CN114883809A

CN114883809A - Frequency selective surface for an antenna and antenna system

Info

Publication number: CN114883809A
Application number: CN202210568868.6A
Authority: CN
Inventors: 张茜茜; 孙静
Original assignee: Rosenberger Technologies Co Ltd
Current assignee: Rosenberger Technologies Co Ltd
Priority date: 2022-05-24
Filing date: 2022-05-24
Publication date: 2022-08-09
Also published as: WO2023226528A1

Abstract

The present disclosure relates to a frequency selective surface for an antenna, the frequency selective surface comprising: a first set of frequency selective elements, each first frequency selective element of the first set of frequency selective elements comprising a first conductive pattern; and a second set of frequency selective elements, each second frequency selective element of the second set of frequency selective elements comprising a second conductive pattern, wherein the first conductive pattern and the second conductive pattern are different. Furthermore, the present disclosure also relates to an antenna system having the above-mentioned frequency selective surface, the antenna system comprising a first antenna, a second antenna and the above-mentioned frequency selective surface, wherein the first antenna and the second antenna are respectively arranged on both sides of the frequency selective surface.

Description

Frequency selective surface for an antenna and antenna system

Technical Field

The present disclosure relates to the field of communications, and more particularly, to a frequency selective surface for an antenna and an antenna system having the same.

Background

In recent years, with the development of information communication technologies such as mobile internet and internet of things, data traffic is continuously and explosively increasing. The number of 5G base stations is rapidly increasing, and the problem of shortage of site resources is increasingly appearing.

In order to rapidly deploy 5G communication equipment, a 5G site is mainly implemented by adding a 5G antenna and equipment to the original 4G site resources, so that a multi-frequency base station antenna becomes the mainstream. The 4G and 5G integrated active and passive integrated base station antenna has more advantages in space size, wind load and management, is widely accepted and applied in the 5G base station deployment process, and is an important direction for the future base station antenna evolution. In this case, the frequency selective surface becomes an important choice.

The conventional frequency selective surface can reflect electromagnetic waves of a certain frequency band and transmit electromagnetic waves of another frequency band. Therefore, the radiation units with different frequency bands can be distributed on the same side of the reflecting plate and can also be distributed on two sides of the reflecting plate, the flexibility of the antenna in deployment is improved, and base station resources are saved.

However, since the working environment of a 4G and 5G integrated multi-frequency base station antenna is generally complex, electromagnetic waves radiated by a radiation unit in a certain working frequency band are affected by not only radiation units in other working frequency bands, but also components of each part of the antenna, and the frequency selection surface cannot adjust wave front or beam width or direction.

Disclosure of Invention

The method aims to solve the technical problem in the prior art, namely how to adjust the wave front, the beam width or the beam direction of an emergent wave.

To achieve the above technical effects, a first aspect of the present disclosure proposes a frequency selective surface for an antenna, the frequency selective surface including:

a first set of frequency selective elements, each first frequency selective element of the first set of frequency selective elements comprising a first conductive pattern; and

a second set of frequency selective cells, each second frequency selective cell of the second set of frequency selective cells comprising a second conductive pattern, wherein the first conductive pattern and the second conductive pattern are different.

In the frequency selective surface for an antenna according to the present disclosure, since the first conductive pattern and the second conductive pattern are different, an effect of achieving an optimal adjustment of an outgoing wave by means of the frequency selective surface for an antenna can be achieved.

Preferably, in one embodiment according to the present disclosure, the shape of the first conductive pattern is associated with a first phase shift and the shape of the second conductive pattern is associated with a second phase shift, wherein the first phase shift is different from the second phase shift. In this way, since the first conductive pattern and the second conductive pattern are different, the first phase shift formed by the first conductive pattern and the second phase shift formed by the second conductive pattern are made different, so that different phase shifts can be introduced for the electromagnetic wave passing through the respective conductive patterns, thereby achieving an effect of achieving an optimal adjustment for the outgoing wave by means of the frequency selective surface for the antenna.

Preferably, in one embodiment according to the present disclosure, the first group of frequency selective elements is disposed in the middle of the frequency selective surface and the second group of frequency selective elements is disposed on both sides of the first group of frequency selective elements, and wherein the first phase shift is smaller than the second phase shift or the first phase shift is larger than the second phase shift.

Preferably, in an embodiment according to the present disclosure, the first group of frequency selective elements is located in one row or column, and the second group of frequency selective elements is located in another row or column. In this way the directivity of the outgoing wave can be further optimized.

Further preferably, in an embodiment according to the present disclosure, the frequency selection surface further includes a third set of frequency selection units, each of the third set of frequency selection units includes a third conductive pattern, wherein the third conductive pattern is different from both the first conductive pattern and the second conductive pattern. In this way, since the first conductive pattern, the second conductive pattern, and the third conductive pattern are all different, the first phase shift formed by the first conductive pattern, the second phase shift formed by the second conductive pattern, and the third phase shift formed by the third conductive pattern are made different, so that different phase shifts can be introduced for the electromagnetic wave passing through the respective conductive patterns, thereby achieving an effect of achieving an optimum adjustment for the outgoing wave by means of the frequency selective surface for the antenna.

Preferably, in one embodiment according to the present disclosure, the third conductive pattern has a shape associated with a third phase shift, and wherein the third phase shift is different from both the first phase shift and the second phase shift. In this way, since the third conductive pattern is different from both the first conductive pattern and the second conductive pattern, the first phase shift formed by the first conductive pattern, the second phase shift formed by the second conductive pattern, and the third phase shift formed by the third conductive pattern are different, so that different phase shifts can be introduced to the electromagnetic wave passing through the respective conductive patterns, thereby achieving an effect of achieving an optimum adjustment of the outgoing wave by means of the frequency selective surface for the antenna.

