Transmissive metasurface structure, antenna apparatus, and communication device

Abstract

A transmissive metasurface structure (1), an antenna apparatus, and a communication device. The transmissive metasurface structure (1) comprises: a first transmissive metasurface (12) located between every two adjacent carrier layers (11); each first transmissive metasurface (12) comprises a first metal layer (121), a second metal layer (122), and a liquid crystal layer (123), first metal strips (1211) of the first metal layer (121) are provided with first holes (1212), and second metal strips (1221) of the second metal layer (122) are provided with second holes (1222). A gap between the first metal strips (1211) and a gap between the second metal strips (1221) can ensure the transmission of electromagnetic signals. Liquid crystal molecules in the liquid crystal layers (123) can deflect to any angle, thereby realizing continuous regulation and control of a beam radiation direction. The electromagnetic signals can form a degenerate mode when propagating along the plurality of first transmissive metasurfaces (12), thereby increasing the bandwidth during propagation.

Description

Transmissive metasurface structure, antenna device and communication equipment Technical Field

[0001] The present disclosure relates to the field of antenna technology, and in particular to a transmissive metasurface structure, an antenna device, and a communication device. Background Art

[0002] Beam steering technology, one of the most important technologies in modern wireless communications and radar scanning, has consistently garnered widespread attention. With technological advancements, beam steering technology continues to improve. Phased array technology is a commonly used beam steering technology in related fields. It primarily utilizes phase shifters to adjust the beam radiation direction of an array antenna through multiple phase shifters, enabling wide-range control. However, the introduction of phase shifters inevitably increases the weight, volume, and cost of the antenna assembly. Due to the large size of a single phase shifter, the beam radiation direction of a single element in the array antenna cannot be controlled.

[0003] To address the challenges posed by phased array technology, a reflective metasurface structure has been proposed. Compared to phase shifters, reflective metasurface structures are low-loss, low-cost, and easy to process. Furthermore, reflective metasurface structures can adjust the equivalent impedance of individual elements on an array antenna based on the smaller metasurface units (PIN diodes) they contain, thereby enabling the control of the beam radiation direction of individual elements.

[0004] However, technicians have discovered that reflective metasurfaces in related technologies still have some problems during use. Specifically, reflective metasurfaces are manufactured based on preset phase control, so when applied to an antenna device, the antenna device's beam can only be deflected in a fixed direction, and the beam radiation direction cannot be continuously connected. In addition, the reflective characteristics of the reflective metasurface structure will inevitably block the radiation effect of the antenna device, thereby affecting the propagation of electromagnetic signals. Furthermore, the metasurface units included in the reflective metasurface structure operate in a resonant mode, resulting in a narrow bandwidth of the reflective metasurface structure.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field.

[0006] Summary of the Invention

[0007] The purpose of the present disclosure is to provide a radio-beam surface structure, an antenna device and a communication device, which can realize continuous control of the beam scanning range and ensure a wider frequency band while ensuring the transmission of electromagnetic signals.

[0008] According to a first aspect of the present disclosure, there is provided a transmissive metasurface structure, comprising: at least three stacked carrier layers, and a first transmissive metasurface located between every two adjacent carrier layers;

[0009] The first transmissive metasurface includes a liquid crystal layer, and a first metal layer and a second metal layer located on both sides of the liquid crystal layer, the first metal layer includes a plurality of first metal strips spaced apart along a row direction, the second metal layer includes a plurality of second metal strips spaced apart along a column direction, and the arrangement period of the first metal strips and the arrangement period of the second metal strips are both less than or equal to 0.3λ, where λ refers to the wavelength of an electromagnetic signal propagating along the first transmissive metasurface;

[0010] There is an overlapping area between the first metal strip and the second metal strip in the thickness direction of the carrier layer. The first metal strip has a first aperture extending along the column direction at the position of the overlapping area, and the second metal strip has a second aperture extending along the row direction at the position of the overlapping area. The first aperture and the second aperture are used to achieve tuning of electromagnetic signals, and the electromagnetic signals propagated by the multiple first transmission-type metasurfaces can be coupled to achieve degenerate mode propagation.

[0011] According to any of the transmissive metasurface structures described in the present disclosure, both ends of the first aperture extend out of the overlapping area, and the second aperture is located in the overlapping area;

[0012] The width of the first metal strip is greater than or equal to 0.02λ, and the arrangement period of the first metal strip is less than or equal to 0.1λ. The width of the second metal strip is greater than or equal to 0.02λ, and the arrangement period of the second metal strip is greater than the arrangement period of the first metal strip.

[0013] According to any of the transmissive metasurface structures described in the present disclosure, the width of the second metal strip is less than or equal to 0.04λ.

[0014] According to any of the transmissive metasurface structures disclosed herein, the arrangement period of the first metal strips is 0.25 to 1.0 mm, and 6 to 20 consecutive metasurface units in the row direction constitute a wavelength control unit.

[0015] According to any of the transmissive metasurface structures described in the present disclosure, both ends of the first aperture and both ends of the second aperture extend out of the overlapping area;

[0016] The orthographic projections of the first metal strip and the second metal strip on the carrier layer form a plurality of grid areas distributed in an array. The transmissive metasurface structure also has a plurality of first metal patches corresponding one-to-one to the plurality of grid areas. The orthographic projection of each first metal patch on the carrier layer is located within the area enclosed by the orthographic projection of the corresponding grid area on the carrier layer.

[0017] According to any of the transmissive metasurface structures described in the present disclosure, the first metal patch is in the same layer as the first metal strip or the second metal strip.

[0018] According to any of the transmissive metasurface structures of the present disclosure, the width of the first metal strips in the overlapping area is greater than or equal to 1 / 3 of the arrangement period of the first metal strips and less than or equal to 2 / 3 of the arrangement period of the first metal strips;

[0019] The width of the second metal strips in the overlapping area is greater than or equal to 1 / 3 of the arrangement period of the second metal strips and less than or equal to 2 / 3 of the arrangement period of the second metal strips.

[0020] According to any of the transmissive metasurface structures described in the present disclosure, the distance between the first metal patch and the adjacent first metal strip along the width direction of the first metal strip, and the distance between the first metal patch and the adjacent second metal strip along the width direction of the second metal strip are both less than or equal to 0.05 mm.

[0021] According to any of the transmissive metasurface structures disclosed in the present invention, the shape of the first metal patch is similar to but not congruent with the shape enclosed by the corresponding grid area, and the center point of the first metal patch coincides with the center point of the corresponding grid area in the thickness direction of the carrier layer.

[0022] According to any of the transmissive metasurface structures described in the present disclosure, the grid area and the first metal patch are both rectangular.

[0023] According to any of the transmissive metasurface structures described in the present disclosure, the width of at least one of the first metal strip and the second metal strip at the overlapping area is greater than the width at the position directly opposite to the side of the grid area, and the first metal patch is a rectangular structure with a notch at the corner.

[0024] According to any of the transmissive metasurface structures described in the present disclosure, the operating frequency band of the transmissive metasurface structure is 27 GHz to 30 GHz.

[0025] According to any of the transmissive metasurface structures described in the present disclosure, when an electromagnetic signal propagates along the transmissive metasurface structure, the difference between the maximum and minimum values ​​of the transmission coefficient within the working frequency band is less than or equal to 1 decibel.

[0026] According to any of the transmissive metasurface structures described in the present disclosure, the first transmissive metasurface further includes a first alignment layer located between the liquid crystal layer and the first metal layer, and a second alignment layer located between the liquid crystal layer and the second metal layer.

[0027] According to a second aspect of the present disclosure, there is provided a transmissive metasurface structure, comprising: a plurality of stacked carrier layers, and a second transmissive metasurface located between every two adjacent carrier layers;

[0028] The second transmissive metasurface includes a third metal layer and a fourth metal layer disposed opposite to each other, and a liquid crystal layer, a metal grid, and a support layer located between the third metal layer and the fourth metal layer, wherein the support layer is located between the third metal layer and the metal grid, and liquid crystal molecules are provided on both sides of the metal grid;

[0029] The third metal layer includes a plurality of second metal patches distributed in an array, and the fourth metal layer includes a plurality of third metal patches. The plurality of second metal patches and the plurality of third metal patches correspond to each other one by one, and there is an overlapping area between the corresponding second metal patches and the third metal patches in the thickness direction of the carrier layer. The electromagnetic signal propagating between the second metal patch and the metal grid and the electromagnetic signal propagating between the third metal patch and the metal grid can be coupled to realize degenerate mode propagation.

