Frequency selective surface structure, antenna system, and base station

Abstract

The present application provides a frequency selective surface structure, an antenna system, and a base station. The frequency selective surface structure comprises a frequency selective surface, a feed network, and a phase shifter. The frequency selective surface comprises a metal layer, the phase shifter is electrically connected to the feed network, and the phase shifter and the feed network are integrated into the metal layer of the frequency selective surface. When the phase shifter does not obstruct an antenna beam, the frequency selective surface structure may reduce transmission loss, and both coverage range and transmission quality of an antenna signal may be considered, solving the problem of difficult layout of a phase shifter in a multi-band integrated antenna system.

Description

Frequency selective surface structures, antenna systems, and base stations

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 31, 2023, with application number: 202310962161.8 and application name: "Frequency Selective Surface Structure, Antenna System and Base Station", all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a frequency selective surface structure, an antenna system and a base station. Background Art

[0003] Base station antennas are the foundation of current mobile communications and play a crucial role in them. To meet the growing demand for mobile communication speeds and bandwidth, higher-speed, higher-capacity communication systems are needed. As base station antenna systems evolve from fourth-generation (4G) to fifth-generation (5G) mobile communication technology, a key technology currently lies in providing operators with multi-band integrated antenna systems.

[0004] In existing multi-band integrated antenna systems, antennas of multiple frequency bands are stacked, and each layer of antennas is equipped with a corresponding feed network. Because multiple antennas are stacked on top of each other in the antenna system, the signals between antennas of different frequency bands interfere with each other, resulting in distortion of the antenna radiation pattern. To reduce the mutual influence between antennas of different frequency bands and obtain the desired antenna waveform, phase shifters, frequency selective surfaces, and other structures are usually installed in the multi-band integrated antenna system. By changing the passband and band-stop characteristics of the feed network and phase modulation, flexible beam scanning is achieved, reducing the coupling effect between antennas of different frequency bands, thereby obtaining the ideal antenna waveform. At the same time, it can also increase the coverage range of the base station antenna and adapt to the installation layout requirements of multiple scenarios.

[0005] However, with high antenna density, phase shifter placement becomes a major challenge. Because phase shifters need to be connected to the antenna's feed network, when multiple antennas are stacked, some phase shifters must also be placed between the stacked antennas along with the antenna feed network. Due to their size, phase shifters can block some antenna beams, affecting antenna signal coverage. This can result in slow internet speeds or signal blind spots in certain areas.

[0006] To prevent phase shifters from obstructing antenna waveforms, some operators have improved the layout of antenna systems and phase shifters, staggering the phase shifters and affected antennas through partitioned layouts. While this method can improve the phenomenon of phase shifters obstructing antenna waveforms to a certain extent, it can also lead to problems such as increased antenna size and a less compact layout. This also lengthens the transmission line structure between the phase shifter and the antenna system's radiator, increasing losses over long-distance transmission.

[0007] Therefore, the phase shifter layout of the multi-band integrated antenna system in the prior art is difficult, and will result in high transmission loss when the phase shifter does not block the antenna beam, making it impossible to balance the coverage range and transmission quality of the antenna signal.

[0008] Summary of the Invention

[0009] The frequency selective surface structure, antenna system and base station provided in the embodiments of the present application solve the difficulties in the phase shifter layout of the multi-band integrated antenna system in the prior art. When the phase shifter does not block the antenna waveform, it will cause high transmission loss and cannot take into account the coverage range and transmission quality of the antenna signal.

[0010] The present invention provides a frequency selective surface structure including a frequency selective surface, a feed network, and a phase shifter. The frequency selective surface includes a metal layer, the phase shifter is electrically connected to the feed network, and the phase shifter and the feed network are integrated into the metal layer of the frequency selective surface.

[0011] The frequency selective surface structure provided in the embodiments of the present application can be applied to antenna systems, where the phase shifter and feed network are integrated on the metal layer of the frequency selective surface. The metal layer of the frequency selective surface has spatial filter characteristics. By changing the antenna's wave transmission characteristics through the design of the metal layer, the requirements for antenna electromagnetic wave transmission control can be met. The frequency selective surface can be designed to have a completely transparent effect on part of the antenna, that is, a structure that is electromagnetically transparent to part of the antenna. The phase shifter and feed network are integrated on the metal layer, and the metal layer has a stealth effect on the phase shifter. If a miniaturized phase shifter is used, the phase shifter can be completely hidden on one side of the metal layer, and the metal layer also has the same stealth effect on the transmission line structure in the feed network. The feed network and phase shifter will not affect the filtering characteristics of the frequency selective surface structure. In this way, the frequency selective surface structure composed of the frequency selective surface, phase shifter and feed network can still produce an electromagnetically transparent effect on part of the antenna, thereby not blocking the beam of this part of the antenna. The other antenna can be placed on the other side of the FSS structure, radiating its electromagnetic waves away from the FSS structure without obstructing the beam of this antenna. Furthermore, the compact integration of the phase shifter and the feed network shortens the transmission line structure in the feed network, reducing transmission losses.

[0012] Therefore, the frequency selective surface structure provided in this application can reduce transmission loss without blocking the antenna beam by the phase shifter, and can take into account both the coverage range and transmission quality of the antenna signal, thus solving the problem of difficult phase shifter layout in a multi-band integrated antenna system.

[0013] In some embodiments, the metal layer has a metal area, and a hollow area is formed around the metal area; the feeding network and the phase shifter are integrated in the metal area, and the projections of the feeding network and the phase shifter onto the metal layer along a first direction are entirely located within the metal area; wherein the first direction is perpendicular to the plane where the metal layer is located.

[0014] With the above solution, the phase shifter and feed network are integrated on the metal area and supported by the metal area. The phase shifter and feed network do not overlap with the hollow area in the first direction to prevent the phase shifter and feed network from blocking the antenna beam.

[0015] In some embodiments, the metal layer includes a metal grid, the metal grid forming a metal region, and the spaces enclosed by each grid in the metal grid collectively forming a hollow region. The grid-shaped frequency selective surface has a relatively regular shape and is easy to process, and the grid lines in the metal grid facilitate wiring.

[0016] In some embodiments, the metal layer includes a metal grid and multiple metal patches, with the multiple metal patches correspondingly arranged within the multiple grids of the metal grid. The metal grid and metal patches constitute the metal area, and the gaps between the metal patches and the metal grid constitute the hollow area. The grid-shaped frequency-selective surface has a relatively regular shape and is easy to process. The grid lines of the metal grid facilitate wiring, and the metal patches can also be used to layout feed networks and phase shifters.

[0017] In some embodiments, the frequency selective surface includes multiple metal layers stacked and arranged parallel to each other in a first direction, wherein the feed network and the phase shifter are integrated on at least one of the multiple metal layers. The first direction is perpendicular to the plane of the metal layers.

[0018] In some embodiments, the multiple metal layers include two metal layers, each of the two metal layers includes two surfaces opposite to each other in a first direction, and the feeding network and the phase shifter are integrated on any one or more surfaces of the two metal layers.

[0019] In some embodiments, the feed network includes multiple transmission line structures, and the frequency selective surface structure includes a phase shifter electrically connected to all of the multiple transmission line structures. Alternatively, the frequency selective surface structure includes multiple phase shifters, each of the multiple phase shifters electrically connected to a portion of the multiple transmission line structures.

[0020] In some embodiments, a phase shifter includes an outer conductor, a fixed dielectric, a sliding dielectric, and at least one signal line winding. A cavity is formed within the outer conductor, and the fixed dielectric, sliding dielectric, and at least one signal line winding are all housed within the cavity. The fixed dielectric is fixedly connected to the outer conductor, and the sliding dielectric is positioned between the fixed dielectric and the outer conductor and slidably connected to the fixed dielectric. Each signal line winding in the at least one signal line winding is wound and fixed around the fixed dielectric, and each signal line winding is positioned between the fixed dielectric and the sliding dielectric. The phase shifter is electrically connected to the feed network via each signal line winding. At least a portion of the outer conductor is configured as a planar structure, and the phase shifter is fixedly connected to the metal layer via the planar structure.

[0021] In this solution, the signal windings are fixed to a fixed medium, while the sliding medium covers and slides over the surface of the signal windings. Changing the position of the sliding medium changes the extent of each signal winding's coverage. The uncovered portion of the signal winding is exposed to air, changing the electrical length of the signal windings and, consequently, the phase shift of the radiator corresponding to each signal winding.

[0022] In some embodiments, at least one signal line winding comprises multiple signal line windings, the multiple signal line windings forming at least one group of signal line windings, and each group of signal line windings within the at least one group of signal line windings comprises at least one signal line winding. Within each group of signal line windings, at least one signal line winding comprises one signal line winding or at least two signal line windings, one end of one signal line winding or one end of at least two signal line windings connected together constitutes an input end of a phase shifter, and the other end of at least one signal line winding constitutes at least one output end of the phase shifter, each of the at least one output end being electrically connected to a corresponding transmission line structure. A single phase shifter can perform phase modulation on multiple radiators.

[0023] In some embodiments, the plurality of transmission line structures include at least one first transmission line structure, each of the at least one first transmission line structure includes an outer conductor and a core, the core is enclosed in a cavity inside the outer conductor, and a gap is provided between the core and the outer conductor.

[0024] At least a portion of the outer conductor is configured as a planar structure, and the first transmission line structure is fixedly connected to the metal layer via the planar structure.

[0025] In the above solution, the medium between the outer conductor and the core is air. The core is suspended in the cavity of the outer conductor and is surrounded by the air in the cavity. The dielectric constant of air is relatively small, which can reduce the transmission loss of the first transmission line structure.

[0026] In some embodiments, the first transmission line structure further includes a plurality of supports disposed between the outer conductor and the core, the plurality of supports being spaced apart along an extension direction of the core, and the core being fixedly connected to the outer conductor via the plurality of supports.

[0027] In some embodiments, the first transmission line structure includes a plurality of cores spaced apart from each other, and the outer conductor has a cavity, with the plurality of cores located within the cavity. Alternatively, the outer conductor has a plurality of interconnected cavities, with the plurality of cavities corresponding one-to-one to the plurality of cores, with each core located within a corresponding cavity.

[0028] In some embodiments, the plurality of transmission line structures include at least one second transmission line structure, each of the at least one second transmission line structure is configured as a power divider, the power divider including a conductive shell and a battery cell, the battery cell being enclosed in a cavity within the conductive shell, with a gap between the battery cell and the conductive shell; the battery cell having an input end and a plurality of output ends, the input end of the battery cell being electrically connected to the phase shifter;

[0029] At least a portion of the conductive housing is configured as a planar structure, and the second transmission line structure is fixedly connected to the metal layer via the planar structure.

[0030] With the above solution, the battery cell is suspended in the conductive shell and surrounded by air to reduce the transmission loss of the power divider.

[0031] In some embodiments, when the phase shifter includes an outer conductor, the outer conductor of the phase shifter is electrically connected to the metal layer. When the feed network includes multiple transmission line structures, the multiple transmission line structures include at least one first transmission line structure, and each of the at least one first transmission line structure includes an outer conductor, the outer conductor of each first transmission line structure is electrically connected to the metal layer. When the feed network includes multiple transmission line structures, the multiple transmission line structures include at least one first transmission line structure, and each of the at least one second transmission line structure includes a conductive housing, the conductive housing of each second transmission line structure is electrically connected to the metal layer.