Preferably, in one embodiment according to the present disclosure, the frequency selective surface further includes a parasitic element disposed at an edge of the frequency selective surface. The parasitic element is used for optimizing the directional diagram of the radiation element deteriorated by the border environment, thereby effectively improving the radiation directional diagram of the multi-frequency base station antenna. Further preferably, in one embodiment according to the present disclosure, the parasitic element is configured as a square metal sheet.

Preferably, in an embodiment according to the present disclosure, the frequency selective surface further includes a metal layer, the metal layer is provided with a plurality of hollow areas, and the first conductive pattern and the second conductive pattern are respectively disposed in the hollow areas. Still preferably, in an embodiment according to the present disclosure, a distance between the first conductive pattern and the ground layer is a first pitch and a distance between the second conductive pattern and the metal layer is a second pitch, and wherein the first pitch and the second pitch are not equal.

Still preferably, in an embodiment according to the present disclosure, the first conductive pattern or the second conductive pattern includes at least two metal patches, and wherein the at least two metal patches have a gap therebetween. Further preferably, in one embodiment according to the present disclosure, one of the at least two metal patches is provided with a groove and the other is provided with a protrusion, the protrusion being at least partially located within the groove. Still further preferably, in an embodiment according to the present disclosure, the number of the metal patches is 4, and each of the metal patches has the same shape.

Optionally or alternatively, in an embodiment according to the present disclosure, the number of the second group of frequency selective elements is twice the number of the first group of frequency selective elements, and wherein the first group of frequency selective elements is located between a pair of the second group of frequency selective elements.

Furthermore, a second aspect of the present disclosure proposes an antenna system comprising: a first antenna, a second antenna, and a frequency selective surface as set forth in accordance with a first aspect of the present disclosure, wherein the first antenna and the second antenna are respectively disposed on both sides of the frequency selective surface.

Preferably, in one embodiment according to the present disclosure, the first antenna and the second antenna are respectively configured as independent structures. Further preferably, in an embodiment according to the present disclosure, the antenna system further includes a radome of the first antenna and a radome of the second antenna, which are respectively configured to protect the first antenna and the second antenna, wherein the radome of the first antenna and the radome of the second antenna include mounting and fixing structures adapted to each other.

Preferably, in one embodiment according to the present disclosure, the frequency selective surface is disposed in the radome of the first antenna or the radome of the second antenna.

Preferably, in one embodiment according to the present disclosure, the first antenna is configured as a 5G antenna and the second antenna is configured as a non-5G antenna.

Preferably, in one embodiment according to the present disclosure, the antenna system further comprises a support configured to support the frequency selective surface, and wherein a feed cable for feeding the first antenna or the second antenna runs along the support. Further preferably, in one embodiment according to the present disclosure, a feed cable for feeding the first antenna or the second antenna is routed along a ground grid line of the frequency selective surface.

In summary, in the technical solution according to the present disclosure, since the first conductive pattern and the second conductive pattern are different, different phase shifts can be introduced to the electromagnetic wave passing through the corresponding conductive patterns, so as to achieve an effect of realizing an optimal adjustment of the outgoing wave by means of the frequency selective surface for the antenna.

Drawings

The features, advantages and other aspects of various embodiments of the present disclosure will become more apparent by referring to the following detailed description in conjunction with the accompanying drawings, in which several embodiments of the present disclosure are shown by way of illustration and not limitation, wherein:

FIG. 1 shows a schematic diagram of a frequency selective surface for an antenna according to the present disclosure;

FIG. 2 shows a schematic of a structure of a frequency selective surface 200 for an antenna according to the present disclosure;

FIG. 3A shows a schematic structural diagram of a frequency selective surface 300A for an antenna in accordance with one embodiment of the present disclosure;

FIG. 3B shows a schematic structural diagram of a frequency selective surface 300B for an antenna in accordance with another embodiment of the present disclosure;

fig. 3C shows a schematic structural diagram of a frequency selective surface 300C for an antenna according to yet another embodiment of the present disclosure;

fig. 3D shows a schematic structural diagram of a frequency selective surface 300D for an antenna according to yet another embodiment of the present disclosure;

FIG. 4 shows a schematic structural diagram of a frequency selective surface 400 for an antenna in accordance with another embodiment of the present disclosure;

fig. 5A illustrates an assembled schematic of an active and passive integrated antenna system 500 according to one embodiment of the present disclosure;

fig. 5B illustrates an exploded schematic view of the antenna system 500 shown in fig. 5A; and

fig. 5C shows a wiring schematic of the feeder cable 41 of the radiating element 4 in fig. 5B.

Detailed Description

Various exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Although the exemplary methods, apparatus, and devices described below include software and/or firmware executed on hardware among other components, it should be noted that these examples are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of the hardware, software, and firmware components could be embodied exclusively in hardware, exclusively in software, or in any combination of hardware and software. Thus, while the following describes example methods and apparatus, persons of ordinary skill in the art will readily appreciate that the examples provided are not intended to limit the manner in which the methods and apparatus may be implemented.

Furthermore, the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of methods and systems according to various embodiments of the present disclosure. It should be noted that the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

As described above, the prior art has a technical problem that the wavefront of an incident wave in a conventional antenna generally cannot be adjusted by a frequency selective surface, so that the radiation pattern of the antenna does not achieve an ideal effect. In view of this technical problem, the inventors of the present disclosure newly conceived to change the structure of the frequency selective surface, i.e., the conductive pattern, thereby achieving an optimal adjustment for the outgoing wave. In summary, the present disclosure provides a novel Frequency Selective Surface (FSS), the panel having the Frequency selective Surface has the function of selecting Frequency of a conventional Frequency selective Surface, i.e. the Frequency band in the working Frequency band of a certain radiation unit is a pass band, which has little influence on the radiation performance of the radiation unit and is approximately equivalent to a layer of air; and the other radiation unit is a stop band in the working frequency band, the reflectivity of the radiation signal of the radiation unit is close to 100 percent, and the reflectivity is close to equivalent to a continuous metal surface. In addition, the frequency selective surface according to the present disclosure is accompanied by a function of modulating the outgoing wave, which is mainly realized by modifying the conductive pattern of the specific unit of the frequency selective surface of the portion, so that the modified specific unit of the frequency selective surface introduces different phase shifts, thereby achieving an effect of modulating the outgoing wave.

