Antenna unit, array antenna and network equipment

Abstract

The invention relates to the technical field of communication devices, and discloses an antenna unit, an array antenna and network equipment, and the antenna unit comprises a first dielectric substrate, a metal floor layer and a second dielectric substrate which are sequentially stacked, and further comprises a plurality of radiation units, a first feed unit and a second feed unit, the plurality of radiation units comprise four first radiation units distributed in a rectangular array and a second radiation unit group arranged between every two adjacent first radiation units, and the second radiation unit group comprises at least one second radiation unit; the size of the first radiation unit is larger than that of the second radiation unit along the side length direction of the rectangular array; the metal floor layer is provided with coupling slots, and each second radiation unit group corresponds to one coupling slot; the first feed unit and the second feed unit are respectively used for coupling connection with a group of opposite coupling slots. According to the antenna unit, the array antenna and the network equipment, the problem that the isolation degree of two orthogonal excitation source ports of a bilinearly polarized antenna is poor is solved.

Description

Technical Field

[0001] This application relates to the field of communication device technology, and in particular to an antenna unit, an array antenna, and a network device. Background Technology

[0002] A bilinearly polarized antenna has two orthogonal linear polarization modes, excited using two ports of the same antenna element. Bilinearly polarized antennas can achieve polarization diversity. Compared to traditional tilted dipole antennas, antenna elements with two orthogonal ports provide lower output correlation and higher diversity gain. Therefore, bilinearly polarized antennas are widely used in the field of wireless communication. Summary of the Invention

[0003] This application provides an antenna unit, an array antenna, and a network device.

[0004] The embodiments of this application provide the following technical solutions:

[0005] An antenna unit includes a first dielectric substrate, a metal ground plane, and a second dielectric substrate stacked sequentially. It also includes a plurality of radiating elements disposed on the surface of the first dielectric substrate facing away from the second dielectric substrate, and a first feed element and a second feed element disposed on the surface of the second dielectric substrate facing away from the first dielectric substrate. The plurality of radiating elements includes four first radiating elements arranged in a rectangular array and a group of second radiating elements disposed between each pair of adjacent first radiating elements. Each group of second radiating elements includes at least one second radiating element, and there is a gap between each pair of adjacent radiating elements. Along the side length of the rectangular array, in each radiating element on the same side of the rectangular array, the size of the first radiating element is larger than the size of the second radiating element. The metal ground plane has coupling gaps, and each group of second radiating elements corresponds to one coupling gap. The first feed element is used to couple to one set of opposing coupling gaps, and the second feed element is used to couple to another set of opposing coupling gaps.

[0006] In this scheme, a potential difference exists on both sides of the gap between two adjacent radiating elements, which can be equivalent to a capacitor. Dividing a single radiating patch into multiple non-uniformly sized small patches (i.e., radiating elements), and adjusting the gap width between two adjacent patches, can change the current distribution and improve the isolation between the two orthogonal excitation source ports. Furthermore, designing the patches at the four corners to be larger provides sufficient design space for the feeding structure and increases the radiation area at the gap-coupled feeding point, thereby improving antenna gain.

[0007] Optionally, the dimensions of the second radiating element group on the long side and the short side of the rectangular array are both constant values.

[0008] Optionally, the second radiating unit group includes two second radiating units, the arrangement direction of the two second radiating units is the same as the arrangement direction of the two first radiating units adjacent to the second radiating unit group; the extension direction of the coupling gap is perpendicular to the extension direction of the gap between the two second radiating units corresponding to the coupling gap, and the orthographic projection of the coupling gap on the first dielectric substrate overlaps with the orthographic projection of the two second radiating units corresponding to the coupling gap on the first dielectric substrate.

[0009] Optionally, the plurality of radiating units includes four third radiating units disposed in the middle of the surface of the first dielectric substrate away from the second dielectric substrate. The four third radiating units are arranged in a rectangular array, and any adjacent pair of third radiating units is on the same straight line as two second radiating units located on either side of them.

[0010] Optionally, the pattern formed by all the radiating units is a centrally symmetric pattern, and the pattern formed by all the coupling gaps is a centrally symmetric pattern. The center of symmetry of the pattern formed by all the coupling gaps coincides with the center of symmetry of the pattern formed by all the radiating units, thereby ensuring that the two orthogonal polarizations have similar radiation performance.

[0011] Optionally, both the first radiating element and the third radiating element are square.

[0012] Optionally, the ratio of the side length of the first radiating element to that of the third radiating element is 1.8:1.

[0013] Optionally, the side length of the first radiating unit is 10.6 mm, and the side length of the third radiating unit is 5.8 mm.

[0014] Optionally, the width of the gap between any two adjacent radiating elements is 1 mm.

[0015] Optionally, the power allocation ratio of the first power supply unit and the second power supply unit is 1:1.

[0016] Optionally, the first power supply unit includes a first power distribution structure, which includes a first input segment and two first output segments. The first input segment is used to connect to the power supply network, and the two first output segments are used to couple to a set of opposite coupling slots. The difference in length between the two first output segments is half the waveguide wavelength, so that the current phase difference between the two coupling slots coupled to the two first output segments is 180°.

[0017] The second power supply unit includes a second power distribution structure, which includes a second input segment and two second output segments. The second input segment is used to connect to the power supply network, and the two second output segments are used to couple to another set of opposite coupling slots. The difference in length between the two second output segments is half the waveguide wavelength, so that the current phase difference between the two coupling slots coupled to the two second output segments is 180°.

[0018] Optionally, the first power distribution structure further includes two first quarter-wavelength converters, each of which is connected to the end of the first input segment closest to the first output segment. The two first output segments are each connected to the first input segment through a first quarter-wavelength converter, so that the impedance of the first input segment is matched with that of the two first output segments.

[0019] And / or, the second power distribution structure further includes a second quarter-wavelength converter connected to the end of the second input segment near the second output segment, and both second output segments are connected to the second input segment through the second quarter-wavelength converter to make the impedance of the second input segment matched with that of the two second output segments.

