A circularly polarized antenna based on a receiver-radiator metasurface

Abstract

This invention relates to the field of antenna technology and provides a circularly polarized antenna based on a receiver-radiator metasurface. The antenna includes a metasurface array composed of multiple metasurface units. Each metasurface unit comprises a first metal patch, a first dielectric substrate, a second metal patch, a second dielectric substrate, and a third metal patch stacked from top to bottom. It also includes metal vias that pass through the second metal patch to connect the first and third metal patches. This invention achieves linear control of the transmission phase by rotating the first metal patch. Simultaneously, the unit possesses polarization selection functionality: reflecting x-polarized waves and converting y-polarized waves into circularly polarized waves for radiation. The antenna array operates in the 7.7-9.4 GHz frequency band, achieving a gain of 23.4 dBi at 8.5 GHz. It exhibits advantages such as high gain, low loss, and adjustable polarization, making it suitable for satellite communication, radar, and other fields.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, specifically to a circularly polarized antenna based on a receiver-radiator metasurface. Background Technology

[0002] The gain of traditional antennas is generally related to their aperture and operating frequency band, and is typically improved by assembling arrays. However, to ensure that the energy of the array elements is concentrated, phase compensation is required for each element. Traditional phase compensation methods generally involve adjusting the array feed network to achieve phase shifting. However, feed network design is not suitable for large-scale arrays. As the array size increases, its feed network becomes more complex, and feed network losses also increase, making it unsuitable for large-scale arrays.

[0003] Therefore, in view of the above situation, there is an urgent need to provide a circularly polarized antenna based on a receiver-radiator metasurface to overcome the shortcomings in current practical applications. Summary of the Invention

[0004] The purpose of this invention is to provide a circularly polarized antenna based on a receiver-radiator metasurface, which aims to solve the problems in the background art.

[0005] The present invention is implemented as follows: a circularly polarized antenna based on a receiving-radiating metasurface includes a metasurface array composed of multiple metasurface units, wherein each metasurface unit includes a first metal patch, a first dielectric substrate, a second metal patch, a second dielectric substrate, and a third metal patch stacked from top to bottom.

[0006] It also includes a metal through-hole, which passes through a second metal patch to connect the first metal patch and the third metal patch.

[0007] As a further aspect of the present invention: the first metal patch is a circular patch, with four isosceles triangles removed from its perimeter and a rectangle and two isosceles trapezoidal patches removed from its center, and the center of the first metal patch is 2.4 mm away from the center of the metasurface unit.

[0008] As a further aspect of the present invention: the second metal patch is a square metal patch with a side length of 16.8 mm, and a circular isolation ring with a radius of 0.8 mm is provided at its center.

[0009] As a further aspect of the present invention: both the first dielectric substrate and the second dielectric substrate are F4B dielectric boards with a thickness of 1.8 mm and a dielectric constant of 3.5.

[0010] As a further aspect of the present invention: the third metal patch has a hexagonal structure, consisting of a large rectangle with isosceles triangular patches loaded on both sides, and the center of the third metal patch is 1.2 mm away from the center of the metasurface unit.

[0011] As a further aspect of the present invention: the metal through hole is a cylindrical structure with a radius of 0.4 mm.

[0012] As a further aspect of the present invention: the antenna has polarization adjustable characteristics in the 7.7GHz-9.4GHz frequency band, and when the incident electromagnetic wave is an x-polarized wave, the metasurface array reflects the x-polarized electromagnetic wave;

[0013] When the incident electromagnetic wave is a γ-polarized wave, the metasurface array radiates a circularly polarized electromagnetic wave.

[0014] As a further aspect of the present invention: having phase modulation characteristics, when the first metal patch rotates around the center by an angle of θ degrees, the metasurface unit can compensate for the phase of the angle of θ degrees.

[0015] As a further aspect of the present invention, the value of the θ angle is 0°, 60°, 120°, 180°, 240° or 300°.

[0016] As a further aspect of the present invention: the focal diameter ratio of the metasurface array is 0.6, and the peak gain at 8.5 GHz is 23.4 dBi.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] This invention achieves polarization control through a receiver-radiator metasurface structure: it can selectively reflect x-polarized waves and efficiently convert y-polarized waves into circularly polarized wave radiation.

[0019] This invention achieves high-precision phase modulation by rotating the first metal patch. The rotation angle is linearly related to the amount of transmission phase change, providing a simple and effective means for antenna beamforming and high-gain design, and avoiding the losses caused by traditional complex feed networks.

[0020] By optimizing the geometry and center offset of the first and third metal patches, the operating bandwidth was widened, and the power transfer efficiency and polarization selectivity were improved.

[0021] An array composed of multiple metasurface units exhibits excellent performance in the 7.7 GHz to 9.4 GHz frequency band, achieving a peak gain of up to 23.4 dBi at 8.5 GHz, and features a compact structure. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the three-dimensional structure of a metasurface unit.

