Intelligent metasurface unit and array antenna

Abstract

The invention provides an intelligent metasurface unit and an array antenna, the intelligent metasurface unit comprises a first patch, a first dielectric plate, a fork-shaped coupling branch knot, a metal floor, a second dielectric plate and a second patch which are stacked in sequence, the fork-shaped coupling branch knot and the second patch are electrically connected to transmit energy, the first patch is used for transmitting signals, and the second patch is used for transmitting the signals. The second patch is used for receiving signals, the first patch is provided with a filtering groove, the fork-shaped coupling branch knot comprises at least two coupling branch knots with different lengths, and the fork-shaped coupling branch knot and the filtering groove jointly filter the signals received by the second patch. By adopting the scheme, different out-of-band rejection levels and bandwidths can be effectively realized through the matching of the coupling branches with different lengths and the filtering grooves, and the conditions of large size, high cost, heavy weight and the like which are not beneficial to miniaturization and lightweight design when an integrated filter is added for auxiliary filtering are avoided; interference in space can be effectively suppressed and filtering can be realized by means of the structure of the intelligent metasurface unit.

Description

Technical Field

[0001] The present invention relates to the technical field of antennas, and more particularly, to an intelligent metasurface unit and an array antenna. Background Art

[0002] (Reflection / transmission) intelligent metasurfaces and array antennas have both the characteristics of high gain of parabolic antennas and the feature of beam scanning of phased array antennas. Therefore, intelligent metasurfaces and their arrays have been widely studied. By adjusting the phase of each unit on it, an intelligent metasurface can flexibly control the incident electromagnetic wave, realizing advanced functions such as beamforming and beam scanning, thereby optimizing the signal transmission path, improving the transmission quality and efficiency of wireless communication. Compared with parabolic antennas, planar reflection / transmission intelligent metasurfaces are convenient for processing and easy to control processing errors. Compared with phased arrays, intelligent metasurfaces can achieve beam control without adding phase shifters, greatly reducing the cost of the antenna.

[0003] However, the existing intelligent metasurface designs have certain limitations. Especially in the face of the increasingly tense spectrum resources environment, the out-of-band suppression ability of intelligent metasurfaces is insufficient, resulting in the processing of out-of-band interference signals while receiving in-band signals. This not only increases the complexity and cost of the system, but also reduces the overall performance of the wireless communication system. Especially in multi-band communication systems, the processing ability of this out-of-band interference is particularly important.

[0004] Currently, the method to solve the insufficient out-of-band suppression of intelligent metasurfaces is usually to integrate filters in the feed antenna or receiving antenna. These filters can effectively filter out unwanted radio frequency signals and reduce the mutual interference between different wireless systems. However, this method has some inherent disadvantages, such as increased volume, weight, and cost. The design and integration of filters require additional space and cost, which is not conducive to miniaturization and lightweight design. The intelligent metasurface and its array realized by adding filtering functions through the feed antenna do not have filtering functions for the intelligent metasurface itself, so they cannot effectively suppress interference in space. Summary of the Invention

[0005] The present invention provides an intelligent metasurface unit and an array antenna to solve the problem that the intelligent metasurface itself does not have filtering functions.

[0006] To solve the above problems, according to one aspect of the present invention, the present invention provides an intelligent metasurface unit. The intelligent metasurface unit includes a first patch, a first dielectric plate, a fork-shaped coupling stub, a metal floor, a second dielectric plate, and a second patch stacked in sequence. The fork-shaped coupling stub and the second patch are electrically connected to transmit energy. The first patch is used to emit signals, and the second patch is used to receive signals. The first patch has a filtering slot. The fork-shaped coupling stub includes at least two coupling stubs with different lengths. The fork-shaped coupling stub and the filtering slot jointly perform filtering processing on the signals received by the second patch.

[0007] Further, the fork-shaped coupling stub is an end-asymmetric fork-shaped microstrip feeder, which includes a cross section, a long coupling stub, and a short coupling stub. The cross section is electrically connected to the second patch. Both the long coupling stub and the short coupling stub are connected to the cross section. The length of the long coupling stub is greater than that of the short coupling stub. The long coupling stub forms a low-frequency transmission zero point, and the short coupling stub forms a high-frequency transmission zero point. The filtering slot is directly opposite to the long coupling stub and the short coupling stub in the stacking direction of the intelligent metasurface unit.

[0008] Further, the extending directions of the long coupling stub and the short coupling stub are parallel, and the long coupling stub and the short coupling stub are connected to the same side of the cross section. The filtering slot is a rectangular slot, and the projection of the rectangular slot on the plane where the fork-shaped coupling stub is located perpendicularly passes through the long coupling stub and the short coupling stub.

