Antenna Element and Antenna Array

Abstract

The present disclosure provides an antenna unit and an antenna array. The antenna unit includes: an antenna, an upper metal reflector, a lower metal reflector, and a thin film disposed between the upper metal reflector and the lower metal reflector. An opening is provided in the upper metal reflector. The antenna is disposed in the opening and on the upper surface of the thin film, and the upper surface of the antenna is located at a higher horizontal position than the upper surface of the upper metal reflector. A transmission bus and transmission branches are provided on the lower surface of the thin film. The transmission bus and the transmission branches are integrally formed, and the transmission branches are used to couple and feed the antenna. A first groove is provided on the lower surface of the upper metal reflector, and a second groove is provided on the upper surface of the lower metal reflector. The first groove and the second groove form a cavity, and the transmission bus is disposed in the cavity.

Description

Technical Field

[0001] The present disclosure relates to the field of wireless communication technologies, and in particular, to an antenna unit and an antenna array. Background Art

[0002] With the development of the fifth-generation (5G) communication network and even the future sixth-generation (6G) communication network, the market scale of base stations has shown a rapid growth trend, and antenna units are developing towards miniaturization, high gain, and greenness. The 3rd Generation Partnership Project (3GPP) has officially defined the U6G band (i.e., the upper half of the 6 GHz band, 6425 to 7125 MHz) as authorized spectrum. In the near future, commercial deployment of the U6G band will be achieved, further promoting the continuous development of wireless communication technologies.

[0003] Therefore, research on high-gain antenna arrays suitable for higher frequency bands and their feeding technologies is crucial. Summary of the Invention

[0004] The present disclosure provides an antenna unit and an antenna array.

[0005] In a first aspect, an embodiment of the present disclosure provides an antenna unit, including: an antenna, an upper metal reflector, a lower metal reflector, and a thin film disposed between the upper metal reflector and the lower metal reflector. An opening is provided in the upper metal reflector, the antenna is disposed in the opening and on the upper surface of the thin film, and the upper surface of the antenna is located at a higher horizontal position than the upper surface of the upper metal reflector. A transmission bus and transmission branches are provided on the lower surface of the thin film, the transmission bus and the transmission branches are integrally formed, and the transmission branches are used to couple-feed the antenna. A first groove is provided on the lower surface of the upper metal reflector, and a second groove is provided on the upper surface of the lower metal reflector. The first groove and the second groove form a cavity, and the transmission bus is disposed in the cavity.

[0006] In a second aspect, an embodiment of the present disclosure provides an antenna array, including a plurality of antenna units arranged in an array, wherein each of the plurality of antenna units is an antenna unit according to an embodiment of the present disclosure.

[0007] According to the antenna unit of an embodiment of the present disclosure, by disposing the antenna in the opening of the upper metal reflector, the metal cavity formed by the opening of the upper metal reflector can improve the directivity of the antenna, making the energy radiate more concentratedly and enhancing the gain; by disposing the transmission line on the lower surface of the thin film, the additional dielectric loss brought by the printed circuit board can be reduced; in addition, by disposing the transmission bus in the slot cavity, an air stripline can be realized. Description of the Drawings

[0008] In the drawings of the embodiments of the present disclosure:

[0009] Figure 1 is a schematic diagram showing the architecture of an antenna array according to an embodiment of the present disclosure;

[0010] Figure 2 schematically shows an example of an antenna unit obtained by applying a conventional patch antenna to the overall architecture according to an embodiment of the present disclosure;

[0011] Figure 3A is a schematic diagram showing the antenna unit according to an embodiment of the present disclosure;

[0012] Figure 3B is Figure 3A a schematic diagram of the antenna in the shown antenna unit;

[0013] Figure 3C shows another example of the antenna in the antenna unit according to an embodiment of the present disclosure;

[0014] Figure 4A is a cross-sectional view showing the antenna unit according to an embodiment of the present disclosure;

[0015] Figure 4B is a top view showing the antenna unit according to an embodiment of the present disclosure;

[0016] Figure 4C is Figure 4A and Figure 4B a perspective view of the antenna in the shown antenna unit;

[0017] Figure 4D is Figure 4A and Figure 4B a top view of the antenna in the shown antenna unit;

[0018] Figure 5 is a schematic diagram showing the thin film in the antenna array according to an embodiment of the present disclosure;

[0019] Figure 6 is a top view and a bottom view showing the upper metal reflector in the antenna array according to an embodiment of the present disclosure;

[0020] Figure 7 shows a top view and a bottom view of a lower metal reflector in an antenna array according to an embodiment of the present disclosure;

[0021] Figure 8 is a schematic diagram showing a signal connection device in an antenna element according to an embodiment of the present disclosure;

[0022] Figure 9 shows a top view and a bottom view of an adapter board in an antenna array according to an embodiment of the present disclosure;

[0023] Figure 10 is a schematic diagram showing a connection manner of a signal connection device in an antenna element according to an embodiment of the present disclosure;

[0024] Figure 11 shows a perspective view and a cross-sectional view of an antenna element according to an embodiment of the present disclosure;

[0025] Figure 12A shows the standing wave ratio of an antenna element according to an embodiment of the present disclosure;

[0026] Figure 12B shows the port isolation of an antenna element according to an embodiment of the present disclosure;

[0027] Figure 12C shows the gain of an antenna element according to an embodiment of the present disclosure and an antenna element of a comparative example;

[0028] Figure 13 shows an exploded perspective view of an antenna array according to an embodiment of the present disclosure;

[0029] Figure 14A shows the standing wave ratio of an antenna array according to an embodiment of the present disclosure;

[0030] Figure 14B shows the port isolation of an antenna array according to an embodiment of the present disclosure;

[0031] Figure 14C shows the gain of an antenna array according to an embodiment of the present disclosure. Detailed Embodiments

[0032] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0033] In the following, the present disclosure will be described more fully with reference to the accompanying drawings. However, the illustrated embodiments may be embodied in different forms and the present disclosure should not be construed as limited to the embodiments set forth below. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0034] The accompanying drawings of the embodiments of the present disclosure are used to provide a further understanding of the embodiments of the present disclosure, and constitute a part of the specification. Together with the detailed embodiments, they are used to explain the present disclosure and do not constitute a limitation to the present disclosure. By describing the detailed embodiments with reference to the accompanying drawings, the above and other features and advantages will become more obvious to those skilled in the art.