[0020] Optionally, a fan-shaped stub is connected to the end of the first output segment away from the first input segment and / or the end of the second output segment away from the second input segment. By adjusting the radius and angle of the fan-shaped stub, the coupling slot resonates with the end of the corresponding first or second feed unit, thereby achieving a connection between the coupling slot and the impedance discontinuity of the microstrip line, thus improving impedance matching within the bandwidth. Designing a fan-shaped stub at the end of the feed unit, with a radius smaller than that of the matching scheme using a 1 / 4 wavelength stub, can reduce the coupling between the first and second feed units. For example, the radius r of the fan-shaped stub is 0.1 to 0.2 times the waveguide wavelength, and the unfolding angle of the fan-shaped stub is 90 to 120°.

[0021] This application also provides an array antenna, which includes a first feed network, a second feed network, and multiple antenna elements provided in any of the above-described technical solutions. The multiple antenna elements are arranged in an array, with the first feed network electrically connected to each first feed element and the second feed network electrically connected to each second feed element. This array antenna includes the aforementioned antenna elements, and therefore achieves at least the technical effects achievable by the aforementioned antenna elements, namely, the existence of a potential difference on both sides of the gap between two adjacent radiating elements, which can be equivalent to a capacitor. Dividing a single radiating patch into multiple non-uniformly sized small patches (i.e., radiating elements) and adjusting the gap width between two adjacent patches can change the current distribution and improve the isolation between the two orthogonal excitation source ports. Furthermore, designing the patches at the four corners to be larger provides sufficient design space for the feed structure and increases the radiation area at the gap-coupled feed point, thereby improving the antenna gain.

[0022] Optionally, the above-mentioned array antenna includes eight antenna elements, which are arranged in a one-dimensional linear pattern.

[0023] In the arrangement direction of the eight antenna elements, the distance between the centers of two adjacent antenna elements is 0.5 to 1 times the wavelength of the array antenna. This spacing achieves a higher gain while avoiding the generation of grating lobes.

[0024] Optionally, the first power supply network includes four first output terminals, each of which is connected to two adjacent first power supply units via a 1-to-2 power divider; the second power supply network includes four second output terminals, each of which is connected to two adjacent second power supply units via a 1-to-2 power divider.

[0025] Optionally, both output terminals of the 1-to-2 power divider include microstrip lines; the width of the two output terminals of each 1-to-2 power divider is determined based on the power ratio of the plurality of first feed units and the power ratio of the plurality of second feed units, in order to reduce the sidelobe level of the radiation pattern of the array antenna and reduce the difference in gain between the two polarizations of the array antenna. For example, along the arrangement direction of the antenna elements, the power ratio of each first feed unit is: 0.385:0.5:0.769:1:1:0.769:0.5:0.385; along the arrangement direction of the antenna elements, the power ratio of each second feed unit is: 0.267:0.427:0.667:1:1:0.667:0.427:0.267. The feed network of the array antenna adopts a non-equal amplitude, in-phase parallel feed structure. By reasonably controlling the power allocated to each radiating element, the sidelobe level can be suppressed.

[0026] Optionally, the array antenna includes a reflector, and each of the radiating elements is located on the side of the first dielectric substrate facing away from the reflector. The distance between the second dielectric substrate and the reflector is a quarter wavelength, and each antenna element is fixed to the reflector via the second dielectric substrate. In this design, the reflector improves the front-to-back ratio of the array antenna, reduces the sidelobe level at the horizontal angle, and the quarter-wavelength distance between the second dielectric substrate and the reflector allows the electric field reflected by the reflector to superimpose with the electric field not reflected by the reflector, thereby improving the signal radiation capability of the array antenna.

[0027] This application also provides a network device that includes any of the array antennas provided in the above technical solutions. The network device can at least achieve the technical effects that the array antennas can achieve, which will not be elaborated here. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1a This is a schematic diagram of the structure of an antenna unit provided in an embodiment of the present invention;

[0030] Figure 1b for Figure 1a The front view of the antenna element shown;

[0031] Figure 2 for Figure 1a An exploded view of the antenna element shown.

[0032] Figure 3 This is a schematic diagram of another antenna unit structure provided in an embodiment of the present invention;

[0033] Figure 4 This is a simulation diagram of the current distribution of a traditional microstrip patch antenna.

[0034] Figure 5 A simulation diagram of the current distribution of an antenna element provided in an embodiment of the present invention;

[0035] Figure 6 A simulation diagram of the current distribution of another antenna element provided in an embodiment of the present invention;

[0036] Figure 7 The reflection phase characteristics of antenna element C and antenna element D are shown in the diagram.

[0037] Figure 8aThe current distribution of antenna element C at 5.24 GHz indicates that;

[0038] Figure 8b The current distribution of antenna element C at 6.02 GHz indicates that;

[0039] Figure 9a The current distribution of antenna element D at 5.24 GHz indicates that;

[0040] Figure 9b The current distribution of antenna element D at 6.02 GHz indicates that;

[0041] Figure 10 A comparison diagram of the radiation patterns for single-sided and double-sided power supply;

[0042] Figure 11 This is a schematic diagram of the structure of a first feeding unit and a second feeding unit in an antenna unit provided in an embodiment of the present invention;

[0043] Figure 12 A front view of an array antenna provided in an embodiment of the present invention;

[0044] Figure 13a A front view of another array antenna provided in an embodiment of this application;

[0045] Figure 13b for Figure 13a A three-dimensional structural diagram of the array antenna shown.

[0046] Figure 14 A front view of a first feed network, a second feed network, a first feed unit, and a second feed unit in an array antenna provided for an embodiment of the present invention;

[0047] Figure 15a for Figure 12 The simulation diagram of port isolation of the array antenna is shown.

[0048] Figure 15b for Figure 13a The simulation diagram of port isolation of the array antenna is shown.

[0049] Figure 16a for Figure 12 The vertical polarization pattern of the array antenna shown;

[0050] Figure 16b for Figure 12 The horizontal polarization pattern of the array antenna is shown.

[0051] Figure 16c for Figure 12 The simulation graph shows the gain of the array antenna as a function of frequency.

[0052] Figure 17a for Figure 13a The vertical polarization pattern of the array antenna shown;

[0053] Figure 17b for Figure 13a The horizontal polarization pattern of the array antenna is shown.