[0009] Further, the intelligent metasurface unit has a metallized via. The extending direction of the metallized via is parallel to the stacking direction of the intelligent metasurface unit. The metallized via includes a circular through hole penetrating the metal floor and the second dielectric plate and a metal coating coated on at least part of the inner wall of the circular through hole. The metal coating extends along the axial direction of the circular through hole and is electrically connected to the fork-shaped coupling stub and the second patch at both ends respectively. The metal coating is spaced from the metal floor.

[0010] Further, a circular through hole for forming the metallized via is provided on the metal floor, and the metal coating passing through the circular through hole is spaced from the inner wall of the circular through hole.

[0011] Further, the metallized via also penetrates the first dielectric plate and the fork-shaped coupling stub, and the first patch is arranged to avoid the metallized via.

[0012] Further, the first patch has an avoidance slot. One end of the metallized via extends into the avoidance slot. Both the first patch and the second patch are rectangular patches, and the projections of the first patch and the second patch on the plane perpendicular to the stacking direction at least partially overlap.

[0013] Further, the intelligent metasurface unit has a metallized via for electrically connecting the fork-shaped coupling stub and the second patch. A phase slot is provided on the second patch. During the installation process of the intelligent metasurface unit, the setting position of the phase slot in the circumferential direction of the metallized via is adjustable, so that the intelligent metasurface unit obtains different phases.

[0014] Further, the phase slot is a U-shaped slot, and the projection of the metallized via on the plane where the U-shaped slot is located is within the U-shaped slot.

[0015] Further, the intelligent metasurface unit further includes a PP layer, which is disposed between the first dielectric plate and the second dielectric plate. The first dielectric plate, the fork-shaped coupling stub, the PP layer, and the second dielectric plate are sequentially press-fitted.

[0016] According to another aspect of the present invention, an array antenna is provided. The array antenna includes a plurality of the above-mentioned intelligent metasurface units. The phases of the plurality of intelligent metasurface units are arranged in a linear polarization or a circular polarization, so that the array antenna is a linear polarization array antenna or a circular polarization array antenna.

[0017] Applying the technical solution of the present invention, an intelligent metasurface unit is provided. The intelligent metasurface unit includes a first patch, a first dielectric plate, a fork-shaped coupling stub, a metal floor, a second dielectric plate, and a second patch stacked in sequence. The fork-shaped coupling stub and the second patch are electrically connected to transmit energy. The first patch is used for transmitting signals, and the second patch is used for receiving signals. The first patch has a filtering slot. The fork-shaped coupling stub includes at least two coupling stubs with different lengths. The fork-shaped coupling stub and the filtering slot jointly perform filtering processing on the signals received by the second patch.

[0018] This solution realizes the filtering function based on the electromagnetic coupling effect between the fork-shaped coupling stub, the first patch, and the filtering slot. The fork-shaped coupling stub forms electromagnetic coupling feeding with the first patch. The filtering slot provided on the first patch can be equivalent to a capacitor, which forms resonance with the coupling inductance of the fork-shaped coupling stub, and then forms a transmission zero point to realize the filtering function. It can be understood that each coupling stub with different lengths can correspond to generating a transmission zero point. With such a setting, the filtering function can be realized through the cooperation of the filtering slot and the fork-shaped coupling stub. Through the cooperation of coupling stubs with different lengths and the filtering slot, different out-of-band suppression levels and bandwidths can be effectively realized, avoiding the situation that when an integrated filter is added for auxiliary filtering, there will be problems such as large volume, high cost, and large weight, which are not conducive to miniaturization and lightweight design. Relying on the structure of the intelligent metasurface unit itself, interference in space can be effectively suppressed and filtering can be realized, and interference from electromagnetic waves in other frequency bands can be avoided on the basis of ensuring the reliability of electromagnetic wave transmission. Description of the Drawings

[0019] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic structural diagram of an intelligent metasurface unit provided by an embodiment of the present invention is shown;

[0021] Figure 2 Shows Figure 1 A side view of

[0022] Figure 3 Shows Figure 1 A top view of

[0023] Figure 4 Shows Figure 1 A schematic structural diagram of the fork-shaped coupling stub in

[0024] Figure 5 Shows Figure 1 A transmission coefficient data diagram of the intelligent metasurface unit of

[0025] Figure 6 A gain frequency curve of the linearly polarized (transmission filtering) intelligent metasurface provided by this embodiment is shown;

[0026] Figure 7 A gain frequency curve of the circularly polarized (transmission filtering) intelligent metasurface provided by this embodiment is shown;

[0027] Figure 8 An x-direction radiation pattern of the linearly polarized array antenna provided by this embodiment is shown;

[0028] Figure 9 A y-direction radiation pattern of the linearly polarized array antenna provided by this embodiment is shown;

[0029] Figure 10 An x-direction radiation pattern of the circularly polarized array antenna provided by this embodiment is shown;

[0030] Figure 11 A y-direction radiation pattern of the circularly polarized array antenna provided by this embodiment is shown.

