field distribution and improve the radiation efficiency and pattern symmetry of the antenna in the second frequency band (e.g., 8.5 GHz band).

[0027] In one embodiment, the third resonant structure 23 includes a plurality of arc-shaped dipole structures; each of the arc-shaped dipole structures is arranged at equal angular intervals along the circumferential direction with the geometric center of the first resonant structure 21 as the center of symmetry, forming a uniform symmetrical distribution.

[0028] In one specific example, the arc-shaped dipole structure is arc-shaped, and its curvature and length can be set according to the required frequency band. Multiple arc-shaped dipole structures are uniformly distributed along the circumference, with equal included angles between adjacent structures, forming a symmetrical ring arrangement. This uniform and symmetrical distribution is beneficial for forming a stable electromagnetic field distribution, improving the antenna's radiation performance and gain in the third frequency band.

[0029] This embodiment, for example, sets up four arc-shaped dipole structures, with an angle of 90 degrees between any two adjacent arc-shaped dipole structures. The third frequency band is, for example, the 11.5 GHz band, suitable for applications such as satellite communication downlink. By adjusting the length of the arc-shaped dipole structures, independent modulation of the reflection phase of the 11.5 GHz band can be achieved, while keeping the phases of other frequency bands essentially unchanged.

[0030] Preferably, the arc-shaped dipole structure is located in the edge region of the surface of the dielectric substrate 1, and the arc-shaped dipole structure is located in the direction of the extension line of the first resonant structure 21.

[0031] Specifically, the arc-shaped dipole structure is positioned near the edge of the dielectric substrate 1, maintaining a large radial distance from the center of the first resonant structure 21. The arc-shaped dipole structure is located along the extension of the cross-shaped arm of the first resonant structure 21, which facilitates resonance using the electromagnetic field generated by the first resonant structure 21. Simultaneously, the arc-shaped design reduces direct coupling with the first resonant structure 21. In this embodiment, placing the arc-shaped dipole structure in the edge region fully utilizes the surface space of the dielectric substrate 1, improving space utilization and integration.

[0032] In one embodiment, the fourth resonant structure 24 includes a plurality of linear dipole structures; each linear dipole structure is arranged at equal angular intervals along the circumferential direction with the geometric center of the first resonant structure 21 as the center of symmetry, forming a uniform symmetrical distribution; the linear dipole structures are disposed adjacent to the first resonant structure 21 and are located in the non-extended direction of the first resonant structure 21.

[0033] In this embodiment, the linear dipole structure is linear in shape, and multiple linear dipole structures are evenly distributed along the circumference, with equal included angles between adjacent linear dipole structures. The linear dipole structure is relatively close to the first resonant structure 21, but located in the gap between the cross arms of the first resonant structure 21, i.e., in the non-extended direction of the cross arms. This arrangement helps reduce the strong coupling between the linear dipole structure and the first resonant structure 21, enabling independent modulation of the fourth frequency band reflection phase, thereby avoiding electromagnetic energy exchange caused by being located in the extended direction.

[0034] In a specific example, this embodiment uses four linear dipole structures, with an angle of 90 degrees between any two adjacent linear dipole structures, and they are located diagonally between the cross-shaped arms of the first resonant structure 21. The fourth frequency band is, for example, the 14.5 GHz band. By adjusting the length and angle of the linear dipole structures, independent modulation of the reflection phase in the 14.5 GHz band can be achieved, while reducing the impact on other frequency bands. Those skilled in the art will understand that the specific geometric parameters and number of the linear dipole structures can be set according to actual needs.

[0035] In one embodiment, the radial distance of the third resonant structure 23 relative to the center of the first resonant structure 21 is greater than the radial distance of the fourth resonant structure 24 relative to the center of the first resonant structure 21. This facilitates spatial isolation between resonant structures of different frequency bands, reduces electromagnetic coupling interference between them, and improves the independence and stability of phase modulation in each frequency band.