[0054] Figure 17c for Figure 13a The simulation graph shows the gain of the array antenna as a function of frequency.

[0055] Figure 18a for Figure 12 The simulation diagram of the return loss of the array antenna is shown.

[0056] Figure 18b for Figure 13a The diagram shows a simulation of the return loss of the array antenna.

[0057] Icons: 1-First dielectric substrate; 2-Metal ground plane; 21-Coupling gap; 3-Second dielectric substrate; 41-First radiating unit; 42-Second radiating unit; 43-Third radiating unit; 5-First feed unit; 6-Second feed unit; 7-First power distribution structure; 71-First input segment; 72-First output segment; 8-Second power distribution structure; 81-Second input segment; 82-Second output segment; 91-First quarter-wavelength converter; 92-Second quarter-wavelength converter; 73-Fan-shaped stub; 100-First feed network; 200-Second feed network. Detailed Implementation

[0058] In related technologies, due to factors such as non-ideal electromagnetic crosstalk effects, the isolation between the two orthogonal excitation source ports is poor when using dual-linear polarized antennas, affecting the anti-interference capability of the entire communication system. Based on this, embodiments of this application provide an antenna element, an array antenna, and a network device to solve the above problems. To make the objectives, technical solutions, and advantages of this application clearer, a further detailed description of this application will be provided below with reference to the accompanying drawings.

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0061] Figure 1a This is a schematic diagram of the structure of an antenna element provided in an embodiment of this application. Figure 1b for Figure 1a The front view of the antenna element shown. Figure 2 for Figure 1a An exploded view of the antenna element shown. Figure 1a , Figure 1b and Figure 2 As shown, the antenna unit includes a first dielectric substrate 1, a metal ground plane layer 2, and a second dielectric substrate 3 stacked sequentially. The antenna unit also includes multiple radiating elements disposed on the surface of the first dielectric substrate 1 facing away from the second dielectric substrate 3, and a first feed element 5 and a second feed element 6 disposed on the surface of the second dielectric substrate 3 facing away from the first dielectric substrate 1. The multiple radiating elements include four first radiating elements 41 arranged in a rectangular array, and two groups of second radiating elements disposed between each pair of adjacent first radiating elements 41. Each group of second radiating elements includes at least one second radiating element 42, and there is a gap between each pair of adjacent radiating elements. It is easy to understand that in this case, the multiple radiating elements are distributed along a rectangular trajectory on the surface of the first dielectric substrate 1 facing away from the second dielectric substrate 3, and no radiating elements are disposed in the middle of the surface of the first dielectric substrate 1 facing away from the second dielectric substrate 3. For example, the radiating elements are metal radiating patches.

[0062] Furthermore, along the side length of the rectangular array, among the radiating units located on the same side of the rectangular array, the size of the first radiating unit 41 is larger than the size of the second radiating unit 42. For example, along the side length a of the rectangular array, the first radiating unit A1, the second radiating unit B1, the second radiating unit B2, and the first radiating unit A2 are arranged sequentially. If the dimensions of the first radiating unit A1, the second radiating unit B1, the second radiating unit B2, and the first radiating unit A2 along the length of side a of the rectangular array are d1, d2, d3, and d4 respectively, then d1 and d4 are both larger than d2 and d3. Similarly, along the side length b of the rectangular array, the first radiating unit A2, the second radiating unit B3, the second radiating unit B4, and the first radiating unit A3 are arranged sequentially. If the dimensions of the first radiating unit A2, the second radiating unit B3, the second radiating unit B4, and the first radiating unit A3 along the length of side b of the rectangular array are d5, d6, d7, and d8 respectively, then d5 and d8 are both larger than d6 and d7.

[0063] Next, please refer to Figure 1b and Figure 2 The metal floor layer 2 has coupling slots 21, with each second radiating unit group corresponding to one coupling slot. The first feeding unit 5 is used for coupling connection with one set of opposite coupling slots 21, and the second feeding unit 6 is used for coupling connection with another set of opposite coupling slots 21. Figure 1b Taking the perspective shown as an example, the first power supply unit 5 is used to couple with the two left and right coupling gaps 21, and the second power supply unit 6 is used to couple with the two upper and lower coupling gaps 21.

[0064] In this scheme, a potential difference exists on both sides of the gap between two adjacent radiating elements, which can be equivalent to a capacitor. A single metal radiating patch is divided into multiple non-uniformly sized small radiating patches (i.e., radiating elements). By adjusting the gap width between two adjacent radiating elements, the current distribution can be changed, improving the isolation between the two orthogonal excitation source ports. Furthermore, the radiating elements at the four corners (i.e., the first radiating elements) are larger, providing sufficient design space for the feed element and increasing the radiation area at the gap-coupled feed point, thereby improving antenna gain.

[0065] The first dielectric substrate 1 serves as the carrier of the radiating element, and its material selection must consider its impact on antenna bandwidth and cost factors. For example, to save costs, the first dielectric substrate 1 can be made of a flame-retardant material with a flame-retardant rating of FR4, or it can be a dielectric substrate with a lower dielectric constant, to achieve the design goal of a large bandwidth. This application uses a flame-retardant material with a flame-retardant rating of FR4 as an example for illustration.

[0066] Depending on actual needs, the second dielectric substrate 3 and the first dielectric substrate 1 can be made of the same material, or they can be dielectric substrates with different electrical parameters. The loss of the feed network affects the radiation efficiency of the antenna; therefore, the second dielectric substrate 3 uses a low-loss substrate. For example, the loss tangent tanδ of the second dielectric substrate 3 is 0.0009 to 0.006. The first dielectric substrate 1, the metal ground layer 2, and the second dielectric substrate 3 can be connected using a mixed-lamination process. The metal ground layer 2 can be a copper-clad metal ground layer, and it can be one layer or two layers. It is easy to understand that when there are two metal ground layers 2, the two metal ground layers 2 are stacked. For example, when there are two metal ground layers 2, the coupling gaps 21 of the two metal ground layers 2 coincide on the orthographic projection onto the first dielectric substrate 1.