[0031] Among them, the above-mentioned drawings include the following reference numerals:

[0032] 10. Intelligent metasurface unit; 101. Metallized via; 102. Filtering slot; 103. Circular through-hole; 104. Phase slot; 105. Avoidance slot;

[0033] 11. First patch; 12. First dielectric plate; 13. Fork-shaped coupling stub; 131. Cross section; 132. Long coupling stub; 133. Short coupling stub; 14. Metal floor; 15. Second dielectric plate; 16. Second patch; 17. PP layer. Detailed implementation mode

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way constitutes a limitation on the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] As Figures 1 to 11 shown, an embodiment of the present invention provides an intelligent metasurface unit 10, which includes a first patch 11, a first dielectric plate 12, a fork-shaped coupling stub 13, a metal floor 14, a second dielectric plate 15, and a second patch 16 stacked in sequence. The fork-shaped coupling stub 13 is electrically connected to the second patch 16 to transmit energy. The first patch 11 is used to emit signals, and the second patch 16 is used to receive signals. The first patch 11 has a filtering slot 102. The fork-shaped coupling stub 13 includes at least two coupling stubs with different lengths. The fork-shaped coupling stub 13 and the filtering slot 102 jointly perform filtering processing on the signals received by the second patch 16.

[0036] The technical solution of this embodiment realizes the filtering function based on the electromagnetic coupling effect between the fork-shaped coupling stub 13, the first patch 11, and the filtering slot 102. The fork-shaped coupling stub 13 and the first patch 11 form electromagnetic coupling feeding. The filtering slot 102 provided on the first patch 11 can be equivalent to a capacitor, which resonates with the coupling inductance of the fork-shaped coupling stub 13 to form a transmission zero point, thereby realizing the filtering function. It can be understood that each coupling stub with a different length can correspondingly generate a transmission zero point. With this setting, the filtering function can be realized by the cooperation of the filtering slot 102 and the fork-shaped coupling stub 13. The cooperation of coupling stubs with different lengths and the filtering slot 102 can effectively achieve different out-of-band rejection levels and bandwidths, avoiding the situation of large volume, high cost, and large weight, which is not conducive to miniaturization and lightweight design, when an integrated filter is added for auxiliary filtering. The intelligent metasurface unit 10 itself can effectively suppress interference in space and realize filtering, and can avoid interference from electromagnetic waves in other frequency bands on the basis of ensuring the reliability of electromagnetic wave transmission.

[0037] It should be noted that the first patch 11 and the second patch 16 in this embodiment are both transmissive patches, that is, the intelligent metasurface unit 10 is a transmissive unit. In other embodiments not shown in the figures, the second patch 16 may not be designed so that the intelligent metasurface unit 10 is a reflective unit.

[0038] The fork-shaped coupling stub 13 in this embodiment is an end-asymmetric fork-shaped microstrip feeder, which includes an intersection segment 131, a long coupling stub 132, and a short coupling stub 133. The intersection segment 131 is electrically connected to the second patch 16. Both the long coupling stub 132 and the short coupling stub 133 are connected to the intersection segment 131. The length of the long coupling stub 132 is greater than that of the short coupling stub 133. The long coupling stub 132 forms a low-frequency transmission zero, and the short coupling stub 133 forms a high-frequency transmission zero. The filtering slot 102 is directly opposite to the long coupling stub 132 and the short coupling stub 133 in the stacking direction of the intelligent metasurface unit 10. In this embodiment, the adjustment of the low-frequency transmission zero and the high-frequency transmission zero can be realized by designing and adjusting the lengths of the long coupling stub 132 and the short coupling stub 133, so as to effectively filter signals in different frequency bands. It can significantly improve the out-of-band rejection ability of the intelligent metasurface unit 10 while maintaining the low-loss characteristic of signal transmission in the passband. At the same time, the position setting of the filtering slot 102 relative to the long coupling stub 132 and the short coupling stub 133 is more conducive to forming a more stable filtering effect.

[0039] It can be understood that the lengths, extension directions, positions, and shapes of the long coupling stub 132, the short coupling stub 133, and the filtering slot 102 can be adaptively adjusted according to actual situations to achieve the best filtering effect and signal transmission performance.