[0032] The electrical connection mode is any one of the following: coupling connection, DC connection or segmented DC connection.

[0033] In some embodiments, the frequency selective surface structure further includes a dielectric layer, the metal layer is mounted on the dielectric layer, and the dielectric layer can be used to support the metal layer.

[0034] An embodiment of the present application also provides an antenna system, including a floor, a plurality of antennas stacked in a first direction, and a plurality of feeding networks for feeding the plurality of antennas, wherein the floor is arranged on one side of the plurality of antennas in the first direction, and the antenna system further includes the frequency selective surface structure provided in any of the above embodiments; the frequency selective surface structure is arranged between adjacent antennas stacked in the plurality of antennas, and the feeding network of the frequency selective surface structure constitutes a feeding network for at least one antenna of the adjacent stacked antennas that is away from the floor.

[0035] The antenna system provided by embodiments of the present application reduces transmission loss without obstructing the antenna beam by the phase shifter, thereby balancing antenna signal coverage and transmission quality. Furthermore, the system is compact, low-cost, and easy to assemble. In some embodiments, the multiple antennas include a first antenna and a second antenna stacked in a first direction, a floor disposed on a side of the second antenna facing away from the first antenna, and a frequency selective surface structure disposed between the first and second antennas.

[0036] The first antenna and the second antenna both include multiple radiators distributed in an array. At least part of the feeding network of the frequency selective surface structure constitutes the feeding network of the first antenna and is electrically connected to the multiple radiators of the first antenna to feed the multiple radiators of the first antenna.

[0037] In some embodiments, when the frequency selective surface structure includes two metal layers, the feeding network and the phase shifter of the frequency selective surface structure are integrated on a metal layer farther from the second antenna among the two metal layers.

[0038] In some embodiments, the multiple radiators of the first antenna form at least one column of radiators, and each column of the at least one radiator includes at least two radiators spaced apart along the second direction. When the feeding network of the frequency selective surface structure includes multiple transmission line structures, each column of radiators has transmission line structures symmetrically distributed on both sides of the third direction, and each column of radiators has phase shifters symmetrically distributed on both sides of the third direction. The first direction, the second direction, and the third direction are mutually perpendicular.

[0039] With the above solution, when the first antenna is a dual-polarized antenna, the phase shifter can perform phase modulation on the two polarization directions of the first antenna respectively.

[0040] In some embodiments, the multiple antennas further include a third antenna disposed on a side of the frequency selective surface structure away from the floor. The third antenna includes a plurality of radiators distributed in an array, with the plurality of radiators of the third antenna alternating with the plurality of radiators of the first antenna in a plane perpendicular to the first direction. At least a portion of the feed network of the frequency selective surface structure constitutes the feed network of the third antenna and is electrically connected to the plurality of radiators of the third antenna to feed the plurality of radiators of the third antenna.

[0041] In some embodiments, the multiple radiators of the third antenna form at least one column of radiators, and each column of the at least one column of radiators includes at least two radiators spaced apart along the second direction. When the feed network of the frequency selective surface structure includes multiple transmission line structures, each column of radiators has transmission line structures symmetrically distributed on both sides of the third direction, and each column of radiators has phase shifters symmetrically distributed on both sides of the third direction; wherein the first direction, the second direction, and the third direction are mutually perpendicular. When the third antenna is a dual-polarized antenna, the phase shifters can adjust the two polarization directions of the third antenna separately.

[0042] In some embodiments, when the frequency selective surface structure includes two metal layers, phase shifters and feed networks are integrated into both metal layers. The portion of the frequency selective surface's feed network that constitutes the first antenna's feed network is integrated into either of the two metal layers, and the portion of the frequency selective surface's feed network that constitutes the third antenna's feed network is integrated into the other of the two metal layers. The first and third feed networks are arranged in layers, facilitating wiring on different metal layers and effectively utilizing space.

[0043] In some embodiments, the antenna system is formed on a printed circuit board. The printed circuit board includes a metal structure and a dielectric structure, with at least a portion of the metal structure constituting a ground plane, a plurality of radiators of each of the plurality of antennas, and a metal layer of a frequency selective surface structure. When the frequency selective surface structure also includes a dielectric layer, at least a portion of the dielectric structure of the printed circuit board constitutes the dielectric layer of the frequency selective surface structure.

[0044] The present application also provides a base station, comprising the antenna system provided in any of the above embodiments and a radio frequency module connected to the antenna system. The base station has high overall integration, wide signal coverage, and few signal blind spots. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figures 1a-1b are schematic structural diagrams of antenna systems in some solutions;

[0046] Figures 2a-2b are schematic structural diagrams of antenna systems in other solutions;

[0047] FIG3 is a schematic diagram showing the working principle of a first embodiment of an antenna system according to an embodiment of the present application;

[0048] Figures 4a-4b-2 are schematic structural diagrams of a first embodiment of the antenna system according to one embodiment of the present application from one angle;

[0049] 5a-5c are schematic structural diagrams from another angle of the first embodiment of the antenna system according to the present application;

[0050] FIG6 is a schematic diagram showing the working principle of a second embodiment of the antenna system according to an embodiment of the present application;

[0051] FIG7 is a schematic structural diagram of a second embodiment of the antenna system according to an embodiment of the present application;

[0052] FIG8 is a schematic structural diagram of the second embodiment of the antenna system according to the present application from another angle;

[0053] FIG9 is a schematic structural diagram of a frequency selective surface structure according to an embodiment of the present application;

[0054] FIG10 a is a schematic structural diagram of another embodiment of a frequency selective surface structure according to an embodiment of the present application;

[0055] FIG10b is a schematic diagram of the local connection structure of part A in FIG10a;

[0056] FIG11a is a schematic structural diagram of a phase shifter in a frequency selective surface structure according to an embodiment of the present application;

[0057] FIG11 b is a schematic structural diagram of another embodiment of a phase shifter in a frequency selective surface structure according to an embodiment of the present application;

[0058] 12a-12c are schematic diagrams showing connections between a phase shifter and a metal layer in a frequency selective surface structure according to an embodiment of the present application;

[0059] FIG13a-FIG13b-2 are schematic structural diagrams of a first embodiment of a first transmission line structure in a frequency selective surface structure according to an embodiment of the present application, wherein FIG13b-1 is a cross-sectional view taken along the BB direction in FIG13a, and FIG13b-2 is a cross-sectional view taken along the CC direction in FIG13a;

[0060] FIG14a is a schematic structural diagram of a second embodiment of the first transmission line structure in the frequency selective surface structure according to an embodiment of the present application;

[0061] FIG14 b is a schematic structural diagram of a third embodiment of the first transmission line structure in the frequency selective surface structure according to an embodiment of the present application;

[0062] 15a to 15b-2 are schematic structural diagrams of a fourth embodiment of the first transmission line structure in the frequency selective surface structure according to an embodiment of the present application, wherein FIG15b-1 is a cross-sectional view taken along the DD direction in FIG15a ; FIG15b-2 is a cross-sectional view taken along the EE direction in FIG15a ;

[0063] 16a-16b are schematic structural diagrams of a fifth embodiment of the first transmission line structure in the frequency selective surface structure according to an embodiment of the present application, wherein FIG16b is a cross-sectional view taken along the FF direction in FIG16a ;

[0064] FIG17 is a schematic structural diagram of a sixth embodiment of the first transmission line structure in the frequency selective surface structure according to an embodiment of the present application;

[0065] FIG18 is a structural diagram of a seventh embodiment of the first transmission line structure in the frequency selective surface structure according to an embodiment of the present application;

[0066] FIG19 is a schematic structural diagram of a power divider in a frequency selective surface structure according to an embodiment of the present application;

[0067] 20a-20c are schematic diagrams showing the connection between the transmission line structure and the metal layer in the frequency selective surface structure according to an embodiment of the present application;

[0068] Figure 21 is a structural diagram of the base station according to an embodiment of the present application.

[0069] Description of reference numerals:

[0070] Some solutions:

[0071] 100': antenna system; 1': first antenna; 10': radiator; 2': second antenna; 20': radiator;

[0072] 3': floor; 4': phase shifter; 5': feed network; 6': frequency selective surface;

[0073] z': first direction; y': second direction; x': third direction.

[0074] Other options:

[0075] 100″: antenna system; 1″: first antenna; 10″: radiator; 2″: second antenna; 20″: radiator;

[0076] 3″: floor; 4″: phase shifter; 5″: feed network; 51″: transmission line structure; 6″: frequency selective surface;

[0077] z″: first direction; y″: second direction; x″: third direction.

[0078] Examples of this application:

[0079] 100: antenna system;

[0080] 1: first antenna; 10: radiator; 11: first feeding network;

[0081] 2: second antenna; 20: radiator; 21: second feeding network;

[0082] 3: third antenna; 30: radiator; 31: third feeding network; 4: floor;

[0083] 200: frequency selective surface structure;

[0084] 5: frequency selective surface; 51: metal layer; 511: first metal layer; 512: second metal layer;

[0085] 513: Metal area; 5131: Metal grille; 5132: Metal patch; 514: Hollow area;

[0086] 6: phase shifter; 61: input end; 62: output end; 63: outer conductor; 63a: bottom;

[0087] 64: fixed medium; 65: sliding medium; 66: signal line winding;

[0088] 7: Feed network; 71: Transmission line structure; 711: First transmission line structure; 7110: Cavity;

[0089] 7111: outer conductor; 7111a: bottom; 7112: core; 7113: gap; 7114: support;

[0090] 712: power divider; 7121: conductive shell; 7122: battery cell; 7122a: input terminal; 7122b: output terminal;

[0091] 7123: gap; 72: feeder;

[0092] 300: base station; 8: radio frequency module;

[0093] z: first direction; y: second direction; x: third direction. DETAILED DESCRIPTION

[0094] The following specific embodiments illustrate the implementation of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Although the description of the present application will be introduced in conjunction with some embodiments, this does not mean that the features of this application are limited to the implementation. On the contrary, the purpose of introducing the application in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present application. In order to provide an in-depth understanding of the present application, the following description will contain many specific details. The present application can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present application, some specific details will be omitted in the description. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other unless there is a conflict.

[0095] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0096] The following explains the terms that may appear in the embodiments of the present application.

[0097] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0098] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0099] Coupling: can be understood as direct coupling and / or indirect coupling, and "coupling connection" can be understood as direct coupling connection and / or indirect coupling connection. Direct coupling can also be referred to as "electrical connection", which is understood as the physical contact and electrical conduction between components; it can also be understood as the form in which different components in the circuit structure are connected through physical lines such as printed circuit board (PCB) copper foil or wires that can transmit electrical signals; "indirect coupling" can be understood as two conductors being electrically conductive in an airless / non-contact manner. In one embodiment, indirect coupling can also be referred to as capacitive coupling, for example, signal transmission is achieved by forming an equivalent capacitance through coupling between the gap between two conductive parts.

