Frequency selective surface for antenna, and antenna system

Abstract

The present disclosure relates to a frequency selection surface for an antenna. The frequency selection surface includes: a first set of frequency selection units, of which each first frequency selection unit includes a first conductive pattern; and a second set of frequency selection units, of which each second frequency selection unit includes a second conductive pattern, wherein the first conductive pattern is different from the second conductive pattern. Besides, the present disclosure also relates to an antenna system having the frequency selection surface as described above. The antenna system includes: a first antenna, a second antenna, and the aforementioned frequency selection surface, wherein the first antenna and the second antenna are disposed on both sides of the frequency selection surface respectively.

Description

FIELD OF THE DISCLOSURE

[0001] The disclosure relates to the communication field and, more particularly, to a frequency selection surface for antenna and an antenna system with the aforementioned frequency selection surface.BACKGROUND

[0002] In recent years, with the development of information and communication technology such as Mobile Internet and the Internet of Things, data traffic experiences sustained and explosive growth. The number of 5G base stations increases rapidly, and the problem of limited base station resources is becoming increasingly apparent.

[0003] In order to quickly deploy 5G communication equipment, 5G base stations are mainly achieved by adding 5G antennas and equipment to the existing 4G base station resources, making multi-band base station antennas the mainstream. Among them, the active and passive integrated base station antennas that integrate 4G and 5G have more advantages in spatial size, wind load, and management, and are widely accepted and applied in the deployment process of 5G base stations, which is an important direction for the evolution of base station antennas in future. At this point, frequency selection surface becomes an important choice.

[0004] Traditional frequency selection surfaces can reflect electromagnetic waves in a certain frequency band and transmit electromagnetic waves in another frequency band. In this way, radiating elements of different frequency bands can be distributed on the same side of the reflector or on two sides of the reflector, which improves the flexibility of antenna deployment and saves base station resources.

[0005] However, due to the complex working environment of multi-band base station antennas that integrate 4G and 5G, the electromagnetic waves radiated by a radiating element in a certain operating band are not only affected by radiating elements in other operating bands, but also by the components of various parts of the antenna. Moreover, the frequency selection surface generally cannot adjust the wave front, beam width, or pointing direction.SUMMARY

[0006] In order to solve the technical problems in the prior art, namely to adjust the wave front, beam width or beam pointing of the outgoing wave.

[0007] In order to achieve the above technical effects, the first aspect of the present disclosure proposes a frequency selection surface for an antenna, the frequency selection surface comprising: a first set of frequency selection units, of which each first frequency selection unit includes a first conductive pattern; and a second set of frequency selection units, of which each second frequency selection unit includes a second conductive pattern, wherein the first conductive pattern is different from the second conductive pattern.

[0008] In the frequency selection surface for an antenna according to the present disclosure, due to the difference between the first conductive pattern and the second conductive pattern, it is possible to achieve the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface for an antenna.

[0009] 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, due to the difference between the first conductive pattern and the second conductive pattern, the first phase shift formed by the first conductive pattern is different from the second phase shift formed by the second conductive pattern, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns, thereby achieving the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface for an antenna.

[0010] Preferably, in one embodiment according to the present disclosure, the first set of frequency selection units is disposed in the middle of the frequency selection surface, and the second set of frequency selection units is disposed on both sides of the first set of frequency selection units, and wherein the first phase shift is smaller than the second phase shift or the first phase shift is bigger than the second phase shift.

[0011] Preferably, in one embodiment according to the present disclosure, the first set of frequency selection units is disposed in one row or column, and the second set of frequency selection units is disposed in another row or column. In this way, it may further optimize the directionality of the outgoing waves.

[0012] Further preferably, in one embodiment according to the present disclosure, the frequency selection surface further comprises a third set of frequency selection units, of which each third frequency selection unit 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, due to the fact that the first conductive pattern, the second conductive pattern, and the third conductive pattern are all different, thus 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 all different, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns, thereby achieving the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface for an antenna.

[0013] Preferably, in one embodiment according to the present disclosure, the shape of the third conductive pattern is associated with the 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, due to the fact that the third conductive pattern is different from the first conductive pattern and the second conductive pattern, thus 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 all different, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns, thereby achieving the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface for an antenna.

[0014] Preferably, in one embodiment according to the present disclosure, the frequency selection surface further comprises a parasitic element disposed at the edge of the frequency selection surface. The parasitic element is used to optimize the direction pattern of the radiating element deteriorated by the edge environment, thereby effectively improving the radiating direction pattern of the multi-band base station antenna. Further preferably, in one embodiment according to the present disclosure, the parasitic element is designed as a square piece of metal.

[0015] Preferably, in one embodiment according to the present disclosure, the frequency selection surface further comprises a metal layer, which is provided with several hollow areas, and wherein the first conductive pattern and the second conductive pattern are disposed in the hollow areas respectively. More preferably, in one embodiment according to the present disclosure, the distance between the first conductive pattern and a ground layer is a first spacing, and the distance between the second conductive pattern and the metal layer is a second spacing, and wherein the first spacing and the second spacing are not equal.

[0016] More preferably, in one embodiment according to the present disclosure, the first conductive pattern or the second conductive pattern includes at least two metal patches, and wherein there is a gap between the at least two metal patches. 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 which is at least partially positioned within the groove. More preferably, in one embodiment according to the present disclosure, the number of the metal patches is four, and each metal patch has the same shape.

[0017] Optionally or alternatively, in one embodiment according to the present disclosure, the number of the second set of frequency selection units is twice the number of the first set of frequency selection units, and wherein the first set of frequency selection units is positioned between a pair of the second sets of frequency selection units.