[0030] According to any of the transmissive metasurface structures described in the present disclosure, the supporting layer includes a plurality of supporting columns, and both ends of each of the supporting columns are in contact with the second metal patch and the metal grid respectively.

[0031] According to any of the transmission metasurface structures described in the present disclosure, the supporting layer is a grid structure, and the orthographic projection of the metal grid on the carrier layer is located within the orthographic projection of the grid structure on the carrier layer.

[0032] According to any of the transmissive metasurface structures disclosed herein, the second metal patch completely overlaps with the corresponding third metal patch in the thickness direction of the carrier layer, and the second metal patch and the third metal patch are both rectangular patches.

[0033] According to a third aspect of the present disclosure, an antenna device is provided, comprising an antenna body and the transmissive metasurface structure described in the first or second aspect above, wherein the transmissive metasurface structure is located at the radiation end of the antenna body.

[0034] According to a third aspect of the present disclosure, a communication device is provided, comprising the antenna device described in the third aspect.

[0035] The embodiments of the present disclosure include at least the following technical effects:

[0036] In the embodiment of the present disclosure, for the first transmission metasurface included in the transmission metasurface structure, since the first metal layer and the second metal layer are both composed of an arrangement of metal strips, it is only necessary to connect the first metal strip and the second metal strip at one end thereof, so as to simplify the wiring of the first transmission metasurface and reduce the design difficulty of the transmission metasurface structure; in addition, an overlapping area of ​​the first metal strip and the second metal strip can correspond to a metasurface unit, and since the arrangement period of the first metal strip and the arrangement period of the second metal strip are both less than or equal to 0.3λ, it is ensured that the size of the multiple metasurface units after splicing along the row direction or column direction is still less than or equal to one wavelength, so as to realize the control of the beam radiation direction of a single vibrator of the array antenna when the phase of the beam is controlled; furthermore, the transmission metasurface structure can be applicable to communication bands such as low frequency, high frequency and even millimeter wave bands, thereby effectively improving the frequency band applicability range of the transmission metasurface structure, and at the same time, compared with the high-frequency band PIN diode included in the transmission metasurface in the related art, it can significantly reduce the production cost.

[0037] In addition, when the electromagnetic signal propagates along the first transmission type metasurface, the gaps between the first metal strips and the gaps between the second metal strips can form a propagation channel to ensure the penetration of the electromagnetic signal, thereby ensuring the propagation effect of the electromagnetic signal; in addition, for the liquid crystal layer included in the first transmission type metasurface, the loaded voltage can be adjusted to cause the liquid crystal molecules in the liquid crystal layer to deflect to any angle, so that when the phase of the beam is controlled by the metasurface unit, the beam phase can be infinitely controlled, thereby realizing continuous control of the beam radiation direction; furthermore, since the transmission metasurface structure includes multiple first transmission type metasurfaces, and the electromagnetic signal can couple and form a degenerate mode when propagating along multiple first transmission type metasurfaces, so as to increase the bandwidth of the electromagnetic signal when propagating in the transmission metasurface structure.

[0038] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0040] FIG1 is a schematic diagram of the cross-sectional structure of a transmission metasurface structure provided in an embodiment of the present disclosure.

[0041] FIG2 is a schematic diagram of a top-view structure of a first transmission-type metasurface provided in an embodiment of the present disclosure.

[0042] FIG3 is a schematic diagram of a top view of another first transmission-type metasurface provided in an embodiment of the present disclosure.

[0043] FIG4 is a schematic diagram of a top view of another first transmission metasurface provided in an embodiment of the present disclosure.

[0044] FIG5 is a schematic diagram of a top view of another first transmission type metasurface provided in an embodiment of the present disclosure.

[0045] FIG6 is a transmission curve of a transmission metasurface structure provided by an embodiment of the present disclosure.

[0046] FIG7 is an in-phase simulation diagram of a degenerate mode of a transmission metasurface structure at an operating frequency provided by an embodiment of the present disclosure.

[0047] FIG8 is an inverse phase simulation diagram of a degenerate mode of a transmission metasurface structure at an operating frequency provided by an embodiment of the present disclosure.

[0048] FIG9 is an in-phase simulation diagram of a degenerate mode of a transmission metasurface structure provided by an embodiment of the present disclosure at another operating frequency.

[0049] FIG10 is an inverse phase simulation diagram of a degenerate mode of a transmission metasurface structure provided by an embodiment of the present disclosure at another operating frequency.

[0050] FIG11 is a transmission phase curve of a transmission metasurface structure provided in an embodiment of the present disclosure.

[0051] FIG12 is a schematic diagram of a top-view structure of a first transmission-type metasurface in a working state provided by an embodiment of the present disclosure.

[0052] FIG13 is a simulated radiation pattern of an antenna device having a transmissive metasurface structure in a working state provided by an embodiment of the present disclosure.

[0053] FIG14 is a schematic diagram of a top-view structure of a first transmission-type metasurface in another working state provided by an embodiment of the present disclosure.

[0054] FIG15 is a simulated radiation pattern of an antenna device with a transmissive metasurface structure in another working state provided by an embodiment of the present disclosure.

[0055] FIG16 is a deflection pattern of an antenna device having a transmissive metasurface structure provided in an embodiment of the present disclosure.

[0056] FIG17 is a deflection pattern of another antenna device having a transmissive metasurface structure provided in an embodiment of the present disclosure.

[0057] FIG18 is a directional diagram of a microstrip antenna provided in an embodiment of the present disclosure.

[0058] FIG19 is a directional diagram of a microstrip antenna with a transmissive metasurface structure provided in an embodiment of the present disclosure.

[0059] FIG20 is a schematic diagram of the cross-sectional structure of another transmission metasurface structure provided in an embodiment of the present disclosure.

[0060] Figure 21 is a schematic diagram of the top view structure of another second transmission type metasurface provided in an embodiment of the present disclosure.

[0061] FIG22 is a schematic diagram of the cross-sectional structure of another transmission metasurface structure provided in an embodiment of the present disclosure.

[0062] FIG23 is a schematic diagram of a top view of the structure of a support layer provided in an embodiment of the present disclosure.

[0063] FIG24 is a schematic structural diagram of an antenna device provided in an embodiment of the present disclosure.

[0064] FIG25 is a schematic diagram of the beam coverage of a spotlight antenna provided in an embodiment of the present disclosure.

[0065] FIG26 is a schematic diagram of the beam coverage range of an antenna device provided in an embodiment of the present disclosure.

[0066] FIG27 is a schematic diagram of the beam coverage range of another antenna device provided in an embodiment of the present disclosure.

[0067] FIG28 is a simulation diagram of the lobe width of a spotlight antenna provided in an embodiment of the present disclosure.

[0068] FIG29 is a simulation diagram of the lobe width of an antenna device provided in an embodiment of the present disclosure.

[0069] Figures: 10. Antenna device; 1. Transmissive metasurface structure; 2. Antenna body; 11. Carrier layer; 12. First transmissive metasurface; 13. Second transmissive metasurface; 121. First metal layer; 122. Second metal layer; 123. Liquid crystal layer; 124. First alignment layer; 125. Second alignment layer; 126. Metasurface unit; 1211. First metal strip; 1212. First aperture; 1213. Overlapping area; 1214. Grid area; 1215. First metal patch; 1221. Second metal strip; 1222. Second aperture; 131. Third metal layer; 132. Fourth metal layer; 133. Metal grid; 134. Support layer; 135. Third alignment layer; 136. Fourth alignment layer; 1311. Second metal patch; 1321. Third metal patch 1341. Support column; 1342. Grid structure. DETAILED DESCRIPTION

[0070] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0071] Although relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one illustrated component to another, these terms are used herein for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It will be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via the other structure.

[0072] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used only as labels and are not intended to limit the quantity of their objects.