[0035] The present disclosure can be described with reference to plan views and / or cross-sectional views by means of the ideal schematic diagrams of the present disclosure. Therefore, the example illustrations can be modified according to the manufacturing technology and / or tolerances.

[0036] Without conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0037] The terms used in the present disclosure are only for describing specific embodiments and are not intended to limit the present disclosure. As used in the present disclosure, the term "and / or" includes any and all combinations of one or more related listed items. As used in the present disclosure, the singular forms "a" and "the" are also intended to include the plural forms unless the context clearly indicates otherwise. As used in the present disclosure, the terms "comprising", "made of", specify the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their groups.

[0038] Unless otherwise defined, the meanings of all terms (including technical terms and scientific terms) used in the present disclosure are the same as those commonly understood by those of ordinary skill in the art. It will also be understood that terms such as those defined in common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art and the present disclosure, and will not be interpreted as having idealized or overly formal meanings unless the present disclosure clearly defines otherwise.

[0039] The present disclosure is not limited to the embodiments shown in the drawings, but includes modifications to the configurations formed based on the manufacturing process. Therefore, the regions illustrated in the drawings have schematic properties, and the shapes of the regions shown in the drawings illustrate the specific shapes of the regions, but are not intended to be restrictive.

[0040] 3GPP has officially defined the U6G frequency band (6425 to 7125 MHz) as authorized spectrum. In the near future, commercial deployment of the U6G frequency band will be realized, further promoting the continuous development of wireless communication technology. However, at present, the research on the U6G frequency band in the academic and industrial circles is relatively scarce. One of the technical problems existing in this frequency band is that as the frequency increases, the path loss will intensify, which causes the gain of the antenna to decrease accordingly.

[0041] To solve the loss problem caused by the path, the commonly adopted method in the Sub-6G band (i.e., the band below 6 GHz) is to use an air stripline to feed the antenna element or antenna array. Currently, there are two design schemes for the air cavity of the air stripline: one scheme is the pultruded cavity, which has a large cavity size and poor accuracy; the other scheme is the metallization of the plastic module, but only a semi-air cavity can be realized, and the accuracy is poor, which is not suitable for the U6G band. Therefore, for the U6G band, a new solution for implementing the air stripline needs to be proposed. In addition, the conventional stripline is printed on the upper and lower surfaces of a printed circuit board (PCB), and then the upper and lower layer traces are connected through metallized vias. Therefore, the PCB will bring additional dielectric loss, and the loss will increase as the thickness of the PCB increases.

[0042] Another problem with using an air stripline is the selection of the antenna element. The common forms of antenna elements include patch antennas and dipole antennas. Patch antennas are usually printed on the surface of a dielectric substrate. When using the stripline scheme, the patch antenna needs to be etched separately outside the stripline area, or a metal cavity needs to be set on the metal surface of the stripline for radiation. The overall size of the independently printed antenna array is large and not suitable for large-scale compact multiple-input multiple-output (MIMO) antennas; while setting the patch antenna in a metal cavity with a limited aperture will affect the radiation efficiency of the antenna. Dipole antennas usually use a balun feed, and at least two structures need to be assembled together to achieve dual polarization. For a pure metal antenna, a non-metal structural part needs to be used as a support, which requires high machining accuracy of the structural part, and the machining tolerance of the structural part will affect the performance of the antenna.

[0043] On the other hand, as the frequency band increases, the requirements for the welding process will become more stringent. Currently, the total input port of the feeder is connected to structures such as phase shifters by welding feed pins to build a complete signal path. However, with the continuous expansion of the base station scale and the significant increase in the number of antennas, the traditional welding interconnection method may introduce additional fault points, thus affecting the performance of the antenna. At the same time, a large number of welding operations will increase costs, reduce the assembly efficiency of the antenna, and the smoke and harmful gases generated during the welding process will pollute the surrounding environment. Therefore, a solderless design is needed to improve the reliability of the overall connection, improve production efficiency, and reduce environmental pollution.

[0044] In view of the above various problems, the present disclosure provides an architecture for an antenna element and an antenna array of a base station applicable to the U6G band.

[0045] Figure 1It is a schematic diagram showing the architecture of an antenna array according to an embodiment of the present disclosure.

[0046] As Figure 1 shown, the antenna array according to an embodiment of the present disclosure generally includes an upper metal reflector 110, a lower metal reflector 130, and a thin film 120 disposed between the upper metal reflector 110 and the lower metal reflector 130. An opening 111 is provided in the upper metal reflector 110, and the antenna 100 is disposed in the opening 111 and on the upper surface of the thin film 120. The opening 111 is used for the radiation of the antenna 100, and the distance between the opening 111 and the radiator of the antenna 100 is 0.01λ to 0.1λ (λ is the wavelength in free space at the center frequency point).

[0047] A transmission line 121 is provided on the lower surface of the thin film 120. The transmission line 121 includes a transmission bus and transmission branches, and the transmission bus and the transmission branches are integrally formed. The transmission branches are used to couple and feed the antenna 100.

[0048] In addition, Figure 1 a signal connection device 140 is also shown. The signal connection device 140 vertically passes through a hole 134 provided in the lower metal reflector 130, and one end of the signal connection device 140 is electrically connected to the transmission line 121 provided on the lower surface of the thin film 120 to transmit an external signal to the transmission line 121.

[0049] Although the antenna array shown in Figure 1 includes an array of 1×4 antenna elements, it should be recognized that the number of antenna elements is not limited to four, and the arrangement of the antenna array is not limited to the shown arrangement. In practical applications, the scale of the antenna array can be arbitrarily expanded to implement a large-scale MIMO array.

[0050] Figure 2 Schematically shows an example of an antenna element obtained by applying a conventional patch antenna to the overall architecture according to an embodiment of the present disclosure.