In addition, since the edge-column environment of the multi-frequency base station antenna is usually complex, including the supporting members, cables, metal supporting frames, etc., the edge-column pattern is deteriorated seriously. In view of this problem, the inventors of the present disclosure also innovatively think of additionally adding a row of parasitic elements on each side of the frequency selective surface according to the present disclosure for optimizing the patterns of the radiating elements deteriorated by the side-row environment, thereby effectively improving the radiation patterns of the multi-frequency base station antenna.

In order to be able to more clearly describe the frequency selective surface for an antenna disclosed according to the present disclosure, before describing the frequency selective surface for an antenna according to the present disclosure, the influence of the conductive pattern on the electromagnetic wave pattern will be described first.

According to the working principle of the antenna array, currents with different phases are fed into each radiating unit, and the effect of controlling the beam width and the beam direction can be achieved. Fig. 1 shows a schematic diagram of a frequency selective surface for an antenna according to the present disclosure. As shown in fig. 1, the signal radiated by the radiation unit may regulate a beam width or regulate a beam pointing direction after being subjected to a frequency selective surface treatment including the conductive pattern 110, the conductive pattern 120, and the conductive pattern 130. The

conductive patterns

110, 120, 130 are used to refer to different conductive patterns. In which the conductive pattern 110 delays the phase of the signal by 0 degrees, the conductive pattern 120 delays the phase of the signal by γ, and the conductive pattern 130 delays the phase of the signal by 2 γ. At this time, after the processing of the frequency selective surface including the three different

conductive patterns

110, 120, and 130, the beam width or beam direction of the outgoing wave is regulated.

In summary, based on the above principle, the inventors of the present disclosure can modify the conductive patterns of the units in the conventional frequency selective surface, so that the conductive patterns of the units of the frequency selective surface at different positions can introduce desired phase shifts, thereby realizing the modulation of the beam. Here, the phase shift is a difference between a phase of the signal on the propagation path after passing through the frequency selective surface and a phase thereof before passing through the frequency selective surface. When the phase shift is less than zero, phase delay is indicated; when the phase shift is greater than zero, a phase lead is indicated. The operation principle of the frequency selective surface is as shown in fig. 1, in which each cell of each frequency selective surface has a different structure, i.e. a different conductive pattern, and such different structure also generates a different phase shift for the incident wave, so that the beam of the outgoing wave transmitted through the frequency selective surface is shifted compared to the incident wave. Of course, the actual incident wave is not necessarily an ideal plane wave, but by adjusting the conductive patterns of the units of the frequency selective surfaces, the units of the frequency selective surfaces generate different phase shifts, and the effects of regulating the beam width and the beam direction can still be achieved. It is noted that the frequency selective function of the frequency selective surface does not disappear while the additional function is implemented. That is, for a certain frequency band equivalent to a metal plate, all signals are reflected back; at the same time, the signal is transparent with respect to the other frequency band, i.e., does not have any influence on the signal of the other frequency band.

The present disclosure is based on the above two theories, and the present disclosure provides a frequency selective surface with a function of adjusting and controlling an antenna directional pattern, and the structure of the frequency selective surface is shown in fig. 2. The panel has the characteristic of frequency selection, and can achieve the effect of beam forming according to the compensation of the transmission phase of the electromagnetic waves. Since the path difference between the phase center and each frequency selective surface unit causes a corresponding phase difference when the spherical wavefront radiated by the radiation element reaches the frequency selective surface, the frequency selective surface unit is required to compensate the phase difference of different paths in order to convert the spherical wavefront into a desired wavefront. The present disclosure realizes phase compensation by varying the size or structure of each element of the frequency selective surface so that the phase shift of the electromagnetic wave at different positions through the frequency selective surface is different. Fig. 2 shows the conductive pattern of 3 different frequency selective surfaces employed by the panel of the present disclosure, resulting in a graded structure of the frequency selective surfaces. For example, the transmission phase of the conductive pattern 220 of the frequency selective surface lags behind the conductive pattern 210 of the frequency selective surface by about 10 degrees, and the transmission phase of the conductive pattern 230 of the frequency selective surface lags behind the conductive pattern 220 of the frequency selective surface by about 10 degrees. Thus, the different frequency selective surface elements direct the electromagnetic energy into a desired radiation direction, thereby widening the lobe width of the antenna pattern.

In particular, based on such principles, the inventors of the present disclosure innovatively contemplate involving frequency selective surfaces having different conductive patterns. Fig. 2 shows a schematic of a structure of a frequency selective surface 200 for an antenna according to the present disclosure. In particular, fig. 2 shows a schematic diagram of a frequency selective surface 200 in accordance with one possible implementation form of the inventive concepts of the present disclosure. As can be seen from fig. 2, the frequency selective surface includes a dielectric layer (e.g., the lower portion of the white region and the black region in fig. 2) and a metal layer (e.g., the black frame portion in fig. 2). The metal area can be grounded, i.e. form a ground plane, for example. As can be seen from fig. 2, the metal layer is provided with a hollow-out area. In the example shown in fig. 2, the metal layer includes three conductive patterns, which are, from left to right, a conductive pattern 210, a conductive pattern 220, and a conductive pattern 230, wherein the three

conductive patterns

210, 220, and 230 are disposed in the hollow area.

