Beam forming antenna

Abstract

The invention discloses a beam forming antenna, and relates to the technical field of wireless communication. The beamforming antenna comprises a radiator and at least two metamaterial structures, the at least two metamaterial structures are sequentially connected end to end to define a containing space, the radiator is arranged in the containing space and provided with a feed port, the metamaterial structures can be switched between a reflection state and a transmission state, and the feed port is communicated with the feed port. Under the condition that the metamaterial structure is in the reflection state, the metamaterial structure can reflect electromagnetic waves radiated by the radiator; under the condition that the metamaterial structure is in the transmission state, electromagnetic waves radiated by the radiator can penetrate through the metamaterial structure. According to the scheme, the problem that the size of an existing beam forming antenna is large can be solved.

Description

Technical Field

[0001] This application belongs to the field of wireless communication technologies, and particularly relates to a beamforming antenna. Background Art

[0002] Beamforming is a signal preprocessing technology based on an antenna array. By adjusting the elements of the array antenna to aggregate the beam, the antenna gain can be increased, enabling the terminal device to have higher anti-interference performance, thereby improving the communication link quality.

[0003] Currently, most of the beamforming antenna solutions are composed of multiple radiators and switches. According to the usage requirements, different radiators are controlled to work through the switches to radiate electromagnetic beams in a preset direction. However, the size of the beamforming antenna with such a structure is relatively large, and correspondingly, the space it occupies is also large. Summary of the Invention

[0004] The purpose of the embodiments of this application is to provide an antenna, which is beneficial to solving the problem that the current beamforming antenna has a relatively large size.

[0005] To solve the above technical problems, this application is implemented as follows:

[0006] The embodiments of this application provide an antenna, including a radiator and at least two metamaterial structures. The at least two metamaterial structures are sequentially connected end to end to enclose an accommodation space. The radiator is disposed in the accommodation space. The radiator has a feeding port. The metamaterial structure can be switched between a reflection state and a transmission state.

[0007] When the metamaterial structure is in the reflection state, the metamaterial structure can reflect the electromagnetic waves radiated by the radiator; when the metamaterial structure is in the transmission state, the electromagnetic waves radiated by the radiator can pass through the metamaterial structure.

[0008] In an embodiment of the present application, a radiator is disposed in a receiving space surrounded by at least two metamaterial structures. The metamaterial structures can be switched between a reflection state and a transmission state. When the metamaterial structure is in the reflection state, the reflection coefficient of the metamaterial structure is close to 0 dB, and the metamaterial structure can prevent the electromagnetic waves radiated by the radiator from passing through. When the metamaterial structure is in the transmission state, the transmission coefficient of the metamaterial structure is close to 0 dB, and the electromagnetic waves radiated by the radiator can pass through the metamaterial structure. In this solution, only one radiator can be disposed in the receiving space surrounded by at least two metamaterial structures, and then the metamaterial structures in different orientations are controlled to be switched between the reflection state and the transmission state. When beam steering is required in any orientation within 360°, the metamaterial structure in this orientation can be controlled to be in the transmission state, while the metamaterial structures in other orientations are in the reflection state, so that the electromagnetic waves radiated by the radiator converge to the orientation where the metamaterial structure in the transmission state is located, without the need to provide multiple radiators and control the radiators in different orientations to work through switches to achieve beam steering. Therefore, the embodiment of the present application can solve the problem of the large size of the current beamforming antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic structural diagram of a metamaterial unit disclosed in an embodiment of the present application;

[0010] Figure 2 is a schematic structural diagram of a radiator disclosed in an embodiment of the present application;

[0011] Figure 3 is a top view of a beamforming antenna disclosed in an embodiment of the present application;

[0012] Figure 4 is a partial structural schematic diagram of a beamforming antenna disclosed in an embodiment of the present application;

[0013] Figure 5 is a transmission and reflection coefficient curve graph when the metamaterial structure is in the reflection state in an embodiment of the present application, where the dashed line represents the transmission performance of the metamaterial structure and the solid line represents the reflection performance of the metamaterial structure;

[0014] Figure 6 is a transmission and reflection coefficient curve graph when the metamaterial structure is in the transmission state in an embodiment of the present application, where the dashed line represents the transmission performance of the metamaterial structure and the solid line represents the reflection performance of the metamaterial structure;

[0015] Figure 7 is a reflection coefficient curve graph of a radiator disclosed in an embodiment of the present application;

[0016] Figure 8 is a radiation azimuth graph of a radiator disclosed in an embodiment of the present application;

[0017] Figure 9 The reflection coefficient curve graph of the beamforming antenna disclosed in the embodiment of the present application;

[0018] Figure 10 The beamforming diagrams of the beamforming antenna disclosed in the embodiment of the present application at different azimuths;

[0019] Figure 11 The beamforming diagrams of the beamforming antenna disclosed in the embodiment of the present application in the omnidirectional antenna and the directional antenna.