[0018] In addition, the second aspect of the present disclosure proposes an antenna system comprising: a first antenna, a second antenna, and the frequency selection surface according to the first aspect of the present disclosure, wherein the first antenna and the second antenna are disposed on both sides of the frequency selection surface respectively.

[0019] Preferably, in one embodiment according to the present disclosure, the first antenna and the second antenna are designed as independent structures respectively. Further preferably, in one embodiment according to the present disclosure, the antenna system further comprises an antenna cover of the first antenna and an antenna cover of the second antenna, wherein the antenna cover of the first antenna and the antenna cover of the second antenna are designed to protect the first antenna and the second antenna respectively, wherein the antenna cover of the first antenna and the antenna cover of the second antenna include fixing structures matched with one another.

[0020] Preferably, in one embodiment according to the present disclosure, the frequency selection surface is disposed in the antenna cover of the first antenna or the antenna cover of the second antenna.

[0021] Preferably, in one embodiment according to the present disclosure, the first antenna is designed as a 5G antenna, and the second antenna is designed as a non-5G antenna.

[0022] Preferably, in one embodiment according to the present disclosure, the antenna system further comprises a bracket for supporting the frequency selection surface, and wherein a feeder cable for feeding the first antenna or the second antenna is routed along the bracket. Further preferably, in one embodiment according to the present disclosure, the feeder cable for feeding the first antenna or the second antenna is routed along the grounding grid line of the frequency selection surface.

[0023] In summary, in the technical solution according to the present disclosure, due to the difference between the first conductive pattern and the second conductive pattern, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns, thereby achieving the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface for an antenna.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Combining with the drawings and referring to the following detailed description, the features, advantages, and other aspects of each embodiment of the present disclosure would become more apparent. Several embodiments of the present disclosure are shown Herein for example rather than limitation. In the drawings: FIG. 1 illustrates a principle diagram of a frequency selection surface for an antenna according to the present disclosure. FIG. 2 illustrates a schematic diagram of the structure of the frequency selection surface 200 for an antenna according to the present disclosure. FIG. 3A illustrates a schematic diagram of the structure of the frequency selection surface 300A for an antenna according to an embodiment of the present disclosure. FIG. 3B illustrates a schematic diagram of the structure of the frequency selection surface 300B for an antenna according to another embodiment of the present disclosure. FIG. 3C illustrates a schematic diagram of the structure of the frequency selection surface 300C for an antenna according to another embodiment of the present disclosure. FIG. 3D illustrates a schematic diagram of the structure of the frequency selection surface 300D for an antenna according to another embodiment of the present disclosure. FIG. 4 illustrates a schematic diagram of the structure of the frequency selection surface 400 for an antenna according to another embodiment of the present disclosure. FIG. 5A illustrates an assembly schematic diagram of an active and passive integrated antenna system 500 according to an embodiment of the present disclosure. FIG. 5B illustrates an exploded schematic diagram of the antenna system 500 shown in FIG. 5A. FIG. 5C illustrates the wiring schematic diagram of the feeder cable 41 of the radiating element 4 in FIG. 5B. DETAILED DESCRIPTION

[0025] Various exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Although the exemplary methods and apparatuses described below include software and / or firmware executed on hardware in other components, it should be noted that these examples are only illustrative and should not be regarded as limited. For example, it can be considered that any or all hardware, software, and firmware components can be implemented exclusively in hardware, exclusively in software, or in any combination of hardware and software. Therefore, although exemplary methods and apparatuses have been described below, those skilled in the art should easily appreciate that the provided examples are not used to limit the ways for implementing these methods and devices.

[0026] In addition, the flowcharts and block diagrams in the accompanying drawings illustrate the possible implemented architecture, functions, and operations of the method and system according to various embodiments of the present disclosure. It should be noted that the functions noted in the blocks may also occur in a different order than the order noted in the drawings. For example, two blocks shown in succession may be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the flowchart and / or block diagrams, and the combination of the blocks in the flowchart and / or block diagrams can be implemented using a dedicated hardware-based system that performs the specified functions or operations, or can be implemented using a combination of dedicated hardware and computer instructions.

[0027] As previously stated, there is a technical problem in the prior art, that is, generally, the wave front of the incident wave of traditional antennas cannot be adjusted with the frequency selection surface, resulting in the radiating direction pattern of the antenna cannot achieving the desired effect. To solve this technical problem, the inventor of the present disclosure innovatively proposes to change the structure of the frequency selection surface, namely the conductive pattern, to achieve optimization and adjustment of the outgoing wave. In summary, the present disclosure provides a novel Frequency Selection Surface (FSS), a panel with the frequency selection surface has the frequency selection function of the traditional frequency selection surface, that is, it is a passband within the operating band of a certain radiating element, and has almost no effect on the radiating performance of the radiating element, which is approximately equivalent to a layer of air. Within the operating band of another radiating element, it is a stopband, and the reflectivity of the radiating signal of the radiating element is close to 100%, which is approximately equivalent to a continuous metal surface. In addition, according to the present disclosure, the frequency selection surface also has the function of regulating the outgoing waves. This function is mainly achieved by modifying the conductive patterns of specific elements of partial frequency selection surface, so that different phase shifts are introduced into the specific elements of the modified frequency selection surface, thereby achieving the effect of regulating the outgoing waves.