As can be seen from fig. 2, if the distance between the conductive pattern 210 and the ground layer, i.e., the black frame portion, is a first pitch and the distance between the conductive pattern 220 and the ground layer, i.e., the black frame portion, is a second pitch. For example, the top edge of the conductive pattern 210 is spaced apart from the black frame portion by a first distance, and the top edge of the conductive pattern 220 is spaced apart from the black frame portion by a second distance, which is obviously not equal in the example of fig. 2, and the first distance may be larger than the second distance.

Those skilled in the art will appreciate that the three conductive patterns herein are merely exemplary and not limiting. The inventive idea underlying the present disclosure is primarily that different conductive patterns introduce different phase shifts for the processed signal, so that a frequency selective surface according to the present disclosure should have at least two different conductive patterns, and to the extent that several conductive patterns are included, it can be designed according to specific requirements, and a frequency selective surface comprising at least two different conductive patterns will fall within the scope of the claims as claimed in accordance with the present disclosure.

As shown in fig. 2, the frequency selective surface conductive pattern employed in the present disclosure is not a monolithic piece of metal. In general, the conductive pattern 210 or the conductive pattern 220 includes at least two metal patches, 4 metal patches in the example shown in fig. 2, and each metal patch has the same shape. Any two of the metal patches have a gap between them. Furthermore, as can be seen from fig. 2, recesses and/or projections are provided in the metal patch, which projections can, for example, be located at least partially within the recesses. The metal patch becomes gradually larger from left to right, and accordingly, the distance from the top edge of the metal patch to the ground layer, namely the black frame part, becomes smaller and smaller, so that the frequency selection surface can form a gradual structure. The effect of changing the transmission phase can be achieved by changing the size of the space without changing the size of the period of the frequency selective surface, so that the frequency selective surface can be ensured to have frequency selective surface units with the same period, and the distribution of the gradual frequency selective surface units is simpler and more flexible.

The number of the conductive patterns of the different frequency selective surfaces employed in the present disclosure is not limited to 3, and may be a plurality of different conductive patterns of the frequency selective surfaces. Here, the conductive pattern is mainly composed of a metal patch and a gap between different metal patches, and preferably, the metal patch distribution may include a plurality of metal patches, and a gap can be provided between the plurality of metal patches. Further, the hollow portion formed by the first pitch or the second pitch may be formed between the metal sheet and the frame.

Further preferably, in an embodiment according to the present disclosure, the first group of frequency selective elements is disposed in the middle of the frequency selective surface and the second group of frequency selective elements is disposed on both sides of the first group of frequency selective elements, and wherein the first phase shift is smaller than the second phase shift or the first phase shift is larger than the second phase shift. In other words, the phase shift of the conductive pattern of the frequency selective surface may be larger from the center toward both sides or smaller from the center toward both sides. Therefore, the frequency selection surface with the expanded beam width can be designed, the frequency selection surface with the compressed beam width can be designed, and even the frequency selection surface with the changed beam direction can be designed, so that the directional diagram can be flexibly regulated. In addition, the distribution of the frequency selective surface units is not limited to the distribution in the edge columns, and may be distributed according to different requirements, such as the distribution in the middle column, the distribution in the center radial, and the like.

Here, the present disclosure proposes a frequency selective surface having a function of a directivity pattern, which may be a single-layer or multi-layer planar structure, and may also be a band-pass frequency selective surface or a high-pass frequency selective surface.

A frequency selective surface for an antenna proposed according to the present disclosure is described below with reference to fig. 3A to 5C. Wherein, fig. 3A shows a schematic structural view of a frequency selective surface 300A for an antenna according to one embodiment of the present disclosure, fig. 3B shows a schematic structural view of a frequency selective surface 300B for an antenna according to another embodiment of the present disclosure, fig. 3C shows a schematic structural view of a frequency selective surface 300C for an antenna according to still another embodiment of the present disclosure, and fig. 3D shows a schematic structural view of a frequency selective surface 300D for an antenna according to still another embodiment of the present disclosure.

As can be seen from the four implementations of fig. 3A to 3D: the frequency selective surface 300A for an antenna shown in fig. 3A includes only two kinds of conductive patterns, and there is only one column of each conductive pattern in succession; the frequency selective surface 300B for an antenna shown in fig. 3B also includes only two kinds of conductive patterns, but there are two columns of each conductive pattern in series; the frequency selection surface 300C for an antenna shown in fig. 3C includes three kinds of conductive patterns, and the middle conductive patterns exist in two columns in series; the frequency selective surface 300D for an antenna shown in fig. 3D includes three kinds of conductive patterns, and the central conductive patterns are continuously present in a plurality of columns.

In particular, the frequency selective surface 300A for an antenna shown in fig. 3A includes four rows and three columns of conductive patterns. In summary, the frequency selective surface 300A according to the present disclosure includes a first set of frequency selective elements 310A, each of which first frequency selective elements 310A includes a first conductive pattern 3101A, the conductive pattern shown in the middle. Furthermore, the frequency selective surface 300A according to the present disclosure further comprises a second group of frequency selective cells 320A, each of the second group of frequency selective cells 320A comprising a second conductive pattern 3201A, i.e. the conductive pattern shown by the edge. As can be seen in fig. 3A, the first conductive pattern 3101A and the second conductive pattern 3201A are different. As can be seen from fig. 3A, if the distance between the conductive pattern 3101A and the ground layer, i.e., the black frame portion, is a first pitch and the distance between the conductive pattern 3102A and the metal layer is a second pitch. For example, the top side of conductive pattern 3101A may be spaced apart from the black frame portion by a first pitch, and the top side of conductive pattern 3102A may be spaced apart from the black frame portion by a second pitch, which may be significantly different in the example of FIG. 3A and may be greater than the second pitch. In the frequency selective surface 300A for an antenna according to the present disclosure, since the first conductive pattern 3101A and the second conductive pattern 3201A are different, it is possible to achieve an effect of achieving an optimal adjustment of an outgoing wave by means of the frequency selective surface 300A for an antenna. Here, the black frame, e.g., 330A, of the outer periphery of each conductive pattern constitutes a ground layer.