[0067] When the antenna unit is working, radio frequency energy enters the feeding unit through the antenna port. When it passes through the coupling gap 21, the electromagnetic energy is transferred to the radiating unit through aperture coupling. Then, the radiating unit radiates the energy into space.

[0068] When designing antenna elements, the length and width of the antenna elements are initially determined based on the antenna's operating wavelength. Therefore, after the first radiating element is determined, the dimensions of the second radiating element group on the long and short sides of the rectangular array are also determined and are constants. In other words, the sum of the dimensions of the second radiating element on the same side of the rectangular array is a constant.

[0069] Please continue to refer to Figure 1b In one specific implementation, the second radiating unit group includes two second radiating units 42, and the arrangement direction of the two second radiating units is the same as the arrangement direction of the two first radiating units adjacent to the second radiating unit group. The extension direction of the coupling gap 21 is perpendicular to the extension direction of the gap between the two second radiating units 42 corresponding to the coupling gap, and the orthographic projection of the coupling gap 21 on the first dielectric substrate 1 overlaps with the orthographic projection of the two second radiating units 42 corresponding to the coupling gap 21 on the first dielectric substrate 1.

[0070] Of course, in other implementations, the second radiating unit group may also include one second radiating unit 42. In this case, the extension direction of the coupling gap 21 is the same as the arrangement direction of the two first radiating units adjacent to the second radiating unit 42, and the orthographic projection of the coupling gap 21 on the first dielectric substrate 1 overlaps with the orthographic projection of the second radiating unit 42 on the first dielectric substrate 1. The second radiating unit group may also include more than two second radiating units 42, and the arrangement direction of each second radiating unit is the same as the arrangement direction of the two first radiating units adjacent to the second radiating unit group. The extension direction of the coupling gap 21 is perpendicular to the extension direction of the gap between the second radiating units 42 corresponding to the coupling gap, and the orthographic projection of the coupling gap 21 on the first dielectric substrate 1 overlaps with the orthographic projection of each second radiating unit 42 corresponding to the coupling gap 21 on the first dielectric substrate 1.

[0071] The dimensions of the second radiating unit group on the same side of the rectangular array are fixed. For example, the second radiating unit group includes one second radiating unit 42. The arrangement direction of the two first radiating units 41 adjacent to the second radiating unit 42 is taken as the first direction, and the extension direction of the side of the rectangular array perpendicular to the first direction is taken as the second direction. The dimensions of the second radiating unit 42 in the first direction are both W2 and W2. In another embodiment, the second radiating unit group includes two second radiating units 42, and the arrangement direction of the two second radiating units 42 is the same as the arrangement direction of the two first radiating units adjacent to the second radiating unit group. Taking the arrangement direction of the two first radiating units 41 adjacent to the second radiating unit group as the first direction, and the extension direction of the side of the rectangular array perpendicular to the first direction as the second direction, the sum of the dimensions of the multiple second radiating units 42 in the first direction is W11, and the dimension in the second direction is W22; therefore, W11 = W1, W22 = W2. That is, in the first direction, the more second radiating units 42 there are in the second radiating unit group, the smaller the dimension of each second radiating unit 42 in the first direction. It is worth noting that W11 is the dimension of the second radiating unit group in the first direction, which may include the sum of the dimensions of multiple second radiating units 42 in the first direction, and the sum of the dimensions of the gap between two adjacent second radiating units 42 in the first direction.

[0072] Figure 3 This is a schematic diagram of another antenna element provided in an embodiment of this application. Figure 3 As shown, in some embodiments, the plurality of radiating units further includes four third radiating units 43 disposed in the middle of the surface of the first dielectric substrate 1 facing away from the second dielectric substrate 3, and the four third radiating units 43 are arranged in a rectangular array. The first radiating unit 41 and the second radiating unit 42 surround the outer periphery of the four third radiating units 43, and any adjacent pair of third radiating units 43 and the two second radiating units 42 located on either side of them are on the same straight line. Exemplarily, the third radiating unit 43 can be a complete metal radiating patch, or it can be further divided into multiple sub-radiating units. In one specific implementation, the third radiating unit 43 may include four sub-radiating units arranged in a rectangular array; in another specific implementation, the third radiating unit 43 may include two equally divided sub-radiating units. In this embodiment, each third radiating unit 43 is described as a complete metal radiating patch.

[0073] Next, the current distribution of traditional microstrip patch antennas and the antenna element of this application will be introduced. Figure 4 This is a simulation diagram of the current distribution in a traditional microstrip patch antenna, where a larger arrow indicates a larger current. Figure 4As can be seen from the simulation results, the traditional microstrip patch antenna has a strong radiated current distribution at all four coupling slots 41. The current is transmitted to another polarization port through the feed unit, which causes the isolation to deteriorate.

[0074] Figure 5 This application provides a simulation diagram of the current distribution of an antenna element. Figure 6 A simulation diagram of the current distribution of another antenna element provided in an embodiment of this application. By adjusting the size ratio of each radiating element, the degree of freedom in antenna design can be increased, for example... Figure 6 In the corresponding antenna elements, the radiating elements are divided into three different sizes. To maximize the radiating surface at each coupling slot 21, the size of the radiating elements at the perimeter is larger than that at the center. The current is mainly concentrated in the upper and lower rows of radiating elements, that is, the two rows including the first radiating element 41, and the current at the two coupling slots 21 in the middle row is further reduced. In this scheme, high isolation between the two orthogonal excitation source ports is achieved by reducing the current distribution at the coupling slot 21 corresponding to one of the orthogonal excitation source ports.

[0075] Figure 6 In the corresponding antenna elements, the four middle radiating elements have almost no current distribution. Therefore, Figure 6 The corresponding antenna element can be simplified by removing the intermediate radiating element. Figure 5 The corresponding antenna element. Figure 6 The current distribution of the corresponding antenna element and Figure 5 The current distribution of the corresponding antenna elements remains consistent, and their bandwidth and radiation characteristics are similar. Figure 5 In the corresponding antenna elements, the current at the coupling gap 21 corresponding to the left and right columns of radiating elements will be further reduced. Figure 5 The corresponding antenna elements and Figure 6 The corresponding antenna units can all meet the communication requirements of the WLAN 5G band.