[0024] Figure 2 This is a schematic diagram showing the dimensions of the first metal patch.

[0025] Figure 3 Radiation amplitude diagrams at different rotation angles;

[0026] Figure 4 Phase value diagrams at different rotation angles;

[0027] Figure 5 The phase state diagram of the first metal patch when θ=0°;

[0028] Figure 6 The phase state diagram of the first metal patch when θ=60°;

[0029] Figure 7 The phase state diagram of the first metal patch when θ=120°;

[0030] Figure 8 The phase state diagram of the first metal patch when θ=180°;

[0031] Figure 9 The phase state diagram of the first metal patch when θ=240°;

[0032] Figure 10 The phase state diagram of the first metal patch when θ=300°;

[0033] Figure 11 The phase distribution diagram of the metasurface array;

[0034] Figure 12 This is a schematic diagram of the radiative layer of a metasurface array;

[0035] Figure 13 This is a schematic diagram of the back side of the metasurface array;

[0036] Figure 14 This is the two-dimensional radiation pattern of the antenna at 8.5 GHz.

[0037] In the attached diagram: 1-first metal patch, 2-first dielectric substrate, 3-second metal patch, 4-second dielectric substrate, 5-third metal patch, 6-metal via. Detailed Implementation

[0038] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] The present invention will be further explained below with reference to specific embodiments.

[0042] Please see Figures 1-14 The present invention provides a circularly polarized antenna based on a receiving-radiating metasurface, comprising a metasurface array consisting of 324 metasurface units (arranged in a periodic 18×18 pattern), wherein each metasurface unit consists of two dielectric substrates, two metal patches, a metal pillar, and a metal ground plane.

[0043] The metasurface unit, from top to bottom, consists of a first metal patch 1, a first dielectric substrate 2, a second metal patch 3, a second dielectric substrate 4, and a third metal patch 5;

[0044] The first metal patch 1 is printed on top of the first dielectric substrate 2, and the second metal patch 3, which is the metal ground plate, is printed below the first dielectric substrate 2 and above the second dielectric substrate 4.

[0045] The third metal patch 5 is printed below the second dielectric substrate 4;

[0046] The cylindrical metal through-hole 6 with a radius of 0.4 mm passes through the circular isolation ring on the second metal patch 3, connecting the first metal patch 1 and the third metal patch 5 together.

[0047] The first metal patch 1 is composed of a circular patch with a radius of 4.7 mm. Four isosceles triangles are cut out around the perimeter of the circular patch to further widen the current path and the bandwidth of circularly polarized radiation. Simultaneously, a rectangular patch and two isosceles trapezoidal patches are cut out at the center of the circular patch, enabling excellent phase modulation. The relatively large central hole in the metal patch results in a significant electromagnetic difference when the first metal patch 1 rotates around the center of the metasurface unit, thereby generating a phase difference and thus enabling phase modulation.

[0048] Furthermore, the center of the first metal patch 1 does not overlap with the center of the metasurface unit (see reference). Figure 2 The two have a physical distance of 2.4mm, which ensures that the first metal patch 1 has a large electromagnetic change when it rotates around the center, thus generating a phase difference.

[0049] The second metal patch 3 is a square metal patch with a side length of 16.8 mm, and has a circular isolation ring with a radius of 0.8 mm at its center, which is used to isolate the receiving patch and the radiating patch.

[0050] The first dielectric substrate 2 and the second dielectric substrate 4 are both F4B dielectric boards with a thickness of 1.8 mm and a dielectric constant of 3.5.

[0051] The third metal patch 5 is composed of a hexagonal structure. The hexagonal patch consists of a large rectangle with isosceles triangular patches loaded on both sides, which has a larger electromagnetic energy absorption area and can maintain excellent polarization selectivity characteristics (that is, while ensuring that the area is widened, one side is still longer than the other, which is conducive to the differentiation of linear polarization).

[0052] In embodiments of the present invention, metasurface technology can achieve linear phase adjustment by controlling the structural parameters of the metasurface. For example, by changing the length of a microstrip line on the metasurface, the reflection phase or radiation phase of the metasurface can be linearly changed. This method of phase adjustment by changing the physical dimensions of the metasurface has higher phase resolution, i.e., it can obtain more accurate compensation phase values, which is more conducive to high-gain designs. Moreover, compared with traditional feed grid designs for phase shifting, it avoids the losses caused by the feed grid and better ensures energy concentration.

[0053] Furthermore, metasurface technology not only possesses controllability in the phase dimension but also in the polarization dimension. Receiver-radiator metasurfaces exhibit polarization selectivity for incident waves. For correctly polarized electromagnetic waves, the receiving layer absorbs the energy of the incident electromagnetic wave and transmits it to the radiating layer through metal vias. The polarization state of the final radiated electromagnetic wave is then determined based on the structural characteristics of the radiating layer.