Furthermore, as shown in fig. 3A, the conductive pattern of the frequency selective surface employed by the present disclosure is not a unitary piece of metal. In general, the conductive pattern 3101A or the conductive pattern 3102A includes at least two metal patches, 4 metal patches are included in the example shown in fig. 3A, and the shape of each metal patch is the same. Any two of the metal patches have a gap between them. Furthermore, as can be seen from fig. 3A, recesses and/or projections are provided in the metal patch, which projections can be located at least partially within the recesses, for example.

More specifically, the shape of the first conductive pattern 3101A is associated with a first phase shift and the shape of the second conductive pattern 3201A is associated with a second phase shift, wherein the first phase shift is different from the second phase shift. In this way, since the first conductive pattern 3101A and the second conductive pattern 3201A are different, the first phase shift formed by the first conductive pattern 3101A and the second phase shift formed by the second conductive pattern 3201A are made different, so that different phase shifts can be introduced to the electromagnetic wave passing through the respective conductive patterns 3101A or 3201A, thereby achieving an effect of achieving an optimum adjustment of the outgoing wave by means of the frequency selective surface 300A for the antenna. Here, the first group of frequency selective cells 310A is disposed in one column including four first conductive patterns 3101A, and the second group of frequency selective cells 320A is disposed in two columns each including four second conductive patterns 3201A. Here, it is possible to provide several columns of frequency selective elements and to include several conductive patterns per column of frequency selective elements, which may be designed according to specific design requirements.

The frequency selective surface 300B for an antenna shown in fig. 3B includes four rows and six columns of conductive patterns. In summary, the frequency selective surface 300B according to the present disclosure comprises a first set of frequency selective elements 310B, each of which first frequency selective elements 310B comprises a first conductive pattern 3101B, i.e. the conductive pattern shown in the middle. Furthermore, the frequency selective surface 300B according to the present disclosure further comprises a second group of frequency selective cells 320B, each of the second group of frequency selective cells 320B comprising a second conductive pattern 3201B, i.e. the conductive pattern shown by the edge. As can be seen in fig. 3B, the first conductive pattern 3101B and the second conductive pattern 3201B are different. In the frequency selective surface 300B for an antenna according to the present disclosure, since the first conductive pattern 3101B and the second conductive pattern 3201B are different, it is possible to achieve an effect of achieving an optimal adjustment of an outgoing wave by means of the frequency selective surface 300B for an antenna.

More specifically, the shape of the first conductive pattern 3101B is associated with a first phase shift and the shape of the second conductive pattern 3201B is associated with a second phase shift, wherein the first phase shift is different from the second phase shift. In this way, since the first conductive pattern 3101B and the second conductive pattern 3201B are different, the first phase shift formed by the first conductive pattern 3101B and the second phase shift formed by the second conductive pattern 3201B are made different, so that different phase shifts can be introduced for the electromagnetic wave passing through the respective

conductive pattern

3101B or 3201B, thereby achieving an effect of achieving an optimum adjustment for the outgoing wave by means of the frequency selective surface 300B for the antenna. Here, the first group of frequency selective cells 310B is disposed in two columns each including four first conductive patterns 3101B, and the second group of frequency selective cells 320B is disposed in four columns each including four second conductive patterns 3201B. Here, it is possible to provide several columns of frequency selective elements and to include several conductive patterns per column of frequency selective elements, which may be designed according to specific design requirements.

The frequency selective surface 300C for the antenna shown in fig. 3C includes four rows and eight columns of conductive patterns. In summary, the frequency selective surface 300C according to the present disclosure comprises a first set of frequency selective cells 310C, each of which first frequency selective cells 310C comprises a first conductive pattern 3101C, the conductive pattern shown in the middle. Furthermore, the frequency selective surface 300C according to the present disclosure further comprises a second group of frequency selective elements 320C, each of the second group of frequency selective elements 320C comprising a second conductive pattern 3201C, i.e. the conductive patterns shown in the second, third, sixth and seventh columns. Furthermore, the frequency selective surface 300C according to the present disclosure further comprises a third set of frequency selective units 330C, each of the third set of frequency selective units 330C comprising a third conductive pattern 3301C, i.e. the conductive pattern shown by the edge.

As can be seen in fig. 3C, the third conductive pattern 3301C is different from both the first conductive pattern 3101C and the second conductive pattern 3201C. In this way, in the frequency selective surface 300C for an antenna according to the present disclosure, since the first conductive pattern 3101C, the second conductive pattern 3201C, and the third conductive pattern 3301C are all different, so that the first phase shift formed by the first conductive pattern 3101C, the second phase shift formed by the second conductive pattern 3201C, and the third phase shift formed by the third conductive pattern 3301C are different, it is possible to introduce different phase shifts for electromagnetic waves passing through the respective

conductive patterns

3101C, 3201C, and 3301C, thereby achieving an effect of achieving an optimal adjustment for an outgoing wave by means of the frequency selective surface 300C for an antenna. That is, in the frequency selective surface 300C for an antenna according to the present disclosure, since the first conductive pattern 3101C, the second conductive pattern 3201C, and the third conductive pattern 3201C are all different, an effect of achieving an optimal adjustment of an outgoing wave by means of the frequency selective surface 300C for an antenna can be achieved. Here, the first group of frequency selective cells 310C is disposed in two columns, each of which includes four first conductive patterns 3101C, the second group of frequency selective cells 320C is disposed in four columns, and the third group of frequency selective cells 330C is disposed in two columns, each of which includes four third conductive patterns 3301C. Here, it is possible to provide several columns of frequency selective elements and to include several conductive patterns per column of frequency selective elements, which may be designed according to specific design requirements.