[0028] In addition, due to the complex edge environment of multi-band base station antennas, including support components, cables, metal support frames, etc., the deterioration of the edge direction pattern is quite severe. To solve this problem, the inventor of the present disclosure also innovatively proposes to add a column of parasitic elements on each side of the frequency selection surface according to the present disclosure, in order to optimize the direction pattern of the radiating element deteriorated due to the edge environment, thereby effectively improving the radiating direction pattern of the multi-band base station antennas.

[0029] In order to provide a clearer introduction to the frequency selection surface for an antenna disclosed in the present disclosure, the influence of the conductive pattern on the electromagnetic wave direction pattern would be introduce firstly before introducing the frequency selection surface for an antenna disclosed in the present disclosure.

[0030] According to the working principle of the antenna array, it can achieve the effect of controlling the beam width and beam direction by feeding currents of different phases into each radiating element. FIG. 1 shows a schematic diagram of the frequency selection surface for an antenna according to the present disclosure. As shown in FIG. 1, the beam width or the beam pointing direction of the signal radiated by the radiating element can be modulated by frequency selection surface including conductive patterns 110, 120, and 130. Conductive patterns 110, 120, and 130 refer to different conductive patterns. Among them, conductive pattern 110 delays the phase of the signal by 0 degree, conductive pattern 120 delays the phase of the signal by γ, and conductive pattern 130 delays the phase of the signal by 2γ. At this point, the beam width or beam pointing direction of the outgoing wave is modulated with the treatment of the frequency selection surface including these three different conductive patterns 110, 120, and 130.

[0031] In summary, based on the above principle, the inventor of the present disclosure can modify the conductive patterns of each element in the traditional frequency selection surface, so that the conductive patterns of each element in different positions of the frequency selection surface can introduce the desired phase shift, thereby achieving the beam modulation. Herein, the phase shift refers to the difference between the phase of the signal on the propagation path after passing through the frequency selection surface and the phase of the signal before passing through the frequency selection surface. When the phase shift is less than zero, it indicates phase delay; and when the phase shift is bigger than zero, it indicates phase lead. The working principle of the frequency selection surface is shown in FIG. 1. Each element of the frequency selection surface in the figure has different structures, namely different conductive patterns. These different structures also produce different phase shifts for incident waves, so that the beam of the outgoing wave passing through the frequency selection surface is shifted compared to the incident wave. Of course, the actual incident wave may not be an ideal plane wave, but by adjusting the conductive patterns of each element of the frequency selection surface, different phase shifts are generated by each element of the frequency selection surface, thus still achieving the effect of modulating the beam width and pointing direction. It should be noted that the frequency selection function of the frequency selection surface doesn't disappear while implementing the additional functions. That is, for a certain frequency band, it is equivalent to a metal plate reflecting all its signals back; at the same time, it is equivalent to transparency for another frequency band, i.e., it does not have any impact on the signal of another frequency band.

[0032] Based on the above two theories, the present disclosure proposes a frequency selection surface with the function of modulating the antenna direction pattern, the structure of which is shown in FIG. 2. The panel has the characteristics of frequency selection and can achieve beamforming by compensating for the phase of electromagnetic wave transmission. Due to the path difference between the phase center and each frequency selection surface unit when the spherical wave front radiated by the radiating element reaches the frequency selection surface, the corresponding phase difference is caused. In order to convert the spherical wave front into the desired wave front, the frequency selection surface units need to compensate for the phase difference of different paths. The present disclosure achieves phase compensation by changing the size or structure of each unit of the frequency selection surface to make phase shifts of electromagnetic waves passing through different positions on the frequency selection surface different. FIG. 2 shows three different conductive patterns of frequency selection surface used by the panel disclosed in the present disclosure, forming a gradient structure on the frequency selection surface. For example, the transmission phase of conductive pattern 220 of the frequency selection surface lags behind that of conductive pattern 210 of the frequency selection surface by about 10 degrees, and the transmission phase of conductive pattern 230 of the frequency selection surface lags behind that of conductive pattern 220 of the frequency selection surface by about 10 degrees. Thus, different frequency selection surface units direct electromagnetic energy to the desired radiating direction, thereby widening the lobe width of the antenna direction pattern.

[0033] Specifically, based on this principle, the inventor of the present disclosure innovatively come up with the frequency selection surface with different conductive patterns. FIG.2 shows a schematic diagram of the structure of a frequency selection surface 200 for an antenna according to the present disclosure. Specifically, FIG.2 illustrates a schematic diagram of the frequency selection surface 200 according to one possible implementation of the inventive concept of the present disclosure. FIG.2 shows that the frequency selection surface includes a dielectric layer (such as the white area and the lower layer of the black area in FIG.2) and a metal layer (such as the black frame in FIG.2). Herein, the metal layer, for example, can be grounded, forming a ground layer. FIG.2 shows that the metal layer is provided with hollow area. In the example shown in FIG.2, the metal layer includes three types of conductive patterns, from left to right, namely conductive pattern 210, conductive pattern 220, and conductive pattern 230. And these three conductive patterns 210, 220, and 230 are set in the hollow area.

[0034] FIG.2 shows that if the distance between conductive pattern 210 and the ground layer (i.e., the black frame) is set as the first spacing, and the distance between conductive pattern 220 and the ground layer (i.e., the black frame) is set as the second spacing. For example, the distance between the top edge of conductive pattern 210 and the black frame is the first spacing, while the distance between the top edge of conductive pattern 220 and the black frame is the second spacing. In the example of FIG.2, the first spacing is clearly not equal to the second spacing, and the first spacing is bigger than the second spacing.