[0040] Preferably, the extension directions of the long coupling stub 132 and the short coupling stub 133 in this embodiment are parallel, and the long coupling stub 132 and the short coupling stub 133 are connected to the same side of the intersection segment 131. The filtering slot 102 is a rectangular slot, and the projection of the rectangular slot on the plane where the fork-shaped coupling stub 13 is located perpendicularly passes through the long coupling stub 132 and the short coupling stub 133.

[0041] With such a setting, by making the long coupling stub 132 and the short coupling stub 133 parallel and on the same side, it is beneficial to enhance the electromagnetic coupling between them. At the same time, the vertical position of the rectangular slot helps to form a more stable filtering effect, so that the intelligent metasurface unit 10 has a more stable transmission performance in the passband and a better out-of-band rejection effect.

[0042] It should be noted that the current on the fork-shaped coupling stub 13 of the intelligent metasurface unit 10 is mainly concentrated on the long coupling stub 132, and the current on the short coupling stub 133 is relatively small. The current on the first patch 11 is mainly distributed around the rectangular slot. Correspondingly, the current at the part of the rectangular slot opposite to the long coupling stub 132 is larger than that at the part of the rectangular slot opposite to the short coupling stub 133, and the current on the fork-shaped coupling stub 13 is out of phase with the current on the first patch 11.

[0043] At the position of the low-frequency transmission zero point, the electromagnetic interaction between the long coupling stub 132 and the first patch 11 plays a dominant role. The current on the long coupling stub 132 is out of phase with the current on the part of the rectangular slot opposite to it, and the radiation cancels each other out. The current on the edge of the first patch 11 is very weak, and the energy cannot be effectively radiated, so a low-frequency transmission zero point is formed. Different from the low-frequency transmission zero point, at the high-frequency transmission zero point, the short coupling stub 133 plays a dominant role. At this time, the current on the fork-shaped coupling stub 13 is mainly distributed on the short coupling stub 133. The current on the part of the rectangular slot opposite to the short coupling stub 133 is also mainly concentrated on the side where the short coupling stub 133 is located, and the current on the short coupling stub 133 is out of phase with the current on the rectangular slot, and the two cancel each other out, so a high-frequency transmission zero point is formed. Among them, in the passband, the currents on the long coupling stub 132 and the short coupling stub 133 of the metasurface unit are nearly equal in magnitude and opposite in direction. At this time, the different coupling effects generated by the two stubs with different lengths cancel each other out, and the currents around the rectangular slot cancel each other out in the vertical direction, and the direction of the combined current is the same as the direction of the current on the first patch 11.

[0044] Preferably, in this embodiment, the PCB process (a mature process) is preferably used to fabricate the intelligent metasurface unit 10, which has low cost and is easy for large-scale processing. Specifically, the intelligent metasurface unit 10 of this embodiment further includes a PP layer 17, and the PP layer 17 is disposed between the first dielectric plate 12 and the second dielectric plate 15. The first dielectric plate 12, the fork-shaped coupling stub 13, the PP layer 17, and the second dielectric plate 15 are sequentially press-fitted. Among them, the first dielectric plate 12 and the second dielectric plate 15 in this embodiment can be low-loss high-frequency substrates with a dielectric constant of 3. It can be understood that the selection of the material of the PP layer 17 (functionally similar to glue), the selection of the PCB material (such as ceramic composite material, fiberglass cloth material, etc.), the design of the thickness, the design of the dielectric constant, etc. can all be adjusted adaptively according to the actual situation. Such a setting can improve the stability of the unit structure and the convenience of installation, and at the same time is beneficial to reducing the processing cost.

[0045] Such as Figures 1 to 3As shown, the intelligent metasurface unit 10 has a metallized via 101. The extending direction of the metallized via 101 is parallel to the stacking direction of the intelligent metasurface unit 10. The metallized via 101 includes a circular through-hole 103 penetrating through the metal floor 14 and the second dielectric layer 15, and a metal coating coated on at least part of the inner wall of the circular through-hole 103. The metal coating extends along the axial direction of the circular through-hole 103 and is electrically connected to the fork-shaped coupling stub 13 and the second patch 16 at both ends respectively. The metal coating is spaced from the metal floor 14.