[0054] In this embodiment, the antenna is composed of 324 metasurface units, and has excellent polarization and phase controllability characteristics in the 7.7GHz-9.4GHz frequency band.

[0055] When the incident electromagnetic wave is an x-polarized wave, the metasurface array will reflect the x-polarized electromagnetic wave;

[0056] When the incident electromagnetic wave is y-polarized, the metasurface array will radiate circularly polarized electromagnetic waves.

[0057] The antenna has polarization control capabilities.

[0058] Figure 3 The transmission amplitude under y-polarized incident light at different rotation angles was demonstrated, verifying the stability of transmittance during phase modulation, i.e., high transmittance at different rotation angles within the operating frequency band.

[0059] Figure 4 The data shows the change in transmission phase when the first metal patch 1 is rotated θ degrees around the center. Clearly, this data verifies that the transmission phase also changes by θ degrees when the first metal patch is rotated θ degrees around the center.

[0060] Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 The six phase states of the circularly polarized metasurface are represented by red dots, which represent the center of the unit cell. The patches rotate around the center of the unit cell at 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees and 300 degrees respectively. The angles that the corresponding unit cell can compensate for are also 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees and 300 degrees respectively.

[0061] An 18×18 array with a focal diameter ratio of 0.6 is configured, and a high-gain array is arranged with a center frequency of 8.5. The phase distribution of the array is as follows. Figure 11 As shown; Figure 12 and Figure 13 The radiating and reflecting portions of the array are shown. Figure 14 The two-dimensional radiation pattern at 8.5 GHz is shown. As can be seen, the simulated gain reaches 23.4 dBi.

[0062] In one embodiment of the present invention, please refer to Figure 1 The third metal patch 5 does not coincide with the center of the metasurface unit, and the two have a physical distance of 1.2 mm, which can better absorb and transmit energy and perform polarization screening.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circularly polarized antenna based on a receiver-radiator metasurface, characterized in that, It includes a metasurface array composed of multiple metasurface units, wherein the metasurface units include a first metal patch (1), a first dielectric substrate (2), a second metal patch (3), a second dielectric substrate (4), and a third metal patch (5) stacked from top to bottom. It also includes a metal through hole (6), which passes through the second metal patch (3) to connect the first metal patch (1) and the third metal patch (5); The first metal patch (1) is a circular patch. Four isosceles triangles are removed from the periphery of the circular patch, and a rectangle and two isosceles trapezoidal patches are removed from the center. The center of the first metal patch (1) is 2.4 mm away from the center of the metasurface unit.

2. The circularly polarized antenna based on a receiver-radiator metasurface according to claim 1, characterized in that, The second metal patch (3) is a square metal patch with a side length of 16.8 mm, and a circular isolation ring with a radius of 0.8 mm is provided in the center.

3. The circularly polarized antenna based on a receiver-radiator metasurface according to claim 1, characterized in that, The first dielectric substrate (2) and the second dielectric substrate (4) are both F4B dielectric boards with a thickness of 1.8 mm and a dielectric constant of 3.

5.

4. The circularly polarized antenna based on a receiver-radiator metasurface according to claim 1, characterized in that, The third metal patch (5) has a hexagonal structure, consisting of a large rectangle with isosceles triangular patches loaded on both sides, and the center of the third metal patch (5) is 1.2 mm away from the center of the metasurface unit.

5. The circularly polarized antenna based on a receiver-radiator metasurface according to claim 1, characterized in that, The metal through hole (6) is a cylindrical structure with a radius of 0.4 mm.

6. The circularly polarized antenna based on a receiver-radiator metasurface according to claim 1, characterized in that, The antenna has adjustable polarization characteristics in the 7.7GHz–9.4GHz frequency band. When the incident electromagnetic wave is an x-polarized wave, the metasurface array reflects the x-polarized electromagnetic wave. When the incident electromagnetic wave is a γ-polarized wave, the metasurface array radiates a circularly polarized electromagnetic wave.

7. The circularly polarized antenna based on a receiver-radiator metasurface according to claim 1, characterized in that, With phase control characteristics, when the first metal patch (1) rotates around the center by an angle of θ degrees, the metasurface unit can compensate for the phase of the angle of θ degrees.

8. The circularly polarized antenna based on a receiver-radiator metasurface according to claim 7, characterized in that, The value of the θ angle is 0°, 60°, 120°, 180°, 240° or 300°.

9. The circularly polarized antenna based on a receiver-radiator metasurface according to claim 1, characterized in that, The metasurface array has a focal diameter ratio of 0.6 and a peak gain of 23.4 dBi at 8.5 GHz.

Images