[0076] For ease of description, the following text will use the format " Figure 5 The corresponding antenna element is antenna element C, with Figure 6 The corresponding antenna element is antenna element D.

[0077] The periodic structure of the aforementioned antenna element also exhibits metasurface properties. Figure 7 The diagram shows the reflection phase characteristics of antenna elements C and D. The upper curve represents the reflection phase characteristic of antenna element D, and the lower curve represents the reflection phase characteristic of antenna element C. Figure 7It can be observed that the reflection phase characteristics of both are similar. Therefore, they have similar radiation characteristics. Antenna element C and antenna element D have a reflection phase of 0 degrees near 5.6 GHz and 5.5 GHz, respectively, exhibiting metasurface characteristics at these frequencies.

[0078] Figure 8a and Figure 8b The current distribution of antenna element C at 5.24 GHz and 6.02 GHz is shown respectively, indicating that... Figure 9a and Figure 9b The current distribution of antenna element D at 5.24 GHz and 6.02 GHz is shown respectively. Figure 8a , Figure 8b , Figure 9a and Figure 9b It is evident that the two frequency points operate in different resonant modes. By introducing multimode, the antenna excites more resonant modes, increasing the number of resonant points and thus improving the antenna's bandwidth. Furthermore, it can be seen that the current modes of the two antenna elements are similar; therefore, their bandwidth and radiation characteristics are also similar, and antenna element C does not lead to a decrease in antenna performance.

[0079] Please continue to refer to Figure 9b The pattern formed by all radiating elements is centrally symmetric, as is the pattern formed by all coupling slots 21. Furthermore, the center of symmetry of the pattern formed by all coupling slots 21 coincides with the center of symmetry of the pattern formed by all radiating elements. This ensures that the two orthogonal polarizations have similar radiation performance. Additionally, please refer to... Figure 10 The diagram shows a comparison of single-sided and dual-sided feeding radiation patterns, where curve m1 represents the dual-sided feeding pattern and curve m2 represents the single-sided feeding pattern. The antenna element simultaneously feeds the metasurface radiating patch through two symmetrical coupling slots 21. Compared to single-sided feeding, dual-sided feeding increases the antenna's maximum gain from 5.7 dBi to 7.8 dBi and avoids the pattern shift problem caused by single-sided feeding, improving the frontal gain by 3 dBi. Compared to traditional probe feeding or side feeding, this antenna element further increases the antenna bandwidth and reduces spurious radiation from the feeding network, ensuring the directivity of the antenna radiation.

[0080] In specific implementations, both the first radiating unit 41 and the third radiating unit 43 can be square, and the side length ratio of the first radiating unit 41 to the third radiating unit 43 can be 1.8:1. For example, the side length of the first radiating unit 41 is 10.6 mm, and the side length of the third radiating unit 43 is 5.8 mm. Exemplarily, the width of the gap between any two adjacent radiating units is 1 mm, the width of the coupling gap 21 is 1 mm, and the length of the coupling gap 21 is 9 mm.

[0081] In some embodiments, the power distribution ratio of the first feeding unit 5 and the second feeding unit 6 is 1:1, that is, the antenna unit adopts an equal-amplitude differential feeding structure.

[0082] Please refer to Figure 11 The diagram shows the structures of the first feed unit 5 and the second feed unit 6. The first feed unit 5 includes a first power distribution structure 7, which comprises a first input segment 71 and two first output segments 72. The first input segment 71 is used to connect to the feed network, and the two first output segments 72 are used to couple to a set of opposing coupling slots. The difference in length between the two first output segments 72 is half the waveguide wavelength, resulting in a 180° phase difference in the current of the two coupling slots 21 coupled to the two first output segments 72. The second feed unit 6 includes a second power distribution structure 8, which comprises a second input segment 81 and two second output segments 82. The second input segment 81 is used to connect to the feed network, and the two second output segments 82 are used to couple to another set of opposing coupling slots. The difference in length between the two second output segments 82 is half the waveguide wavelength, resulting in a 180° phase difference in the current of the two coupling slots 21 coupled to the two second output segments 82. For example, the difference in length between the two first output segments 72 is 16.5 mm, and the difference in length between the two second output segments 82 is also 16.5 mm. It is worth noting that in the same power distribution structure, the difference in length between the two output segments being half the waveguide wavelength is not a strict limitation; approximating half the waveguide wavelength is sufficient.

[0083] Please continue to refer to Figure 11The first power distribution structure 7 includes two first quarter-wavelength converters 91, each connected to the end of the first input segment 71 near the first output segment 72. The two first output segments 72 are each connected to the first input segment 71 through a first quarter-wavelength converter 91, ensuring impedance matching between the first input segment 71 and the two first output segments 72. The second power distribution structure 8 includes a second quarter-wavelength converter 92, connected to the end of the second input segment 81 near the second output segment 82. The two second output segments 82 are each connected to the second input segment 81 through this second quarter-wavelength converter 92, ensuring impedance matching between the second input segment 81 and the two second output segments 82. This design avoids the need for vias due to wiring, improving structural reliability. For example, the first power distribution structure 7 uses a first quarter-wavelength converter 91 with an impedance of 71Ω to achieve impedance matching and equal-amplitude power distribution. The second power distribution structure 8 uses two second quarter-wavelength converters 92 with an impedance of 35Ω to achieve impedance matching. By adopting the two power distribution structures mentioned above, the area of ​​the power supply network can be reduced, while the coupling between the two power supply units can be reduced, preventing the deterioration of port isolation.

[0084] The first feed unit 5 and the second feed unit 6 mainly include microstrip lines, and there will be an impedance discontinuity from the microstrip lines to the coupling gap 21. In some embodiments, such as Figure 11 As shown, both the end of the first output segment 72 furthest from the first input segment 71 and the end of the second output segment 82 furthest from the second input segment 81 are connected to fan-shaped stubs 73. By adjusting the radius and angle of the fan-shaped stubs, the coupling slot 21 resonates with the end of the corresponding first feed unit 5 or second feed unit 6, thereby achieving a connection between the coupling slot 21 and the impedance discontinuity of the microstrip line, thus improving impedance matching within the bandwidth. Designing fan-shaped stubs 73 at the end of the feed unit, with a radius smaller than that of the matching scheme using a 1 / 4 wavelength stub, can reduce the coupling between the first feed unit and the second feed unit. For example, the radius r of the fan-shaped stub 73 is 0.1 to 0.2 times the waveguide wavelength, and the unfolding angle of the fan-shaped stub 73 is 90 to 120°.