[0100] Ground / Floor: This generally refers to at least a portion of any ground layer, ground plate, or ground metal layer within a communication device (such as a base station), or at least a portion of any combination of any of the above ground layers, ground plates, or grounding components. "Ground / Floor" can be used to ground components within the communication device. In one embodiment, the "ground / floor" may include any one or more of the following: the ground layer of the communication device's circuit board, the ground plate formed by the communication device's midframe, the ground metal layer formed by the metal film below the screen, the battery's conductive ground layer, and conductive or metal parts electrically connected to the above ground layer / ground plate / metal layer. In one embodiment, the circuit board may be a printed circuit board (PCB), such as an 8-layer, 10-layer, or 12-to-14-layer board having 8, 10, 12, 13, or 14 layers of conductive material, or an element separated and electrically insulated by a dielectric or insulating layer such as fiberglass, polymer, or the like. In one embodiment, the circuit board includes a dielectric substrate, a ground layer, and a trace layer, with the trace layer and the ground layer being electrically connected via vias. In one embodiment, components such as a display, touch screen, input buttons, transmitter, processor, memory, battery, charging circuit, and system-on-chip (SoC) structures can be mounted on or connected to a circuit board, or electrically connected to a trace layer and / or ground layer in the circuit board. For example, a radio frequency source can be located on a trace layer.

[0101] Any of the above-mentioned grounding layers, grounding plates, or grounding metal layers are made of a conductive material. In one embodiment, the conductive material can be any of the following: copper, aluminum, stainless steel, brass, and alloys thereof, copper foil on an insulating substrate, aluminum foil on an insulating substrate, gold foil on an insulating substrate, silver-plated copper, silver-plated copper foil on an insulating substrate, silver foil and tin-plated copper on an insulating substrate, cloth impregnated with graphite powder, a graphite-coated substrate, a copper-plated substrate, a brass-plated substrate, and an aluminum-plated substrate. Those skilled in the art will appreciate that the grounding layer / grounding plate / grounding metal layer can also be made of other conductive materials.

[0102] Electrical length: Electrical length can be expressed as the ratio of the physical length (i.e., mechanical length or geometric length) multiplied by the transmission time of an electrical or electromagnetic signal in a medium to the time required for the signal to travel the same distance as the physical length of the medium in free space. The electrical length can satisfy the following formula:

[0103] Where L is the physical length, a is the propagation time of the electrical or electromagnetic signal in the medium, and b is the propagation time in free space.

[0104] Alternatively, electrical length can also refer to the ratio of physical length (i.e., mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave. The electrical length can satisfy the following formula:

[0105] Where L is the physical length and λ is the wavelength of the electromagnetic wave.

[0106] Dielectric constant: the main parameter reflecting the dielectric properties or polarization properties of the dielectric under the action of electrostatic field.

[0107] Transmittance: The ratio of the amount of electromagnetic waves that penetrate a medium, such as glass, to the amount they can penetrate. Higher transmittance means more electromagnetic waves pass through the medium, while lower transmittance means fewer electromagnetic waves pass through.

[0108] Reflectivity: The ratio of the signal received by the antenna in the reverse direction to the forward signal, which is the ratio of the reflected wave to the incident wave.

[0109] Antenna pattern: also known as radiation pattern. It is a graph showing how the relative field strength (normalized modulus) of the antenna's radiation field changes with direction at a certain distance from the antenna.

[0110] The limitations of collinearity, coaxiality, coplanarity, symmetry (e.g., axisymmetry or central symmetry), parallelism, perpendicularity, and identity (e.g., same length, same width, etc.) mentioned in the embodiments of this application are based on current technological standards and are not strictly mathematical definitions. A predetermined angle (e.g., ±5°, ±10°) may exist between two parallel or perpendicular structures.

[0111] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0112] Base station antennas are the foundation of current mobile communications and play a crucial role in them. To meet the growing demand for mobile communication speeds and bandwidth, higher-speed, higher-capacity communication systems are needed. As base station antenna systems evolve from fourth-generation (4G) to fifth-generation (5G) mobile communication technology, a key technology currently lies in providing operators with multi-band integrated antenna systems.

[0113] In existing multi-band integrated antenna systems, antennas of multiple frequency bands are stacked, and each layer of antennas is equipped with a corresponding feed network. Because multiple antennas are stacked on top of each other in the antenna system, the signals between antennas of different frequency bands interfere with each other, resulting in distortion of the antenna radiation pattern. In order to reduce the mutual influence between antennas of different frequency bands and obtain the required antenna waveform, phase shifters, frequency selective surfaces and other structures are usually installed in the multi-band integrated antenna system. By changing the passband and band-stop characteristics of the feed network and phase modulation, flexible beam scanning is achieved, reducing the coupling effect between antennas of different frequency bands, thereby obtaining the ideal antenna waveform. At the same time, it can also increase the coverage range of the base station antenna and adapt to the installation layout requirements of multiple scenarios.

[0114] However, when multi-band antenna arrays are densely packed, phase shifter placement becomes a major challenge. Because phase shifters need to be connected to the antenna's feed network, when multiple antennas are stacked, some phase shifters must also be placed between the stacked antennas along with the antenna feed network. Due to their size, phase shifters can block some antenna beams, affecting signal coverage. This can result in slow internet speeds or signal blind spots in certain areas.

[0115] To prevent phase shifters from obstructing antenna waveforms, some operators have improved the layout of antenna systems and phase shifters, staggering the phase shifters and affected antennas through various methods, such as partitioning. While this approach can mitigate the problem of phase shifters obstructing antenna beams to a certain extent, it also results in increased antenna size and a less compact layout. This also lengthens the transmission line structure between the phase shifters and the feed network, increasing transmission losses over long distances. Therefore, conventional multi-band integrated antenna systems face difficulties in phase shifter layout, resulting in high transmission losses even when the phase shifters do not obstruct the antenna beam. This makes it difficult to balance antenna signal coverage and transmission quality.

[0116] The following uses two antenna systems as examples to specifically illustrate the layout of phase shifters in antenna systems.

[0117] Please refer to FIG. 1 a - FIG. 1 b , which are schematic structural diagrams of antenna systems in some solutions.

[0118] As shown in Figures 1a-1b, antenna system 100' includes a first antenna 1' and a second antenna 2' stacked in a first direction z'. A floor 3' is placed below second antenna 2', and first antenna 1' is located above second antenna 2'. A frequency selective surface 6', incorporating a feed network 5' for first antenna 1', and a phase shifter 4' connected to feed network 5' are located between the first and second antennas 1' and 2'. Each of the first and second antennas 1' and 2' includes multiple radiators, each of which forms multiple columns of radiators. Each column includes at least two radiators spaced apart along a second direction y', and the multiple columns of radiators are arranged along a third direction x'. Electromagnetic waves from second antenna 2' are radiated generally toward the side of first antenna 1' in the first direction z'. To reduce obstruction of the second antenna 2''s beam by the phase shifters 4', phase shifters 4' are placed on both sides of all radiators 10' of first antenna 1' in the third direction x', and are located outside of the frequency selective surface 6'. With this structure, when the electromagnetic waves from each radiator 20' in the second antenna 2' radiate vertically (along the first direction z' toward the side where the first antenna 1' is located), the phase shifter 4' will not block the beam of the second antenna 2'. However, when the radiator 20' of the second antenna 2' radiates in a direction at a certain angle to the first direction z', the phase shifter 4' will still block the beam of the second antenna 2', increasing the transmission loss of the second antenna 2' and affecting the coverage range of the antenna signal, resulting in slow network speeds in some areas and signal blind spots. This layout also increases the size of the antenna system in the third direction, affecting the competitiveness of base station antenna products.

[0119] Please refer to FIG. 2 a - FIG. 2 b , which are schematic structural diagrams of antenna systems in other solutions.

[0120] As shown in Figures 2a and 2b, the antenna system 100" includes a first antenna 1" and a second antenna 2" stacked in a first direction z", the second antenna 2" is connected to a floor 3", the first antenna 1" is located above the second antenna 2", and the feeding network 5" of the first antenna 1" is arranged between the first antenna 1" and the second antenna 2". The first antenna 1" and the second antenna 2" both include multiple radiators, and the multiple radiators of each antenna constitute multiple columns of radiators, each column of radiators includes at least two radiators spaced apart along the second direction y", and the multiple columns of radiators are arranged along the third direction x". The multiple radiators 20" of the second antenna 2" are concentrated in one area, and only a portion of the first antenna 1" and the second antenna 2" are stacked. In order to reduce the obstruction of the second antenna beam by the phase shifter 4", the phase shifter 4" is arranged at a position where the second antenna 2" is not set, so that the phase shifter 4" and the second antenna 2" are offset in the second direction y", and the two are not overlapped in the first direction z". At the same time, a frequency selective surface 6" is set directly above the second antenna 2". The frequency selective surface 6" is an electromagnetically transparent structure to the second antenna 2", and the electromagnetic waves radiated by the second antenna 2" can pass through the frequency selective surface 6". With this structure, the beam of the second antenna 6" will not be blocked by the phase shifter 4". However, since the phase shifter 4" needs to be used to control the phase of each radiator 10" in the first antenna 1", the phase shifter 4" is electrically connected to each radiator 10" of the first antenna 10" through a transmission line structure 51" (such as a cable, microstrip line, etc.). The phase shifter 4″ is arranged on the side of the frequency selective surface 6″ away from the radiator 10″ of the first antenna 1″, which will result in a longer length of the transmission line structure 51″ between the phase shifter 4″ and each radiator 10″ in the first antenna 1″, and a larger transmission loss. In particular, for the radiator 10″ located directly above the second antenna 2″, the distance between it and the phase shifter 4″ in the second direction y″ is longer, resulting in an increase in the length of the transmission line structure 51″ between the phase shifter 4″ and this part of the radiator 10″, and an increase in transmission loss. In addition, the transmission line structure 51″ is fixed on the frequency selective surface 6″, and its longer length also increases the number of manual solder joints, making assembly complicated. When the transmission line structure 51″ uses a microstrip line with lower loss, more RF boards are required, which increases the cost.

[0121] To solve the above problems, the present application provides an antenna system that integrates the phase shifter and the feeding network on the frequency selective surface to achieve the effect of phase shifter stealth. This can ensure that the phase shifter does not block the antenna beam while shortening the length of the transmission line structure in the feeding network and reducing transmission loss.

[0122] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: multi-band integrated antenna systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, universal mobile telecommunications systems (UMTS), world-wide interoperability for microwave access (WiMAX) communication systems, fifth generation (5G) systems or new radio (NR), device to device (D2D) systems, vehicle to everything (V2X) systems, etc.

[0123] The following describes the technical solutions adopted by the antenna system of the present application and the beneficial effects thereof by way of example, in combination with the structures of several multi-band antenna systems.

[0124] Please refer to Figures 3-5c, Figure 3 is a schematic diagram of the working principle of the first embodiment of the antenna system of the embodiment of the present application; Figures 4a-4b-2 are structural schematic diagrams of the first embodiment of the antenna system of the embodiment of the present application at one angle; Figures 5a-5c are structural schematic diagrams of the first embodiment of the antenna system of the embodiment of the present application at another angle.