The frequency selective surface 300D for the antenna shown in fig. 3D includes four rows and sixteen columns of conductive patterns. In summary, the frequency selective surface 300D according to the present disclosure includes a first set of frequency selective elements 310D, each of which first frequency selective elements 310D includes a first conductive pattern 3101D, the conductive pattern shown in the middle. Furthermore, the frequency selecting surface 300D according to the present disclosure further includes a second group of frequency selecting units 320D, each of the second group of frequency selecting units 320D including a second conductive pattern 3201D, i.e., the conductive patterns shown in the second column, the third column, and the second last column and the third column. Furthermore, the frequency selective surface 300D according to the present disclosure further comprises a third set of frequency selective units 330D, each of the third set of frequency selective units 330D comprising a third conductive pattern 3301D, i.e. the conductive patterns shown in the first and last-but-one columns. As can be seen in fig. 3D, the third conductive pattern 3301D is different from both the first conductive pattern 3101D and the second conductive pattern 3201D. In this manner, in the frequency selective surface 300D for an antenna according to the present disclosure, since the first conductive pattern 3101D, the second conductive pattern 3201D, and the third conductive pattern 3301D are all different, so that the first phase shift formed by the first conductive pattern 3101D, the second phase shift formed by the second conductive pattern 3201D, and the third phase shift formed by the third conductive pattern 3301D are different, it is possible to introduce different phase shifts for electromagnetic waves passing through the respective

conductive patterns

3101D, 3201D, and 3301D, thereby achieving an effect of achieving an optimal adjustment for an outgoing wave by means of the frequency selective surface 300D for an antenna. That is, in the frequency selective surface 300D for an antenna according to the present disclosure, since the first conductive pattern 3101D, the second conductive pattern 3201D, and the third conductive pattern 3201D are all different, an effect of achieving an optimal adjustment of an outgoing wave by means of the frequency selective surface 300D for an antenna can be achieved. Here, the first group of frequency selective cells 310D is disposed in ten columns, each of which includes four first conductive patterns 3101D, the second group of frequency selective cells 320D is disposed in four columns, and the third group of frequency selective cells 330D is disposed in two columns, each of which includes four third conductive patterns 3301D. Here, it is possible to provide several columns of frequency selective elements and to include several conductive patterns per column of frequency selective elements, which may be designed according to specific design requirements.

Among the four specific implementations shown in fig. 3A to 3D, the conductive pattern of the frequency selective surface adopted in the present disclosure can change the transmission phase while ensuring that the period of the frequency selective surface is not changed, so that the layout of each unit of the frequency selective surfaces with different sizes is more convenient and flexible. The frequency selective surface with the directional diagram regulating function of the present disclosure may make the phase shift of each unit of the frequency selective surface constant or gradually smaller toward the edge direction of the frequency selective surface, so as to widen the beam width of the antenna; it is also possible to make the phase shift of the individual elements of the frequency selective surface constant or gradually larger towards the edge of the frequency selective surface for compressing the beam width of the antenna. Of course, it is understood from the above description that the phase shifts of the respective elements of the frequency selective surface may be distributed in a staggered manner, i.e. for example, first becoming larger, then becoming smaller, and then becoming larger, so as to adjust the antenna pattern. In the frequency selection table with the directional diagram regulating function of the present disclosure, each unit of the frequency selection surface generating different phase shifts may be distributed in a partial region of the frequency selection surface, that is, the shape changes along only one direction; or may be distributed over the entire frequency selective surface, i.e. the shape varies in one direction only; or may be radially distributed on a portion or the entire frequency selective surface in the center.

Fig. 4 shows a schematic structural diagram of a frequency selective surface 400 for an antenna according to another embodiment of the present disclosure. The frequency selective surface 400 for an antenna shown in fig. 4 includes four rows and eighteen columns of conductive patterns. In summary, the frequency selective surface 400 according to the present disclosure comprises a first set of frequency selective cells 410, each first frequency selective cell of said first set of frequency selective cells 410 comprising a first electrically conductive pattern 4101, i.e. the electrically conductive pattern shown in the middle. Furthermore, the frequency selective surface 400 according to the present disclosure further comprises a second set of frequency selective elements 420, each of the second set of frequency selective elements 420 comprising a second conductive pattern 4201, i.e. the conductive patterns shown in the third, fourth and third to last and fourth columns. Furthermore, the frequency selective surface 400 according to the present disclosure further comprises a third set of frequency selective cells 430, each of the third set of frequency selective cells 430 comprising a third conductive pattern 4301, i.e. the conductive patterns shown in the second and penultimate columns. Furthermore, the frequency selective surface 400 shown in fig. 4 further comprises a parasitic element 440, said parasitic element 440 being arranged at an edge of said frequency selective surface 440. Wherein the parasitic element 440 includes a pattern 4401. The parasitic element 440 is used to optimize the pattern of the radiating element deteriorated by the border environment, thereby effectively improving the radiation pattern of the multi-frequency base station antenna. Further preferably, in one embodiment according to the present disclosure, the parasitic element 440 is configured as a square metal sheet. That is, according to the inventive concept of the present disclosure, parasitic elements are added to both sides of the frequency selective surface, so that the directional patterns of the edge-row radiating elements can be effectively improved. The parasitic cells 440 of the present disclosure are shown in fig. 4 as squares, but are not limited to squares. Moreover, the number and the position of the parasitic elements 440 in the present disclosure are not limited, and can be adjusted according to actual requirements. In addition, the parasitic elements 440 of the present disclosure can be added on both sides of the frequency selective surface having the function of a directivity pattern, or on both sides of the conventional periodic non-gradual frequency selective surface. Furthermore, the parasitic element 440 of the present disclosure can be used to both broaden the pattern of the side columns of radiating elements and narrow the pattern of the side columns of radiating elements.