[0085] Figure 12 This is a front view of an array antenna provided in an embodiment of this application. Figure 13a This is a front view of another array antenna provided in an embodiment of this application. Figure 13b for Figure 13a The diagram shows a three-dimensional structure of the array antenna. Figure 12 and Figure 13a , Figure 13bAs shown, the array antenna includes a first feed network 100, a second feed network 200, and multiple antenna elements. These antenna elements are arranged in an array. The first feed network 100 is electrically connected to each first feed element 5, and the second feed network 200 is electrically connected to each second feed element 6. It is easy to understand that, in specific implementations, the first dielectric substrate of each antenna element can be integrally formed, the second dielectric substrate of each antenna element can be integrally formed, and the metal ground plane of each antenna element can be integrally formed. The array antenna provided in this embodiment can be applied to multi-MIMO bridge devices, but is not limited to multi-MIMO bridge devices.

[0086] In specific implementation, the first feed unit 5, the second feed unit 6, the first feed network 100, and the second feed network 200 are integrally formed. For example, the first feed network 100 and the second feed network 200 are also microstrip lines. The first feed unit 5, the second feed unit 6, the first feed network 100, and the second feed network 200 are fabricated in the same layer by etching process.

[0087] For example, the array antenna includes eight antenna elements arranged linearly in one dimension. In the arrangement direction of each antenna element, the distance between the centers of two adjacent antenna elements is 0.5 to 1 times the wavelength of the array antenna. For example, the distance between the centers of two adjacent antenna elements is 0.8 times the wavelength of the array antenna.

[0088] Antenna elements are combined into an array antenna according to design requirements, such as gain and beamwidth. To control the antenna pattern, the antenna elements are interconnected via a non-uniform amplitude feed network. Precise power distribution control can be achieved by adjusting the microstrip line width of each stage of the feed network. By rationally controlling the power allocated to each antenna element, the sidelobe level of the radiation pattern can be effectively reduced.

[0089] Figure 12 and Figure 13a The two array antennas shown can use the same feed network structure. However, because the superposition effect of different polarized electric fields on a one-dimensional linear array differs, the gains of the two polarized array antennas will be inconsistent. Therefore, feed networks with different power distribution ratios need to be designed for the two polarization ports to reduce the gain difference. According to Chebyshev array theory:

[0090] T m (x)=cos(m×arccosx),-1≤x≤1

[0091] T m (x) = ch(m × archx), x > 1

[0092] T m (x)=(-1)m ch(m×archx), x<-1

[0093] The initial power ratio of multiple first feed units and multiple second feed units can be determined by the preset sidelobe level; then, by combining the gain and beamwidth of the array antenna, the final power ratio of multiple first feed units and multiple second feed units can be optimized and determined.

[0094] For example, both outputs of the 1-to-2 power divider include microstrip lines. The width of the two outputs of each 1-to-2 power divider is determined based on the power ratio of the multiple first feed units and the power ratio of the multiple second feed units, so as to reduce the sidelobe level of the radiation pattern of the array antenna and reduce the difference between the gains of the two polarizations of the array antenna.

[0095] Because the antenna gains at the two polarization ports are inconsistent, the first feed network 100 and the second feed network 200 employ different power distribution ratios. Please refer to... Figure 14The diagram shows a front view of the first feed network 100, the second feed network 200, the first feed unit 5, and the second feed unit 6. The eight first feed units 5 and eight second feed units 6 are arranged from left to right. The first feed network 100 includes four first output terminals F1, each of which is connected to two adjacent first feed units 5 via a 1-to-2 power divider. Along the antenna unit arrangement direction, the power ratio of each first feed unit 5 (i.e., the power distribution ratio at the end of the first feed network 100) is: 0. 0.385:0.5:0.769:1:1:0.769:0.5:0.385; The second feed network 200 includes four second output terminals F2, each of which is connected to two adjacent second feed units 6 through a 1-to-2 power divider; Along the arrangement direction of the antenna units, the power ratio of each second feed unit 6 (that is, the power distribution ratio at the end of the second feed network 200) is: 0.267:0.427:0.667:1:1:0.667:0.427:0.267. That is, P1:P2:P3:P4:P5:P6:P7:P8 = 0.385:0.5:0.769:1:1:0.769:0.5:0.385, P1':P2':P3':P4':P5':P6':P7':P8' = 0.267:0.427:0.667:1:1:0.667:0.427:0.267. The power distribution ratios at the ends of the first feed network 100 and the second feed network 200 are both symmetrically distributed. Antenna elements are interconnected through non-uniform amplitude feed networks to form an array antenna. The distance between the centers of two adjacent antenna elements is 0.8 × c / the center frequency of the array antenna. At this distance, a large gain can be obtained while avoiding the generation of grating lobes. In addition, the array antenna's feed network adopts a non-equal amplitude and same phase parallel feed structure. By reasonably controlling the power allocated to each radiating element, the sidelobe level can be suppressed.

[0096] Please continue to refer to Figure 14In specific implementation, both the first power supply network 100 and the second power supply network 200 may include one first-stage 1-to-2 power divider E1, two second-stage 1-to-2 power dividers E2, and four third-stage 1-to-2 power dividers E3. Each of the two output terminals of the first-stage 1-to-2 power divider E1 is connected to one second-stage 1-to-2 power divider E2, each of the two output terminals of each second-stage 1-to-2 power divider E2 is connected to one third-stage 1-to-2 power divider E3, and each of the two output terminals of the third-stage 1-to-2 power divider E3 is connected to a power supply unit. The power ratio of the first-stage 1-to-2 power dividers E1 in both the first power supply network 100 and the second power supply network 200 is 1:1, the power ratio of the two second-stage 1-to-2 power dividers E2 in the first power supply network 100 is 1:2, and the power ratio of the four third-stage 1-to-2 power dividers E3 in the first power supply network 100 is 1:1.3. The power ratio of the two second-stage 1-to-2 power dividers E2 in the second power supply network 200 is 1:2.5. The power ratio of the first and third third-stage 1-to-2 power dividers E3 from the left in the second power supply network 200 is 1:1.6. The power ratio of the second and fourth third-stage 1-to-2 power dividers E3 in the second power supply network 200 is 1:1.5.