[0073] FIG1 illustrates a schematic cross-sectional structure diagram of a transmission metasurface structure 1 provided in an embodiment of the present disclosure, and FIG2 illustrates a schematic top-view structure diagram of a first transmission metasurface 12 provided in an embodiment of the present disclosure. As shown in FIG1 and FIG2, the transmission metasurface structure 1 includes: at least three stacked carrier layers 11, and a first transmission metasurface 12 located between each two adjacent carrier layers 11. The first transmission metasurface 12 includes a liquid crystal layer 123, and a first metal layer 121 and a second metal layer 122 located on both sides of the liquid crystal layer 123. The first metal layer 121 includes a plurality of first metal strips 1211 spaced apart along the row direction, and the second metal layer 122 includes a plurality of second metal strips 1221 spaced apart along the column direction. The arrangement period Px of the first metal strips 1211 and the arrangement period Py of the second metal strips 1221 are both less than or equal to 0.3λ, where λ refers to the wavelength of the electromagnetic signal when it propagates along the first transmission metasurface 12; There is an overlapping area 1213 between a metal strip 1211 and a second metal strip 1221 in the thickness direction of the carrier layer 11. The first metal strip 1211 has a first aperture 1212 extending along the column direction at the position of the overlapping area 1213, and the second metal strip 1221 has a second aperture 1222 extending along the row direction at the position of the overlapping area 1213. The first aperture 1212 and the second aperture 1222 are used to achieve tuning of electromagnetic signals. The electromagnetic signals transmitted by multiple first transmission-type metasurfaces 12 can be coupled to achieve degenerate mode propagation.

[0074] In the embodiment of the present disclosure, for the first transmission metasurface 12 included in the transmission metasurface structure 1, since the first metal layer 121 and the second metal layer 122 are both composed of an arrangement of metal strips, it is only necessary to connect the first metal strip 1211 and the second metal strip 1221 at one end thereof, so as to simplify the wiring of the first transmission metasurface 12 and reduce the design difficulty of the transmission metasurface structure 1; in addition, an overlapping area 1213 of the first metal strip 1211 and the second metal strip 1221 can correspond to a metasurface unit 126, and since the arrangement of the first metal strip 1211 is The arrangement period of the first and second metal strips 1221 is less than or equal to 0.3λ, thereby ensuring that the size of the multiple metasurface units 126 after splicing along the row direction or column direction is still less than or equal to one wavelength, so as to realize the control of the beam radiation direction of a single vibrator of the array antenna when the phase of the beam is controlled; furthermore, the transmissive metasurface structure 1 can be applied to communication bands such as low frequency, high frequency and even millimeter wave bands, thereby effectively improving the frequency band applicability range of the transmissive metasurface structure 1, and at the same time, compared with the high-frequency band PIN diode included in the transmissive metasurface in the related art, it can significantly reduce the production cost.

[0075] In addition, when the electromagnetic signal propagates along the first transmission metasurface 12, the gaps between the first metal strips 1211 and the gaps between the second metal strips 1221 can form a propagation channel to ensure the penetration of the electromagnetic signal, thereby ensuring the propagation effect of the electromagnetic signal; in addition, for the liquid crystal layer 123 included in the first transmission metasurface 12, the loaded voltage can be adjusted to cause the liquid crystal molecules in the liquid crystal layer 123 to deflect to any angle, so that when the phase of the beam is controlled by the metasurface unit 126, the beam phase can be infinitely controlled, thereby achieving continuous control of the beam radiation direction; furthermore, since the transmission metasurface structure 1 includes multiple first transmission metasurfaces 12, and the electromagnetic signal can be coupled and form a degenerate mode when propagating along the multiple first transmission metasurfaces 12, so as to increase the bandwidth of the electromagnetic signal when propagating in the transmission metasurface structure 1.

[0076] The carrier layer 11 included in the transmissive metasurface structure 1 may be a substrate made of insulating materials such as a glass substrate, a polymer substrate, a PCB substrate, and a ceramic substrate.

[0077] The liquid crystal layer 123 included in the first transmissive metasurface 12 is very thin, and can be on the order of several microns, to avoid excessively increasing the thickness of the first transmissive metasurface 12. For example, the thickness of the liquid crystal layer 123 is greater than or equal to 2 microns and less than or equal to 10 microns. The lengths of the first apertures 1212 and second apertures 1222 included in the first metal strip 1211 and the second metal strip 1221 can be set based on the size of the overlapping region 1213 formed by the first metal strip 1211 and the second metal strip 1221. The widths of the first apertures 1212 and the second apertures 1222 can be set to tens to hundreds of microns to ensure the tuning effect of the electromagnetic signal between the first aperture 1212 and the second aperture 1222.

[0078] In addition, in addition to including the first metal layer 121, the second metal layer 122, and the liquid crystal layer 123, as shown in FIG1 , the first transmissive metasurface 12 also includes a first alignment layer 124 located between the first metal layer 121 and the liquid crystal layer 123, and a second alignment layer 125 located between the second metal layer 122 and the liquid crystal layer 123. Thus, by providing the first alignment layer 124 and the second alignment layer 125, it is convenient to pre-set the deflection angle of the liquid crystal molecules in the liquid crystal layer 123, thereby facilitating the subsequent regulation of the deflection angle of the liquid crystal molecules.

[0079] In addition, the first transmissive metasurface 12 also includes spacers positioned between the first metal layer 121 and the second metal layer 122, as well as a plastic frame for bonding the first and second metal layers 121, 122. The liquid crystal layer 123 is positioned within the area enclosed by the plastic frame. The spacers ensure the stability of the liquid crystal receiving cavity between the first and second metal layers 121, 122, thereby facilitating the filling of the liquid crystal layer 123 between the first and second alignment layers 124, 125. The plastic frame surrounds the liquid crystal layer 123 to prevent leakage of the liquid crystal layer.

[0080] The transmissive metasurface structure 1 provided in the embodiments of the present disclosure can be applied to single-polarization antennas as well as dual-polarization antennas.

[0081] When the transmissive metasurface structure 1 is applied to a single-polarization antenna, as shown in Figure 2, both ends of the first aperture 1212 extend out of the overlapping area 1213, and the second aperture 1222 is located in the overlapping area 1213; the width of the first metal strip 1211 is greater than or equal to 0.02λ, and the arrangement period Px of the first metal strip 1211 is less than or equal to 0.1λ, the width of the second metal strip 1221 is greater than or equal to 0.02λ, and the arrangement period Py of the second metal strip 1221 is greater than the arrangement period Px of the first metal strip 1211.

[0082] Among them, on the orthographic projection of the first transmission metasurface 12, as shown in Figure 2, the unit structure surrounded by the long side of the first metal strip 1211 and the rectangular area including the first hole 1212 constitutes a metasurface unit 126.

[0083] In this way, by setting the arrangement period of the first metal strip 1211 to be less than or equal to 0.1λ, the metasurface unit 126 included in the first transmission metasurface 12 is a deep subwavelength structure, thereby further ensuring that the size of the multiple metasurface units 126 after splicing along the row direction is less than one wavelength, so that when the phase of the beam is controlled, the beam radiation direction of a single element of the array antenna can be controlled. At the same time, combined with a smaller arrangement period, more metasurface units 126 can be set to form a wavelength control unit to improve the continuity of the beam radiation direction control and reduce the beam radiation. The step-by-step direction control is achieved; in addition, the arrangement period of the second metal strips 1221 is set to be greater than the arrangement period of the first metal strips 1211 to ensure that the single-polarized electromagnetic signal (the electromagnetic signal polarized along the column direction) propagates along the gap between the two adjacent first metal strips 1211, and at the same time, the end of the first aperture 1212 is extended out of the overlapping area 1213, thereby ensuring the coupling effect between the two adjacent first transmission-type metasurfaces 12 when the single-polarized electromagnetic signal propagates along the gap between the two adjacent first metal strips 1211, thereby ensuring the degeneracy effect of the single-polarized electromagnetic signal.

[0084] Optionally, the gaps between adjacent first metal strips 1211 are used to propagate single-polarized electromagnetic signals, and the smaller the gaps between adjacent first metal strips 1211, the higher the transmittance of the single-polarized electromagnetic signals. Thus, on the basis of limiting the minimum width of the first metal strips 1211, the width of the first metal strips 1211 can be set close to the arrangement period of the first metal strips 1211, and it is sufficient to ensure that there are gaps between adjacent first metal strips 1211.

[0085] Optionally, the larger the gap between adjacent second metal strips 1221, the longer the gap between adjacent first metal strips 1211, and the higher the transmittance of the single-polarized electromagnetic signal. Therefore, on the basis of defining the minimum width of the second metal strip 1221, the maximum width of the second metal strip 1221 can be defined to ensure the transmittance of the single-polarized electromagnetic signal. For example, the maximum width of the second metal strip 1221 can be set to 0.04λ, that is, the width of the second metal strip 1221 can be set to be less than or equal to 0.04λ. Of course, the width of the second metal strip 1221 can also be set to be slightly greater than 0.04λ, as long as the first transmission metasurface 12 has sufficient transmittance for the single-polarized electromagnetic signal.