[0036] In one specific example, the dielectric substrate 1 is made of a high dielectric constant material. The conductive structure layer is made of metallic copper and is uniformly printed on the surface of the dielectric substrate 1. Those skilled in the art will know that the dielectric substrate 1 can also include other material choices besides those in this embodiment, such as polytetrafluoroethylene, ceramic, FR4, etc. The conductive structure layer can also be made of other conductive materials such as gold, silver, aluminum, etc.

[0037] In one specific embodiment, for example, the dielectric substrate 1 has a thickness of 1.5 mm, a relative permittivity of 14, and a loss tangent of 0.001. The periodic dimension P of the metasurface unit can be set according to the operating frequency band, for example, the periodic dimension P is 10 mm. The arm width W1 of the cross-shaped structure of the first resonant structure 21 can be set according to the unit period and the operating frequency band, for example, W1 is 1 mm. The arm length L1 of the L-shaped angular dipole structure of the second resonant structure 22 can be adjusted within a certain range to achieve phase modulation, for example, the adjustment range of L1 is 3-3.5 mm, and the line width W2 is 0.5 mm. The length L2 of the arc-shaped dipole structure of the third resonant structure 23 can be adjusted within a certain range to achieve phase modulation, for example, the adjustment range of L2 is 2-2.5 mm, the line width W3 is 0.5 mm, the inner radius R1 is 4.8 mm, and the outer radius R2 is 5 mm. The length L3 of the linear dipole structure of the fourth resonant structure 24 can be adjusted within a certain range to achieve phase modulation. For example, the adjustment range of L3 is 1-1.5 mm. The angle θ between the linear dipole structure and the center of the first resonant structure 21 can be adjusted within a certain range. For example, the adjustment range of θ is 30-38 degrees. Those skilled in the art will understand that the above geometric parameters can be adjusted and optimized according to the actual operating frequency band, the characteristics of the dielectric substrate 1, and the antenna performance requirements.

[0038] In this embodiment, the first resonant structure 21, the second resonant structure 22, the third resonant structure 23, and the fourth resonant structure 24, through optimized geometric layout and parameter settings, can achieve orthogonalization of field distribution and decoupling of structural topology. By setting the shape, position, and orientation of each resonant structure, the electromagnetic field modes of adjacent resonators are orthogonalized, which can suppress near-field coupling energy exchange. At the same time, through non-collinear bending settings and multivariable decoupling optimization in parameter space, strong coupling phenomena caused by overlapping geometric parameters and positional relationships between different resonant structures can be avoided. Through this decoupling setting, this embodiment allows each resonant structure to independently control the reflection phase of its corresponding frequency band. When adjusting the phase of one frequency band, the phases of the other three frequency bands remain almost constant within an acceptable tolerance range, which can improve the independent modulation capability of multiple frequency bands, simplify the design process of metasurface array antennas, and thus reduce the time and computational costs in the design process.

[0039] like Figures 3-6 As shown, the composition and structure of the metasurface unit and its phase shift characteristics at different frequency bands are illustrated. Figure 3 It is the 6GHz band. Figure 4 It is the 8.5GHz band. Figure 5 It is the 11.5GHz band. Figure 6The frequency band is 14.5 GHz. By adjusting the geometric parameters of each resonant structure, continuous modulation of the reflection phase in each frequency band within the range of 0-360 degrees can be achieved. For example, by changing the arm length of the L-shaped angular dipole structure, the reflection phase in the 8.5 GHz band can be modulated, while the reflection phases in the 6 GHz, 11.5 GHz, and 14.5 GHz bands are less affected, thus exhibiting good independent modulation characteristics.

[0040] Furthermore, this embodiment also proposes a metasurface reflective array antenna, including a feed source, a reflector 3, and a plurality of metasurface elements as described above, wherein the plurality of metasurface elements are arranged in an array to form a reflective surface array; the feed source is used to radiate electromagnetic waves to the reflective surface array; the reflector 3 is disposed on the side of the dielectric substrate 1 away from the conductive structure layer.