[0051] As Figure 2 shown, a patch-shaped antenna 100' is etched on the upper surface of the thin film 120, which will generate relatively large dielectric losses at higher frequencies. In addition, the metal cavity formed by the opening 111 around the antenna 100' will couple part of the energy, resulting in a reduction in the efficiency of the antenna.

[0052] To overcome this problem, the present disclosure proposes an antenna element based on the overall architecture according to an embodiment of the present disclosure.

[0053] Figure 3A It is a schematic diagram showing the antenna element according to an embodiment of the present disclosure, Figure 3B is Figure 3ASchematic diagram of the antenna in the antenna unit shown Figure 3C Another example of the antenna in the antenna unit according to an embodiment of the present disclosure is shown Figure 4A Is a cross-sectional view showing the antenna unit according to an embodiment of the present disclosure Figure 4B Is a top view showing the antenna unit according to an embodiment of the present disclosure Figure 4C Is Figure 4A And Figure 4B Perspective view of the antenna in the antenna unit shown Figure 4D Is Figure 4A And Figure 4B Top view of the antenna in the antenna unit shown

[0054] See Figures 3A to 4D According to an embodiment of the present disclosure, the antenna unit includes: an antenna 100, an upper metal reflector 110, a lower metal reflector 130, and a thin film 120 disposed between the upper metal reflector 110 and the lower metal reflector 130

[0055] An opening 111 is provided in the upper metal reflector 110, the antenna 100 is disposed in the opening 111, and is disposed on the upper surface of the thin film 120. The upper surface of the antenna 100 is located at a higher horizontal position than the upper surface of the upper metal reflector 110, that is, the height H1 of the antenna 100 is greater than the height H2 of the upper metal reflector 110

[0056] A transmission bus and transmission branches (i.e., the transmission line 121 shown in Figure 1 ) are provided on the lower surface of the thin film 120. The transmission bus and the transmission branches are integrally formed, and the transmission branches are used to couple-feed the antenna 100

[0057] A first groove (not shown in the figure) is provided on the lower surface of the upper metal reflector 110, and a second groove (not shown in the figure) is provided on the upper surface of the lower metal reflector 130. The first groove and the second groove form a cavity, and the transmission bus is disposed in the cavity

[0058] According to the antenna unit of the embodiment of the present disclosure, the antenna is disposed in the metal cavity formed by the opening of the upper metal reflector, which is equivalent to forming a metal wall around the antenna to improve the directivity of the antenna, so that the energy is more concentratedly radiated and the gain is improved; by disposing the transmission line on the lower surface of the thin film, the additional dielectric loss brought by the PCB can be reduced; in addition, by disposing the transmission bus in the cavity, an air stripline can be realized

[0059] The antenna unit according to an embodiment of the present disclosure will be described below in conjunction with the detailed diagrams of each part

[0060] See Figures 4A to 4D, the antenna 100 is a metal patch antenna and includes a radiator 101 and a plurality of metal support blocks 102 disposed on the lower surface of the radiator 101. The transmission branch line 1212 feeds the metal patch antenna 100 by coupling through the plurality of metal support blocks 102. The material of the radiator 101 of the antenna 100 may be aluminum. Aluminum has a relatively small internal resistance and strong corrosion resistance.

[0061] It should be recognized that although the transmission branch line 1212 is shown in Figures 4B to 4D , the transmission branch line 1212 and the transmission bus are integrally formed on the lower surface of the thin film 120. The size and shape of the transmission branch line 1212 can be designed according to actual needs. In Figures 4B to 4D 's example, the transmission branch line 1212 is shown as having a T-shaped structure. By means of coupled feeding, the transmission branch line 1212 can excite the ±45° polarization of the antenna element. By adjusting the length-width configuration of the T-shaped structure of the transmission branch line 1212, good matching can be achieved within the required frequency band for the antenna element.

[0062] According to an embodiment of the present disclosure, referring to Figure 3A and Figure 4A , the height of the plurality of metal support blocks 102 is greater than the height of the upper metal reflector 110, so that the upper surface of the antenna 100 is located at a higher horizontal position than the upper surface of the upper metal reflector 110, to avoid the metal cavity formed by the opening 111 from reducing the efficiency of the antenna. The opening 111 in the upper metal reflector 110 surrounds the plurality of metal support blocks 102.

[0063] In the antenna element according to the embodiment of the present disclosure, a metal patch antenna is adopted. By controlling the size of the radiator 101, the operating frequency band of the antenna can be controlled. The metal support blocks 102 below the radiator 101 are used to lift the antenna profile. The lifting of the antenna profile reduces the energy coupling of the metal cavity and improves the radiation efficiency. The metal cavity is equivalent to forming a metal wall around the antenna to improve the directivity of the antenna, so that the energy is radiated more concentratedly and the gain is increased.

[0064] It should be recognized that although the metal support blocks 102 are shown as four in the figure, the present disclosure is not limited thereto. For dual polarization, since the transmission branch line feeds the metal patch antenna by coupling through the plurality of metal support blocks 102, the number of metal support blocks 102 is at least two. On the other hand, although the radiator 101 is shown as square in the figure, the present disclosure is not limited thereto. The shape of the radiator can be square, circular (as shown in Figure 3C ) or other symmetric structures. In addition, according to needs, slotting or punching designs can be carried out on the radiator 101. For example, in Figure 4C and Figure 4DIn the antenna shown, the radiator 101 is formed as a square with a certain thickness, and slots are provided at the central portions of the four sides of the radiator 101, so that the current path can be extended while meeting the radiation performance requirements, the size of the antenna can be reduced, and the miniaturized design of the antenna can be achieved.

[0065] According to an embodiment of the present disclosure, referring to Figure 4A and Figure 4B , a third groove 112 is provided on the upper surface of the upper metal reflector 110, and the third groove 112 surrounds the opening 111.

[0066] A square structure with a side length of L1 and a thickness of H2 is removed from the upper metal reflector 110 to form the opening 111, that is, a metal cavity for accommodating the antenna 100. On the upper surface of the upper metal reflector 110, a square structure body with a side length of L2 and a thickness of H3 is removed around the opening 111 to form the third groove 112, where L2 is greater than L1 and H3 is less than H2. By forming the third groove 112 on the upper surface of the upper metal reflector 110, the mutual coupling between the upper metal reflector 110 and the radiator 101 of the antenna 100 can be reduced, and the antenna profile can be lowered. The depth H3 of the third groove 112 should be less than the height H2 of the upper metal reflector 110, and the depth H3 of the third groove 112 can be designed according to the frequency band and the type of the antenna.