[0125] As shown in Figures 3-5c, the antenna system 100 includes a floor 4, multiple antennas stacked in a first direction z, and multiple feed networks 7 for feeding the multiple antennas. The floor 4 is arranged on one side of the multiple antennas in the first direction z. The antennas are used to receive or transmit signals. Those skilled in the art will appreciate that the types of antennas are not limited and can be active antennas, passive antennas, single-polarization antennas, dual-polarization antennas, directional antennas, omnidirectional antennas, and the like. Active antennas are antennas that integrate modules such as a receiving antenna module, a low-noise amplifier module, and a power supply module. They require an additional power supply and may have multiple input and output ports. Their circuits are relatively complex. Passive antennas, on the other hand, are antennas without any active components and generally have only a single output port. They are simple in structure, low in cost, and easy to install. A dual-polarized antenna is an antenna that combines two mutually orthogonal polarization directions of +45° and -45°. It can operate in both transmit and receive duplex modes, saving the number of antennas required for a single directional base station. Using dual-polarized antennas in mobile communication networks can reduce interference and improve the quality of service across the entire network. Therefore, dual-polarized antennas are commonly used in mobile communications. Single polarization, which only has horizontal or vertical polarization, provides better coverage than dual-polarized antennas in open plains or mountainous areas. The antenna system 100 can include multiple types of antennas, including active antennas, passive antennas, single-polarized antennas, and dual-polarized antennas, and can be designed based on the actual application scenario.

[0126] Each antenna includes multiple radiators (also called radiating elements) that radiate or receive electromagnetic waves. The specific form of the radiator is not limited; for example, it can be composed of antenna elements. Antenna elements, referred to as elements, guide and amplify electromagnetic waves.

[0127] The floor 4 is also called a reflector, bottom plate, or antenna panel. It is used to reflect electromagnetic waves so that the electromagnetic waves of each antenna are concentrated and radiated in one direction. It can also be used to ground each antenna. The feeding network is also called a power distribution network. It is used to feed power to the antenna. Feeding can be to supply power or energy to the antenna. The function of the feeding network is to feed the signal to each radiator of the antenna according to a certain amplitude and phase, or to feed the signal received from each radiator to the signal processing unit of the base station according to a certain amplitude and phase. Each of the multiple antennas is provided with a corresponding feeding network. The feeding networks between different antennas can be independent or shared. For example, two antennas share one feeding network, etc. This application does not impose any restrictions on this.

[0128] Those skilled in the art will appreciate that the specific number of antennas in antenna system 100 is not limited, and may include, for example, two, three, four, or more antennas. In one embodiment, the multiple antennas include a first antenna 1 and a second antenna 2 arranged in a stacked manner. The first antenna 1 includes a plurality of radiators 10 distributed in an array, and the second antenna 2 includes a plurality of radiators 20 distributed in an array. The floor 4 is disposed on a side of the second antenna 2 facing away from the first antenna 1.

[0129] The specific number and arrangement of the radiators 10 of the first antenna 1 are not limited and can be designed based on the actual application scenario. In one embodiment, the multiple radiators 10 of the first antenna 1 form at least one column of radiators 10, each column of radiators 10 including at least two radiators 10 spaced apart along the second direction y, wherein the first direction z, the second direction y, and the third direction x are mutually perpendicular. Alternatively, the multiple radiators 10 of the first antenna 1 are arranged in a rectangular array, the second direction y can be the length of the rectangular array, and the third direction x can be the width of the rectangular array. The multiple radiators 10 arranged along the length of the rectangular array form a column of radiators 10, and at least one column of radiators 10 is arranged along the width of the rectangular array (for example, one, two, or three columns, etc., without limitation; only one column is shown in the figure for illustration), and the number of radiators 10 in a column of radiators 10 is at least two (for example, two, three, or four columns, without limitation; only a few are shown in the figure for illustration). Likewise, the specific number and arrangement of the radiators 20 of the second antenna 2 are not limited, and they may be arranged in a rectangular array or an array of other shapes, which will not be described in detail here.

[0130] Furthermore, antenna system 100 also includes a first feeding network 11 that feeds first antenna 1, and a second feeding network 21 that feeds second antenna 2. First feeding network 11 is located between first antenna 1 and second antenna 2 in a first direction z and is electrically connected to each radiator 10 of first antenna 1. Second feeding network 21 is electrically connected to each radiator 20 of second antenna 2 and can be located anywhere on the side of first feeding network 11 away from first antenna 1, such as integrated into floor 4, although this application is not limited thereto. In one embodiment, second feeding network 21 is also electrically connected to floor 4 for grounding.

[0131] It should be noted that in the perspectives of Figures 4a-5c, the antenna system 100 is placed horizontally, with the first antenna 1 and the second antenna 2 both located above the floor 4. However, in actual application scenarios, the placement of the antenna system 100 is not limited and can be either horizontal (with the floor 4 parallel to the horizontal ground) or vertical (with the floor 4 perpendicular to the horizontal ground). In an example scenario, the antenna system 100 is placed vertically, with the floor 4 perpendicular to the horizontal ground. This allows the radiators of the first antenna 1 and the second antenna 2 to be arranged in greater numbers in the vertical direction (i.e., the second direction y), and the signal coverage of the antenna system 100 in the vertical direction is wider, for example, it can cover all floors of a high-rise building.

[0132] Furthermore, the antenna system 100 also includes a frequency selective surface 5 (FSS) disposed between the stacked antennas. The FSS 5 is a two-dimensional periodic array structure that can effectively control the transmission and reflection of electromagnetic waves and has a specific frequency selection effect. The FSS 5 can be a spatial filter that exhibits obvious bandpass or bandstop filtering characteristics when interacting with electromagnetic waves. It will be understood by those skilled in the art that the specific form of the FSS 5 is not limited. For example, it can be transmissive, reflective, or both transmissive and reflective to the incident electromagnetic waves. Referring to the arrow directions in Figures 4b-1, 4b-2, and 5b-5c, in one embodiment, the FSS 5 is transmissive to the electromagnetic waves of the second antenna 2 and reflective to the electromagnetic waves of the first antenna 1. The electromagnetic waves radiated by the second antenna 2 are reflected on the floor 4 and can be radiated upward through the FSS 5, that is, the FSS 5 is an electromagnetically transparent structure to the second antenna 2. The electromagnetic waves of the second antenna 2 are all radiated in the direction away from the floor 4 in the second direction y. The electromagnetic waves of the first antenna 1 are reflected on the frequency selective surface 5 (or it can be understood that the frequency selective surface 5 acts as the floor of the first antenna 1), so that the electromagnetic waves of the first antenna 1 can only be radiated in the direction away from the floor 4 in the first direction z, and the radiation directions of the first antenna 1 and the second antenna 2 are consistent.

[0133] Among them, the frequency selective surface 5 includes a metal layer 51, which is the structure that actually produces the spatial filtering effect in the frequency selective surface 5. The metal layer 51 may include a metal area 513 formed by metals of various shapes (see Figures 9 to 10b). Through the design of the metal area 513, the frequency selective surface 5 can exhibit bandpass or bandstop characteristics, which will be described in detail later.

[0134] Furthermore, a phase shifter 6 and a feeding network 7 are integrated on the metal layer 51 of the frequency selective surface 5, so that the frequency selective surface 5, the phase shifter 6, and the feeding network 7 constitute a frequency selective surface structure 200. The phase shifter 6 is a device capable of modulating the phase of the antenna output signal. In one embodiment, the phase shifter 6 is electrically connected to each radiator 10 of the first antenna 1 through the feeding network 7 in the frequency selective surface structure 200, thereby controlling the radiation direction of each radiator 10 and obtaining the desired antenna waveform. The feeding network 7 of the frequency selective surface structure 200 may include a transmission line structure 71 for signal transmission, such as a coaxial cable or a microstrip line. The feeding network 7 constitutes the feeding network 7 of at least one of the stacked adjacent antennas that is away from the floor 4. In one embodiment, the feeding network 7 constitutes a first feeding network 11, that is, the first feeding network 11 is integrated on the metal layer 51 of the frequency selective surface 5.

[0135] By integrating the phase shifter 6 and the first feed network 11 on the metal layer 51 of the frequency selective surface 5, a miniaturized phase shifter 6 can be used. The phase shifter 6 and the transmission line structure 71 of the feed network 7 are hidden within the metal region 513 of the metal layer 51, creating a stealth effect for the phase shifter 6 and the feed network 7. "Stealth" can be understood as meaning that the projection of the phase shifter 6 and the feed network 7 onto the metal layer 51 along the first direction z lies entirely within the metal region 513. In this manner, the phase shifter 6 and the feed network 7 do not affect the spatial filtering characteristics of the frequency selective surface 5, allowing it to maintain the reflectivity of the first antenna 1 and the transmittance of the second antenna 2. Furthermore, the phase shifter 6 and the feed network 7 do not block the electromagnetic waves of the second antenna 2. Furthermore, compared to the antenna system shown in Figures 1a and 1b, the phase shifter 6 in the antenna system 100 of the present application does not need to be located on both sides of each radiator of the first antenna 1, resulting in a smaller size. Compared to the antenna systems shown in Figures 2a and 2b , the antenna system 100 of the present application integrates phase shifter 6 and feed network 7, resulting in a compact structure. This shortens the length of transmission line structure 71 in feed network 7 and reduces transmission losses. The shortened transmission line structure 71 also avoids the need for excessive manual soldering and RF board materials, resulting in lower costs and simpler assembly.

[0136] Therefore, the antenna system 100 provided in the embodiment of the present application can reduce transmission loss when the phase shifter 6 does not block the antenna beam, and can take into account the coverage range and transmission quality of the antenna signal. At the same time, it has a smaller size, lower cost and is easy to assemble.

[0137] Those skilled in the art will appreciate that the number of metal layers 51 in the frequency selective surface 5 is not limited, and there can be one, two, three, or more metal layers 51. When the frequency selective surface 5 has multiple metal layers 51, the phase shifter 6 and the feed network 7 can be integrated on at least one of the metal layers 51. As shown in FIG4b-1, in one embodiment, the frequency selective surface 5 includes a single metal layer 51. As shown in FIG4b-2 and FIG5b-5c, in another embodiment, the frequency selective surface 5 includes two metal layers 51 stacked in a first direction z, namely, a first metal layer 511 and a second metal layer 512, wherein the second metal layer 512 is located between the first metal layer 511 and the second antenna 2 in the first direction z. Furthermore, the first metal layer 511 and the second metal layer 512 each include two surfaces facing each other in the first direction z, and the feed network 7 and the phase shifter 6 can be integrated on any one or more surfaces of the two metal layers. As shown in Figures 4b-2 and 5b, in one embodiment, the phase shifter 6 and the feed network 7 are both integrated on the first metal layer 511 and located on the surface of the first metal layer 511 facing away from the second metal layer 512. As shown in Figure 5c, in one embodiment, the phase shifter 6 and the feed network 7 can also be integrated on the surface of the first metal layer 511 on the side closer to the second metal layer 512. In other alternative embodiments, the phase shifter 6 and the feed network 7 can also be integrated on both the first metal layer 511 and the second metal layer 512, which are not listed here.

[0138] It will be understood by those skilled in the art that the specific number and layout of the phase shifters 6 are not limited, and the specific number and layout of the transmission line structures 71 in the feeding network 7 are not limited. In one embodiment, the first antenna 1 is a dual-polarized antenna, the frequency selective surface structure 200 includes a plurality of phase shifters 6, the feeding network 7 includes a plurality of transmission line structures 71, and each column of radiators 10 of the first antenna 1 has transmission line structures 71 symmetrically distributed on both sides in the third direction x, and each column of radiators 10 has phase shifters 6 symmetrically distributed on both sides in the third direction x. In this form, the phase shifter 6 can phase-modulate the two polarization directions in the first antenna 1 respectively. In other alternative embodiments, if the first antenna 1 is a single-polarized antenna, the phase shifter 6 and the transmission line structure 71 in the feeding network 7 can also be distributed only on one side of the first antenna 1.