[0046] With such a setting, through the metal coating of the metallized via 101, the energy transfer from the fork-shaped coupling stub 13 to the second patch 16 is realized. At the same time, the interval between the metal coating and the metal floor 14 avoids short-circuiting with the metal floor 14, ensuring the normal transmission of signals, so that the intelligent metasurface unit 10 can maintain good filtering performance while realizing efficient energy transfer. And the way of realizing transmission through the metallized via 101 is beneficial to the miniaturization and functional integration of the intelligent metasurface unit 10, and there is no need to set additional other components to assist in transmission.

[0047] Specifically, in this embodiment, the metallized via 101 sequentially penetrates through the PP layer 17, the metal floor 14 and the second dielectric layer 15. A circular through-hole 103 for forming the metallized via 101 is provided on the metal floor 14, and the metal coating inserted in the circular through-hole 103 is spaced from the inner wall of the circular through-hole 103.

[0048] In this embodiment, the design of the metal floor 14 ensures the stability and reliability of the circuit. By providing a circular through-hole 103 on the metal floor 14, space is provided for the formation of the metallized via 101. At the same time, the interval between the metal coating and the inner wall of the circular through-hole 103 can avoid unnecessary electromagnetic interference and maintain the purity of signal transmission. The introduction of the circular through-hole 103 avoids short-circuiting between the metallized via 101 and the metal floor 14, thus ensuring the smoothness of the energy transfer path, improving the electrical performance and durability of the intelligent metasurface unit 10, reducing the failure rate, effectively avoiding electromagnetic interference, and improving the quality of signal transmission.

[0049] It can be understood that the size, shape, etc. of the circular through-hole 103 can be adjusted according to the actual situation, as long as the inner wall is spaced from the metal coating.

[0050] The metallized vias 101 in this embodiment also penetrate through the first dielectric layer 12 and the fork-shaped coupling stub 13, and the first patch 11 is arranged to avoid the metallized vias 101. That is, the metallized vias 101 in this embodiment sequentially penetrate through the first dielectric layer 12, the fork-shaped coupling stub 13, the PP layer 17, the metal ground plane 14, and the second dielectric layer 15. Such an arrangement facilitates the processing of the metallized vias 101 and avoids the problem that it is difficult to process the metallized vias 101 when they are only processed inside the intelligent metasurface unit 10.

[0051] As Figures 1 to 3 shown, the first patch 11 has an avoidance groove 105, one end of the metallized via 101 extends into the avoidance groove 105, both the first patch 11 and the second patch 16 are rectangular patches, and the projections of the first patch 11 and the second patch 16 on the plane perpendicular to the stacking direction at least partially overlap. With such an arrangement, the avoidance groove 105 can ensure non-direct contact between the metallized via 101 and the first patch 11, thus avoiding the short-circuit situation caused by the electrical connection between the metallized via 101 and the first patch 11. At the same time, the overlapping arrangement of the projections of the first patch 11 and the second patch 16, combined with the arrangement of the avoidance groove 105 and the fork-shaped coupling stub 13, is beneficial to improving the miniaturization and integration of the intelligent metasurface.

[0052] The shape of the avoidance groove 105 in this embodiment is rectangular. It can be understood that the shapes of the first patch 11 and the second patch 16, the installation overlapping situation, the shape and size of the avoidance groove 105, etc. can all be adaptively adjusted according to the actual situation.

[0053] Among them, the intelligent metasurface unit 10 has a metallized via 101 for electrically connecting the fork-shaped coupling stub 13 and the second patch 16. A phase groove 104 is provided on the second patch 16. During the installation process of the intelligent metasurface unit 10, the setting position of the phase groove 104 in the circumferential direction of the metallized via 101 is adjustable, so that the intelligent metasurface unit 10 can obtain different phases.

[0054] In this embodiment, by adjusting the position of the phase groove 104 in the circumferential direction of the metallized via 101, the phase of the signal received by the second patch 16 can be changed, thereby realizing the phase regulation of the intelligent metasurface unit 10 and enabling the intelligent metasurface to adapt to different communication requirements.

[0055] Preferably, the phase slot 104 is a U-shaped slot, and the projection of the metallized via 101 on the plane where the U-shaped slot is located is within the U-shaped slot. Different phase quantizations are achieved by rotating the U-shaped slot etched on the second patch 16, that is, the phase adjustment of the intelligent metasurface unit 10. When the U-shaped slot is rotated by 180°, the electric field distribution on the U-shaped slot will be opposite to that before, so as to achieve two states of 0 and 180, thereby realizing 1-bit resolution. Adopting 1-bit phase quantization can effectively reduce the design complexity and reduce the processing cost. At the same time, such a setting facilitates the positioning of the second patch 16 and the metallized via 101, which is beneficial to improving the installation convenience and the integration degree of the intelligent metasurface unit 10.