[0035] However, those skilled in the art should understand that the three conductive patterns mentioned here are merely exemplary and not limiting. The main inventive of the present disclosure is that different conductive patterns introduce different phase shifts to the processed signal. Therefore, the frequency selection surface of the present disclosure should have at least two different conductive patterns. As for how many conductive patterns to be included, it can be designed according to specific requirements, as long as the frequency selection surface including at least two different conductive patterns fall within the scope of protection of the claims claimed in the present disclosure.

[0036] As shown in FIG.2, the conductive pattern of the frequency selection surface used in the present disclosure is not a whole piece of metal. In summary, conductive pattern 210 or conductive pattern 220 includes at least two metal patches. In the example shown in FIG.2, it includes four metal patches, and each metal patch has the same shape. There is a gap between any two of these metal patches. In addition, FIG.2 shows that the metal patch is provided with grooves and / or protrusions, and the protrusions for example can be positioned at least partially within the grooves. The metal patch gradually increases in size from left to right, and correspondingly, the distance from the top edge of the metal patch to the ground layer (i.e., the black frame) becomes smaller and smaller, allowing a gradient structure is formed on the frequency selection surface. The effect of changing the transmission phase can be achieved by changing the spacing size here without changing the period size of the frequency selection surface. It ensures that the frequency selection surface has frequency selection surface units with the same period, making the distribution of gradient frequency selection surface units simpler and more flexible.

[0037] The number of different conductive patterns of the frequency selection surface used in the present disclosure are not limited to three, but can be multiple different conductive patterns of the frequency selection surface. Herein, the conductive pattern is mainly composed of metal patches and gaps between different metal patches. Preferably, the distribution of metal patches can include multiple metal patches, and there can be gaps between multiple metal patches. In addition, there can also be a hollow portion formed by the first spacing or the second spacing mentioned above between the piece of metal and the frame.

[0038] Further preferably, in one embodiment according to the present disclosure, the first set of frequency selection units is disposed in the middle of the frequency selection surface, and the second set of frequency selection units is disposed on both sides of the first set of frequency selection units, and wherein the first phase shift is smaller than the second phase shift or the first phase shift is bigger than the second phase shift. In other words, the phase shift of the conductive pattern of the frequency selection surface can increase or decrease from the center to both sides. Therefore, it is possible to design frequency selection surfaces that can widen the beam width, compress the beam width, and even change the beam pointing direction. The direction pattern can be modulated flexibly. In addition, the distribution of frequency selection surface units is not limited to the edge distribution, and can be distributed according to different requirements, such as being distributed in the middle or being distributed radially from the center.

[0039] Herein, the present disclosure proposes a frequency selection surface with the function of modulating the direction pattern. The frequency selection surface can be a single-layer or multi-layer planar structure, and can also be a bandpass frequency selection surface or a highpass frequency selection surface.

[0040] The frequency selection surface for an antenna proposed in accordance with the present disclosure is described combining with FIG. 3A to FIG. 5C. Among them, FIG. 3A shows a schematic diagram of the structure of a frequency selection surface 300A for an antenna according to an embodiment of the present disclosure, FIG. 3B shows a schematic diagram of the structure of a frequency selection surface 300B for an antenna according to another embodiment of the present disclosure, FIG. 3C shows a schematic diagram of the structure of a frequency selection surface 300C for an antenna according to another embodiment of the present disclosure, and FIG. 3D shows a schematic diagram of the structure of a frequency selection surface 300D for an antenna according to another embodiment of the present disclosure.

[0041] It can be seen from the four implementation forms of FIG. 3A to 3D that the frequency selection surface 300A for an antenna shown in FIG. 3A only includes two types of conductive patterns, and each conductive pattern is arranged continuously in only one column. The frequency selection surface 300B for an antenna shown in FIG. 3B also only includes two types of conductive patterns, but each conductive pattern is arranged continuously in two columns. The frequency selection surface 300C for an antenna shown in FIG. 3C includes three types of conductive patterns, and the conductive pattern in the middle is arranged continuously in two columns. The frequency selection surface 300D for an antenna shown in FIG. 3D includes three types of conductive patterns, and the conductive pattern in the middle is arranged continuously in multiple columns.

[0042] Specifically, the frequency selection surface 300A for an antenna shown in FIG. 3A includes four rows and three columns of conductive patterns. In summary, according to the present disclosure, the frequency selection surface 300A includes a first set of frequency selection units 310A, and each first frequency selection unit in the first set of frequency selection units 310A includes a first conductive pattern 3101A, i.e., the conductive pattern shown in the middle. In addition, according to the present disclosure, the frequency selection surface 300A further includes a second set of frequency selection units 320A, and each second frequency selection unit in the second set of frequency selection units 320A includes a second conductive pattern 3201A, i.e., the conductive pattern shown at the edge. From FIG. 3A, it can be seen that the first conductive pattern 3101A and the second conductive pattern 3201A are different. From FIG. 3A, it can be seen that if the distance between conductive pattern 3101A and the ground layer (i.e., the black frame) is set as the first spacing, and the distance between conductive pattern 3102A and the metal layer is set as the second spacing. For example, the distance between the top edge of conductive pattern 3101A and the black frame is the first spacing, while the distance between the top edge of conductive pattern 3102A and the black frame is the second spacing. In the example of FIG. 3A, the first spacing is clearly not equal to the second spacing, and the first spacing is larger than the second distance. In the frequency selection surface 300A for an antenna according to the present disclosure, due to the difference between the first conductive pattern 3101A and the second conductive pattern 3201A, it is possible to achieve the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface 300A for an antenna. Herein, the black frame of the outer ring of each conductive pattern, for example 330A, constitutes the ground layer.

