EP-4742453-A1 - FREQUENCY SELECTIVE SURFACE STRUCTURE, ANTENNA SYSTEM, AND BASE STATION

EP4742453A1EP 4742453 A1EP4742453 A1EP 4742453A1EP-4742453-A1

Abstract

This application provides a frequency selective surface structure, an antenna system, and a base station. The frequency selective surface structure includes a frequency selective surface, a feeding network, and a phase shifter. The frequency selective surface includes 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. The frequency selective surface structure can further reduce a transmission loss caused to avoid blocking of an antenna beam by the phase shifter, and can balance a coverage area and transmission quality of an antenna signal, thereby resolving a problem that it is difficult to arrange a phase shifter in a multi-band integrated antenna system.

Inventors

SHENG, HAIQIANG
Su, Guoyu
XIAO, WEIHONG
QIN, Wenfei
LV, JINSONG

Assignees

Huawei Technologies Co., Ltd.

Dates

Publication Date: 20260513
Application Date: 20240226

Claims (20)

A frequency selective surface structure, comprising a frequency selective surface, a feeding network, and a phase shifter, wherein 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.
The frequency selective surface structure according to claim 1, wherein the metal layer has a metal area, a hollow area is enclosed in the metal area, the feeding network and the phase shifter are integrated into the metal area, a projection of the feeding network and the phase shifter onto the metal layer along a first direction is entirely located in the metal area, and the first direction is perpendicular to a plane on which the metal layer is located.
The frequency selective surface structure according to claim 2, wherein the metal layer comprises a metal grille, the metal grille forms the metal area, and space enclosed by all grids of the metal grille jointly forms the hollow area.
The frequency selective surface structure according to claim 2, wherein the metal layer comprises a metal grille and a plurality of metal patches, the plurality of metal patches are correspondingly disposed in a plurality of grids of the metal grille, the metal grille and the metal patch form the metal area, and a gap between the metal patch and the metal grille forms the hollow area.
The frequency selective surface structure according to any one of claims 1 to 4, wherein the frequency selective surface comprises a plurality of metal layers that are stacked in the first direction and that are disposed in parallel with each other, the feeding network and the phase shifter are integrated into at least one of the plurality of metal layers, and the first direction is perpendicular to the plane on which the metal layer is located.
The frequency selective surface structure according to claim 5, wherein the plurality of metal layers comprise two metal layers, each of the two metal layers comprises two surfaces facing away from 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.
The frequency selective surface structure according to any one of claims 1 to 6, wherein the feeding network comprises a plurality of transmission line structures; and the frequency selective surface structure comprises one phase shifter, and the phase shifter is electrically connected to all of the plurality of transmission line structures; or the frequency selective surface structure comprises a plurality of phase shifters, and each of the plurality of phase shifters is electrically connected to a part of the plurality of transmission line structures.
The frequency selective surface structure according to claim 7, wherein the phase shifter comprises an external conductor, a fixed dielectric, a sliding dielectric, and at least one signal-line winding, an accommodation cavity is formed in the external conductor, and the fixed dielectric, the sliding dielectric, and the at least one signal-line winding are all accommodated in the accommodation cavity; the fixed dielectric is fastened to the external conductor, the sliding dielectric is located between the fixed dielectric and the external conductor and is slidably connected to the fixed dielectric, each of the at least one signal-line winding is wound around and fastened to the fixed dielectric, each signal-line winding is located between the fixed dielectric and the sliding dielectric, and the phase shifter is electrically connected to the feeding network through each signal-line winding; and at least a part of the external conductor is set to be of a planar structure, and the phase shifter is fastened to the metal layer through the planar structure.
The frequency selective surface structure according to claim 8, wherein the at least one signal-line winding is a plurality of signal-line windings, the plurality of signal-line windings form at least one group of signal-line windings, and each of the at least one group of signal-line windings comprises at least one signal-line winding; and the at least one signal-line winding in each group of signal-line windings is one signal-line winding or at least two signal-line windings, one terminal of the one signal-line winding forms one input terminal of the phase shifter or the at least two signal-line windings are connected at one terminal to form one input terminal of the phase shifter, the other terminal of the at least one signal-line winding forms at least one output terminal of the phase shifter, and each of the at least one output terminal is electrically connected to a corresponding transmission line structure.
The frequency selective surface structure according to any one of claims 7 to 9, wherein the plurality of transmission line structures comprise at least one first transmission line structure, each of the at least one first transmission line structure comprises an external conductor and a core, the core is wrapped in a cavity inside the external conductor, and there is an airgap between the core and the external conductor; and at least a part of the external conductor is set to be of a planar structure, and the first transmission line structure is fastened to the metal layer through the planar structure.