[0067] According to an embodiment of the present disclosure, referring to Figure 4A and Figure 4B , a fourth groove 131 is provided on the upper surface of the lower metal reflector 130, and a boss 132 is provided at the center of the fourth groove 131, and the height of the boss 132 is the same as the height of the lower metal reflector 130. As Figure 4B shown, the projection of the opening 111 in the upper metal reflector 110 on the upper surface of the lower metal reflector 130 covers the fourth groove 131, and the projection of each of the plurality of metal support blocks 102 on the upper surface of the lower metal reflector 130 partially overlaps with the upper surface of the boss 132.

[0068] Since there is only one thin film 120 between the lower metal reflector 130 and the metal support block 102 of the antenna 100, and the distance is very close, resulting in large conductor losses, therefore, a square structure body with a side length of L3 and a thickness of about 1 mm is removed from the lower metal reflector 130 to form the fourth groove 131. To ensure the stability of the antenna unit, L3 is less than L1. To further support the antenna 100, a boss 132 with a side length of L4 is provided at the center of the fourth groove 131.

[0069] According to an embodiment of the present disclosure, referring to Figure 4A and Figure 4C, an adhesive layer 103 is provided on the lower surface of the plurality of metal support blocks 102, and the metal patch antenna 100 is disposed on the upper surface of the thin film 120 via the adhesive layer 103.

[0070] According to an embodiment of the present disclosure, refer to Figures 4A to 4D , a positioning protrusion 104 is provided on the lower surface of at least one of the plurality of metal support blocks 102.

[0071] Providing the positioning protrusion 104 at the bottom of the antenna 100 can facilitate the installation and fixation of the antenna 100. In Figure 4C and Figure 4D 's example, the positioning protrusion 104 is shown as a cylinder, but the present disclosure is not limited thereto. It should be recognized that the position of the positioning protrusion 104 should avoid the transmission branch line 1212 below the antenna 100. In Figure 4C and Figure 4D 's example, the antenna 100 includes four metal support blocks 102, and the positioning protrusions 104 are provided on the lower surfaces of two of the metal support blocks 102, while the transmission branch line 1212 is disposed below the other two metal support blocks 102 to couple-feed the antenna 100 through the metal support blocks 102.

[0072] According to an embodiment of the present disclosure, the thin film 120 includes one of the following: a polyphenylene oxide (PPO) film, a polyetherimide (PEI) film, and a polyester (PET) film, and a transmission bus and transmission branch lines are formed on the lower surface of the thin film 120 using conductive silver paste through a screen printing process.

[0073] The thickness of the thin film 120 can be less than or equal to 0.3 mm, the dielectric constant is less than 4, the loss tangent angle is less than 0.003, and it has advantages such as chemical resistance, electrical insulation, and easy processing. The thin film 120 can be a PPO film, a PEI film, a PET film, etc. According to an embodiment of the present disclosure, the thin film 120 can be a PPO film, and its thickness can be less than or equal to 0.1 mm. A transmission line 121 (refer to Figure 1 ) is formed on the lower surface of the thin film 120 using conductive silver paste through a screen printing process. The combination of a low dielectric constant and a low loss factor can significantly reduce the overall loss of the transmission line.

[0074] Figure 5 is a schematic diagram showing the thin film in the antenna array according to an embodiment of the present disclosure, Figure 6 is a top view and a bottom view showing the upper metal reflector in the antenna array according to an embodiment of the present disclosure, Figure 7 is a top view and a bottom view showing the lower metal reflector in the antenna array according to an embodiment of the present disclosure.

[0075] It should be recognized that, for the convenience of explaining the structure of the thin film, a schematic diagram of the thin film in the antenna array is shown in Figure 5 . For the antenna elements that make up the antenna array, the structure of the thin film in the antenna element is the same as that of the thin film in the antenna array.

[0076] Refer to Figures 5 to 7 . In the thin film 120, a plurality of metal vias 122 are arranged around the transmission bus 1211. A first groove 113 is provided on the lower surface of the upper metal reflector 110, and a second groove 133 is provided on the upper surface of the lower metal reflector 130. The first groove 113 and the second groove 133 can form a cavity, and the transmission bus 1211 can be arranged in the cavity. The first groove 113 can be formed on the lower surface of the upper metal reflector 110 and the second groove 133 can be formed on the upper surface of the lower metal reflector 130 by using a Computerized Numerical Control (CNC) machine tool.

[0077] The materials of the transmission bus 1211 and the transmission branch line 1212 can be silver, and are formed on the lower surface of the thin film 120 by using conductive silver paste through a screen printing process. The materials of the upper metal reflector 110 and the lower metal reflector 130 can be aluminum, and the thickness of each is about 2 mm. In other embodiments, the upper metal reflector 110 and the lower metal reflector 130 can have other thicknesses, and the thicknesses of the upper metal reflector 110 and the lower metal reflector 130 can be unequal.

[0078] To ensure effective electrical connection between the upper metal reflector 110 and the lower metal reflector 130 to reduce the wiring loss of the air cavity, metal vias 122 can be arranged around the transmission bus 1211. The upper metal reflector 110, the thin film 120, and the lower metal reflector 130 can be pressed together by using rivets.

[0079] The transmission bus 1211 is arranged between the upper metal reflector 110 and the lower metal reflector 130. To avoid the transmission bus 1211, a first groove 113 and a second groove 133 are respectively provided on one side of the upper metal reflector 110 and the lower metal reflector 130 close to the thin film 120. After the upper metal reflector 110 and the lower metal reflector 130 are combined, a cavity is formed by the first groove 113 and the second groove 133, and the cavity is located around the transmission bus 1211.