[0043] In addition, as shown in FIG. 3A, the conductive pattern of the frequency selection surface used in the present disclosure is not a whole piece of metal. In summary, conductive pattern 3101A or conductive pattern 3102A includes at least two metal patches. In the example shown in FIG. 3A, it includes four metal patches, and each metal patch has the same shape. There is a gap between any two of these metal patches. In addition, FIG. 3A shows the metal patch is provided with grooves and / or protrusions, and the protrusions for example can be positioned at least partially within the grooves.

[0044] 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, due to the difference between the first conductive pattern 3101A and the second conductive pattern 3201A, the first phase shift formed by the first conductive pattern 3101A is different from the second phase shift formed by the second conductive pattern 3201A, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns 3101A or 3201A, thereby achieving the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface 300A for an antenna. Herein, the first set of frequency selection units 310A is disposed to one column, which includes four of the first conductive patterns 3101A, while the second set of frequency selection units 320A is disposed to two columns with each column including four of the second conductive patterns 3201A. Herein, the number of columns of frequency selection units and the number of conductive patterns included in each column of frequency selection units can be varied and designed according to specific design requirements.

[0045] The frequency selection surface 300B for an antenna shown in FIG. 3B includes four rows and six columns of conductive patterns. In summary, according to the present disclosure, the frequency selection surface 300B includes the first set of frequency selection units 310B, and each first frequency selection unit of the first set of frequency selection units 310B includes the first conductive pattern 3101B, i.e., the conductive pattern shown in the middle. In addition, according to the present disclosure, the frequency selection surface 300B further includes the second set of frequency selection units 320B, and each second frequency selection unit of the second set of frequency selection units 320B includes the second conductive pattern 3201B, i.e., the conductive pattern shown at the edge. From FIG. 3B, it can be seen that the first conductive pattern 3101B is different from the second conductive pattern 3201B. In the frequency selection surface 300B for an antenna according to the present disclosure, due to the difference between the first conductive pattern 3101B and the second conductive pattern 3201B, it is possible to achieve the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface 300B for an antenna.

[0046] More specifically, the shape of the first conductive pattern 3101B is associated with the first phase shift, and the shape of the second conductive pattern 3201B is associated with the second phase shift, wherein the first phase shift is different from the second phase shift. In this way, due to the difference between the first conductive pattern 3101B and the second conductive pattern 3201B, the first phase shift formed by the first conductive pattern 3101B is different from the second phase shift formed by the second conductive pattern 3201B, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns 3101B or 3201B, thereby achieving the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface 300B for an antenna. Herein, the first set of frequency selection units 310B is disposed to two columns with each column including four of the first conductive patterns 3101B, while the second set of frequency selection units 320B is disposed to four columns with each column including four of the second conductive patterns 3201B. Herein, the number of columns of frequency selection units and the number of conductive patterns included in each column of frequency selection units can be varied and designed according to specific design requirements.

[0047] The frequency selection surface 300C for an antenna shown in FIG. 3C includes four rows and eight columns of conductive patterns. In summary, according to the present disclosure, the frequency selection surface 300C includes the first set of frequency selection units 310C, and each the first frequency selection unit of the first set of frequency selection units 310C includes the first conductive pattern 3101C, i.e., the conductive pattern shown in the middle. In addition, according to the present disclosure, the frequency selection surface 300C further includes the second set of frequency selection units 320C, and each the second frequency selection unit of the second set of frequency selection units 320C includes the second conductive pattern 3201C, i.e., the conductive patterns shown in the second, third, sixth, and seventh columns. Furthermore, according to the present disclosure, the frequency selection surface 300C also includes the third set of frequency selection units 330C, and each the third frequency selection unit of the third set of frequency selection units 330C includes the third conductive pattern 3301C, i.e., the conductive pattern shown at the edge.

[0048] FIG, 3C shows that the third conductive pattern 3301C is different from the first conductive pattern 3101C and the second conductive pattern 3201C. In this way, in the frequency selection surface 300C for an antenna according to the present disclosure, due to the difference among the first conductive pattern 3101C, the second conductive pattern 3201C, and the third conductive pattern 3301C, 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, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns 3101C, 3201C, and 3301C, thereby achieving the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface 300C for an antenna. That is, in the frequency selection surface 300C for an antenna according to the present disclosure, due to the difference among the first conductive pattern 3101C, the second conductive pattern 3201C, and the third conductive pattern 3201C, it is possible to achieve the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface 300C for an antenna. Herein, the first set of frequency selection units 310C is disposed to two columns with each column including four of the first conductive patterns 3101C, the second set of frequency selection units 320C is disposed to four columns, and the third set of frequency selection units 330C is disposed to two columns with each column including four of the third conductive patterns 3301C. Herein, the number of columns of frequency selection units and the number of conductive patterns included in each column of frequency selection units can be varied and designed according to specific design requirements.