[0056] Another embodiment of the present invention provides an array antenna. The array antenna includes a plurality of the above-mentioned intelligent metasurface units 10, and the phases of the plurality of intelligent metasurface units 10 are arranged in a linear polarization or a circular polarization, so that the array antenna is a linearly polarized array antenna or a circularly polarized array antenna. With such a setting, through the phase arrangement of the plurality of intelligent metasurface units 10, the signal transmission of linear polarization or circular polarization can be realized, thereby improving the directivity and gain of the array antenna, enabling the array antenna to achieve signal transmission with high gain, low loss and good filtering performance, adapting to different communication requirements, and being applicable to occasions requiring high gain, low loss and good filtering performance.

[0057] It can be understood that a plurality of intelligent metasurface units 10 are integrated according to a specific phase arrangement to form a linearly polarized or circularly polarized array antenna, realizing efficient and pure signal transmission. The arrangement method and the like can be adaptively adjusted and selected according to the actual situation, and no examples are given here one by one.

[0058] Such as Figures 1 to 11As shown, in a specific embodiment of the present invention, the first dielectric plate 12 and the second dielectric plate 15 are Rogers 3003 plates with thicknesses of 0.127 mm and 0.254 mm respectively, a dielectric constant of 3, and a loss tangent of 00013; the PP layer 17 is a Rogers 4450 plate with a thickness of 0.1 mm, the first patch 11 is a rectangular patch with dimensions of 2 mm × 2 mm, the filtering slot 102 is a rectangular slot with a width of 0.2 mm and a length of 1.17 mm; the second patch 16 is a rectangular patch with dimensions of 2 mm × 2 mm, the phase slot 104 is a U-shaped slot with an opening width of 0.6 mm, an opening depth of 0.485 mm, and a slot width of 0.15 mm, the metallized via 101 has a radius of 0.1 mm, the cross-section 131 of the fork-shaped coupling stub 13 has dimensions of 0.81 mm × 0.3 mm, the short coupling stub 133 has dimensions of 0.9 mm × 0.1 mm, and the long coupling stub 132 has dimensions of 1.19 mm × 0.1 mm. The first dielectric plate 12, the second dielectric plate 15, the PP layer 17, and the metal floor 14 are all rectangular plates and have the same dimensions. The first patch 11 and the second patch 16 are respectively arranged on the opposite sides of the first dielectric plate 12 and the second dielectric plate 15, with one installed on the left and the other installed on the right. The projections of the first patch 11 and the second patch 16 in the direction perpendicular to the stacking direction of the intelligent metasurface unit 10 coincide in the central area of the first dielectric plate 12. The filtering slot 102 is arranged at the center of the first patch 11, the phase slot 104 is arranged at the center of the second patch 16, the phase slot 104 is a U-shaped slot, the metallized via 101 passes through the area surrounded by the U-shaped slot and passes through the cross-section 131 of the fork-shaped coupling stub 13. An avoidance slot 105 corresponding to the metallized via 101 is opened on the first patch 11 to avoid short circuit. Similarly, the metal coating is spaced from the metal floor 14 through the metallized via 101 to avoid short circuit with the metal floor 14. By means of the different lengths of the long coupling stub 132 and the short coupling stub 133 and the positions where the stubs are separated, the matching of the antenna can be effectively adjusted, realizing different out-of-band rejection levels and bandwidths. The U-shaped slot plays a role in feeding. When the rotation angle is different, the direction of the current of the excited antenna is different. When the current is mapped to the x-axis direction or the y-axis direction (in this embodiment, the filtering slot 102 extends along the y-axis direction, the metallized via 101 extends along the z-axis direction, and the fork-shaped coupling stub 13 extends along the x-axis direction), the current phase equivalently changes. By adjusting the rotation angle of the U-shaped slot, the required phase can be achieved and linear polarization or circular polarization of the array antenna can be realized.

[0059] Figure 5Transmission coefficient data graph of the (transmission filtering) intelligent metasurface unit 10 provided in this specific embodiment. As can be seen from the figure, the unit presents transmission zeros at 32.75 GHz and 37.75 GHz, the high-frequency stopband suppression level exceeds 20 dB, the low-frequency stopband suppression level exceeds 30 dB, and stable performance can still be maintained under 30° oblique incidence.

[0060] In a specific embodiment of the present invention, the array antenna includes multiple intelligent metasurface units 10 arranged in an array. Combining the phase adjustment method of a rotating U-shaped slot, MATLAB is used to calculate the compensated phase distribution of the entire array surface. The period of the array antenna unit is 3.4 mm, approximately 0.4λ (λ is the free space wave corresponding to the operating frequency), the array scale is 16×16, the feed source is a linearly polarized conical horn, and the focal ratio is 1.125. Among them, when the array antenna is a circularly polarized array antenna, the size of the entire array surface is 54.4 mm * 54.4 mm.