In summary, to further broaden the pattern of the side columns of radiating elements, the present disclosure adds parasitic elements on both sides of the frequency selective surface that function as a steering antenna pattern, as shown in fig. 4. The parasitic elements operate in the operating frequency band of the radiation elements needing to widen the directional diagram, the number and the relative positions of the parasitic elements are related to the positions and the number of the radiation elements needing to widen the directional diagram, and the shape of the parasitic elements can be a square but is not limited to the square. In this way, parasitic elements on both sides of the frequency selective surface having a function of controlling the pattern can further broaden the pattern of the side columns of radiating elements. Similarly, the parasitic elements may be added on both sides of a conventional periodic non-tapered frequency selective surface to broaden or narrow the pattern of the side columns of radiating elements.

In addition, as can be seen from fig. 4, the third conductive pattern 4301 is different from both the first conductive pattern 4101 and the second conductive pattern 4201. In this manner, in the frequency selective surface 400 for an antenna according to the present disclosure, since the first conductive pattern 4101, the second conductive pattern 4201, and the third conductive pattern 4301 are all different, so that the first phase shift formed by the first conductive pattern 4101, the second phase shift formed by the second conductive pattern 4201, and the third phase shift formed by the third conductive pattern 4301 are different, it is possible to introduce different phase shifts for electromagnetic waves passing through the respective

conductive patterns

4101, 4201, and 4301, thereby achieving an effect of achieving optimum adjustment of outgoing waves by means of the frequency selective surface 400 for an antenna. In other words, in the frequency selective surface 400 for an antenna according to the present disclosure, since the first conductive pattern 4101, the second conductive pattern 4201 and the third conductive pattern 4301 are different, an effect of achieving an optimum adjustment of an outgoing wave by means of the frequency selective surface 400 for an antenna can be achieved. Here, the first group of frequency selective cells 410 is arranged in ten columns each including four first conductive patterns 4101, the second group of frequency selective cells 420 is arranged in four columns, and the third group of frequency selective cells 430 is arranged in two columns each including four third conductive patterns 4301. Here, it is possible to provide several columns of frequency selective elements and to include several conductive patterns per column of frequency selective elements, which may be designed according to specific design requirements.

Fig. 5A illustrates an assembly schematic of an active and passive integrated antenna system 500 according to one embodiment of the present disclosure. The antenna system proposed according to the present disclosure, illustrated in fig. 5A, comprises a first antenna, a second antenna, and a frequency selective surface as described according to the above aspect of the present disclosure, wherein the first antenna and the second antenna are respectively disposed on both sides of the frequency selective surface. Since fig. 5A is an assembly view, the frequency selective surface proposed according to the present disclosure is not seen. But the mounting bracket 13 of the first antenna, the radome top 1 of the second antenna, and the radome bottom 7 of the second antenna can be seen.

Fig. 5B illustrates an exploded schematic view of the antenna system 500 shown in fig. 5A. As shown in fig. 5B, the antenna system 500 shown in this embodiment includes a first antenna 9 and a second antenna 4, and the first antenna 9 and the second antenna 4 are antennas operating in different operating frequency bands. Illustratively, the first antenna 9 is a 5G antenna and the second antenna 4 is a 2G, 3G or 4G antenna. With continued reference to fig. 5B, the antenna system 500 in this embodiment further includes a radome top 1 of the second antenna, a radome support 2 of the second antenna, a second antenna support 3, a frequency selective surface 5, a metal frame support 6, a radome bottom 7 of the second antenna, a radome 8 of the first antenna, a first reflector plate 10, a fixture 11, and a first radio remote unit RRU 12. The first reflector plate 10 is fixed above the first remote radio unit RRU 12 by a fixing member 11, the first antenna 9 is disposed above the first reflector plate 10, and the radome 8 of the first antenna is fixed above the first remote radio unit RRU 12 by screws, and covers the first antenna 9 and the first reflector plate 10 thereunder. The above-described unit may be regarded as an a-antenna module. The frequency selective surface 5 is fixed above an antenna housing bottom 7 of the second antenna through a metal frame support 6, the second antenna 4 comprises a second antenna radiator, a second antenna feed balun, a second antenna substrate and a second antenna feed cable 41, the upper end of the second antenna feed balun is electrically connected with the second antenna radiator, the lower end of the second antenna feed balun is electrically connected with the second antenna substrate and is fed by the second antenna feed cable, and the second antenna feed cable is fixed above the metal frame support 6. The frequency selective surface 5 is open-circuited for the first antenna 9 and is structured as a ground for the second antenna 4. Two rows of enlarged frequency selective surface units with different sizes are arranged on two sides of the frequency selective surface 5, so that the directional diagram of the radiation unit can be widened. Further, a row of parasitic elements is added on each side of the frequency selective surface 5, for widening the radiation pattern of the side row of radiating elements. The above-described unit may be regarded as a P-antenna module. Continuing to refer to fig. 5B, for example, an existing base station is provided with a P antenna module, and when an a antenna module needs to be added, the a antenna module and the P antenna module are fixed together through the mounting bracket 13, and then can work together. By adopting the mode, the communication frequency range of the base station can be increased without large-scale modification and extension of the existing base station, and the communication effect of the base station is improved. Meanwhile, the antenna module A and the antenna module P can respectively and independently work, so that the modularization degree of the antenna is improved, the flexibility of the base station antenna is improved, and the construction cost of the base station antenna is saved.