[0086] The wavelength control unit described above refers to a phase control structure within a wavelength range. The arrangement period of the first metal strips 1211 can be set to be even smaller to increase the number of metasurface units 126 that constitute a wavelength control unit in the row direction, thereby further improving the continuity of beam radiation direction control. For example, the arrangement period of the metasurface units 126 can be set to be less than or equal to 0.05λ.

[0087] Furthermore, considering that the arrangement period Px of the first metal strips 1211 is less than or equal to 0.1λ as described above, the arrangement period Px of the first metal strips 1211 can be set to 0.25 to 1.0 mm, and 6 to 20 consecutive metasurface units 126 in the row direction constitute a wavelength control unit. Specifically, by adjusting the arrangement period Px of the first metal strips 1211, the number of metasurface units 126 in the row direction that constitute a wavelength control unit can be adjusted. This improves the continuity of beam radiation direction control and reduces the step-wise nature of beam radiation direction control through the multiple metasurface units 126.

[0088] For example, for an electromagnetic signal with a wavelength of 12 mm, the arrangement period of the first metal strip 1211 can be set to 0.5 mm (less than 1.2 mm), and 11 continuous metasurface units 126 in the row direction constitute a wavelength control unit.

[0089] When the transmissive metasurface structure 1 is applied to a dual-polarized antenna, as shown in Figure 3 or Figure 4, both ends of the first aperture 1212 and both ends of the second aperture 1222 extend out of the overlapping area 1213; the orthographic projections of the first metal strip 1211 and the second metal strip 1221 on the carrier layer 11 form a plurality of grid areas 1214 distributed in an array, and the transmissive metasurface structure 1 also has a plurality of first metal patches 1215 corresponding one-to-one to the plurality of grid areas 1214, and the orthographic projection of each first metal patch 1215 on the carrier layer 11 is located within the area enclosed by the orthographic projection of the corresponding grid area 1214 on the carrier layer 11.

[0090] As shown in FIG. 3 or FIG. 4 , a unit structure formed by a rectangular area connected by the center points of the four first metal patches 1215 in a 2*2 distribution as vertices constitutes a metasurface unit 126 .

[0091] In this way, by setting the first metal patch 1215 in the area surrounded by multiple grid areas 1214, the first metal patch 1215 is coupled with the radiation patch of the array antenna to realize the propagation of dual-polarized electromagnetic signals (electromagnetic signals polarized along the row direction and electromagnetic signals polarized along the column direction) along the gaps between the first gold patch and the first metal strip 1211 and the second metal strip 1221 respectively; in addition, both ends of the first aperture 1212 and both ends of the second aperture 1222 are extended out of the overlapping area 1213, thereby ensuring the coupling effect between the two adjacent first transmission-type metasurfaces 12 when the dual-polarized electromagnetic signal propagates along the gaps between the first gold patch and the first metal strip 1211 and the second metal strip 1221 respectively, thereby ensuring the degeneracy effect of the dual-polarized electromagnetic signal.

[0092] Among them, the first metal patch can be set in the same layer as the first metal strip or the second metal strip to simplify the structure of the first transmission type metasurface 12, thereby simplifying the manufacturing process of the first transmission type metasurface 12. Of course, in addition to being set in the first metal layer or the second metal layer, the first metal patch can also be set between the first metal layer and the second metal layer. Of course, it can also be set on the side of the first metal layer away from the second metal layer, or on the side of the second metal layer away from the first metal layer. This is not limited in the implementation of the present disclosure. At this time, in order to ensure the propagation of dual-polarized electromagnetic signals, the distance between the first metal patch and the adjacent metal layer can be set to be less than or equal to 200 microns. For example, the distance between the first metal patch and the adjacent metal layer can be 10 microns, 30 microns, 50 microns, 80 microns, 120 microns, 160 microns, 200 microns, etc.

[0093] In some embodiments, the width of the first metal strip 1211 in the overlapping area 1213 is greater than or equal to 1 / 3 of the arrangement period of the first metal strip 1211, and less than or equal to 2 / 3 of the arrangement period of the first metal strip 1211; the width of the second metal strip 1221 in the overlapping area 1213 is greater than or equal to 1 / 3 of the arrangement period of the second metal strip 1221, and less than or equal to 2 / 3 of the arrangement period of the second metal strip 1221.

[0094] In this way, by limiting the width of the first metal strip 1211 and the second metal strip 1221 in the overlapping area 1213, and at the same time limiting the size of the grid area 1214 surrounded by the first metal strip 1211 and the second metal strip 1221, the length of the first hole 1212 and the second hole 1222 on the first metal strip 1211 and the second metal strip 1221 is guaranteed to ensure the tuning effect of the dual-polarized electromagnetic signal when propagating along the first transmission metasurface 12; at the same time, by limiting the size of the grid area 1214 surrounded by the first metal strip 1211 and the second metal strip 1221, the size of the first metal patch 1215 is guaranteed, thereby facilitating the coupling between the electromagnetic signal radiated by the array antenna and the first metal patch 1215, and facilitating improving the antenna effect of the antenna device 10 including the transmission metasurface structure.

[0095] Optionally, the width of the first metal strip 1211 in the overlapping area 1213 is equal to the width of the second metal strip 1221 in the overlapping area 1213, and the arrangement period of the first metal strip 1211 is equal to the arrangement period of the second metal strip 1221. This makes it convenient to set the lengths of the first holes 1212 and the second holes 1222 on the first metal strip 1211 and the second metal strip 1221 to be equal, so as to ensure that the tuning effects of the two polarized electromagnetic signals included in the dual-polarized electromagnetic signal are consistent when propagating along the first transmission-type metasurface 12; at the same time, it can ensure that the size of the grid area 1214 surrounded by the first metal strip 1211 and the second metal strip 1221 in the row direction is equal to the size in the column direction, thereby ensuring the consistency of the transmittance of the two polarized electromagnetic signals included in the dual-polarized electromagnetic signal when propagating.

[0096] In the embodiment of the present disclosure, the gap between the first metal patch 1215 and the first metal strip 1211 and the second metal strip 1221 is used to transmit dual-polarized electromagnetic signals, and the smaller the gap between the first metal patch 1215 and the first metal strip 1211 and the second metal strip 1221, the higher the transmittance of the dual-polarized electromagnetic signal. Therefore, when the first metal patch 1215 is set in the grid area 1214 formed by the first metal strip 1211 and the second metal strip 1221, the distance between the first metal patch 1215 and the adjacent first metal strip 1211 along the width direction of the first metal strip 1211 and the distance between the first metal patch 1215 and the adjacent second metal strip 1221 along the width direction of the second metal strip 1221 can be set to be less than or equal to 0.05 mm. In this way, the transmittance of the dual-polarized electromagnetic signal can be guaranteed when the dual-polarized electromagnetic signal propagates through the gap between the first metal patch 1215 and the first metal strip 1211 and the second metal strip 1221, thereby ensuring the propagation effect of the dual-polarized electromagnetic signal.

[0097] Furthermore, the distance between the first metal patch 1215 and the adjacent first metal strip 1211 along the width direction of the first metal strip 1211, and the distance between the first metal patch 1215 and the adjacent second metal strip 1221 along the width direction of the second metal strip 1221 can be set to be greater than or equal to 0.01 mm. In this way, it is avoided that the first metal patch 1215 is directly connected to the first metal strip 1211 and / or the second metal strip 1221 due to processing errors when manufacturing the first metal strip 1211, the second metal strip 1221, and the first metal patch 1215.

[0098] Of course, under the premise of ensuring that the dual-polarized electromagnetic signal can pass through the first transmissive metasurface 12, the distance between the first metal patch 1215 and the adjacent first metal strip 1211 along the width direction of the first metal strip 1211, and the distance between the first metal patch 1215 and the adjacent second metal strip 1221 along the width direction of the second metal strip 1221 can be set to be slightly greater than 0.05 mm. In addition, the distance between the first metal patch 1215 and the adjacent first metal strip 1211 along the width direction of the first metal strip 1211 and the distance between the first metal patch 1215 and the adjacent second metal strip 1221 along the width direction of the second metal strip 1221 can be the same or different, as long as the effective propagation of the dual-polarized electromagnetic signal can be ensured, and the embodiments of the present disclosure are not limited to this. When the distance between the first metal patch 1215 and the adjacent first metal strip 1211 along the width direction of the first metal strip 1211, and the distance between the first metal patch 1215 and the adjacent second metal strip 1221 along the width direction of the second metal strip 1221 are the same, the consistency of the transmittance of the two polarized electromagnetic signals included in the dual-polarized electromagnetic signal during propagation can be guaranteed.