[0049] The frequency selection surface 300D for an antenna shown in FIG. 3D includes four rows and sixteen columns of conductive patterns. In summary, according to the present disclosure, the frequency selection surface 300D includes the first set of frequency selection units 310D, and each first frequency selection unit of the first set of frequency selection units 310D includes the first conductive pattern 3101D, i.e., the conductive pattern shown in the middle. In addition, according to the present disclosure, the frequency selection surface 300D further includes the second set of frequency selection units 320D, and each second frequency selection unit of the second set of frequency selection units 320D includes the second conductive pattern 3201D, i.e., the conductive patterns shown in the second column, the third column, and the second to last and third columns. Furthermore, according to the present disclosure, the frequency selection surface 300D also includes the third set of frequency selection units 330D, and each third frequency selection unit of the third set of frequency selection units 330D includes the third conductive pattern 3301D, i.e., the conductive patterns shown in the first and last columns. From FIG. 3D, it can be seen that the third conductive pattern 3301D is different from the first conductive pattern 3101D and the second conductive pattern 3201D. In this way, in the frequency selection surface 300D for an antenna according to the present disclosure, due to the difference among the first conductive pattern 3101D, the second conductive pattern 3201D, and the third conductive pattern 3301D, 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, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns 3101D, 3201D, and 3301D, thereby achieving the effect of optimizing and adjusting the outgoing waves with the help of the frequency selection surface 300D for an antenna. That is, in the frequency selection surface 300D for an antenna according to the present disclosure, due to the difference among the first conductive pattern 3101D, the second conductive pattern 3201D, and the third conductive pattern 3201D, it is possible to achieve the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface 300D for an antenna. Herein, the first set of frequency selection units 310D is disposed to ten columns with each column including four of the first conductive patterns 3101D, the second set of frequency selection units 320D is disposed to four columns, and the third set of frequency selection units 330D is disposed to two columns with each column including four of the third conductive patterns 3301D. Herein, the number of columns of frequency selection units and the number of conductive patterns included in each column of frequency selection units can be varied and designed according to specific design requirements.

[0050] Among the four specific implementations shown in figures 3A to 3D above, the conductive pattern of the frequency selection surface used in the present disclosure can change the transmission phase while ensuring that the period of the frequency selection surface remains unchanged, making the layout of each unit of different sizes of frequency selection surfaces more convenient and flexible. The frequency selection surface with directional modulation function disclosed herein can maintain or gradually reduce the phase shift of each unit of the frequency selection surface towards the edge direction of the frequency selection surface, in order to widen the beam width of the antenna. It is also possible to maintain or gradually increase the phase shift of each unit of the frequency selection surface towards the edge direction of the frequency selection surface, in order to compress the beam width of the antenna. As it should be, based on the above description, the phase shift of each unit on the frequency selection surface can also be distributed in a staggered manner, for example, increasing first, then decreasing, and then increasing again, to modulate the direction pattern of the antenna. In the frequency selection table with the function of modulating direction patterns disclosed herein, the various units of the frequency selection surface that causing different phase shifts can be distributed on a partial area of the frequency selection surface, that is, the shape only changes along one direction. It can also be distributed on the overall of the frequency selection surface, that is, the shape can change only along one direction. It can also be distributed in a radial pattern at the center on a partial area of or on the overall of the frequency selection surface.

[0051] FIG. 4 shows a schematic diagram of the structure of the frequency selection surface 400 for an antenna according to another embodiment of the present disclosure. The frequency selection surface 400 for an antenna shown in FIG. 4 includes four rows and eighteen columns of conductive patterns. In summary, the frequency selection surface 400 according to the present disclosure includes a first set of frequency selection units 410, each first frequency selection unit of the first set of frequency selection units 410 includes a first conductive pattern 4101, i.e., the conductive pattern shown in the middle. In addition, according to the present disclosure, the frequency selection surface 400 further includes a second set of frequency selection units 420, each second frequency selection unit of the second set of frequency selection units 420 includes a second conductive pattern 4201, i.e., the conductive patterns shown in the third column, the fourth column, and the third to last and the fourth to last column. Furthermore, according to the present disclosure, the frequency selection surface 400 further includes a third set of frequency selection units 430, wherein each third frequency selection unit of the third set of frequency selection units 430 includes a third conductive pattern 4301, i.e., the conductive patterns shown in the second column and the second to last column. Furthermore, the frequency selection surface 400 shown in FIG. 4 also includes parasitic element 440 disposed at the edge of the frequency selection surface 400. The parasitic element 440 includes pattern 4401. The parasitic element 440 is used to optimize the direction pattern of the radiating element deteriorated due to the edge environment, thereby effectively improving the radiating direction pattern of the multi-band base station antenna. Further preferably, in one embodiment according to the present disclosure, the parasitic element 440 is designed as a square piece of metal. That is, according to the inventive concept disclosed herein, it can effectively improve the direction pattern of the edge column radiating elements by adding parasitic elements on both sides of the frequency selection surface. The parasitic element 440 of the present disclosure is shown as a square in FIG. 4, but is not limited to a square. Moreover, the number and location of parasitic element 440 in the present disclosure are not limited and can be adjusted according to actual needs. In addition, the parasitic element 440 of the present disclosure can be added on both sides of a frequency selection surface with directional modulation function, or on both sides of a traditional periodic non gradient frequency selection surface. Furthermore, the parasitic element 440 disclosed in the present disclosure can be used to widen the direction pattern of the edge column radiating element or narrow the direction pattern of the edge column radiating element.

[0052] In summary, in order to further widen the direction pattern of the edge column radiating element, the parasitic elements are added on both sides of the frequency selection surface with the function of modulating direction pattern of the antenna, as shown in FIG. 4. The parasitic element operates in the frequency band of the radiating element that needs to widen the direction pattern. The number and relative position of the parasitic element are related to the number and position of the radiating element that needs to widen the directional pattern. The shape of the parasitic element can be square but not limited to square. In this way, the parasitic elements on both sides of the frequency selection surface with directional modulation function can further widen the direction pattern of the edge column radiating elements. Similarly, the parasitic elements can also be added on both sides of a traditional periodic non gradient frequency selection surface to widen or narrow the direction pattern of the edge column radiating elements.