[0041] In this embodiment, the feed source can be in the form of a horn antenna, dipole antenna, patch antenna, etc., to radiate electromagnetic waves to the reflector array. The reflector 3 is a metal plate disposed on the back side of the dielectric substrate 1 to reflect electromagnetic waves, improve the antenna's radiation efficiency and gain, and isolate back radiation.

[0042] Preferably, the metasurface units at different positions in the reflector array have different resonant structure geometric parameters to form phase gradient distributions for each frequency band. In this embodiment, according to the generalized Snell's law, the direction of the reflected beam can be controlled by setting the reflection phase distribution of the metasurface units at various positions on the reflector array. By adjusting the geometric parameters of the first resonant structure 21, the second resonant structure 22, the third resonant structure 23, and the fourth resonant structure 24, different reflection phases are obtained for the metasurface units at different positions, thereby forming a specific phase gradient distribution on the reflector array. Through this phase gradient distribution, functions such as beam scanning, beamforming, and anomalous reflection of reflected electromagnetic waves can be achieved, improving the flexibility and multifunctionality of the antenna.

[0043] like Figures 7-10 As shown, the far-field radiation patterns of the metasurface array antenna at different frequency bands are displayed. Figure 4 In the diagram, a represents the 6GHz band, b represents the 8.5GHz band, c represents the 11.5GHz band, and d represents the 14.5GHz band. The far-field diagram shows that the reflected beams in each band achieve the expected deflection angles, with clear beam pointing and low sidelobe levels, thus verifying the multi-band independent modulation capability and beam control capability of the metasurface array antenna in this embodiment.

[0044] In this embodiment, the metasurface unit achieves multi-band independent phase modulation based on the metasurface electromagnetic control principle and the decoupling design of the resonant structure. When electromagnetic waves are incident on the surface of the metasurface unit, electromagnetic waves of different frequency bands resonate with their corresponding resonant structures. Specifically, electromagnetic waves of the first frequency band mainly resonate with the first resonant structure 21, electromagnetic waves of the second frequency band mainly resonate with the second resonant structure 22, electromagnetic waves of the third frequency band mainly resonate with the third resonant structure 23, and electromagnetic waves of the fourth frequency band mainly resonate with the fourth resonant structure 24. By optimizing the geometry, position layout, and orientation design of each resonant structure, the electromagnetic field modes of different resonant structures are orthogonally distributed, and the near-field coupling energy exchange between adjacent resonant structures is effectively suppressed. When the geometric parameters of a certain resonant structure are adjusted to change the reflection phase of that frequency band, due to the orthogonal field distribution and the decoupling design of the structural topology, the adjustment has little impact on the electromagnetic field distribution of other frequency band resonant structures, thereby achieving independent modulation of the reflection phase of each frequency band. The reflected electromagnetic waves are reflected at the conductive structure layer of the metasurface unit and phase-modulated according to the phase delay introduced by each resonant structure. The reflector 3 then reflects the transmitted electromagnetic waves back, further improving the reflection efficiency. When multiple metasurface units form a reflector array, by designing the phase distribution of metasurface units at different positions in the array, phase gradients are formed for each frequency band, causing the reflected waves of each frequency band to superimpose in phase in a specific direction, forming a directional radiation beam, thus realizing the multi-band independent beam control function. In this embodiment, the metasurface unit achieves independent control of electromagnetic waves in four frequency bands through passive phase modulation, avoiding the complex feed network and phase shifter design in traditional multi-frequency antennas, reducing system complexity and cost, while improving the antenna's integration and reliability.

[0045] In summary, the metasurface element and metasurface reflective array antenna proposed in this invention have the following advantages: By setting a first resonant structure, a second resonant structure, a third resonant structure, and a fourth resonant structure in the conductive structure layer, respectively, the electromagnetic wave reflection phases of the first, second, third, and fourth frequency bands are modulated. These resonant structures are coplanarly disposed on the same surface of the dielectric substrate. The first resonant structure is located at the center of the dielectric substrate surface; the second resonant structure is located at a corner of the dielectric substrate surface; the third resonant structure is located along the extension line of the first resonant structure; and the fourth resonant structure is located along the non-extension line of the first resonant structure. This allows the geometric parameters of each resonant structure to be set independently, thereby achieving independent phase modulation across multiple frequency bands. This avoids phase coupling interference between different frequency bands, improves the phase modulation accuracy and flexibility of the metasurface unit when operating in multiple frequency bands, and enhances the multi-band performance of the metasurface reflective array antenna.