[0080] The edge of the slot cavity maintains a spacing of approximately 1 mm from the transmission bus 1211 in all directions (i.e., in directions such as length, width, and depth). This spacing can be set arbitrarily, but the following principles must be followed: 1) The spacing should be less than the thickness of the anti-metal reflection plate to prevent penetration of the metal reflection plate, which may weaken the structural strength of the metal reflection plate or cause electromagnetic energy leakage; 2) Try to ensure that each transmission bus has an independent cavity space to reduce mutual interference between the traces and improve the isolation between ports.

[0081] The slot cavity is parallel to the transmission bus 1211 and extends along the direction of the transmission bus 1211 to place the transmission bus 1211 in the air cavity, making air the main medium of the transmission line. The low dielectric constant of air is used to further reduce losses. In addition, the slot cavity can also achieve the effect of electromagnetic shielding to prevent external interference.

[0082] At the total input port of the transmission bus 1211, a signal connection device 140 can be used to transfer an external signal to the transmission bus 1211. The signal connection device 140 can vertically pass through the hole 134 provided in the lower metal reflection plate 130 to connect to the external signal.

[0083] Figure 8 is a schematic diagram showing the signal connection device in the antenna unit according to an embodiment of the present disclosure. Figure 9 is a top view and a bottom view showing the adapter board in the antenna array according to an embodiment of the present disclosure. Figure 10 is a schematic diagram showing the connection method of the signal connection device in the antenna unit according to an embodiment of the present disclosure.

[0084] According to an embodiment of the present disclosure, the antenna unit may further include a signal connection device 140 and an adapter board 150. The adapter board 150 is disposed below the lower metal reflection plate 130, and an adapter device is provided in the adapter board 150. The signal connection device 140 vertically passes through the lower metal reflection plate 130. One end of the signal connection device 140 is electrically connected to the transmission bus 1211 provided on the lower surface of the thin film 120, and the other end of the signal connection device 140 is electrically connected to the adapter device.

[0085] As Figure 8 shown, the signal connection device 140 may include a metal elastic column 141, an insulating column 142, and an insulating cover 143 provided above the metal elastic column 141 and the insulating column 142. It should be recognized that Figure 8The signal connection device 140 shown is only for illustration, and the present disclosure is not limited thereto. The signal connection device 140 can have various forms. For example, it can be a wool button, a spring probe, etc. The signal connection device 140 can be a connector with the ability of telescoping or elastic deformation, and can be used in combination with an insulating medium or alone. The two ends of the signal connection device 140 can be elastically contacted with the transmission bus 1211 on the lower surface of the thin film 120 and the microstrip line on the printed circuit board (for example, Figure 9 the adapter board 150 shown), respectively, so as to achieve a solderless design, and can provide stable connection in various environments, and at the same time can simplify the assembly process of the antenna.

[0086] As Figure 9 shown, a first microstrip line 151 is provided on the upper surface of the adapter board 150, and a second microstrip line 152 is provided on the lower surface of the adapter board 150. The first microstrip line 151 and the second microstrip line 152 are electrically connected via a metal via passing through the adapter board 150. The adapter device provided on the adapter board 150 includes the first microstrip line 151, the second microstrip line 152, and the metal via connecting the first microstrip line 151 and the second microstrip line 152.

[0087] As Figure 10 shown, a metal elastic column 141 is provided between the thin film 120 and the adapter board 150. One end of the metal elastic column 141 is electrically connected to the transmission bus 1211, and the other end is electrically connected to the adapter device on the adapter board 150. Specifically, the other end of the metal elastic column 141 is electrically connected to the first microstrip line 151 on the upper surface of the adapter board 150. The metal elastic column 141 can include beryllium bronze alloy wire, molybdenum wire, nickel-chromium alloy wire, etc., and its diameter is about 1 mm.

[0088] An insulating column 142 surrounds the metal elastic column 141 and is provided between the metal elastic column 141 and the lower metal reflector 130. That is to say, the insulating column 142 fills the hole 134 in the lower metal reflector 130 to achieve insulation between the metal elastic column 141 and the lower metal reflector 130. The size of the hole 134 in the lower metal reflector 130 matches the size of the insulating column 142. The material of the insulating column 142 can be polytetrafluoroethylene, and a hole with a diameter of about 1.2 mm can be formed in the middle of the insulating column 142. The metal elastic column 141 is embedded in the insulating column 142 to prevent the metal elastic column 141 from shifting.

[0089] An insulating cover 143 is embedded in the lower surface of the upper metal reflector 110, and the projection of the insulating cover 143 on the upper surface of the lower metal reflector 130 covers the projection of the metal elastic column 141 on the upper surface of the lower metal reflector 130.

[0090] The transmission bus 1211 formed on the lower surface of the thin film 120 is electrically connected to the first microstrip line 151 formed on the upper surface of the adapter board 150 through the metal elastic column 141. Since the upper end of the metal elastic column 141 contacts the transmission bus 1211 printed on the thin film 120, and the thickness of the thin film 120 is very thin, its physical properties cannot achieve a stable and reliable elastic connection. Therefore, it is necessary to embed the insulating cover 143 on the lower surface of the upper metal reflector 110. Through the mutual cooperation of the insulating cover 143 and the adapter board 150, the metal elastic column 141 can be compressed to ensure the stability of the electrical performance.

[0091] In Figure 8 and Figure 10 example, the number of the metal elastic columns 141 is 1, but the present disclosure is not limited thereto. In other embodiments, the signal connection device 140 may include a plurality of metal elastic columns 141, and the plurality of metal elastic columns 141 may be symmetrically arranged around the center of the first microstrip line 151.

[0092] Figure 11 FIGS. are a perspective view and a cross-sectional view showing an antenna unit according to an embodiment of the present disclosure.

[0093] As Figure 11 shown, the antenna unit according to an embodiment of the present disclosure may further include a parasitic patch board 160 disposed above the antenna 100. The parasitic patch board 160 includes a dielectric board, a first parasitic patch 161 formed on the upper surface of the dielectric board, and a second parasitic patch 162 formed on the lower surface of the dielectric board. The first parasitic patch 161 corresponds to the position and shape of the antenna 100, and the second parasitic patch 162 corresponds to the position and shape of the antenna 100.