To reduce the effect of the second antenna feed cable 41 on the edge column radiation pattern of the first antenna 9, the second antenna feed cable 41 may be routed along the ground grid lines of the frequency selective surface 5. Fig. 5C shows a wiring schematic of the feed cable of the radiating element in fig. 5B. Further, the second antenna feed cable 41 may be soldered to the ground grid of the frequency selective surface 5, thereby substantially eliminating the influence of the transverse runs of the second antenna feed cable 41 on the radiation pattern of the first antenna 9. Further, the second antenna feed cable 41 may be routed away from the first antenna 9, above the metal frame support 6. Further, the second antenna feed cable 41 may be hidden inside the metal frame support 6, thereby substantially eliminating the influence of the vertical runs of the second antenna feed cable 41 on the radiation pattern of the first antenna 9, as shown in fig. 5C. That is, the present disclosure welds the transverse traces of the second antenna feed cable to the ground grid of the frequency selective surface, thereby substantially eliminating the effect of the transverse traces of the second antenna feed cable on the radiation pattern of the first antenna. The present disclosure conceals the vertical trace of the second antenna feed cable inside the metal frame support, thereby substantially eliminating the effect of the vertical trace of the second antenna feed cable on the radiation pattern of the first antenna.

In summary, in the technical solution according to the present disclosure, since the first conductive pattern and the second conductive pattern are different, different phase shifts can be introduced to the electromagnetic wave passing through the corresponding conductive patterns, so as to achieve an effect of realizing an optimal adjustment of the outgoing wave by means of the frequency selective surface for the antenna. That is, the present disclosure adds a function of adjusting and controlling a directional pattern to a conventional frequency selective surface to form a frequency selective surface of a gradual change structure, and the frequency selective surface according to the present disclosure not only has a frequency selective function, but also can effectively improve a directional pattern of a radiation unit.

In the foregoing embodiments, the pattern on the frequency selective surface can generate, for example, a phase delay, but in other embodiments, the pattern on the frequency selective surface can be designed so that the phase is advanced, and a similar effect can be achieved.

The above description is only an alternative embodiment of the present disclosure and is not intended to limit the embodiment of the present disclosure, and various modifications and variations of the embodiment of the present disclosure may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present disclosure should be included in the scope of protection of the embodiments of the present disclosure.

Although embodiments of the present disclosure have been described with reference to several particular embodiments, it should be understood that embodiments of the present disclosure are not limited to the particular embodiments disclosed. The embodiments of the disclosure are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A frequency selective surface for an antenna, the frequency selective surface comprising:

a first set of frequency selective elements, each of the first frequency selective elements of the first set of frequency selective elements comprising a first conductive pattern; and

a second set of frequency selective elements, each second frequency selective element of the second set of frequency selective elements comprising a second conductive pattern, wherein the first conductive pattern and the second conductive pattern are different.

2. The frequency selective surface of claim 1, wherein a shape of the first conductive pattern is associated with a first phase shift and a shape of the second conductive pattern is associated with a second phase shift, wherein the first phase shift is different from the second phase shift.

3. The frequency selective surface of claim 2, wherein the first set of frequency selective elements is disposed in the middle of the frequency selective surface and the second set of frequency selective elements is disposed on both sides of the first set of frequency selective elements, and wherein the first phase shift is smaller or larger than the second phase shift.

4. The frequency selective surface of claim 1, wherein the first set of frequency selective elements are located in one row or column and the second set of frequency selective elements are located in another row or column.

5. The frequency selective surface of claim 1, further comprising:

a third set of frequency selective elements, each of the third set of frequency selective elements comprising a third conductive pattern, wherein the third conductive pattern is different from both the first conductive pattern and the second conductive pattern.

6. The frequency selective surface of claim 5, wherein the third conductive pattern has a shape associated with a third phase shift, and wherein the third phase shift is different from both the first phase shift and the second phase shift.

7. The frequency selective surface of claim 1, further comprising:

a parasitic element disposed at an edge of the frequency selective surface.

8. The frequency selective surface of claim 7, wherein the parasitic element is configured as a square metal sheet.

9. The frequency selective surface of claim 1, further comprising a metal layer having a plurality of hollowed-out regions, and wherein the first conductive pattern and the second conductive pattern are disposed in the hollowed-out regions, respectively.

10. The frequency selective surface of claim 9, wherein a distance between the first conductive pattern and a ground layer is a first pitch and a distance between the second conductive pattern and a metal layer is a second pitch, and wherein the first pitch and the second pitch are not equal.

11. The frequency selective surface of claim 1, wherein the first or second conductive pattern comprises at least two metal patches, and wherein the at least two metal patches have a gap therebetween.

12. Frequency selective surface according to claim 11, wherein one of the at least two metal patches is provided with a recess and the other is provided with a protrusion, the protrusion being at least partially located within the recess.

13. The frequency selective surface of claim 12, wherein the number of metal patches is 4 and each metal patch has the same shape.

14. The frequency selective surface of claim 1, wherein the number of frequency selective elements of the second set is twice the number of frequency selective elements of the first set, and wherein the frequency selective elements of the first set are located between a pair of the frequency selective elements of the second set.

15. An antenna system, characterized in that the antenna system comprises:

a first antenna;

a second antenna; and

the frequency selective surface of any one of claims 1 to 14, wherein the first antenna and the second antenna are disposed on either side of the frequency selective surface.

16. The antenna system of claim 15, wherein the first antenna and the second antenna are each configured as a separate structure.

17. The antenna system of claim 16, further comprising a first antenna radome and a second antenna radome configured to protect the first antenna and the second antenna, respectively, wherein the first antenna radome and the second antenna radome comprise mounting fixtures that are adapted to each other.

18. The antenna system of claim 17, wherein the frequency selective surface is disposed within a radome of the first antenna or a radome of the second antenna.

19. The antenna system of claim 15, wherein the first antenna is configured as a 5G antenna and the second antenna is configured as a non-5G antenna.

20. The antenna system of claim 15, further comprising a support configured to support the frequency selective surface, and wherein a feed cable for feeding the first antenna or the second antenna is routed along the support.

21. The antenna system of claim 20, wherein a feed cable for feeding the first antenna or the second antenna is routed along a ground grid line of the frequency selective surface.