[0061] As Figure 6 shown, the maximum gain measured by the linearly polarized (transmission filtering) intelligent metasurface array antenna is 19.28 dBi, the aperture efficiency is 16.5%, the measured low-frequency stopband suppression level exceeds 18 dB, the measured high-frequency stopband suppression level exceeds 25 dB, and the measured 3-dB gain bandwidth is 6% (33.6 - 35.4 GHz). This result verifies that the linearly polarized transmission filtering intelligent metasurface array antenna has an obvious filtering response.

[0062] As Figure 7 shown, the maximum gain measured by the circularly polarized (transmission filtering) intelligent metasurface is 19.66 dBi, the aperture efficiency is 18.1%, the measured high-frequency and low-frequency stopband suppression levels both exceed 18 dB, and the measured 3-dB gain bandwidth is 6% (33.8 - 35.8 GHz). This result verifies that the circularly polarized transmission filtering intelligent metasurface array antenna has a good circular polarization effect and filtering response.

[0063] As Figure 8 and Figure 9 shown, the radiation patterns in the x and y directions of the linearly polarized (transmission filtering) intelligent metasurface array antenna are as follows: the sidelobe level in the x direction is less than -15 dB, the cross polarization is lower than -25 dB, and the front-to-back ratio is greater than 20 dB; the sidelobe level in the y direction is approximately -15 dB, the cross polarization is lower than -22 dB, and the front-to-back ratio is greater than 20 dB.

[0064] As Figure 10 and Figure 11As shown, it is the radiation pattern in the x and y directions of the circularly polarized (transmission filtering) intelligent metasurface array antenna. The sidelobe level in the x direction is less than -17 dB, the cross polarization in the maximum radiation direction is lower than -20 dB. Beyond the range of plus or minus 30°, the cross polarization is almost equal to the main polarization in magnitude, and the front-to-back ratio is greater than 20 dB; the sidelobe level in the y direction is less than -17 dB, the cross polarization in the maximum radiation direction is about -20 dB, and the front-to-back ratio is greater than 20 dB.

[0065] The intelligent metasurface unit 10 provided in this embodiment has a symmetric structure and good cross-polarization performance. By rotating the second patch 16, a 1-bit phase shift is generated, and the phase difference between the two states is 180°. The performance is stable within the passband. The insertion loss within the passband is stable and less than 3 dB. The high-frequency stopband suppression level exceeds 20 dB, and the low-frequency stopband suppression level exceeds 30 dB, which can effectively suppress out-of-band interference clutter. Further, for the intelligent metasurface array provided in this embodiment, both the simulated and measured gain curves show obvious filtering responses. The maximum simulated gain is 22.3 dBi, the aperture efficiency is 33%, the high-frequency stopband suppression level is about 15 dB, the low-frequency stopband suppression level is 13 dB, the 3-dB gain bandwidth is 6%, and the 3-dB axial ratio bandwidth is 4.3%. The measured maximum gain is 19.66 dBi, the aperture efficiency is 18.1%, the out-of-band suppression level is greater than 18 dB, and the 3-dB gain bandwidth is 6%.

[0066] In summary, the present invention provides an intelligent metasurface unit 10 and an array antenna, which are designed based on the principle of reception-filtering-transmission, with low loss. It can simultaneously achieve the functions of transmission and filtering, effectively suppress out-of-band clutter and interference, and there is no need to add a filtering design above the feed antenna, simplifying the system design. The phase regulation and the adjustment of linear polarization and circular polarization can be achieved through the rotation angle of the U-shaped slot. By adjusting the lengths and separated positions of the long coupling stub 132 and the short coupling stub 133, the matching of the antenna can be effectively adjusted to achieve different out-of-band suppression levels and bandwidths. The transmission array has a low profile, a simple structure, a low cost, and good polarization effects and filtering responses.

[0067] Preferably, switch devices such as PIN diodes or MEMS switches can be added on the intelligent metasurface unit 10. By adjusting the on and off characteristics of the PIN diodes or MEMS switches, the real-time phase adjustment of the intelligent metasurface unit 10 can be achieved.

[0068] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0069] Unless otherwise specifically stated, the relative arrangements of the components and steps set forth in these embodiments, numerical expressions, and numerical values do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0070] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0071] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations are made for the spatial relative descriptions used herein.