[0099] In the embodiment of the present disclosure, the gap between the first metal patch 1215 and the first metal strip 1211 and the second metal strip 1221 is used to propagate dual-polarized electromagnetic signals. At this time, an equivalent capacitor is approximately formed between the first metal patch 1215 and the first metal strip 1211 and the second metal strip 1221. In order to ensure that the capacitance value of the equivalent capacitor approximately formed between the first metal patch 1215 and the first metal strip 1211 and the second metal strip 1221 is the same at any position, the shape of the first metal patch 1215 can be set to be similar but not identical to the shape enclosed by the corresponding grid area 1214, and the center point of the first metal patch 1215 and the center point of the corresponding grid area 1214 coincide with each other in the thickness direction of the carrier layer 11.

[0100] In this way, by limiting the shape of the grid area 1214 to be similar but not identical to the shape of the corresponding first metal patch 1215, it is convenient to set the first metal patch 1214 in the area enclosed by the grid area 1214, thereby ensuring that the distance between the edge of the first metal patch 1215 and the grid area 1214 at any position is equal, thereby ensuring that the capacitance value of the equivalent capacitor approximately formed between the first metal patch 1215 and the first metal strip 1211 and the second metal strip 1221 is uniform.

[0101] In some embodiments, as shown in FIG3 , the first metal strip 1211 and the second metal strip 1221 are both strip-shaped structures of constant width. In this case, the grid area 1214 and the first metal patch 1215 are both rectangular (e.g., square or rectangular). This effectively ensures that the distance between the first metal patch 1215 and the first metal strip 1211 is equal to the distance between the first metal patch 1215 and the second metal strip 1221. This also facilitates the fabrication of the first transmissive metasurface 12 and simplifies the fabrication process.

[0102] In other embodiments, at least one of the first metal strip 1211 and the second metal strip 1221 is a strip-shaped structure with a width that alternates along its length. By adjusting the widths of the first metal strip 1211 and the second metal strip 1221, the effective area of ​​the first metal patch 1215 can be maintained while simultaneously compressing the size of adjacent overlapping regions 1213 in the row or column direction, thereby effectively reducing the arrangement period of the metasurface units 126.

[0103] Optionally, the width of at least one of the first metal strip 1211 and the second metal strip 1221 in the overlapping area 1213 is greater than the width at a position directly facing the side of the grid area 1214 . Specifically, as shown in Figure 5, the first metal strip 1211 is a strip structure with a constant width, that is, the width of the first metal strip 1211 at any position in the length direction is equal, and the width of the second metal strip 1221 in the overlapping area 1213 is greater than the width at the position directly opposite the side of the grid area 1214; or, the width of the first metal strip 1211 in the overlapping area 1213 is greater than the width at the position directly opposite the side of the grid area 1214, and the second metal strip 1221 is a strip structure with a constant width, that is, the width of the second metal strip 1221 at any position in the length direction is equal; or, as shown in Figure 4, the widths of the first metal strip 1211 and the second metal strip 1221 in the overlapping area 1213 are greater than the widths at the position directly opposite the side of the grid area 1214.

[0104] In the aforementioned cases where the widths of the first metal strip 1211 and the second metal strip 1221 are set, the first metal patch 1215 is a rectangular structure with notches at the corners. Specifically, for the first two cases, as shown in FIG5 , the first metal patch 1215 is a patch structure with rectangular notches at all four corners. For the third case, as shown in FIG4 , the first metal patch 1215 is a patch structure with L-shaped notches at all four corners.

[0105] In the embodiment of the present disclosure, combined with the above-mentioned transmission metasurface structure 1, based on the coupling between multiple first transmission metasurfaces 12, the characteristic of electromagnetic signals propagating in a degenerate mode is realized. Taking the transmission metasurface structure 1 working in the millimeter wave frequency band as an example, a wide frequency band of 27GHz to 30GHz can be achieved, thereby ensuring that the transmission metasurface structure 1 has a wider operating frequency band to improve the applicability of the transmission metasurface structure 1.

[0106] Optionally, when an electromagnetic signal propagates along the transmissive metasurface structure 1, the difference between the maximum and minimum transmission coefficients within the operating frequency band of 27 GHz to 30 GHz is less than or equal to 1 decibel. This ensures that the transmissive metasurface structure 1 has high transmittance within a wider operating frequency band, and that the transmission coefficients within the wider operating frequency band are close, thereby ensuring the transmittance and transmission stability of the electromagnetic signal propagating along the transmissive metasurface structure 1.

[0107] Taking the transmission metasurface structure 1 applied to a single-polarized antenna as an example, for an electromagnetic signal with a wavelength of 12 mm, the transmission metasurface structure 1 is provided to include two first transmission metasurfaces 12, and for the structural layer included in the first transmission metasurface 12, the thickness of the first metal strip 1211 and the second metal strip 1221 are both 3 microns, the width of the first metal strip 1211 and the second metal strip 1221 are both 0.46 mm, the arrangement period of the first metal strip 1211 is 0.5 mm, the arrangement period of the second metal strip 1221 is 1.8 mm, and the length of the first hole 1212 on the first metal strip 1211 is 0.9 mm. m, and the length of the second hole 1222 on the second metal strip 1221 is 0.4 mm; in addition, the carrier layers 11 on both sides are glass substrates with a thickness of 0.5 mm, and the middle carrier layer 11 is a glass substrate with a thickness of 1.0 mm. The dielectric constant of the glass substrate is 4.6, and the loss tangent value is 0.003. The thickness of the liquid crystal layer 123 is 5 μm, and the dielectric constant perpendicular to the liquid crystal director is 2.453, the dielectric constant parallel to the liquid crystal director is 3.582, the loss tangent perpendicular to the liquid crystal director is 0.011, and the loss tangent parallel to the liquid crystal director is 0.006.

[0108] Combined with the above-mentioned transmission metasurface structure 1, simulation is performed to obtain transmission curves 1, 2, and 3 as shown in Figure 6. Transmission curve 1 is the transmission coefficient curve of the electromagnetic signal when the liquid crystal molecules are deflected to the long axis direction perpendicular to the plane where the glass substrate is located after the voltage is applied. Transmission curve 2 is the transmission coefficient curve of the electromagnetic signal when the liquid crystal molecules are deflected to the long axis direction and form a 45-degree angle with the plane where the glass substrate is located after the voltage is applied. Transmission curve 3 is the transmission coefficient curve of the electromagnetic signal when the liquid crystal molecules are deflected to the long axis direction parallel to the plane where the glass substrate is located after the voltage is applied. The horizontal coordinates of transmission curves 1, 2, and 3 are all frequencies (in GHz), and the vertical coordinates are all transmission coefficients (in dB).

[0109] As shown in Figure 6, transmission curves 1, 2, and 3 have high transmission coefficients in the frequency band of 27 GHz to 32 GHz. Furthermore, due to the degenerate mode propagation of the electromagnetic signal formed by the two first transmission metasurfaces 12, the transmission coefficient exhibits two peaks, and the transmission coefficient between the two peaks is maintained at a high level. Thus, combined with the simulation results, it can be seen that the degenerate method of the two first transmission metasurfaces 12 described above can ensure that the transmission metasurface structure 1 has a high transmission coefficient within a wider operating frequency band, and the transmission coefficients within this wider operating frequency band are close, thereby ensuring the stability of the transmission of electromagnetic signals.

[0110] Among them, the two peaks in the transmission curve 1 and the transmission curve 3 shown in Figure 6 correspond to two degenerate modes respectively. When the frequency corresponding to the first peak of the transmission curve 1 is 27 GHz, as shown in Figure 7, the electromagnetic signal presents a degenerate mode close to the same phase on the two first transmission type metasurfaces 12, and when the frequency corresponding to the second peak is 29.2 GHz, as shown in Figure 8, the electromagnetic signal presents a degenerate mode close to the opposite phase on the two first transmission type metasurfaces 12; when the frequency corresponding to the first peak of the transmission curve 3 is 29.4 GHz, as shown in Figure 9, the electromagnetic signal presents a degenerate mode close to the same phase on the two first transmission type metasurfaces 12, and when the frequency corresponding to the second peak is 31.8 GHz, as shown in Figure 10, the electromagnetic signal presents a degenerate mode close to the opposite phase on the two first transmission type metasurfaces 12.