[0094] By disposing a parasitic patch above the antenna 100, the gain of the antenna can be further improved. The parasitic patch board 160 includes a first parasitic patch 161 printed on the upper surface of the dielectric board and a second parasitic patch 162 printed on the lower surface of the dielectric board, and the structures of the first parasitic patch 161 and the second parasitic patch 162 are exactly the same. As shown in the figure, both the first parasitic patch 161 and the second parasitic patch 162 are squares with slots on four sides, and have the same shape as the radiator 101 of the antenna shown in Figure 4C and Figure 4D . By introducing the parasitic patch, the current distribution on the surface and around the space of the antenna can be changed, and the directivity of the radiator of the antenna can be enhanced, thereby effectively improving the gain of the antenna.

[0095] Figure 12A FIG. shows the standing wave ratio of the antenna unit according to an embodiment of the present disclosure, Figure 12B FIG. shows the port isolation of the antenna unit according to an embodiment of the present disclosure, Figure 12CShows the gain of the antenna unit according to an embodiment of the present disclosure and Figure 2 the gain of the antenna unit of the comparative example shown.

[0096] As Figure 12A and Figure 12B shown, the antenna unit according to the embodiment of the present disclosure has good standing wave ratio and port isolation in the designed frequency band. As Figure 12C shown, compared with the traditional patch antenna with parasitic structure ( Figure 12C the dotted line in), the gain of the antenna unit according to the embodiment of the present disclosure ( Figure 12C the solid line in) has an average increase of 0.7 dBi in the whole frequency band.

[0097] For the antenna unit according to the embodiment of the present disclosure, the antenna is arranged in the metal cavity formed by the opening of the upper metal reflector, which improves the directivity of the antenna, makes the energy radiate more concentratedly, and improves the gain; by arranging the transmission line on the lower surface of the thin film, the additional dielectric loss brought by the PCB can be reduced; in addition, by arranging the transmission bus in the slot cavity, an air stripline can be realized.

[0098] The antenna unit according to the embodiment of the present disclosure is applicable to the U6G frequency band and can be applied to the antenna array of the base station. By using the transmission branch line to couple and feed the antenna and using the signal connection device, a solderless design is realized. Compared with the traditional scheme, the dielectric loss is reduced, the radiation efficiency is improved, the welding defects such as false soldering and de-soldering generated during the welding process are avoided, the reliability of the antenna is improved, the assembly difficulty is reduced, the environmental pollution is reduced, and it is green and environmentally friendly. By using a low-loss thin film, using conductive silver paste to form the transmission bus and transmission branch line through the screen printing process, and arranging the transmission bus in the slot cavity formed by using a CNC machine tool, the loss of the trace can be reduced to an extremely low level, which can meet the process requirements of high-frequency antennas and has a low cost.

[0099] The embodiment of the present disclosure also provides an antenna array, including a plurality of antenna units according to the embodiments of the present disclosure. The antenna unit according to the embodiment of the present disclosure can be applied in a solderless base station antenna array with low loss and high processing accuracy requirements. The antenna array according to the embodiment of the present disclosure can be applied to the field of mobile communication antennas, providing more possibilities for the development of 5G and 6G.

[0100] Figure 13 Shows an exploded perspective view of the antenna array according to the embodiment of the present disclosure.

[0101] As Figure 13As shown, the antenna array according to an embodiment of the present disclosure includes: an antenna layer 1, a feeder layer 2, and an adapter board layer 3. The antenna layer 1 is disposed above the feeder layer 2, and the adapter board layer 3 is disposed below the feeder layer 2. The antenna layer 1 includes at least two antennas 100. The antennas 100 are connected through a transmission bus 1211 located in the feeder layer 2 to form an array, and then are connected to the adapter board layer 3 through a signal connection device 140, so as to be interconnected with structures such as a phase shifter and a coupler.

[0102] The antenna layer 1 includes an antenna 100 and a parasitic patch board 160. A first parasitic patch 161 is formed on the upper surface of the parasitic patch board 160. The feeder layer 2 includes an upper metal reflector 110, a thin film 120, and a lower metal reflector 130. A transmission bus 1211 and transmission branches ( Figure 13 not shown) are formed on the lower surface of the thin film 120 by using a conductive silver paste screen printing process. The adapter board layer 3 includes an adapter board 150. A first microstrip line 151 is formed on the upper surface of the adapter board 150.

[0103] According to an embodiment of the present disclosure, as Figure 13 shown, the upper metal reflectors 110 of multiple antenna units are integrally formed, the lower metal reflectors 130 of multiple antenna units are integrally formed, and the thin films 120 of multiple antenna units are integrally formed. On the lower surface of the integrally formed thin film 120, transmission branches ( Figure 13 not shown) corresponding to each of the multiple antenna units are respectively formed, and the transmission bus 1211 connects the transmission branches corresponding to each of the multiple antenna units together.

[0104] Although the antenna array shown in Figure 13 includes an array of 1×4 antenna units, it should be understood that the number of antenna units is not limited to four. For example, it may include three or six antenna units, and the arrangement of the antenna array is not limited to the shown arrangement. In practical applications, the scale of the antenna array can be arbitrarily expanded to implement a large-scale MIMO array.

[0105] According to an embodiment of the present disclosure, the transmission branches corresponding to each of the multiple antenna units include a first transmission branch and a second transmission branch that are electrically separated from each other (see the examples in Figure 4C and Figure 4D ), and, as Figure 13 shown, the transmission bus 1211 includes a first transmission bus 1211_1 and a second transmission bus 1211_2 that are electrically separated from each other. The first transmission bus 1211_1 connects the first transmission branches corresponding to each of the multiple antenna units together, and the second transmission bus 1211_2 connects the second transmission branches corresponding to each of the multiple antenna units together.

[0106] According to an embodiment of the present disclosure, as Figure 13 shown, the antenna array further includes a first signal connection device 140_1, a second signal connection device 140_2, and an adapter board 150. The adapter board 150 is disposed below the integrally formed lower metal reflector 130, and a first transfer device and a second transfer device are provided in the adapter board 150. The first signal connection device 140_1 and the second signal connection device 140_2 respectively vertically penetrate through the integrally formed lower metal reflector 130. One end of the first signal connection device 140_1 is electrically connected to a first transmission bus 1211_1 provided on the lower surface of the integrally formed thin film 120, and the other end of the first signal connection device 140_1 is electrically connected to the first transfer device. One end of the second signal connection device 140_2 is electrically connected to a second transmission bus 1211_2 provided on the lower surface of the integrally formed thin film 120, and the other end of the second signal connection device 140_2 is electrically connected to the second transfer device.