[0046] Furthermore, by setting the first resonant structure as a cross-shaped structure located at the center of the dielectric substrate surface, setting multiple L-shaped angular dipole structures of the second resonant structure at the four corner positions and symmetrically distributed around the first resonant structure, and arranging multiple arc-shaped dipole structures of the third resonant structure and multiple linear dipole structures of the fourth resonant structure at equal angular intervals along the circumference with the geometric center of the first resonant structure as the center of symmetry, a compact and symmetrical multi-resonant structure layout can be formed, improving the space utilization of the unit, enhancing the symmetry and stability of the resonance in each frequency band, thereby improving the polarization and radiation characteristics of the metasurface unit, and improving the beam quality and radiation efficiency of the metasurface reflective array antenna.

[0047] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A metasurface unit, characterized in that, It includes a dielectric substrate and a conductive structure layer disposed on the surface of the dielectric substrate; The conductive structure layer includes a first resonant structure, a second resonant structure, a third resonant structure, and a fourth resonant structure, which are used to modulate the electromagnetic wave reflection phase of the first frequency band, the second frequency band, the third frequency band, and the fourth frequency band, respectively; the first resonant structure, the second resonant structure, the third resonant structure, and the fourth resonant structure are coplanarly disposed on the same surface of the dielectric substrate; the first resonant structure is located at the center of the surface of the dielectric substrate. The second resonant structure is located at a corner of the surface of the dielectric substrate; the third resonant structure is located along the extension of the first resonant structure; and the fourth resonant structure is located along the non-extension of the first resonant structure.

2. The metasurface unit as described in claim 1, characterized in that, The first resonant structure is cross-shaped.

3. The metasurface unit as described in claim 1, characterized in that, The second resonant structure includes an L-shaped angular dipole structure.

4. The metasurface unit as described in claim 3, characterized in that, The L-shaped angular dipole structure comprises multiple structures; the multiple L-shaped angular dipole structures are respectively located at the four corners of the surface of the dielectric substrate, with their openings all facing the first resonant structure, and are symmetrically distributed around the first resonant structure.

5. The metasurface unit as described in claim 1, characterized in that, The third resonant structure includes multiple arc-shaped dipole structures; each arc-shaped dipole structure is arranged at equal angular intervals along the circumference with the geometric center of the first resonant structure as the center of symmetry, forming a uniform and symmetrical distribution.

6. The metasurface unit as described in claim 5, characterized in that, The arc-shaped dipole structure is located in the edge region of the dielectric substrate surface.

7. The metasurface unit as described in claim 1, characterized in that, The fourth resonant structure includes multiple linear dipole structures; each linear dipole structure is arranged at equal angular intervals along the circumference with the geometric center of the first resonant structure as the center of symmetry, forming a uniform symmetrical distribution; the linear dipole structures are arranged adjacent to the first resonant structure.

8. The metasurface unit as described in claim 1, characterized in that, The radial distance of the third resonant structure relative to the center of the first resonant structure is greater than the radial distance of the fourth resonant structure relative to the center of the first resonant structure.

9. A metasurface reflective array antenna, comprising a feed source, a reflector, and a plurality of metasurface elements as described in any one of claims 1-8, characterized in that, Multiple metasurface unit arrays are arranged to form a reflective surface array; the feed source is used to radiate electromagnetic waves to the reflective surface array; the reflector is disposed on the side of the dielectric substrate away from the conductive structure layer.

10. The metasurface reflective array antenna as described in claim 9, characterized in that, The metasurface units at different positions in the reflective array have different resonant structure geometric parameters to form phase gradient distributions for each frequency band.

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