[0053] In addition, it can be seen from FIG. 4 that the third conductive pattern 4301 is different from the first conductive pattern 4101 and the second conductive pattern 4201. In this way, in the frequency selection 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, 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 all different, so as to introduce different phase shifts for electromagnetic waves passing through the corresponding conductive patterns 4101, 4201, and 4301, thereby achieving the effect of optimizing and adjusting outgoing waves through the frequency selection surface 400 for an antenna. In other words, in the frequency selection 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, it is possible to achieve the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface 400 for an antenna. Herein, the first set of frequency selection units 410 is disposed to ten columns with each column including four first conductive patterns 4101, the second set of frequency selection units 420 is disposed to four columns, and the third set of frequency selection units 430 is disposed to two columns with each column including four third conductive patterns 4301. Herein, the number of columns of frequency selection units and the number of conductive patterns included in each column of frequency selection units can be varied and designed according to specific design requirements.

[0054] FIG. 5A shows an assembly schematic diagram of an active and passive integrated antenna system 500 according to an embodiment of the present disclosure. The antenna system proposed in accordance with the present disclosure shown in FIG. 5A includes a first antenna, a second antenna, and a frequency selection surface described in the above aspects of the present disclosure, wherein the first antenna and the second antenna are respectively arranged on both sides of the frequency selection surface. Since FIG. 5A is an assembly view, it doesn't show the frequency selection surface proposed in accordance with the present disclosure, but the mounting bracket 13 of the first antenna, the top 1 of the antenna cover of the second antenna, and the bottom 7 of the antenna cover of the second antenna.

[0055] FIG. 5B shows a decomposition schematic diagram of the antenna system 500 shown in FIG. 5A. As shown in FIG. 5B, the antenna system 500 in the embodiment includes a first antenna 9 and a second antenna 4, which are antennas operating in different operating bands. For example, the first antenna 9 is a 5G antenna, and the second antenna 4 is a 2G, 3G, or 4G antenna. Continuing with reference to FIG. 5B, the antenna system 500 in the embodiment further includes the top 1 of the antenna cover of the second antenna, the support member 2 of the antenna cover of the second antenna, the support member 3 of the second antenna, the frequency selection surface 5, the metal frame support 6, the bottom 7 of the antenna cover of the second antenna, the antenna cover 8 of the first antenna, the first reflector plate 10, the fixing member 11, and the first RF remote unit RRU 12. The first reflector plate 10 is fixed above the first RF remote unit RRU 12 by the fixing member 11. The first antenna 9 is disposed above the first reflector plate 10. The antenna cover 8 of the first antenna is fixed above the first RF remote unit RRU 12 by screws, covering the first antenna 9 and the first reflector plate 10 below it. The above unit can be regarded as an A antenna module. The frequency selection surface 5 is fixed above the bottom 7 of the antenna cover of the second antenna with the metal frame support 6. The second antenna 4 includes a second antenna radiator, a second antenna feeding balun, a second antenna substrate, and a second antenna feeder cable 41. The upper end of the second antenna feeding balun is electrically connected to the second antenna radiator, the lower end of the second antenna feeding balun is electrically connected to the second antenna substrate, and is fed by the second antenna feeder cable which is fixed above the metal frame support 6. Frequency selection surface 5 forms an open circuit for the first antenna 9 and a ground structure for the second antenna 4. And on both sides of the frequency selection surface 5, there are two columns of enlarged frequency selection surface units of different sizes, which have the function of modulating the direction pattern and can widen the direction pattern of the radiating elements. Furthermore, a column of parasitic elements has been added on both sides of the frequency selection surface 5 to widen the direction pattern of the edge column radiating elements. The above unit can be regarded as a P antenna module. Continuing with reference to FIG. 5B, for example, an existing base station is equipped with a P antenna module, and the A antenna module can be fixed to the P antenna module with the mounting bracket 13 to work together when an A antenna module needs to be added. By adopting the above implementation, the communication frequency band of base stations can be increased to improve their communication performance without the need for large-scale modification and expansion of existing base stations. At the same time, the A antenna module and the P antenna module can work separately, improving the modularity of the antenna, enhancing the flexibility of the base station antenna usage, and saving the construction cost of the base station antenna.

[0056] In order to reduce the influence of the feeder cable 41 of the second antenna on the edge column radiating pattern of the first antenna 9, the second antenna feeder cable 41 can be routed along the grounding grid line of the frequency selection surface 5. FIG. 5C shows the wiring diagram of the feeder cable of the radiating element in FIG. 5B. Furthermore, the feeder cable 41 of the second antenna can be welded onto the grounding grid line of the frequency selection surface 5, thereby basically eliminating the influence of the lateral routing of the feeder cable 41 of the second antenna on the radiating direction pattern of the first antenna 9. Furthermore, the routing of the feeder cable 41 of the second antenna can be moved away from the first antenna 9 and routed above the metal frame support 6. Furthermore, the feeder cable 41 of the second antenna can be hidden inside the metal frame support 6, thereby basically eliminating the influence of the vertical routing of the feeder cable 41 of the second antenna on the radiating direction pattern of the first antenna 9, as shown in FIG. 5C. That is, in the present disclosure, the lateral routing of the feeder cable of the second antenna is welded onto the grounding grid line of the frequency selection surface, thereby basically eliminating the influence of the lateral routing of the feeder cable of the second antenna on the radiating direction pattern of the first antenna. In the present disclosure, the vertical routing of the feeder cable of the second antenna is hid inside the metal frame support, thereby basically eliminating the influence of the vertical routing of the feeder cable of the second antenna on the radiating direction pattern of the first antenna.