[0139] Please refer to Figures 6-8, Figure 6 is a schematic diagram of the working principle of the second embodiment of the antenna system of the embodiment of the present application; Figure 7 is a structural schematic diagram of the second embodiment of the antenna system of the embodiment of the present application; Figure 8 is a structural schematic diagram of the second embodiment of the antenna system of the embodiment of the present application from another angle.

[0140] As shown in Figures 6-8 , in one embodiment, the antenna system 100 further includes a third antenna 3, which is disposed on a side of the frequency selective surface structure 200 away from the floor 4. Similarly, the type of the third antenna 3 is not limited. In one embodiment, the third antenna 3 is a dual-polarized antenna.

[0141] Furthermore, the third antenna 3 includes a plurality of radiators 30 distributed in an array. The plurality of radiators 30 of the third antenna 3 are arranged alternately with the plurality of radiators 10 of the first antenna 1 in a plane perpendicular to the first direction z. A third feeding network 31 is provided corresponding to the third antenna 3. At least a portion of the feeding network 7 of the frequency selective surface structure 200 constitutes the third feeding network 31 and is electrically connected to the plurality of radiators 30 of the third antenna 3 to feed the plurality of radiators 30 of the third antenna 3. Alternatively, it can be understood that the first antenna 1 and the third antenna 3 are located in the same layer structure in the first direction z, the radiators 10 of the first antenna 1 and the radiators 30 of the third antenna 3 are interlaced within this layer structure, and the third feeding network 31 of the third antenna 3 is also integrated on the metal layer 51 of the frequency selective surface 5. The feeding network 7 of the frequency selective surface structure 200 simultaneously constitutes the first feeding network 11 and the third feeding network 31. Among them, the first antenna 1 and the third antenna 3 can respectively operate in different frequency bands. For example, the first antenna 1 can be a 4G antenna, the third antenna 3 can be a 3G antenna, etc., and this application does not impose any restrictions on this.

[0142] The specific number and arrangement of the radiators 30 of the third antenna 3 are not limited and can be designed according to the actual application scenario. In one embodiment, the multiple radiators 30 of the third antenna 3 constitute at least one column of radiators, and each column of radiators includes at least two radiators 30 spaced apart along the second direction y. Alternatively, it can be understood that the multiple radiators 30 of the third antenna 3 are distributed in a rectangular array, the second direction y can be the length direction of the rectangular array, and the third direction x can be the width direction of the rectangular array. The radiators 30 arranged along the length direction of the rectangular array constitute a column of radiators, and at least one column of radiators is arranged along the width direction of the rectangular array (for example, one, two, or three columns, etc., without specific limitation), and the number of radiators 30 in a column of radiators is at least two (for example, two, three, or four columns, without specific limitation, and only a few are shown in the figure for illustration).

[0143] As shown in FIG8 , in one embodiment, the first antenna 1 has a column of radiators 10 , the third antenna 3 has two columns of radiators 30 , and the two columns of radiators 30 of the third antenna 3 are distributed on both sides of the column of radiators 10 of the first antenna 1 along the second direction y.

[0144] In one embodiment, each column of radiators in the third antenna 3 has transmission line structures 71 symmetrically distributed on both sides in the third direction x, and each column of radiators has phase shifters 6 symmetrically distributed on both sides in the third direction x. In this manner, the phase shifters 6 and the feed network 7 can respectively adjust the two polarization directions of the third antenna 3. In other alternative embodiments, if the third antenna 3 is a single-polarization antenna, the phase shifters 6 and the transmission line structures 71 in the feed network 7 can also be distributed only on one side of the third antenna 3.

[0145] As shown in FIG8 , in one embodiment, a phase shifter 6 and a feed network 7 are integrated on both the first metal layer 511 and the second metal layer 51, and the first feed network 11 is integrated on the second metal layer 512, and the third feed network 31 is integrated on the first metal layer 511. The phase shifter 6 on the first metal layer 511 is electrically connected to the transmission line structure 71 in the third feed network 31, and the phase shifter 6 on the second metal layer 512 is electrically connected to the transmission line structure 71 in the first feed network 11. The first feed network 11 and the third feed network 31 are arranged in layers to facilitate wiring on different metal layers 51 and to rationally utilize space. In other alternative embodiments, the first feed network 11 may also be integrated on the first metal layer 511, and the second feed network 21 may also be integrated on the second metal layer 512, and this application is not limited thereto.

[0146] The above systematically explains the structure of the antenna system 100 provided in the embodiment of the present application, the functions of each component, and the basic principle that the phase shifter 6 in the antenna system 100 does not block the antenna beam. The following is an expansion of the integration method of the phase shifter 6 and the feed network 7 on the frequency selective surface 5 in combination with the frequency selective surface structure 200.

[0147] Please refer to Figures 9-10b, Figure 9 is a structural schematic diagram of the frequency selective surface structure of an embodiment of the present application; Figure 10a is a structural schematic diagram of another implementation method of the frequency selective surface structure of an embodiment of the present application; Figure 10b is a schematic diagram of the local connection structure of part A in Figure 10a.

[0148] As shown in Figures 9 to 10b, the frequency selective surface structure 200 includes a frequency selective surface 5, a feed network 7, and a phase shifter 6. The frequency selective surface 5 includes a metal layer 51, and the phase shifter 6 is electrically connected to the feed network 7. In addition, the phase shifter 6 and the feed network 7 are integrated into the metal layer 51 of the frequency selective surface 5.

[0149] The frequency selective surface structure 200 provided in the embodiment of the present application can be applied to the antenna system 100, and the phase shifter 6 and the feed network 7 are both integrated on the metal layer 51 of the frequency selective surface 5. The metal layer 51 of the frequency selective surface 5 has spatial filter characteristics. By changing the antenna's wave transmission characteristics through the design of the metal layer 51, the requirements of antenna electromagnetic wave transmission control can be met. The frequency selective surface 5 can be designed to have a completely transparent effect on part of the antenna (such as the second antenna 2 in the antenna system 100), that is, a structure that is electromagnetically transparent to this part of the antenna. The phase shifter 6 and the feed network 7 are integrated on the metal layer 51, and the metal layer 51 has a stealth effect on the phase shifter 6. If a miniaturized phase shifter 6 is used, the phase shifter 6 can be completely hidden on one side of the metal layer 51, and the metal layer 51 also has the same stealth effect on the transmission line structure 71 in the feed network 7. The feed network 7 and the phase shifter 6 will not affect the filtering characteristics of the frequency selective surface structure 200. In this way, the frequency selective surface structure 200 composed of the frequency selective surface 5, the phase shifter 6 and the feed network 7 can still produce an electromagnetic transparent effect on part of the antenna, so that the beam of the antenna of this part will not be blocked. Another part of the antenna (such as the first antenna 1 and the third antenna 3 in the antenna system 100) can be set on the other side of the frequency selective surface structure 200, so that its electromagnetic waves radiate in a direction away from the frequency selective surface structure 200, and the phase shifter 6 will not block the beam of this part of the antenna. Furthermore, since the phase shifter 6 and the feed network 7 are integrated together and the structure is compact, the length of the transmission line structure 71 in the feed network 7 can be shortened, reducing transmission loss.

[0150] Therefore, the frequency selective surface structure 200 provided in the embodiment of the present application can reduce transmission loss when the phase shifter 6 does not block the antenna beam, and can take into account the coverage range and transmission quality of the antenna signal, thereby solving the problem of difficult layout of the phase shifter 6 in the multi-band integrated antenna system 100.

[0151] It will be understood by those skilled in the art that the specific shape of the metal layer 51 is not limited. In one embodiment, the metal layer 51 has a metal area 513, and a hollow area 514 is formed around the metal area 513. The feed network 7 and the phase shifter 6 are integrated in the metal area 513, and the projections of the feed network 7 and the phase shifter 6 along the first direction z onto the metal layer 51 are located in the metal area 513 as a whole. The metal layer 51 is located in a plane perpendicular to the first direction z, and the first direction z is perpendicular to the plane where the metal layer 51 is located. Alternatively, it can be understood that the metal layer 51 as a whole is a layered structure made of metal material, and part of the layered structure is hollowed out and processed to form a specific metal pattern. The hollowed-out part constitutes the hollowed-out area 514, and the remaining solid structure portion is the metal area 513.

[0152] The phase shifter 6 and feed network 7 are integrated into and supported by the metal region 513. The projections of the feed network 7 and phase shifter 6 onto the metal layer 51 along the first direction z are entirely located within the metal region 513. This means that the phase shifter 6 and feed network 7 do not overlap with the hollow region 514 in the first direction z, to prevent the phase shifter 6 and feed network 7 from blocking the antenna beam (e.g., blocking the beam of the second antenna 2 in the antenna system 100). It should be noted that the projections of the feed network 7 and phase shifter 6 onto the metal layer 51 along the first direction z are not absolutely located within the metal region 513; a certain deviation is permitted, such as a small portion that may extend beyond the metal region 513. While the portion that extends beyond the metal region 513 may also block the antenna beam to a certain extent, if the portion that extends beyond the metal region 513 is sufficiently small, the antenna beam is not significantly blocked, and its impact on the antenna pattern is negligible. This also achieves the effect of reducing transmission loss while the phase shifter 6 does not block the antenna beam.

[0153] Those skilled in the art will appreciate that the specific shape of the metal layer 51 is not limited. For example, the metal region 513 in the metal layer 51 can be in the form of a grid, a patch, a slit, or the like. As shown in FIG9 , in one embodiment, the metal layer 51 includes a metal grid 5131, which forms the metal region 513. The spaces enclosed by each grid in the metal grid 5131 collectively constitute a hollow region 514. The grid-shaped frequency selective surface 5 has a relatively regular shape and is easy to process, and the grid lines in the grid facilitate wiring. As shown in FIG10a-10b , in one embodiment, the frequency selective surface 5 can also be formed using a metal grid + metal patch configuration. A metal patch 5132 is provided in each grid of the metal grid 5131. The metal grid 5131 and the metal patch 5132 collectively constitute the metal region 513. The gaps between the metal patch 5132 and the metal grid 5131 collectively constitute the hollow region 514. The shape of the metal patch 5132 is not limited, and can be, for example, circular, square, triangular, or the like. In one embodiment, the metal patch 5132 is square in shape.

[0154] In one embodiment, the frequency selective surface structure 200 further includes a dielectric layer (not shown in the figure), and the metal layer 51 is mounted on the dielectric layer. The dielectric layer can be used to support the metal layer 51. For example, the metal layer 51 can be mounted on the surface of the dielectric layer, or the metal layer 51 can be embedded in the dielectric layer. The hollow area 514 of the metal layer 51 can also be filled with a dielectric. The dielectric layer is made of a non-metallic material, such as glass, ceramic, etc., and is not specifically limited. It will be understood by those skilled in the art that the shape and position of the dielectric layer are not limited, as long as it can provide support for the metal layer 51. In an example scenario, when the frequency selective surface 5 includes a first metal layer 511 and a second metal layer 512, the dielectric layer can be a plurality of non-metallic support members arranged between the first metal layer 511 and the second metal layer 512.