[0111] Continuing to simulate the transmission metasurface structure 1 described above, the transmission phase when the long axis direction of the liquid crystal molecules is perpendicular to the plane where the glass substrate is located is taken as the reference phase, and the phase difference curve 1 and the phase difference curve 2 are obtained as shown in Figure 11. The phase difference curve 1 is the phase difference curve of the electromagnetic signal when the liquid crystal molecules are deflected to the long axis direction after the voltage is applied and the angle is 45 degrees with the plane where the glass substrate is located. The phase difference curve 2 is the phase difference curve of the electromagnetic signal when the liquid crystal molecules are deflected to the long axis direction parallel to the plane where the glass substrate is located after the voltage is applied. The horizontal coordinates of the phase difference curve 1 and the phase difference curve 2 are both frequencies (in GHz), and the vertical coordinates are both phase differences (in degrees).

[0112] It can be seen from the phase difference curve 1 shown in Figure 11 that when the long axis direction of the liquid crystal molecules is at an angle of 45 degrees to the plane where the glass substrate is located, the electromagnetic signal can have a phase difference of 48 degrees to 72 degrees (i.e., 60±12 degrees) in the frequency band of 27.5GHz to 30GHz, and can have a phase difference of 48 degrees to 54 degrees (i.e., 51±3 degrees) in the frequency band of 28GHz to 29GHz; it can be seen from the phase difference curve 2 shown in Figure 11 that when the long axis direction of the liquid crystal molecules is parallel to the plane where the glass substrate is located, the electromagnetic signal can have a phase difference of 75 degrees to 105 degrees (i.e., 90±15 degrees) in the frequency band of 27.5GHz to 30GHz, and can have a phase difference of 73 degrees to 77 degrees (i.e., 75±2 degrees) in the frequency band of 28GHz to 29GHz. In this way, combined with the simulation results, it can be seen that through the degenerate method of the two first transmission type metasurfaces 12 described above, when the electromagnetic signal propagates along the transmission metasurface structure 1, a smaller transmission amplitude fluctuation can be guaranteed within a wider frequency band to achieve better phase control linearity.

[0113] Furthermore, in conjunction with the phase difference curve 2 shown in FIG11 , although the phase control amount can be increased to above 90 degrees, it is still far from the control amount of 360 degrees. The fundamental purpose of increasing the phase control amount is to achieve beam control. Because the arrangement period of the metasurface units 126 included in the first transmission metasurface 12 is much smaller than a wavelength, even if the phase control amount achievable by the transmission metasurface structure 1 is still small, the phase gradient achieved can be large.

[0114] Continuing with the above-mentioned transmission metasurface structure 1, assuming that a wavelength of the electromagnetic signal during propagation is 12 mm, when the arrangement period of the first metal strip 1211 is 0.5 mm, as shown in FIG12 , 11 metasurface units 126 arranged continuously in the row direction constitute a wavelength control unit. At this time, the size of the wavelength control unit is 5.5 mm, which is less than half of a wavelength (i.e., less than 6 mm). For the wavelength control unit composed of 11 metasurface units 126, as shown in FIG12 , after the four metasurface units 126 on the left are loaded with voltage, the long axis direction of the liquid crystal molecules is perpendicular to the plane where the glass substrate is located. After the three metasurface units 126 in the middle are loaded with voltage, the long axis direction of the liquid crystal molecules is at a 45-degree angle to the plane where the glass substrate is located. After the four metasurface units 126 on the right are loaded with voltage, the long axis direction of the liquid crystal molecules is parallel to the plane where the glass substrate is located. At this time, the simulation of continuous beam scanning is performed in combination with the waveguide horn antenna, as shown in FIG13 , which can be realized. The beam is now deflected 31 degrees to the left; as shown in Figure 14, after the four metasurface units 126 on the left are loaded with voltage, the long axis direction of the liquid crystal molecules is caused to be parallel to the plane where the glass substrate is located, and after the three metasurface units 126 in the middle are loaded with voltage, the long axis direction of the liquid crystal molecules is caused to form a 45-degree angle with the plane where the glass substrate is located. After the four metasurface units 126 on the right are loaded with voltage, the long axis direction of the liquid crystal molecules is caused to be perpendicular to the plane where the glass substrate is located. At this time, the waveguide horn antenna is combined to simulate continuous beam scanning, as shown in Figure 15, which can achieve a beam deflection of 31 degrees to the right.

[0115] Furthermore, simulations have confirmed that for a wavelength control unit consisting of 11 continuous metasurface units 126 along the row direction, as shown in FIG16 , at 28.2 GHz, the beam can be steered to scan from positive 31 degrees to negative 31 degrees, precisely controlling the beam deflection direction within a ±31-degree range. As shown in FIG17 , at 30 GHz, the beam can be steered to scan from positive 37 degrees to negative 37 degrees, precisely controlling the beam deflection direction within a ±37-degree range. This allows for a beam scanning range of ±(34±3 degrees) to be achieved within a relatively wide bandwidth (1.8 GHz).

[0116] Taking the transmission metasurface structure 1 applied to the dual-polarized antenna as an example, for an electromagnetic signal with a wavelength of 12 mm, the transmission metasurface structure 1 is provided to include two first transmission metasurfaces 12, and for the structural layer included in the first transmission metasurface 12, the thickness of the first metal strip 1211 and the second metal strip 1221 are both 3 microns, the width of the first metal strip 1211 and the second metal strip 1221 are both 0.49 mm, the arrangement period of the first metal strip 1211 and the arrangement period of the second metal strip 1221 are both 1.0 mm, the first metal patch 1215 is a rectangular patch structure of 0.49 mm × 0.49 mm, and the first metal strip 1211 is provided with a plurality of metal strips 1211, 1221, 1215 ... The length of the first hole 1212 and the length of the second hole 1222 on the second metal strip 1221 are both 0.9 mm; in addition, the carrier layers 11 on both sides are set to glass substrates with a thickness of 0.5 mm, and the middle carrier layer 11 is set to a glass substrate with a thickness of 1.0 mm. The dielectric constant of the glass substrate is 4.6, and the loss tangent value is 0.003. The thickness of the liquid crystal layer 123 is set to 5 microns, and the dielectric constant perpendicular to the liquid crystal director is 2.453, the dielectric constant parallel to the liquid crystal director is 3.582, the loss tangent perpendicular to the liquid crystal director is 0.011, and the loss tangent parallel to the liquid crystal director is 0.006.

[0117] In combination with the first transmission metasurface 12 described above, a microstrip antenna without a transmission metasurface structure 1 is simulated, and a radiation pattern as shown in Figure 18 is obtained; a microstrip antenna with a transmission metasurface structure 1 is simulated, and a radiation pattern as shown in Figure 19 is obtained.

[0118] The transmissive metasurface provided at the radiating end of the microstrip antenna includes a first transmissive metasurface 12 having 100 metasurface units 126 arranged in a 10×10 array. The four outer circles of these 10×10 metasurface units 126, when pressurized, align the long axis of the liquid crystal molecules with the plane of the glass substrate. The four inner circles of metasurface units 126, when pressurized, align the long axis of the liquid crystal molecules with the plane of the glass substrate at a 45-degree angle. The two innermost circles of metasurface units 126, when pressurized, align the long axis of the liquid crystal molecules with the plane of the glass substrate. Furthermore, as shown in Figures 18 and 19, the gain of the microstrip antenna without the transmissive metasurface structure 1 is only 0.2 decibels, while the gain of the microstrip antenna with the transmissive metasurface structure 1 can be increased to 3.29 decibels.

[0119] Figure 20 illustrates a cross-sectional schematic diagram of another transmissive metasurface structure 1 provided in an embodiment of the present disclosure, and Figure 21 illustrates a top-down schematic diagram of a second transmissive metasurface provided in an embodiment of the present disclosure. As shown in Figures 20 and 21, the transmissive metasurface includes: a plurality of stacked carrier layers 11, and a second transmissive metasurface 13 located between each two adjacent carrier layers 11. The second transmission type metasurface 13 includes a third metal layer 131 and a fourth metal layer 132 arranged opposite to each other, and a liquid crystal layer 123, a metal grid 133 and a support layer 134 located between the third metal layer 131 and the fourth metal layer 132, the support layer 134 is located between the third metal layer 131 and the metal grid, and there are liquid crystal molecules on both sides of the metal grid; the third metal layer 131 includes a plurality of second metal patches 1311 distributed in an array, and the fourth metal layer 132 includes a plurality of third metal patches 1321, the plurality of second metal patches 1311 and the plurality of third metal patches 1321 correspond to each other one by one, and the corresponding second metal patches 1311 and the third metal patches 1321 have an overlapping area in the thickness direction of the carrier layer 11, and the electromagnetic signal propagating between the second metal patch 1311 and the metal grid 133 can be coupled with the electromagnetic signal propagating between the third metal patch 1321 and the metal grid 133 to achieve degenerate mode propagation.