[0057] In summary, in the technical solution based on the present disclosure, due to the difference between the first conductive pattern and the second conductive pattern, different phase shifts can be introduced for electromagnetic waves passing through the corresponding conductive patterns, thereby achieving the effect of optimizing and adjusting outgoing waves with the help of the frequency selection surface for an antenna. That is, in the present disclosure, the function of modulating the direction pattern is added on the basis of the traditional frequency selection surface to form a frequency selection surface with gradient structure. The frequency selection surface according to the present disclosure not only has frequency selection function, but also can effectively improve the direction pattern of the radiating element.

[0058] In the aforementioned embodiments, the patterns on the frequency selection surface can, for example, generate phase delay. However, in other embodiments, the patterns on the frequency selection surface can also be designed to advance the phase to achieve similar effects.

[0059] The foregoing descriptions are only alternative embodiments of the disclosure of the present disclosure, and are not used to limit the embodiments of the present disclosure, for those skilled in the art, the embodiments of the present disclosure may have various modifications and changes. Any modification, equivalent replacement, improvement, etc., made within the spirit and principle of the embodiment of the present disclosure should be included in the protection scope of the embodiment of the present disclosure.

[0060] Although the embodiments of the present disclosure have been described with reference to several specific embodiments, it should be understood that the embodiments of the present disclosure are not limited to the disclosed specific embodiments. The embodiments of the present disclosure are intended to cover various modifications and equivalent arrangements within the spirit and scope of the appended claims. The scope of the claims accords with the broadest interpretation, so as to include all such modifications and equivalent structures and functions.

Claims

1. A frequency selection surface for an antenna, characterized in that the frequency selection surface comprises: a first set of frequency selection units, each first frequency selection unit of the first set of frequency selection units including a first conductive pattern; and a second set of frequency selection units, each second frequency selection unit of the second set of frequency selection units including a second conductive pattern, wherein the first conductive pattern is different from the second conductive pattern.

2. The frequency selection surface of claim 1, characterized in that 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, and wherein the first phase shift is different from the second phase shift.

3. The frequency selection surface of claim 2, characterized in that the first set of frequency selection units is disposed in the middle of the frequency selection surface, and the second set of frequency selection units is disposed on both sides of the first set of frequency selection units, and wherein the first phase shift is smaller than the second phase shift or the first phase shift is bigger than the second phase shift.

4. The frequency selection surface of claim 1, characterized in that the first set of frequency selection units is disposed in one row or column, and the second set of frequency selection units is disposed in another row or column.

5. The frequency selection surface of claim 1, characterized in that the frequency selection surface further comprising: a third set of frequency selection units, of which each third frequency selection unit includes 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 selection surface of claim 5, characterized in that the shape of the third conductive pattern is associated with the 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 selection surface of claim 1, characterized in that the frequency selection surface further comprises: a parasitic element, disposed at the edge of the frequency selection surface.

8. The frequency selection surface of claim 7, characterized in that the parasitic element is designed as a square piece of metal.

9. The frequency selection surface of claim 1, characterized in that the frequency selection surface further comprises: a metal layer, provided with several hollow areas, and wherein the first conductive pattern and the second conductive pattern are disposed in the hollow areas respectively.

10. The frequency selection surface of claim 9, characterized in that the distance between the first conductive pattern and a ground layer is a first spacing, and the distance between the second conductive pattern and the metal layer is a second spacing, and wherein the first spacing and the second spacing are not equal.

11. The frequency selection surface of claim 1, characterized in that the first conductive pattern or the second conductive pattern includes at least two metal patches, and wherein there is a gap between the at least two metal patches.

12. The frequency selection surface of claim 11, characterized in that one of the at least two metal patches is provided with a groove, and the other is provided with a protrusion which is at least partially positioned within the groove.

13. The frequency selection surface of claim 12, characterized in that the number of the metal patches is four, and each metal patch has the same shape.

14. The frequency selection surface of claim 1, characterized in that the number of the second set of frequency selection units is twice the number of the first set of frequency selection units, and wherein the first set of frequency selection units is positioned between a pair of the second sets of frequency selection units.

15. An antenna system, characterized in that the antenna system comprises: a first antenna; a second antenna; and the frequency selection surface according to any one of claims 1 to 14, wherein the first antenna and the second antenna are disposed on both sides of the frequency selection surface respectively.

16. The antenna system of claim 15, characterized in that the first antenna and the second antenna are designed as independent structures respectively.

17. The antenna system of claim 16, characterized in that the antenna system further comprises: an antenna cover of the first antenna; and an antenna cover of the second antenna, wherein the antenna cover of the first antenna and the antenna cover of the second antenna are designed to protect the first antenna and the second antenna respectively, wherein the antenna cover of the first antenna and the antenna cover of the second antenna include fixing structures matched with one another.

18. The antenna system of claim 17, characterized in that the frequency selection surface is disposed in the antenna cover of the first antenna or the antenna cover of the second antenna.

19. The antenna system of claim 15, characterized in that the first antenna is designed as a 5G antenna, and the second antenna is designed as a non-5G antenna.

20. The antenna system of claim 15, characterized in that the antenna system further comprises: a bracket for supporting the frequency selection surface, and wherein a feeder cable for feeding the first antenna or the second antenna is routed along the bracket.

21. The antenna system of claim 20, characterized in that the feeder cable for feeding the first antenna or the second antenna is routed along the grounding grid line of the frequency selection surface.

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