[0155] As previously mentioned, the number of phase shifters 6 in the frequency selective surface 5 and the number of transmission line structures 71 in the feed network 7 are not limited and can be one or more. When there are multiple radiators in the antenna, one phase shifter 6 and multiple transmission line structures 71 can be provided in the frequency selective surface structure 200. One phase shifter 6 can be electrically connected to all of the multiple transmission line structures 71 and then electrically connected to all radiators in the antenna through each transmission line structure 71. Alternatively, multiple phase shifters 6 can be provided, each phase shifter 6 being electrically connected to a portion of the transmission line structures 71 and then electrically connected to some of the radiators in the antenna through each transmission line structure 71. This is not limited in this application.

[0156] For easier understanding, two scenarios are listed below as illustrations.

[0157] As shown in Figures 9-10b, taking the dual-polarized first antenna 1 in the antenna system 100 as an example, four radiators 10 are shown arranged along the second direction y, with the four radiators 10 constituting a row of radiators 10. As shown in Figure 9, in one exemplary scenario, the frequency selective surface structure 200 includes two phase shifters 6, which are distributed on either side of the row of radiators in the third direction x. Each phase shifter 6 is electrically connected to each of the four radiators 10 via four transmission line structures 71 to adjust the phase of the four radiators 10. As shown in Figure 10a, in another exemplary scenario, the frequency selective surface structure 200 includes four phase shifters 6, with two phase shifters 6 distributed on either side of the row of radiators 10 in the third direction x. Of the two phase shifters 6 on the left side of Figure 10a , the upper phase shifter 6 is electrically connected to two radiators 10 via two transmission line structures 71 to adjust the phases of the two radiators 10. The lower phase shifter 6 is electrically connected to the other two radiators 10 via two transmission line structures 71 to adjust the phases of the other two radiators 10. The layout of the two phase shifters 6 on the right side of Figure 10a is symmetrical to that of the two phase shifters 6 on the left side, and will not be further described here.

[0158] Those skilled in the art will appreciate that the connection method between the transmission line structure 71 and the radiator is not limited. As shown in Figure 10b, in one embodiment, the transmission line structure 71 is electrically connected to the radiator 10 via a feeder line 72, one end of which is connected to the transmission line structure 71 and the other end is connected to the radiator 10. The feeder line can be in any form and can, for example, be a conductive structure such as a cable, a conductive member, or a metal via on a printed circuit board.

[0159] Those skilled in the art will appreciate that the two scenarios in FIG. 9 to FIG. 10 b are merely examples and do not constitute specific limitations to the present application.

[0160] Those skilled in the art will appreciate that the present application does not limit the type or specific structure of the phase shifter 6. For example, it may be a physical mechanical phase shifter, an electronic solid-state phase shifter, a liquid crystal phase shifter, or a switch-type phase shifter. However, due to the limited size of the metal region 513 on the metal layer 51, to prevent the phase shifter 6 from blocking the antenna signal, a miniaturized phase shifter 6 should be used as much as possible, and the phase shifter 6 should have some connection structure for mounting on the metal layer 51. The following illustrates possible structures of the phase shifter 6 with reference to the accompanying figures.

[0161] Please refer to Figures 11a-12c, Figure 11a is a structural schematic diagram of the phase shifter in the frequency selective surface structure of an embodiment of the present application; Figure 11b is a structural schematic diagram of another implementation of the phase shifter in the frequency selective surface structure of an embodiment of the present application; Figures 12a-12c are connection schematic diagrams of the phase shifter and the metal layer in the frequency selective surface structure of an embodiment of the present application.

[0162] As shown in Figures 11a and 11b, in one embodiment, the phase shifter 6 includes an outer conductor 63, a fixed dielectric 64, a sliding dielectric 65, and at least one signal line winding 66. A cavity is formed within the outer conductor 63, and the fixed dielectric 64, the sliding dielectric 65, and the at least one signal line winding 66 are all accommodated within the cavity. The fixed dielectric 64 is fixedly connected to the outer conductor 63, and the sliding dielectric 65 is positioned between the fixed dielectric 64 and the outer conductor 63 and is slidably connected to the fixed dielectric 64. Each signal line winding 66 is wound around and fixed to the fixed dielectric 64, and each signal line winding 66 is positioned between the fixed dielectric 64 and the sliding dielectric 65. The phase shifter 6 is electrically connected to the feed network 7 via each signal line winding 66. At least a portion of the outer conductor 63 is configured as a planar structure, and the phase shifter 6 is fixedly connected to the metal layer 51 via the planar structure.

[0163] The outer conductor 63 is the shell of the phase shifter 6 and is made of metal. In one embodiment, the outer conductor 63 is electrically connected to the metal layer 51 to achieve grounding of the phase shifter 6. The signal line winding 66 is electrically connected to the feed network 7 and then electrically connected to the antenna radiator through the transmission line structure 71 in the feed network 7. The specific number of signal line windings 66 is not limited. In an example scenario, one phase shifter 6 is electrically connected to four radiators, and then four signal line windings 66 are correspondingly provided in the phase shifter 6, and each signal line winding 66 is connected to one radiator through the transmission line structure 71.

[0164] It should be noted that when a phase shifter 6 is electrically connected to multiple radiators, the multiple radiators electrically connected to the phase shifter 6 can be radiators of antennas in the same frequency band or radiators of antennas in different frequency bands. For example, a phase shifter 6 can be electrically connected to the radiator 10 of the first antenna 1 and the radiator 30 of the third antenna 3 at the same time, and this application does not limit this.

[0165] It should be noted that a phase shifter 6 can have multiple input terminals 61 and multiple output terminals 62, and this application does not impose any restrictions on this. In one embodiment, there are multiple signal line windings 66 in the phase shifter 6, and the multiple signal line windings 66 constitute at least one group of signal line windings, and each group of signal line windings includes at least one signal line winding 66. In each group of signal line windings, one end of each signal line winding 66 is connected to form an input terminal 61 of the phase shifter 6, and the other end of each signal line winding 66 constitutes at least one output terminal 62 of the phase shifter 6, and each of the at least one output terminal 62 is electrically connected to the corresponding transmission line structure 71. The number of signal line windings in the phase shifter 6 and the number of signal line windings 66 in each group of signal line windings are not limited. For example, a phase shifter 6 may include 1, 2, 3 or more groups of signal line windings, each group of signal line windings may include 1, 2, 3 or more signal line windings 66, and each group of signal line windings may correspond to the radiator of an antenna connected to a frequency band.

[0166] For example, in the scenario shown in FIG9 , each phase shifter 6 is provided with a set of signal line windings, comprising four signal line windings 66. One end of each of the four signal line windings 66 is connected to form the input end 61 of the phase shifter 6. The other ends of each of the four signal line windings 66 form four output ends 62 of the phase shifter 6 (two of the output ends 62 are integrated into the same outlet on the phase shifter 6, so only three output ends 62 are shown in the figure). Each of the four output ends 62 is electrically connected to a transmission line structure 71 and to a corresponding radiator. The input end 61 of the phase shifter 6 is also electrically connected to a transmission line structure 71, which can be connected to other components in the antenna system 100 or the base station 300, such as a radio frequency module, a power supply circuit, etc. In one embodiment, the input end 61 of the phase shifter 6 is electrically connected to the radio frequency module 8 of the base station 300 via the transmission line structure 71.

[0167] In another example scenario, the phase shifter 6 may also include two groups of signal line windings, one of the two groups of signal line windings being electrically connected to the multiple radiators 10 of the first antenna 1 via multiple signal line windings 66, and the other group of signal line windings being electrically connected to the multiple radiators 30 of the third antenna 3 via multiple signal line windings 66. One end of each signal line winding 66 in the group of signal line windings electrically connected to the first antenna 1 is connected to form an input end 61 of the phase shifter 6, and one end of each signal line winding 66 in the other group of signal line windings electrically connected to the third antenna 3 is connected to form the other input end 61 of the phase shifter 6. The two input ends 61 of the phase shifter 6 can be electrically connected to different RF modules or different ports of the same RF module via different transmission line structures.

[0168] Furthermore, the fixed medium 64 is fixed relative to the outer conductor 63, the signal line windings 66 are fixed to the fixed medium 64, and the sliding medium 65 covers and slides on the surface of the signal line windings 66. The phase shifter 6 adjusts the phase of the radiator by changing the position of the sliding medium 65 to change the range of each signal line winding 66 covered by the sliding medium 65. The portion of the signal line winding 66 not covered by the sliding medium 65 is exposed to the air, changing the electrical length of the signal line winding 66, thereby changing the phase shift of the radiator corresponding to each signal line winding 66.

[0169] When the phase shifter 6 employs the above-described structure, multiple signal line windings are wound together around the fixed dielectric 64. The different signal line windings 66 can be configured as a zigzag structure within the phase shifter 6, concentrating the multiple signal line windings 66 within a small area. This results in a more compact structure and a relatively small volume. The fixed dielectric 64 and sliding dielectric 65 of the phase shifter 6 can also be made of a material with a high dielectric constant, further reducing the volume of the phase shifter 6. Alternatively, a larger number of phase shifters 6 can be arranged within the frequency selective surface structure 200, with each phase shifter 6 having fewer signal line windings 66 (e.g., one or two), similarly reducing the volume of the phase shifter 6.

[0170] Those skilled in the art will appreciate that the specific shape of the outer conductor 63 is not limited. For ease of description, the portion where the phase shifter 6 connects to the metal layer 51 is defined as the bottom 63a of the outer conductor 63. As shown in Figure 11a, in one embodiment, the bottom 63a is entirely planar, forming a closed structure for the outer conductor 63, and the fixing medium 64 can be fixed to the bottom 63a. As shown in Figure 11b, in an alternative embodiment, the bottom 63a of the outer conductor 63 can also be provided with an opening, forming a semi-enclosed structure with an opening, and the fixing medium 64 can be fixedly connected to the sidewalls on both sides of the opening. The bottom 63a of the outer conductor 63 is fixedly connected to the metal layer 51, for example, it can be fixedly connected to the grid lines of the metal grid 5131. When the width d1 of the phase shifter 6 is less than or equal to the width w of the grid lines (see Figures 9-10a), the projection of the phase shifter 6 on the metal layer 51 along the first direction z is entirely located within the metal region 513 and does not obstruct the antenna beam.

[0171] Those skilled in the art will appreciate that when the phase shifter 6 is fixed to the metal layer 51 and the outer conductor 63 is electrically connected to the metal layer 51, the specific method of fixing the phase shifter 6 to the metal layer 51 is not limited and can be directly or indirectly fixed to the metal layer 51. As shown in Figure 12a, in one embodiment, the phase shifter 6 is DC-connected to the metal layer 51, with the bottom 63a of the outer conductor 63 in full contact with the metal layer 51. For example, the outer conductor 63 can be entirely welded to the metal layer 51, providing a more secure connection. As shown in Figure 12b, in an alternative embodiment, the phase shifter 6 can also be DC-connected to the metal layer 51 in sections, with only a portion of the bottom 63a of the outer conductor 63 in contact with the metal layer 51. For example, several weld points can be spaced along the grid lines of the metal grid 5131, and the phase shifter 6 can be welded to the metal layer 51 only at these weld points, which simplifies the operation and saves labor. As shown in Figure 12c, in another alternative embodiment, the phase shifter 6 is coupled to the metal layer 51. It can be understood that the phase shifter 6 does not directly contact the metal layer 51. An insulating support member, such as a plastic clip, may be provided between the two. The phase shifter 6 is fixed to the metal layer 51 via the insulating support member and can be electrically connected to the metal layer 51 through methods such as galvanic coupling. In addition to the three connection methods described above, the phase shifter 6 can also be fixed to the metal layer 51 and electrically connected to the metal layer 51 through other methods, which are not listed here.