[0097] Because a parallel feed network structure is used, the current at each frequency point has the same phase when reaching the output, thus avoiding a shift in the radiation pattern. The mirrored feed structure between every two adjacent radiating elements in the second feed network 200 reduces the length of the feed network, thereby reducing attenuation. Furthermore, the mirrored arrangement does not change the phase difference at the upper and lower coupling gaps 21, and therefore does not affect the radiation characteristics.

[0098] In some embodiments, the array antenna includes a reflector, each antenna element is fixed to the reflector, and each radiating element is located on the side of the first dielectric substrate 1 facing away from the reflector. The distance between the second dielectric substrate and the reflector is one-quarter wavelength. In this scheme, the reflector can improve the front-to-back ratio of the array antenna, reduce the sidelobe level at the horizontal angle, and the distance between the second dielectric substrate and the reflector is one-quarter wavelength, allowing the electric field reflected by the reflector to be superimposed with the electric field not reflected by the reflector, thereby improving the signal radiation capacity of the array antenna. Exemplarily, the second dielectric substrate can be fixed to the reflector by a bracket. It is worth noting that the distance between the second dielectric substrate and the reflector being one-quarter wavelength is not a strict limitation; in specific implementations, the distance between the second dielectric substrate and the reflector can also be approximately one-quarter wavelength.

[0099] Next, the technical effects achievable by the array antenna provided in the embodiments of this application will be described in detail.

[0100] Figure 15a It shows Figure 12 The simulation diagram of the port isolation of the array antenna is shown. Figure 15b It shows Figure 13a The diagram shows a simulation of the port isolation of the array antenna. Figure 15a and Figure 15b As shown, the dual-polarized array antenna achieves high isolation through the design of a novel periodic microstrip structure. Within the 5.15GHz-5.85GHz WLAN band, Figure 12 The isolation between the two polarization ports of the array antenna shown exceeds 44.9 dB. Figure 13a The isolation of the array antenna shown is better than 46.1 dB. Figure 13a The array antenna isolation shown is slightly higher than Figure 12 The array antenna shown is due to Figure 13a The array antenna shown exhibits a lower current distribution at the coupling slot 21 corresponding to the other polarization. Both are significantly better than the 25dB of traditional dual-polarized antennas, meeting the chip-side requirement for antenna isolation greater than 30dB.

[0101] Figure 16a It shows Figure 12 The vertical polarization pattern of the array antenna shown is... Figure 16b It shows Figure 12 The horizontal polarization pattern of the array antenna shown is... Figure 16c It shows Figure 12 The figure shows a simulation of the gain of the array antenna as a function of frequency. As can be seen from the figure, Figure 12 The vertical and horizontal polarizations of the array antenna shown have maximum gains of 16.4 dBi and 17.2 dBi, respectively, within the 5.15 GHz–5.85 GHz band, with in-band gain ripples of 0.3 dBi and 1.1 dBi, respectively. The maximum gain difference between the two polarizations is 0.8 dBi. Through reasonable design of the non-uniform amplitude feed network, the sidelobe level is reduced from -13.1 dB to -19.8 dB compared to uniform amplitude feed.

[0102] Figure 17a It shows Figure 13a The vertical polarization pattern of the array antenna shown is... Figure 17b It shows Figure 13a The horizontal polarization pattern of the array antenna shown is... Figure 17c It shows Figure 13a The figure shows a simulation of the gain of the array antenna as a function of frequency. As can be seen from the figure, Figure 13a The array antenna shown has maximum gains of 16.6 dBi for vertical polarization and 17.1 dBi for horizontal polarization within the 5.15 GHz–5.85 GHz range, with in-band gain ripples of 0.5 dBi and 1.2 dBi, respectively. The maximum gain difference between the two polarizations is 0.6 dBi. The sidelobe level is -19.6 dB. It can be seen that... Figure 13aThe antenna element shown is Figure 12 The antenna elements shown have similar radiation characteristics.

[0103] Figure 18a It shows Figure 12 The simulation diagram of the return loss of the array antenna is shown. Figure 18b It shows Figure 13a The simulation diagram of the return loss of the array antenna is shown. As can be seen from the figure, the dual-polarized array antenna, by introducing multimode radiation and slot-coupled feeding, generates three resonant points within the band. These three resonant points are close to each other, forming a passband, which effectively improves the bandwidth of the array antenna. Among these, Figure 12 The dual-polarized array antenna shown has a relative bandwidth of 21.8%. Figure 13a The dual-polarized array antenna shown has a relative bandwidth of 18.4%. Figure 13a The dual-polarized array antenna shown is compared to Figure 12 The dual-polarized array antenna shown has a slightly reduced relative bandwidth, and the lower frequency shifts slightly towards higher frequencies. Both are superior to traditional microstrip antennas and fully meet the requirements for WLAN 5G band communication.

[0104] In summary, the antenna provided in this application adopts a multilayer dielectric substrate mixed-pressure non-equal amplitude coupled feeding metasurface array method, which can improve the port isolation of the antenna (e.g., multi-MIMO antenna) and reduce the sidelobe level of the radiation pattern.

[0105] This application also provides a network device that includes the above-mentioned array antenna. Therefore, it can at least achieve the technical effect that the above-mentioned array antenna can achieve, that is, increase the radiation area at the slot coupling feed point and improve the antenna gain.