[0120] In the embodiment of the present disclosure, for the second transmission metasurface 13 included in the transmission metasurface structure 1, since the third metal layer 131 and the fourth metal layer 132 are both composed of an arrangement of metal patches, when the electromagnetic signal propagates along the second transmission metasurface 13, the gaps between the second metal patches 1311 and the gaps between the third metal strips can form a propagation channel to ensure the penetration of the electromagnetic signal, thereby ensuring the propagation effect of the dual-polarized electromagnetic signal; in addition, for the liquid crystal layer 123 included in the second transmission metasurface 13, the liquid crystal molecules in the liquid crystal layer 123 can be deflected to the polarized state by adjusting the loaded voltage. Any angle, so when the phase of the beam is controlled by the metasurface unit 126, the beam phase can be infinitely controlled, and then the continuous control of the beam radiation direction can be achieved; furthermore, when the dual-polarized electromagnetic signal propagates along the third metal layer 131, the metal grid 133 and the fourth metal layer 132, the dual-polarized electromagnetic signal propagating between the second metal patch 1311 and the metal grid 133 and the dual-polarized electromagnetic signal propagating between the third metal patch 1321 and the metal grid 133 can be coupled to realize degenerate mode propagation, thereby increasing the bandwidth of the dual-polarized electromagnetic signal when propagating along the transmission metasurface structure 1.

[0121] The carrier layer 11 included in the transmissive metasurface structure 1 may be a substrate made of insulating materials such as a glass substrate, a polymer substrate, a PCB substrate, and a ceramic substrate.

[0122] Among them, for the second metal patch 1311 included in the third metal layer 131 and the third metal patch 1321 included in the fourth metal layer 132, the overlapping area of ​​the second metal patch 1311 and the third metal patch 1321 can constitute a metasurface unit 126. The size of the second metal patch 1311 and the size of the third metal patch 1321 can be the same or different. When the size of the second metal patch 1311 and the size of the third metal patch 1321 are the same, the second metal patch 1311 and the corresponding third metal patch 1321 can completely overlap in the thickness direction of the carrier layer 11 to ensure the coupling effect when the electromagnetic signal propagates along the second transmission metasurface 13, thereby improving the bandwidth after degeneration during the propagation of the electromagnetic signal. In addition, the second metal patch 1311 and the third metal patch 1321 are both rectangular patches (such as square patches and rectangular patches). Therefore, when transmitting dual-polarized electromagnetic signals, the transmittance of the two polarized electromagnetic signals is consistent when propagating in the gap between two adjacent metal patches, thereby ensuring the transmission effect of the dual-polarized electromagnetic signal.

[0123] The metal grid 133 can be a grid structure composed of metal wires, and the width of the metal wires can be from a few microns to tens of microns. The size of the grid formed on the metal grid 133 can be approximately 10 times the width of the metal wires. In addition, the distances between the metal grid 133 and the second metal patch 1311 and the third metal patch 1321 can be equal to ensure the coupling effect between the electromagnetic signal between the second metal patch 1311 and the metal grid 133 and the electromagnetic signal between the third metal patch 1321 and the metal grid 133, thereby improving the degenerate propagation effect of the second transmission metasurface 13 structure on electromagnetic signals.

[0124] Among them, the liquid crystal layer 123 between the third metal layer 131 and the fourth metal layer 132 can be set to be slightly thicker. For example, the thickness of the liquid crystal layer 123 can be set to be greater than or equal to 20 microns to ensure that there is sufficient space between the third metal layer 131 and the fourth metal layer 132 to set the metal grid 133, while ensuring the gap between the metal grid 133 and the third metal layer 131 and the fourth metal layer 132.

[0125] Among them, the support layer 134 is mainly used to support the metal grid 133 to ensure that there is a gap between the metal grid 133 and the third metal layer 131 and the fourth metal layer 132. Optionally, as shown in Figure 20, the support layer 134 includes a plurality of support columns 1341, and the two ends of each support column 1341 are in contact with the second metal patch 1311 and the metal grid, respectively. In this way, the structure of the support layer 134 can be simplified, thereby simplifying the production of the support layer 134. Of course, as shown in Figures 22 and 23, the support layer 134 can also be a grid structure 1342, and the orthographic projection of the metal grid 133 on the carrier layer 11 is located within the orthographic projection of the grid structure 1342 on the carrier layer 11. In this way, not only can the stability of the support layer 134 supporting the metal grid 133 be improved, but also the production process of the second transmission-type metasurface 13 can be simplified.

[0126] The manufacturing process of the support layer 134 and the metal grid 133 is exemplified as follows: if the support layer 134 is a support column 1341, a support structure and a metal structure may be sequentially formed on the third metal layer 131, the metal structure may be etched to form the metal grid 133, and the support structure may be etched to form a plurality of support columns 1341. For example, if the support layer 134 is a grid structure 1342, a support structure may be first formed on the third metal layer 131, and the support structure may be etched to form the grid structure 1342; and the metal grid 133 may be formed on the grid structure 1342 by a process such as evaporation.

[0127] In addition, in addition to the third metal layer 131, the fourth metal layer 132 and the liquid crystal layer 123, as shown in Figure 20, the second transmission type metasurface 13 also includes a third alignment layer 135 located on the side of the third metal layer 131 close to the liquid crystal layer 123, a fourth alignment layer 136 located on the side of the fourth metal layer 132 close to the liquid crystal layer 123, a spacer located between the third metal layer 131 and the fourth metal layer 132 (not shown in the figure), and a glue frame (not shown in the figure) bonding the third metal layer 131 and the fourth metal layer 132. The liquid crystal layer 123 is located in the area surrounded by the glue frame.

[0128] In this way, by setting the third alignment layer 135 and the fourth alignment layer 136, it is convenient to pre-set the deflection angle of the liquid crystal molecules in the liquid crystal layer 123, and then facilitate the subsequent regulation of the deflection angle of the liquid crystal molecules; the spacer is supported between the third metal layer 131 and the fourth metal layer 132 to ensure the stability of the liquid crystal receiving cavity between the third metal layer 131 and the fourth metal layer 132, so as to facilitate filling the liquid crystal layer 123 between the third alignment layer 135 and the fourth alignment layer 136, and the glue frame surrounds the liquid crystal layer 123 to avoid leakage of the liquid crystal layer.

[0129] Optionally, for the transmissive metasurface structure 1 described above, the product of the refractive index of the liquid crystal layer 123 and the arrangement period of the second metal patches 1311 can be set to be less than or equal to 0.5λ, where λ refers to the wavelength of the electromagnetic signal when propagating in the second transmissive metasurface 13. In this way, because the refractive index of the liquid crystal layer 123 is greater than 1.5, the arrangement period of the second metal patches 1311 is less than or equal to 0.3λ, thereby ensuring that the size of the multiple metasurface units 126 continuous in the row direction or column direction on the second transmissive metasurface 13 after splicing is still less than or equal to one wavelength, so as to achieve control of the beam radiation direction of a single element of the array antenna when the phase of the beam is controlled.

[0130] In the embodiment of the present disclosure, combined with the above-mentioned transmission metasurface structure 1, based on the second transmission metasurface 13, the characteristic of electromagnetic signals propagating in a degenerate mode is realized. Taking the transmission metasurface structure 1 working in the millimeter wave frequency band as an example, a wide frequency band of 27GHz to 30GHz can be achieved, thereby ensuring that the transmission metasurface structure 1 has a wider operating frequency band to improve the applicability of the transmission metasurface structure 1.

[0131] Optionally, when an electromagnetic signal propagates along the transmissive metasurface structure 1, the difference between the maximum and minimum transmission coefficients within the operating frequency band of 27 GHz to 30 GHz is less than or equal to 1 decibel. This ensures that the transmissive metasurface structure 1 has high transmittance within a wider operating frequency band, and that the transmission coefficients within the wider operating frequency band are close, thereby ensuring the transmittance and transmission stability of the electromagnetic signal propagating along the transmissive metasurface structure 1.

[0132] The embodiment of the present disclosure also provides an antenna device 10, as shown in Figure 24, the antenna device 10 includes an antenna body 2 and the transmissive metasurface structure 1 described in the above embodiment, and the transmissive metasurface structure 1 is located at the radiation end of the antenna body 2.