[0172] Those skilled in the art will appreciate that the specific type and structure of the transmission line structure 71 in the feed network 7 are not limited, and may be, for example, a microstrip line, a coaxial cable, etc. Several possible structures are illustrated below with reference to the accompanying drawings.

[0173] Please refer to Figures 13a to 20c. Figures 13a to 13b-2 are structural schematic diagrams of the first embodiment of the first transmission line structure in the frequency selective surface structure of the embodiment of the present application, wherein Figure 13b-1 is a cross-sectional view in the BB direction of Figure 13a, and Figure 13b-2 is a cross-sectional view in the CC direction of Figure 13a; Figure 14a is a structural schematic diagram of the second embodiment of the first transmission line structure in the frequency selective surface structure of the embodiment of the present application; Figure 14b is a structural schematic diagram of the third embodiment of the first transmission line structure in the frequency selective surface structure of the embodiment of the present application; Figures 15a to 15b-2 are structural schematic diagrams of the fourth embodiment of the first transmission line structure in the frequency selective surface structure of the embodiment of the present application, wherein Figure 15b-1 is a cross-sectional view in the BB direction of Figure 13a, and Figure 15a is a cross-sectional view in the CC direction of Figure 13a; 15a-15b is a cross-sectional view in the DD direction; Figure 15b-2 is a cross-sectional view in the EE direction in Figure 15a; Figures 16a-16b are structural schematic diagrams of the fifth embodiment of the first transmission line structure in the frequency selective surface structure of an embodiment of the present application, wherein Figure 16b is a cross-sectional view in the FF direction in Figure 16a; Figure 17 is a structural schematic diagram of the sixth embodiment of the first transmission line structure in the frequency selective surface structure of an embodiment of the present application; Figure 18 is a structural schematic diagram of the seventh embodiment of the first transmission line structure in the frequency selective surface structure of an embodiment of the present application; Figure 19 is a structural schematic diagram of the power divider in the frequency selective surface structure of an embodiment of the present application; Figures 20a-20c are schematic diagrams of the connection between the transmission line structure and the metal layer in the frequency selective surface structure of an embodiment of the present application.

[0174] As shown in Figures 13a to 18, in one embodiment, the multiple transmission line structures 71 in the feed network 7 may include a first transmission line structure 711. The first transmission line structure 711 is a linear structure as a whole, which extends along the grid lines of the metal grid 5131 in the metal layer 51. When the width d2 of the first transmission line structure 711 is less than the width w of the grid lines (see Figures 9 to 10b), the projection of the first transmission line structure 711 on the metal layer 51 along the first direction z is entirely located within the metal area 513, thereby avoiding blocking the antenna beam.

[0175] In one embodiment, the first transmission line structure 711 includes an outer conductor 7111 and a core 7112. The core 7112 is enclosed in a cavity 7110 within the outer conductor 7111, with a gap 7113 between the core 7112 and the outer conductor 7111. The outer conductor 7111 serves as the shell of the first transmission line structure 7111, the core 7112 is used to transmit signals, and the gap 7113 indicates that the medium between the outer conductor and the core 7112 is air. With this structure, the core 7112 is entirely suspended within the cavity 7110 of the outer conductor 7111. The core 7112 is surrounded by the air in the cavity 7110. Air has a low dielectric constant, which can reduce transmission loss in the first transmission line structure 711. In one embodiment, the first transmission line structure 711 further includes a plurality of support members 7114 disposed between the outer conductor 7111 and the core 7112. The plurality of support members 7114 are spaced apart along the extension direction of the core 7112. The core 7112 is fixedly connected to the outer conductor 7111 via the plurality of support members 7114. The specific form of the support members 7114 is not limited, and they may be, for example, dielectric structural members.

[0176] Furthermore, at least a portion of the outer conductor 7111 is configured as a planar structure, and the first transmission line structure 711 is fixedly connected to the metal layer 51 via the planar structure. In one embodiment, the outer conductor 7111 is also electrically connected to the metal layer 51 to achieve grounding of the first transmission line structure 711.

[0177] It will be understood by those skilled in the art that the shape of the outer conductor 7111 and the shape of the core 7112 are not limited. For ease of description, the portion of the outer conductor connected to the metal layer 51 is defined as the bottom 7111a of the outer conductor. As shown in Figures 13a-13b-2, Figures 15a-15b-2, and Figure 17, in one embodiment, the outer conductor 7111 is a semi-enclosed structure, and an opening is provided at a position opposite to the bottom 7111a in the first direction z. As shown in Figure 14b, in an alternative embodiment, the bottom 7111a of the outer conductor 7111 may also be provided with an opening, so that the outer conductor 7111 forms a semi-enclosed structure. As shown in Figures 14a and 16a-16b, in other alternative embodiments, the outer conductor 7111 may also be a closed structure.

[0178] In one embodiment, the core 7112 is configured as a linear structure with a rectangular cross-section. As shown in Figures 13b-1, 13b-2, 14a, 15b-1, 15b-2, and 18, in one embodiment, the long sides of the rectangle are arranged vertically, that is, the long sides of the rectangle are perpendicular to the bottom 7111a of the outer conductor 7111. As shown in Figures 14b, 16a-16b, and 17, in an alternative embodiment, the long sides of the rectangle are arranged horizontally, that is, the long sides of the rectangle are parallel to the bottom 7111a of the outer conductor 7111.

[0179] Those skilled in the art will appreciate that, in the first transmission line structure 711, the outer conductor 7111 may have one or more cavities 7110, and may also have one or more cores 7112, without specific limitation. As shown in Figures 13a-14b, in one embodiment, the first transmission line structure 711 includes one core 7112, the outer conductor 7111 has one cavity 7110, and the core 7112 is disposed in the cavity 7110. As shown in Figures 15a-16b, in one embodiment, the first transmission line structure 711 includes two cores 7112, the outer conductor 7111 has one cavity 7110, and the two cores 7112 are disposed in the same cavity 7110 at intervals, with a gap between adjacent cores 7112. As shown in Figures 17 and 18, in one embodiment, the first transmission line structure 711 includes three cores 7112. The outer conductor 7111 has three cavities 7110, and the three cores 7112 are respectively located in different cavities 7110. The three cavities 7110 can be interconnected (as shown in Figure 17) or independent of each other (as shown in Figure 18), and this application does not limit this.

[0180] As shown in FIG19 , in one embodiment, the multiple transmission line structures 71 in the feed network 7 may further include a second transmission line structure, which is configured as a power divider 712. The power divider 712 includes a conductive housing 7121 and a battery cell 7122. The battery cell 7122 is enclosed in a cavity 7110 within the conductive housing 7121, with a gap 7123 between the battery cell 7122 and the conductive housing 7121. At least a portion of the conductive housing 7121 is configured as a planar structure, and the power divider 712 is fixedly connected to the metal layer 51 via the planar structure. Among them, the conductive shell 7121 of the power divider 712 has the same function as the outer conductor in the first transmission line structure 711, and the battery core 7122 of the power divider 712 has the same function as the core 7112 in the first transmission line structure 711. There is a gap 7123 between the battery core 7122 and the conductive shell 7121, that is, the battery core 7122 is suspended in the conductive shell 7121 and surrounded by air to reduce the transmission loss of the power divider 712.

[0181] In one embodiment, the power divider 712 further includes a plurality of support members disposed between the conductive housing 7121 and the battery cell 7122. The plurality of support members are spaced apart to partially support the battery cell 7122 within the conductive housing 7121. The specific form of the support members is not limited, and they may be dielectric structural members, for example.

[0182] Unlike the first transmission line structure, the battery cell 7122 has one input terminal 7122a and multiple output terminals 7122b. The specific number of output terminals is not limited. In one embodiment, the battery cell 7122 has one input terminal 7122a and two output terminals 7122b. The signal is input into the power divider 712 from the input terminal 7122a and is divided into two paths inside the power divider 712, and is output from the two output terminals 7122b respectively. The conductive shell 7121 can be designed as a "T-shaped" structure with three openings. The input terminal 7122a and the output terminal 7122b of the battery cell 7122 extend out of the conductive shell 7121 from the three openings respectively and are electrically connected to other components. In one embodiment, the input terminal 7122a of the battery cell 7122 can be connected to the phase shifter 6, and the output terminal 7122b can be connected to other transmission line structures 71. Alternatively, the input end 7122a and the output end 7122b of the battery cell 7122 may also be connected to other transmission line structures, etc., and this application does not impose any limitation on this.

[0183] To put it more simply, the first transmission line structure 711 is a linear structure with two ports, one of which serves as an input port and the other as an output port. The power divider 712 can be seen as merging multiple first transmission line structures 711 to form a transmission line structure 71 with more than two ports, one or more of which can serve as input ports 7122a, and the remaining ports as output ports 7122b. This application does not impose any restrictions on this. In an example scenario, the battery cell 7122 of the power divider 712 can also have one output port 7122b and multiple input ports 7122a, which can merge multiple signals into one.

[0184] Those skilled in the art will appreciate that the transmission line structure 71 is fixed to the metal layer 51 and can be grounded through the metal layer 51 (for example, the outer conductor in the first transmission line structure 711 is electrically connected to the metal layer 51, and the conductive shell 7121 of the power divider 712 is electrically connected to the metal layer 51). The specific fixing method of the transmission line structure 71 on the metal layer 51 is not limited, and it can be directly fixedly connected to the metal layer 51 or indirectly fixedly connected to the metal layer 51.

[0185] As shown in FIG20a , in one embodiment, the transmission line structure 71 is DC-connected to the metal layer 51. As shown in FIG20b , in one embodiment, the transmission line structure 71 may also be segmented DC-connected to the metal layer 51. As shown in FIG20c , in one embodiment, the transmission line structure 71 is coupled to the metal layer 51. The definitions of DC connection, segmented DC connection, and coupled connection are the same as those for the connection between the phase shifter 6 and the metal layer 51 described above and are not further elaborated here.

[0186] The functions and structures of the various components of the antenna system 100 and the frequency selective surface structure 200 of the present application have been described in detail above. Those skilled in the art will appreciate that the antenna system 100 can be formed in any manner. For example, the various components of the antenna system 100 can be produced separately and then assembled. In one embodiment, the antenna system 100 is formed on a printed circuit board. Specifically, the printed circuit board has a metal structure and a non-metallic structure. For example, the printed circuit board can include multiple stacked metal layers and multiple dielectric layers disposed between adjacent metal layers. The metal layers can be connected via metal vias that penetrate the dielectric layers. The metal layers and metal vias constitute the metal structure of the printed circuit board, while the multiple dielectric layers constitute the dielectric structure of the printed circuit board. In one embodiment, at least a portion of the metal structure constitutes metal components such as the ground plane 4, the radiators of each antenna, and the metal layer 51 of the frequency selective surface 5 in the antenna system 100 (i.e., the aforementioned components are directly machined and formed on the metal structure of the printed circuit board). At least a portion of the dielectric structure of the printed circuit board constitutes non-metal components such as the dielectric layer of the frequency selective surface structure 200 (i.e., the dielectric layer is directly machined and formed within the dielectric structure of the printed circuit board). In other alternative implementations, the antenna system 100 may also be manufactured by other methods, which are not listed here one by one.