[0106] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An antenna unit, characterized by The antenna includes a first dielectric substrate, a metal ground layer and a second dielectric substrate which are sequentially stacked, and further includes a plurality of radiation units arranged on a surface of the first dielectric substrate away from the second dielectric substrate, and a first feeding unit and a second feeding unit arranged on a surface of the second dielectric substrate away from the first dielectric substrate; wherein The plurality of radiation units include four first radiation units arranged in a rectangular array, and a second radiation unit group arranged between each adjacent two first radiation units, the second radiation unit group includes at least one second radiation unit, and each adjacent two radiation units have a gap therebetween; along a length direction of a side of the rectangular array, in the plurality of radiation units on the same side of the rectangular array, a size of the first radiation unit is greater than a size of the second radiation unit. The metal ground layer has a coupling gap, and each second radiation unit group corresponds to one coupling gap. The first feeding unit is used for coupling connection with one group of opposite coupling gaps, and the second feeding unit is used for coupling connection with another group of opposite coupling gaps.

2. The antenna unit of claim 1, wherein, The size of the second radiation unit group on the long side of the rectangular array and the size of the second radiation unit group on the short side of the rectangular array are both constant values.

3. The antenna unit according to claim 1 or 2, characterized by The second radiation unit group includes two second radiation units, and the arrangement direction of the two second radiation units is the same as the arrangement direction of two first radiation units adjacent to the second radiation unit group. The extension direction of the coupling gap is perpendicular to the extension direction of the gap between the two second radiation units corresponding to the coupling gap, and the orthogonal projection of the coupling gap on the first dielectric substrate overlaps the orthogonal projection of the two second radiation units corresponding to the coupling gap on the first dielectric substrate.

4. The antenna unit of claim 3, wherein, The plurality of radiation units include four third radiation units arranged on the middle of the surface of the first dielectric substrate away from the second dielectric substrate, the four third radiation units are arranged in a rectangular array, and any adjacent pair of third radiation units and the two second radiation units located on both sides thereof are located on the same straight line.

5. The antenna unit of claim 1, wherein, A pattern formed by the plurality of radiation units is a central symmetric pattern, a pattern formed by the plurality of coupling gaps is a central symmetric pattern, and the symmetry center of the pattern formed by the plurality of coupling gaps coincides with the symmetry center of the pattern formed by the plurality of radiation units.

6. The antenna unit of claim 4, wherein, The first radiation unit and the third radiation unit are both square.

7. The antenna unit of claim 6, wherein, The side length ratio of the first radiation unit to the third radiation unit is 1.8:

1.

8. The antenna unit of claim 6, wherein, The side length of the first radiation unit is 10.6 millimeters, and the side length of the third radiation unit is 5.8 millimeters.

9. The antenna unit of claim 6, wherein, The width of the gap between any adjacent two radiation units is 1 millimeter.

10. The antenna unit according to any one of claims 1 to 9, characterized by The power distribution ratio of the first feeding unit to the second feeding unit is 1:

1.

11. The antenna unit of claim 1, wherein, The first feeding unit comprises a first power distribution structure, the first power distribution structure comprises a first input section and two first output sections, the first input section is used for connecting with a feeding network, and the two first output sections are used for connecting with a group of opposite coupling slots; the length difference of the two first output sections is half of a waveguide wavelength; The second feeding unit comprises a second power distribution structure, the second power distribution structure comprises a second input section and two second output sections, the second input section is used for connecting with a feeding network, and the two second output sections are used for connecting with another group of opposite coupling slots; the length difference of the two second output sections is half of a waveguide wavelength.

12. The antenna unit of claim 11, wherein, The first power distribution structure further comprises two first quarter-wave transformers, the two first quarter-wave transformers are connected with the first input section near one end of the first output section, and the two first output sections are connected with the first input section through one first quarter-wave transformer respectively, so that the first input section is matched in impedance with the two first output sections; And / or, the second power distribution structure further comprises a second quarter-wave transformer, the second quarter-wave transformer is connected with the second input section near one end of the second output section, and the two second output sections are connected with the second input section through the second quarter-wave transformer, so that the second input section is matched in impedance with the two second output sections.

13. The antenna unit of claim 12, wherein, One end of the first output section away from the first input section is connected with a fan-shaped stub; and / or One end of the second output section away from the second input section is connected with a fan-shaped stub.

14. The antenna unit of claim 13, wherein, The radius of the fan-shaped stub is 0.1-0.2 times of a waveguide wavelength, and the unfolding angle of the fan-shaped stub is 90-120°.

15. An array antenna, characterized by The array antenna comprises a first feeding network, a second feeding network and a plurality of antenna units, the plurality of antenna units are arranged in an array, the first feeding network is electrically connected with the first feeding units of the antenna units, and the second feeding network is electrically connected with the second feeding units of the antenna units.

16. The array antenna of claim 15, wherein, The array antenna comprises eight antenna units, and the eight antenna units are arranged in a one-dimensional line. In the arrangement direction of the eight antenna units, the distance between the centers of two adjacent antenna units is 0.5-1 times of a wavelength of the array antenna.

17. The array antenna of claim 16, wherein, The first feeding network comprises four first output terminals, each first output terminal is connected with two adjacent first feeding units through a one-to-two power divider, the second feeding network comprises four second output terminals, and each second output terminal is connected with two adjacent second feeding units through a one-to-two power divider.

18. The array antenna of claim 17, wherein, Each one-to-two power divider comprises a microstrip line. The widths of the two output terminals of each one-to-two power divider are determined based on the power ratios of the plurality of first feeding units and the power ratios of the plurality of second feeding units, so as to reduce the side lobe level of the radiation pattern of the array antenna and reduce the difference between the gains of the two polarizations of the array antenna.

19. The array antenna of claim 18, wherein, The power ratio of the plurality of first feeding units along the arrangement direction of the antenna units is 0.385:0.5:0.769:1:1:0.769:0.5:0.385; and / or the power ratio of the plurality of second feeding units along the arrangement direction of the antenna units is 0.267:0.427:0.667:1:1:0.667:0.427:0.

267.

20. The array antenna according to any one of claims 15 to 19, characterized in that, The array antenna comprises a reflecting plate, the radiation units are located on the side of the first dielectric substrate away from the reflecting plate, the distance between the second dielectric substrate and the reflecting plate is a quarter of a wavelength, and the antenna units are fixed to the reflecting plate through the second dielectric substrate.

21. A network device, comprising: The array antenna comprises any one of claims 15-20.

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