[0072] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of differentiating the corresponding components. Without further statement, the above terms have no special meaning, and thus should not be construed as limiting the protection scope of the present invention.

[0073] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An intelligent metasurface unit, characterized in that, The intelligent metasurface unit comprises a first patch (11), a first dielectric plate (12), a forked coupling branch (13), a metal floor (14), a second dielectric plate (15) and a second patch (16) stacked in sequence, wherein the forked coupling branch (13) and the second patch (16) are electrically connected to transmit energy, the first patch (11) is used to transmit signals, and the second patch (16) is used to receive signals, the first patch (11) has a filtering slot (102), the forked coupling branch (13) comprises at least two coupling branches of different lengths, and the forked coupling branch (13) and the filtering slot (102) jointly filter the signal received by the second patch (16).

2. The intelligent metasurface unit according to claim 1, characterized in that, The forked coupling branch (13) is an asymmetric forked microstrip feed line with an end, comprising a cross section (131), a long coupling branch (132) and a short coupling branch (133); the cross section (131) is electrically connected to the second patch (16); the long coupling branch (132) and the short coupling branch (133) are both connected to the cross section (131); the length of the long coupling branch (132) is greater than that of the short coupling branch (133); the long coupling branch (132) forms a low-frequency transmission zero point; the short coupling branch (133) forms a high-frequency transmission zero point; and the filtering slot (102) is directly opposite to the long coupling branch (132) and the short coupling branch (133) in the stacking direction of the smart metasurface unit.

3. The intelligent metasurface unit according to claim 2, wherein, The extension direction of the long coupling branch (132) is parallel to the extension direction of the short coupling branch (133), and the long coupling branch (132) and the short coupling branch (133) are connected to the same side of the cross section (131); the filtering slot (102) is a rectangular slot, and the projection of the rectangular slot on the plane where the fork-shaped coupling branch (13) is located vertically passes through the long coupling branch (132) and the short coupling branch (133).

4. The intelligent metasurface unit according to claim 1, wherein The smart metasurface unit has a metallized via (101), the extension direction of the metallized via (101) is parallel to the stacking direction of the smart metasurface unit, the metallized via (101) comprises a circular through hole (103) penetrating the metal floor (14) and the second dielectric plate (15), and a metal coating coated on at least part of the inner wall of the circular through hole (103), the metal coating extending along the axial direction of the circular through hole (103) and having two ends electrically connected to the fork-shaped coupling branch (13) and the second patch (16), respectively, and the metal coating is spaced apart from the metal floor (14).

5. The intelligent metasurface unit according to claim 4, characterized in that, The metal floor (14) is provided with a circular through hole (103) for forming the metallized through hole (101), and the metal coating penetrating the circular through hole (103) is spaced from the inner wall of the circular through hole (103).

6. The intelligent metasurface unit according to claim 4, wherein The metallized via hole (101) also passes through the first dielectric plate (12) and the fork-shaped coupling branch (13), and the first patch (11) is arranged to avoid the metallized via hole (101).

7. The intelligent metasurface unit according to claim 6, wherein The first patch (11) has an avoidance groove (105), one end of the metallized via (101) extends into the avoidance groove (105), both the first patch (11) and the second patch (16) are rectangular patches, and the projections of the first patch (11) and the second patch (16) on a plane perpendicular to the stacking direction at least partially overlap.

8. The intelligent metasurface unit according to claim 2, wherein The intelligent metasurface unit has a metallized via (101) for electrically connecting the fork-shaped coupling stub (13) and the second patch (16), a phase groove (104) is provided on the second patch (16), and during the installation process of the intelligent metasurface unit, the setting position of the phase groove (104) in the circumferential direction of the metallized via (101) is adjustable so that the intelligent metasurface unit obtains different phases.

9. The intelligent metasurface unit according to claim 8, characterized in that, The phase groove (104) is a U-shaped groove, and the projection of the metallized via (101) on the plane where the U-shaped groove is located is located within the U-shaped groove.

10. The intelligent metasurface unit according to claim 1, wherein The intelligent metasurface unit further includes a PP layer (17), the PP layer (17) is disposed between the first dielectric plate (12) and the second dielectric plate (15), and the first dielectric plate (12), the fork-shaped coupling stub (13), the PP layer (17), and the second dielectric plate (15) are press-fitted in sequence.

11. An array antenna, characterized in that, The array antenna includes a plurality of intelligent metasurface units according to any one of claims 1 to 10, and the phases of the plurality of intelligent metasurface units are arranged in a linearly polarized arrangement or a circularly polarized arrangement so that the array antenna is a linearly polarized array antenna or a circularly polarized array antenna.

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