[0133] In this way, combined with the performance of the above-mentioned transmission metasurface structure 1, when applied to the antenna body 2, it can effectively ensure the continuity of scanning of the antenna device 10 within the scanning range, while ensuring that the antenna device 10 has a wider frequency band, thereby improving the applicability of the antenna device 10.

[0134] The antenna body 2 may be an antenna structure such as an array antenna. For example, the antenna body 2 may be a spotlight antenna, as shown in FIG24 , where the transmissive metasurface structure 1 is disposed at the radiation end of the spotlight antenna.

[0135] In addition, for the antenna device 10 provided with the transmissive metasurface structure 1, the lobe width of the beam radiated by the antenna body 2 can also be adjusted through the transmissive metasurface structure 1 to adjust the coverage of the beam. Taking the spotlight antenna as an example, the conventional ray skylight without the transmissive metasurface structure 1 has an antenna gain of about 8 decibels, and the lobe angles in both the vertical and horizontal planes are 50 degrees. At this time, the coverage of the spotlight antenna's beam is circular as shown in FIG25, which is obviously not suitable for high-rise residential buildings with narrow floors, nor for low-rise residential buildings with wide floors. For the spotlight antenna provided with the transmissive metasurface structure 1, the beam of the spotlight antenna can be phase-shifted through the liquid crystal layer 123 of the transmissive metasurface structure 1 to adjust the coverage of the beam. The coverage of the adjusted beam can be an ellipse as shown in FIG26 or FIG27, which is suitable for high-rise residential buildings with narrow floors, but not for low-rise residential buildings with wide floors.

[0136] For example, Figures 28 and 29 show the lobe width of a spotlight antenna operating at 800 MHz without the transmissive metasurface structure 1, and the lobe width of a spotlight antenna operating at 800 MHz with the transmissive metasurface structure 1. Combining Figures 28 and 29, it can be seen that the transmissive metasurface structure 1 can be used to compress the lobe width from 56 degrees to 34 degrees, thereby adjusting the coverage of the beam.

[0137] The present disclosure also provides a communication device, which includes the antenna device 10 described in the above embodiment. The communication device may be a satellite antenna, an electronic device, or the like.

[0138] In combination with the antenna device 10 described above, by setting the transmissive metasurface structure 1, the continuity of scanning of the communication device within the scanning range can be effectively guaranteed, while ensuring that the communication device has a wider frequency band, thereby improving applicability.

[0139] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A transmissive metasurface structure, characterized in that, Including: At least three carrier layers distributed in a stacked manner, and a first transmissive metasurface located between every two adjacent carrier layers; The first transmissive metasurface includes a liquid crystal layer, and a first metal layer and a second metal layer located on both sides of the liquid crystal layer. The first metal layer includes a plurality of first metal strips spaced apart along the row direction, and the second metal layer includes a plurality of second metal strips spaced apart along the column direction. The arrangement period of the first metal strips and the arrangement period of the second metal strips are both less than or equal to 0.3λ, where λ refers to the wavelength when the electromagnetic signal propagates along the first transmissive metasurface; The first metal strips and the second metal strips have an overlapping region in the thickness direction of the carrier layer. The first metal strips have first slit holes extending along the column direction at the positions of the overlapping region, and the second metal strips have second slit holes extending along the row direction at the positions of the overlapping region. The first slit holes and the second slit holes are used to realize the tuning of the electromagnetic signal, and the electromagnetic signals propagated by the plurality of first transmissive metasurfaces can be coupled to realize degenerate mode propagation.

2. The transmissive metasurface structure according to claim 1, wherein Both ends of the first slit holes extend out of the overlapping region, and the second slit holes are located within the overlapping region; The width of the first metal strips is greater than or equal to 0.02λ, and the arrangement period of the first metal strips is less than or equal to 0.1λ. The width of the second metal strips is greater than or equal to 0.02λ, and the arrangement period of the second metal strips is greater than the arrangement period of the first metal strips.

3. The transmissive metasurface structure according to claim 2, characterized in that The width of the second metal strips is less than or equal to 0.04λ.

4. The transmissive metasurface structure according to claim 3, wherein The arrangement period of the first metal strips is 0.25 to 1.0 mm, and 6 to 20 supersurface units consecutive in the row direction form a wavelength tuning unit.

5. The transmissive metasurface structure according to claim 1, wherein Both ends of the first slit holes and both ends of the second slit holes extend out of the overlapping region; The first metal strips and the second metal strips form a plurality of grid regions distributed in an array in the orthographic projection on the carrier layer. The transmissive metasurface structure also has a plurality of first metal patches corresponding to the plurality of grid regions one by one. The orthographic projection of each first metal patch on the carrier layer is located within the region surrounded by the orthographic projection of the corresponding grid region on the carrier layer.

6. The transmissive metasurface structure according to claim 5, wherein The first metal patches are on the same layer as the first metal strips or the second metal strips.

7. The transmissive metasurface structure according to claim 5, wherein The width of the first metal strips in the overlapping region is greater than or equal to 1 / 3 of the arrangement period of the first metal strips and less than or equal to 2 / 3 of the arrangement period of the first metal strips; The width of the second metal strips in the overlapping region is greater than or equal to 1 / 3 of the arrangement period of the second metal strips and less than or equal to 2 / 3 of the arrangement period of the second metal strips.

8. The transmissive metasurface structure according to claim 5, wherein The distance between the first metal patches and the adjacent first metal strips along the width direction of the first metal strips, and the distance between the first metal patches and the adjacent second metal strips along the width direction of the second metal strips are both less than or equal to 0.05 mm.

9. The transmissive metasurface structure according to claim 5, characterized in that, The shape of the first metal patches is similar but not congruent to the shape surrounded by the corresponding grid regions, and the center points of the first metal patches and the corresponding grid regions coincide in the thickness direction of the carrier layer.

10. The transmissive metasurface structure according to claim 9, wherein Both the grid region and the first metal patch are rectangular.

11. The transmissive metasurface structure according to claim 9, wherein The width of at least one of the first metal strip and the second metal strip at the overlapping region is greater than the width at the position facing the side of the grid region, and the first metal patch is a rectangular structure with notches at the corners.

12. The transmissive metasurface structure according to any one of claims 1-11, characterized in that, The operating frequency band of the transmissive metasurface structure is 27 GHz to 30 GHz.

13. The transmissive metasurface structure according to claim 12, wherein When an electromagnetic signal propagates along the transmissive metasurface structure, the difference between the maximum value and the minimum value of the transmission coefficient within the operating frequency band is less than or equal to 1 decibel.

14. The transmissive metasurface structure according to any one of claims 1-11, characterized in that, The first transmissive metasurface further includes a first alignment layer located between the liquid crystal layer and the first metal layer, and a second alignment layer located between the liquid crystal layer and the second metal layer.

15. A transmissive metasurface structure, characterized in that, Comprising: A plurality of carrier layers distributed in a stacked manner, and a second transmissive metasurface located between every two adjacent carrier layers; The second transmissive metasurface includes a third metal layer and a fourth metal layer arranged oppositely, and a liquid crystal layer, a metal grid and a support layer located between the third metal layer and the fourth metal layer. The support layer is located between the third metal layer and the metal grid, and both sides of the metal grid have liquid crystal molecules; The third metal layer includes a plurality of second metal patches distributed in an array, the fourth metal layer includes a plurality of third metal patches, the plurality of second metal patches and the plurality of third metal patches correspond one by one, and the corresponding second metal patch and third metal patch have an overlapping region in the thickness direction of the carrier layer. The electromagnetic signal propagating between the second metal patch and the metal grid and the electromagnetic signal propagating between the third metal patch and the metal grid can be coupled to achieve degenerate mode propagation.

16. The transmissive metasurface structure according to claim 15, characterized in that, The support layer includes a plurality of support columns, and both ends of each support column are in contact with the second metal patch and the metal grid respectively.

17. The transmissive metasurface structure according to claim 15, characterized in that, The support layer is a grid structure, and the orthographic projection of the metal grid on the carrier layer is located within the orthographic projection of the grid structure on the carrier layer.

18. The transmissive metasurface structure according to any one of claims 15-17, characterized in that, The second metal patch and the corresponding third metal patch completely overlap in the thickness direction of the carrier layer, and both the second metal patch and the third metal patch are rectangular patches.

19. An antenna device, characterized in that, Comprising an antenna body and the transmissive metasurface structure according to any one of claims 1-18, and the transmissive metasurface structure is located at the radiation end of the antenna body.

20. A communication device, characterized in that, Comprising the antenna device according to claim 19.

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