The frequency selective surface structure according to claim 10, wherein the first transmission line structure further comprises a plurality of support members disposed between the external conductor and the core, the plurality of support members are spaced apart along an extension direction of the core, and the core is fastened to the external conductor through the plurality of support members.
The frequency selective surface structure according to claim 10 or 11, wherein the first transmission line structure comprises a plurality of cores spaced apart; and the external conductor has one cavity, and the plurality of cores are located in the cavity; or the external conductor has a plurality of cavities that communicate with each other, the plurality of cavities are in one-to-one correspondence with the plurality of cores, and each core is located in a corresponding cavity.
The frequency selective surface structure according to any one of claims 7 to 12, wherein the plurality of transmission line structures comprise 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 comprises a conductive housing and an electrochemical cell, the electrochemical cell is wrapped in a cavity inside the conductive housing, there is an airgap between the electrochemical cell and the conductive housing, the electrochemical cell has one input terminal and a plurality of output terminals, and the input terminal of the electrochemical cell is electrically connected to the phase shifter; and at least a part of the conductive housing is set to be of a planar structure, and the second transmission line structure is fastened to the metal layer through the planar structure.
The frequency selective surface structure according to claim 13, wherein when the phase shifter comprises an external conductor, the external conductor of the phase shifter is electrically connected to the metal layer; when the feeding network comprises the plurality of transmission line structures, the plurality of transmission line structures comprise the at least one first transmission line structure, and each of the at least one first transmission line structure comprises the external conductor, the external conductor of each first transmission line structure is electrically connected to the metal layer; when the feeding network comprises the plurality of transmission line structures, the plurality of transmission line structures comprise the at least one second transmission line structure, and each of the at least one second transmission line structure comprises the conductive housing, the conductive housing of each second transmission line structure is electrically connected to the metal layer; and electrical connection manner is any one of the following: a coupling connection, a direct-current connection, or a segmented direct-current connection.
The frequency selective surface structure according to any one of claims 1 to 14, wherein the frequency selective surface structure further comprises a dielectric layer, and the metal layer is mounted at the dielectric layer.
An antenna system, comprising a ground, a plurality of antennas that are stacked in a first direction, and a plurality of feeding networks configured to feed the plurality of antennas, wherein the ground is disposed on one side of the plurality of antennas in the first direction, the antenna system further comprises the frequency selective surface structure according to any one of claims 1 to 15, the frequency selective surface structure is disposed between adjacent antennas that are stacked in the plurality of antennas, and a feeding network of the frequency selective surface structure forms a feeding network of at least one antenna away from the ground in the adjacent antennas that are stacked.
The antenna system according to claim 16, wherein the plurality of antennas comprise a first antenna and a second antenna that are stacked in the first direction, the ground is disposed on a side that is of the second antenna and that is away from the first antenna, and the frequency selective surface structure is disposed between the first antenna and the second antenna; and the first antenna and the second antenna each comprise a plurality of radiators distributed in an array, and at least a part of the feeding network of the frequency selective surface structure forms the feeding network of the first antenna, and is electrically connected to a plurality of radiators of the first antenna, to feed the plurality of radiators of the first antenna.
The antenna system according to claim 17, wherein when the frequency selective surface structure comprises two metal layers, the feeding network and a phase shifter of the frequency selective surface structure are integrated into a metal layer away from the second antenna in the two metal layers.
The antenna system according to claim 17 or 18, wherein the plurality of radiators of the first antenna form at least one column of radiators, and each of the at least one column of radiators comprises at least two radiators spaced apart along a second direction; and when the feeding network of the frequency selective surface structure comprises a plurality of transmission line structures, the transmission line structures are symmetrically distributed on two sides of each column of radiators in a third direction, a phase shifters are symmetrically distributed on the two sides of each column of radiators in the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other.
The antenna system according to any one of claims 17 to 19, wherein the plurality of antennas further comprise a third antenna, the third antenna is disposed on a side that is of the frequency selective surface structure and that is away from the ground, the third antenna comprises 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 on a plane perpendicular to the first direction; and at least a part of the feeding network of the frequency selective surface structure forms a feeding 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.