[0107] According to an embodiment of the present disclosure, each of the first signal connection device and the second signal connection device respectively includes a metal elastic column 141, an insulating column 142, and an insulating cover 143 provided above the metal elastic column 141 and the insulating column 142 (see the example of Figure 8 ). The metal elastic column 141 is disposed between the integrally formed thin film 120 and the adapter board 150. One end of the metal elastic column 141 of the first signal connection device 140_1 is electrically connected to the first transmission bus 1211_1, and the other end of the metal elastic column 141 of the first signal connection device 140_1 is electrically connected to the first transfer device. One end of the metal elastic column 141 of the second signal connection device 140_2 is electrically connected to the second transmission bus 1211_2, and the other end of the metal elastic column 141 of the second signal connection device 140_2 is electrically connected to the second transfer device. The insulating column 142 surrounds the metal elastic column 141 and is disposed between the metal elastic column 141 and the integrally formed lower metal reflector 130. The insulating cover 143 is embedded in the lower surface of the integrally formed upper metal reflector 110, and the projection of the insulating cover 143 on the upper surface of the lower metal reflector 130 covers the projection of the metal elastic column 141 on the upper surface of the lower metal reflector 130.

[0108] According to an embodiment of the present disclosure, the first transfer device and the second transfer device respectively include a first microstrip line 151 provided on the upper surface of the adapter board 150, and a second microstrip line 152 provided on the lower surface of the adapter board 150 (see Figure 9For example). The first microstrip line 151 and the second microstrip line 152 are electrically connected via a metal via passing through the adapter board 150, and the first signal connection device 140_1 is electrically connected to the first microstrip line 151 of the first adapter device, and the second signal connection device 140_2 is electrically connected to the first microstrip line 151 of the second adapter device.

[0109] According to an embodiment of the present disclosure, as Figure 13 shown, the antenna array further includes a parasitic patch board 160 disposed above the antenna 100. The parasitic patch board 160 includes a dielectric board, and a plurality of first parasitic patches 161 formed on the upper surface of the dielectric board and a plurality of second parasitic patches 162 formed on the lower surface of the dielectric board (see Figure 11 for example). Each of the plurality of first parasitic patches 161 corresponds to the position and shape of the antenna 100 of each antenna unit among the plurality of antenna units, and each of the plurality of second parasitic patches 162 corresponds to the position and shape of the antenna 100 of each antenna unit among the plurality of antenna units.

[0110] Figure 14A shows the standing wave ratio of the antenna array according to an embodiment of the present disclosure, Figure 14B shows the port isolation of the antenna array according to an embodiment of the present disclosure, Figure 14C shows the gain of the antenna array according to an embodiment of the present disclosure.

[0111] Figure 14A shows the standing wave ratio of two ports of the antenna array. As Figure 14A shown, the standing wave ratios of the two ports of the antenna array are both less than 1.55, having good performance. Figure 14B shows the isolation between two ports of the antenna array. As Figure 14B shown, the isolation between the two ports of the antenna array is greater than 25 dB. Compared with the isolation of the antenna unit, it is increased by at least 6.6 dB (see Figure 12B ), and the beneficial effect of the air stripline proposed in the present disclosure on the isolation can be seen. Figure 14C shows the gain result of the 1×4 antenna array. As Figure 14C shown, compared with the gain of the antenna unit, it is increased by 5.7 dBi (see Figure 12C the solid line shown), and it can be seen that the antenna array according to the embodiment of the present disclosure has a high gain, ensuring excellent signal transmission and reception performance.

[0112] The present disclosure has disclosed exemplary embodiments, and although specific terms are employed, they are used only and should be construed only as general illustrative meanings and not for the purpose of limitation. In some instances, it will be apparent to those skilled in the art that, unless otherwise expressly stated, features, characteristics, and / or elements described in connection with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments. Accordingly, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the present disclosure as set forth by the appended claims.

Claims

1. An antenna unit, comprising: An antenna, an upper metal reflector, a lower metal reflector, and a film disposed between the upper metal reflector and the lower metal reflector, wherein an opening is provided in the upper metal reflector, the antenna is provided in the opening and on the upper surface of the film, and the upper surface of the antenna is located at a higher level than the upper surface of the upper metal reflector, A transmission bus and a transmission branch line are arranged on the lower surface of the film, wherein the transmission bus and the transmission branch line are formed in one piece, and the transmission branch line is used for coupling and feeding power to the antenna. A first groove is arranged on the lower surface of the upper metal reflective plate, and a second groove is arranged on the upper surface of the lower metal reflective plate. The first groove and the second groove form a groove cavity, and the transmission bus is arranged in the groove cavity.

2. The antenna unit according to claim 1, wherein: The antenna is a metal patch antenna and includes a radiator and a plurality of metal support blocks arranged on the lower surface of the radiator. The transmission branch line couples and feeds the metal patch antenna via the plurality of metal support blocks.

3. The antenna unit according to claim 2, wherein: The heights of the plurality of metal support blocks are greater than the height of the upper metal reflective plate, and the openings in the upper metal reflective plate surround the plurality of metal support blocks.

4. The antenna unit according to claim 3, wherein: A third groove is arranged on the upper surface of the upper metal reflective plate, and the third groove surrounds the opening.

5. The antenna unit according to claim 2, wherein: A fourth groove is provided on the upper surface of the lower metal reflective plate, and a boss is provided at the center of the fourth groove, and the height of the boss is the same as that of the lower metal reflective plate. The projection of the opening in the upper metal reflective plate on the upper surface of the lower metal reflective plate covers the fourth groove, and the projection of each of the plurality of metal support blocks on the upper surface of the lower metal reflective plate partially overlaps with the upper surface of the boss.