[0187] Please refer to Figure 21, which is a structural diagram of the base station according to an embodiment of the present application.

[0188] As shown in FIG21 , the present application further provides a base station 300, including an antenna system 100 and a radio frequency module 8 connected to the antenna system 100. The base station 300 provided in the present application can be a device for communicating with a terminal device, including a base transceiver station (BTS) in a global system for mobile communications (GSM) system or a code division multiple access (CDMA) system, or a node B (NB) in a wideband code division multiple access (WCDMA) system, or an evolved node B (eNB or eNodeB) in an LTE system, or a wireless controller in a cloud radio access network (CRAN) scenario, or the base station 300 can include a relay station, an access point, an in-vehicle device, a wearable device, a base station in a future 5G network, or a base station in a future evolved public land mobile network (PLMN) network, etc., and the embodiments of the present application are not limited thereto. Antennas of multiple frequency bands can be combined in the base station 300, and the base station 300 has a high overall integration, a wide signal coverage range, and fewer signal blind spots.

[0189] The RF module 8 can perform conversion between airborne RF channels and baseband digital channels, as well as amplification, transmission, and reception of RF channels. Its specific type is not limited. In addition to the RF module 8, the base station 300 may also include other components, such as a power supply circuit for powering the antenna, etc., which are not limited in this application.

[0190] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A frequency selective surface structure, characterized in that: It comprises a frequency selective surface, a feeding network and a phase shifter; the frequency selective surface comprises a metal layer, the phase shifter is electrically connected to the feeding network, and the phase shifter and the feeding network are integrated into the metal layer of the frequency selective surface.

2. The frequency selective surface structure according to claim 1, characterized in that: The metal layer has a metal area, and a hollow area is formed around the metal area; the feeding network and the phase shifter are integrated in the metal area, and the projections of the feeding network and the phase shifter to the metal layer along a first direction are located in the metal area as a whole; wherein the first direction is perpendicular to the plane where the metal layer is located.

3. The frequency selective surface structure according to claim 2, characterized in that: The metal layer includes a metal grid, the metal grid constitutes the metal area, and the space surrounded by each grid in the metal grid together constitutes the hollow area.

4. The frequency selective surface structure according to claim 2, characterized in that: The metal layer includes a metal grid and a plurality of metal patches, wherein the plurality of metal patches are correspondingly arranged in a plurality of grids of the metal grid; the metal grid and the metal patches constitute the metal area, and the gap between the metal patches and the metal grid constitutes the hollow area.

5. The frequency selective surface structure according to any one of claims 1 to 4, characterized in that: The frequency selective surface includes multiple metal layers stacked in a first direction and arranged parallel to each other, and the feeding network and the phase shifter are integrated on at least one metal layer of the multiple metal layers; wherein the first direction is perpendicular to the plane where the metal layers are located.

6. The frequency selective surface structure according to claim 5, characterized in that: The plurality of metal layers include two metal layers, each of the two metal layers includes two surfaces opposite to each other in the first direction, and the feeding network and the phase shifter are integrated on any one or more surfaces of the two metal layers.

7. The frequency selective surface structure according to any one of claims 1 to 6, characterized in that: The feed network includes a plurality of transmission line structures, and: The frequency selective surface structure includes one phase shifter, and one phase shifter is electrically connected to all transmission line structures of the plurality of transmission line structures; Alternatively, the frequency selective surface structure includes a plurality of the phase shifters, and each of the plurality of phase shifters is electrically connected to a portion of the transmission line structures of the plurality of transmission line structures.

8. The frequency selective surface structure according to claim 7, characterized in that: The phase shifter comprises an outer conductor, a fixed medium, a sliding medium and at least one signal line winding, wherein a receiving cavity is formed in the outer conductor, and the fixed medium, the sliding medium and the at least one signal line winding are all received in the receiving cavity; The fixed medium is fixedly connected to the outer conductor, the sliding medium is located between the fixed medium and the outer conductor, and is slidably connected to the fixed medium; each signal line winding in the at least one signal line winding is wound and fixed to the fixed medium, and each signal line winding is located between the fixed medium and the sliding medium, and the phase shifter is electrically connected to the feeding network through each signal line winding; At least a portion of the outer conductor is configured as a planar structure, and the phase shifter is fixedly connected to the metal layer via the planar structure.

9. The frequency selective surface structure according to claim 8, characterized in that: The at least one signal line winding is a plurality of signal line windings, the plurality of signal line windings constitute at least one group of signal line windings, and each group of signal line windings in the at least one group of signal line windings includes at least one signal line winding; In each group of signal line windings, the at least one signal line winding is one signal line winding or at least two signal line windings, one end of the one signal line winding or one end of the at least two signal line windings are connected to form an input end of the phase shifter, and the other end of the at least one signal line winding constitutes at least one output end of the phase shifter, and each of the at least one output end is electrically connected to the corresponding transmission line structure.

10. The frequency selective surface structure according to any one of claims 7 to 9, characterized in that: The plurality of transmission line structures include at least one first transmission line structure, each of the at least one first transmission line structure includes an outer conductor and a core, the core is wrapped in a cavity inside the outer conductor, and there is a gap between the core and the outer conductor; At least a portion of the outer conductor is configured as a planar structure, and the first transmission line structure is fixedly connected to the metal layer via the planar structure.

11. The frequency selective surface structure according to claim 10, characterized in that: The first transmission line structure further includes a plurality of support members disposed between the outer conductor and the core body, the plurality of support members being disposed at intervals along an extension direction of the core body, and the core body being fixedly connected to the outer conductor via the plurality of support members.

12. The frequency selective surface structure according to claim 10 or 11, characterized in that: The first transmission line structure comprises a plurality of cores arranged at intervals, and: The outer conductor has a cavity, and the plurality of cores are located in the cavity; Alternatively, the outer conductor has a plurality of cavities that are interconnected, the plurality of cavities correspond one-to-one to the plurality of cores, and each core is located in a corresponding cavity.

13. The frequency selective surface structure according to any one of claims 7 to 12, characterized in that: The plurality of transmission line structures include at least one second transmission line structure, each of the at least one second transmission line structure is configured as a power divider, the power divider includes a conductive shell and a battery core, the battery core is wrapped in a cavity inside the conductive shell, and there is a gap between the battery core and the conductive shell; the battery core has an input end and a plurality of output ends, and the input end of the battery core is electrically connected to the phase shifter; At least a portion of the conductive housing is configured as a planar structure, and the second transmission line structure is fixedly connected to the metal layer via the planar structure.

14. The frequency selective surface structure according to claim 13, characterized in that: When the phase shifter comprises an outer conductor, the outer conductor of the phase shifter is electrically connected to the metal layer; When the feed network comprises a plurality of transmission line structures, the plurality of transmission line structures comprises at least one first transmission line structure, and each of the at least one first transmission line structure comprises an outer conductor, the outer conductor of each of the first transmission line structures is electrically connected to the metal layer; When the feed network comprises a plurality of transmission line structures, the plurality of transmission line structures comprises at least one second transmission line structure, and each of the at least one second transmission line structure comprises a conductive shell, the conductive shell of each of the second transmission line structures is electrically connected to the metal layer; The electrical connection mode is any one of the following: coupling connection, direct current connection or segmented direct current connection.

15. The frequency selective surface structure according to any one of claims 1 to 14, characterized in that: The frequency selective surface structure further includes a dielectric layer, and the metal layer is mounted on the dielectric layer.

16. An antenna system, comprising a floor, a plurality of antennas stacked in a first direction, and a plurality of feeding networks for feeding the plurality of antennas, wherein the floor is arranged on one side of the plurality of antennas in the first direction, characterized in that: The antenna system also includes a frequency selective surface structure as described in any one of claims 1-15; the frequency selective surface structure is arranged between adjacent antennas stacked in the multiple antennas, and the feeding network of the frequency selective surface structure constitutes a feeding network of at least one antenna away from the floor among the adjacent antennas stacked.

17. The antenna system according to claim 16, characterized in that The plurality of antennas include a first antenna and a second antenna stacked in the first direction, the floor is arranged on a side of the second antenna away from the first antenna, and the frequency selective surface structure is arranged between the first antenna and the second antenna; The first antenna and the second antenna both include a plurality of radiators distributed in an array, and at least a portion of the feeding network of the frequency selective surface structure constitutes the feeding network of the first antenna and is electrically connected to the plurality of radiators of the first antenna to feed the plurality of radiators of the first antenna.

18. The antenna system according to claim 17, characterized in that When the frequency selective surface structure includes two metal layers, the feeding network and the phase shifter of the frequency selective surface structure are integrated on a metal layer far away from the second antenna among the two metal layers.

19. The antenna system according to claim 17 or 18, characterized in that: The plurality of radiators of the first antenna constitute at least one column of radiators, and each column of the at least one column of radiators includes at least two radiators spaced apart along the second direction; When the feeding network of the frequency selective surface structure includes multiple transmission line structures, the transmission line structures are symmetrically distributed on both sides of each column of radiators in the third direction, and the phase shifters are symmetrically distributed on both sides of each column of radiators in the third direction; wherein the first direction, the second direction, and the third direction are perpendicular to each other.

20. The antenna system according to any one of claims 17 to 19, characterized in that: The multiple antennas further include a third antenna, which is disposed on a side of the frequency selective surface structure away from the floor; the third antenna includes a plurality of radiators distributed in an array, and the plurality of radiators of the third antenna and the plurality of radiators of the first antenna are alternately arranged in a plane perpendicular to the first direction; At least a portion of the feeding network of the frequency selective surface structure constitutes a feeding network of the third antenna and is electrically connected to a plurality of radiators of the third antenna to feed the plurality of radiators of the third antenna.

21. The antenna system according to claim 20, characterized in that The plurality of radiators of the third antenna constitute at least one column of radiators, and each column of the at least one column of radiators includes at least two radiators spaced apart along the second direction; When the feeding network of the frequency selective surface structure includes multiple transmission line structures, the transmission line structures are symmetrically distributed on both sides of each column of radiators in the third direction, and the phase shifters are symmetrically distributed on both sides of each column of radiators in the third direction; wherein the first direction, the second direction, and the third direction are perpendicular to each other.

22. The antenna system according to claim 20 or 21, characterized in that When the frequency selective surface structure includes two metal layers, the phase shifter and the feeding network are integrated on both metal layers; the part of the feeding network of the frequency selective surface that constitutes the feeding network of the first antenna is integrated on any one of the two metal layers, and the part of the feeding network of the frequency selective surface that constitutes the feeding network of the third antenna is integrated on the other of the two metal layers.

23. The antenna system according to any one of claims 16 to 22, characterized in that: The antenna system is formed on a printed circuit board; the printed circuit board includes a metal structure and a dielectric structure, at least a portion of the metal structure constitutes the floor, a plurality of radiators of each of the plurality of antennas, and the metal layer of the frequency selective surface structure; when the frequency selective surface structure also includes a dielectric layer, at least a portion of the dielectric structure of the printed circuit board constitutes the dielectric layer of the frequency selective surface structure.

24. A base station, characterized in that: The base station comprises the antenna system according to any one of claims 16 to 23 and a radio frequency module connected to the antenna system.

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