Description

This application claims priority to Chinese Patent Application No. 202310962161.8, filed with the China National Intellectual Property Administration on July 31, 2023 and entitled "FREQUENCY SELECTIVE SURFACE STRUCTURE, ANTENNA SYSTEM, AND BASE STATION", which is incorporated herein by reference in its entirety. TECHNICAL FIELD This application relates to the field of communication technologies, and in particular, to a frequency selective surface structure, an antenna system, and a base station. BACKGROUND A base station antenna is the basis of current mobile communication and plays an important role in mobile communication. A higher-rate and larger-capacity communication system needs to be designed, to meet people's increasing requirements on a mobile communication rate and a bandwidth. A base station antenna system is evolving from a 4th generation (4th generation, 4G) mobile communication technology to a 5th generation (5th generation, 5G) mobile communication technology. A current key technology is to provide a multi-band integrated antenna system for an operator. In an existing multi-band integrated antenna system, antennas on a plurality of bands are stacked, and a corresponding feeding network is disposed for each layer of antenna. Because a plurality of antennas in the antenna system are stacked, signals between the antennas on the bands interfere with each other, and consequently, an antenna radiation pattern is distorted. Structures such as a phase shifter and a frequency selective surface are usually disposed in the multi-band integrated antenna system, to reduce mutual impact between antennas on different bands and obtain a required antenna waveform. Flexible beam scanning is implemented by changing a band-pass characteristic, a band-stop characteristic, phase modulation, and the like of the feeding network, to reduce a coupling effect between the antennas on the different bands, thereby obtaining an ideal antenna waveform, increasing a coverage area of a base station antenna, and adapting to mounting and layout requirements in a plurality of scenarios. However, when antenna layout density is high, layout of the phase shifter becomes a difficult problem. Because the phase shifter needs to be connected to the feeding network of the antenna, when the plurality of antennas are stacked, a part of phase shifters need to be arranged between the stacked antennas along with the feeding network of the antenna. The phase shifter has a size, and therefore, blocks beams of a part of antennas, affecting a coverage area of an antenna signal. Consequently, a user directly feels a too slow network speed or a signal coverage hole is generated in a part of areas. To prevent the phase shifter from blocking the antenna waveform, some operators improve layout of the antenna system and the phase shifter, by using methods like separate layout or the like to stagger the phase shifter and an affected antenna. This method can mitigate, to some extent, a phenomenon that the phase shifter blocks the antenna waveform, but lead to drawbacks such as increased antenna size, less compact layout. Consequently, a transmission line structure between the phase shifter and a radiator of the antenna system is extended, resulting in a higher loss due to long-distance transmission. Therefore, in the conventional technology, it is difficult to arrange a phase shifter of a multi-band integrated antenna system, a high transmission loss is caused to avoid blocking of an antenna beam by the phase shifter, and a coverage area and transmission quality of an antenna signal cannot be balanced. SUMMARY Embodiments of this application provide a frequency selective surface structure, an antenna system, and a base station, to resolve a problem in the conventional technology that it is difficult to arrange a phase shifter in a multi-band integrated antenna system, a high transmission loss is caused to avoid blocking of an antenna beam by the phase shifter, and a coverage area and transmission quality of an antenna signal cannot be balanced. An embodiment of this application provides a frequency selective surface structure, including a frequency selective surface, a feeding network, and a phase shifter. The frequency selective surface includes 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. The frequency selective surface structure provided in this embodiment of this application can be applied to an antenna system, and both the phase shifter and the feeding network are integrated into the metal layer of the frequency selective surface. The metal layer of the frequency selective surface has a spatial filter characteristic, and a wave transmission characteristic of an antenna is changed by designing the metal layer, to meet a requirement for transmitting and adjusting and controlling of an electromagne