6. The antenna unit according to claim 2, wherein: An adhesive layer is disposed on the lower surfaces of the plurality of metal support blocks, and the metal patch antenna is disposed on the upper surface of the film via the adhesive layer.

7. The antenna unit according to claim 2, wherein: A positioning protrusion is provided on the lower surface of at least one metal support block among the plurality of metal support blocks.

8. The antenna unit according to claim 1, wherein: The film includes one of the following: a polyphenylene ether PPO film, a polyetherimide PEI film and a polyester PET film, and the transmission bus line and the transmission branch line are formed on the lower surface of the film by a conductive silver paste screen printing process.

9. The antenna unit according to claim 8, wherein: In the film, a plurality of metal vias are arranged around the transmission bus.

10. The antenna unit according to claim 1, further comprising: Signal connection device and adapter board, The adapter plate is arranged below the lower metal reflector plate, and an adapter device is arranged in the adapter plate. The signal connection device vertically passes through the lower metal reflective plate, one end of the signal connection device is electrically connected to the transmission bus arranged on the lower surface of the film, and the other end of the signal connection device is electrically connected to the switching device.

11. The antenna unit according to claim 10, wherein: The signal connection device includes a metal elastic column, an insulating column, and an insulating cover arranged above the metal elastic column and the insulating column. The metal elastic column is arranged between the film and the adapter plate, one end of the metal elastic column is electrically connected to the transmission bus, and the other end of the metal elastic column is electrically connected to the adapter. The insulating column surrounds the metal elastic column and is arranged between the metal elastic column and the lower metal reflective plate. The insulating cover is embedded in the lower surface of the upper metal reflective plate, and the projection of the insulating cover on the upper surface of the lower metal reflective plate covers the projection of the metal elastic column on the upper surface of the lower metal reflective plate.

12. The antenna unit according to claim 10, wherein: The adapter device includes a first microstrip line arranged on the upper surface of the adapter plate, and a second microstrip line arranged on the lower surface of the adapter plate, The first microstrip line is electrically connected to the second microstrip line via a metal via that passes through the adapter board, and the other end of the signal connection device is electrically connected to the first microstrip line.

13. The antenna unit according to any one of claims 1 to 12, further comprising a parasitic patch plate arranged above the antenna, in, The parasitic patch plate includes a dielectric plate, a first parasitic patch formed on an upper surface of the dielectric plate, and a second parasitic patch formed on a lower surface of the dielectric plate. The first parasitic patch corresponds to the position and shape of the antenna, and the second parasitic patch corresponds to the position and shape of the antenna.

14. An antenna array, comprising a plurality of antenna elements arranged in an array, wherein: Each of the plurality of antenna units is the antenna unit according to any one of claims 1 to 9.

15. The antenna array according to claim 14, wherein: The upper metal reflectors of the plurality of antenna units are formed in one piece, the lower metal reflectors of the plurality of antenna units are formed in one piece, and the thin films of the plurality of antenna units are formed in one piece. The transmission branch lines corresponding to each of the plurality of antenna units are formed on the lower surface of the integrally formed film, respectively, and the transmission bus connects the transmission branch lines corresponding to each of the plurality of antenna units together.

16. The antenna array according to claim 15, wherein: The transmission branch corresponding to each of the plurality of antenna units includes a first transmission branch and a second transmission branch electrically separated from each other, and the transmission bus includes a first transmission bus and a second transmission bus electrically separated from each other, The first transmission bus connects the first transmission branch corresponding to each of the plurality of antenna units. The second transmission bus connects the second transmission branches corresponding to each of the plurality of antenna units.

17. The antenna array according to claim 16, further comprising: A first signal connection device, a second signal connection device and a transfer board, The adapter plate is arranged below the integrally formed lower metal reflector plate, and a first adapter device and a second adapter device are arranged in the adapter plate. The first signal connection device and the second signal connection device respectively vertically pass through the integrally formed lower metal reflective plate, One end of the first signal connection device is electrically connected to the first transmission bus disposed on the lower surface of the integrally formed film, and the other end of the first signal connection device is electrically connected to the first switching device, One end of the second signal connection device is electrically connected to the second transmission bus disposed on the lower surface of the integrally formed film, and the other end of the second signal connection device is electrically connected to the second switching device.

18. The antenna array according to claim 17, wherein: Each of the first signal connection device and the second signal connection device comprises a metal elastic column, an insulating column and an insulating cover disposed above the metal elastic column and the insulating column. The metal elastic column is arranged between the integrally formed film and the adapter board, one end of the metal elastic column of the first signal connection device is electrically connected to the first transmission bus, and the other end of the metal elastic column of the first signal connection device is electrically connected to the first adapter, one end of the metal elastic column of the second signal connection device is electrically connected to the second transmission bus, and the other end of the metal elastic column of the second signal connection device is electrically connected to the second adapter, The insulating column surrounds the metal elastic column and is arranged between the metal elastic column and the lower metal reflective plate formed integrally therewith. The insulating cover is embedded in the lower surface of the integrally formed upper metal reflector, and the projection of the insulating cover on the upper surface of the lower metal reflector covers the projection of the metal elastic column on the upper surface of the lower metal reflector.

19. The antenna array according to claim 17, wherein: The first adapter and the second adapter respectively include a first microstrip line arranged on the upper surface of the adapter plate, and a second microstrip line arranged on the lower surface of the adapter plate. The first microstrip line is electrically connected to the second microstrip line via a metal via passing through the adapter board, and the other end of the first signal connection device is electrically connected to the first microstrip line of the first adapter, and the other end of the second signal connection device is electrically connected to the first microstrip line of the second adapter.

20. The antenna array according to any one of claims 14 to 19, further comprising a parasitic patch plate arranged above the antenna, in, The parasitic patch plate includes a dielectric plate, a plurality of first parasitic patches formed on an upper surface of the dielectric plate, and a plurality of second parasitic patches formed on a lower surface of the dielectric plate. Each of the plurality of first parasitic patches corresponds to the position and shape of the antenna of each of the plurality of antenna units, and each of the plurality of second parasitic patches corresponds to the position and shape of the antenna of each of the plurality of antenna units.

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