[0020] Explanation of reference numerals:

[0021] 200 - radiator, 210 - feed port;

[0022] 300 - metamaterial structure, 310 - metamaterial unit, 311 - split ring resonator, 311a - first part, 311a1 - arc segment, 311a2 - first straight segment, 311a3 - second straight segment, 311b - second part, 312 - closed central ring, 313 - power on / off switch, 314 - first metamaterial unit, 315 - second metamaterial unit, 316 - substrate, 320 - first metamaterial structure, 330 - second metamaterial structure, 340 - third metamaterial structure, 350 - fourth metamaterial structure, 360 - fifth metamaterial structure, 370 - sixth metamaterial structure. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] The terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order different from those illustrated or described herein. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally means an "or" relationship between the associated objects before and after.

[0025] Next, the beamforming antenna provided in the embodiments of the present application will be described in detail in conjunction with the accompanying drawings through specific embodiments and their application scenarios.

[0026] Refer to Figures 1 to 11, an embodiment of the present application discloses a beamforming antenna, which includes a radiator 200 and at least two metamaterial structures 300. The at least two metamaterial structures 300 are connected end to end in sequence to enclose an accommodation space. Optionally, the at least two metamaterial structures 300 are connected end to end in sequence along a curve direction, so as to enclose an accommodation space inside the metamaterial structures 300. The radiator 200 is disposed in the accommodation space. Optionally, a fixing structure (such as a fixing bracket, etc.) can be provided in the accommodation space to fix the radiator 200; optionally, the top surface and the bottom surface of the accommodation space can be closed or open. When both the top surface and the bottom surface of the accommodation space are closed, dust and other impurities in the external environment can be prevented from entering the accommodation space to protect the radiator 200. The radiator 200 has a feeding port 210. Optionally, the feeding port 210 can be located at the middle position of the radiator 200, so that the distances from the ends of the radiator 200 to the feeding port 210 are approximately equal, so that the current path lengths in the radiator 200 are approximately equal, and further the electromagnetic waves radiated by the radiator 200 are more uniform.

[0027] The metamaterial structure 300 can be switched between a reflection state and a transmission state. When the metamaterial structure 300 is in the reflection state, the reflection coefficient of the metamaterial structure 300 is close to 0 dB, and the metamaterial structure 300 can reflect the electromagnetic waves radiated by the radiator 200, that is, the metamaterial structure 300 can prevent the electromagnetic waves radiated by the radiator 200 from passing through; when the metamaterial structure 300 is in the transmission state, the transmission coefficient of the metamaterial structure 300 is close to 0 dB, and the electromagnetic waves radiated by the radiator 200 can pass through the metamaterial structure 300. Optionally, after the radiator 200 is fed through the feeding port 210, it radiates electromagnetic waves, and the electromagnetic waves are beamformed through the metamaterial structure 300.

[0028] In the embodiment of the present application, only one radiator 200 can be provided in the accommodation space enclosed by at least two metamaterial structures 300, and then the metamaterial structures 300 in different orientations are controlled to be switched between the reflection state and the transmission state. When beam orientation is required in any orientation within 360°, the metamaterial structure 300 in this orientation can be controlled to be in the transmission state, while the metamaterial structures 300 in other orientations are in the reflection state, so that the electromagnetic waves radiated by the radiator 200 converge to the orientation where the metamaterial structure 300 in the transmission state is located, without the need to provide multiple radiators 200 and control the radiators 200 in different orientations to work through switches to achieve beam orientation. Therefore, the embodiment of the present application can solve the problem that the size of the current beamforming antenna is relatively large.

[0029] In addition, since the beamforming antenna disclosed in the present application does not need to provide multiple radiators 200, the manufacturing cost can be saved.

[0030] In an alternative embodiment, the metamaterial structure 300 includes at least one metamaterial unit 310. The metamaterial unit 310 includes a substrate 316, and a split-ring resonator 311 and a closed central loop 312 that are spaced apart and disposed on the substrate 316. The split-ring resonator 311 can be used to adjust the transmission characteristics of the metamaterial structure 300, and the closed central loop 312 can be used to adjust the reflection characteristics of the metamaterial structure 300. The split-ring resonator 311 is sleeved outside the closed central loop 312, that is, the closed central loop 312 is located in the accommodation space of the split-ring resonator 311. The split-ring resonator 311 is provided with a power on / off switch 313, and the power on / off switch 313 is used to change the current path of the split-ring resonator 311. Optionally, the power on / off switch 313 can be a PIN diode, which has the characteristics of low conduction resistance, high capacitance in the off state, high-speed switching, and high sensitivity. Of course, the metamaterial structure 300 can also be an artificial magnetic conductor.

[0031] The power on / off switch 313 can control the switching of the metamaterial structure 300 between the reflection state and the transmission state. When the power on / off switch 313 is in the off state, both sides of the power on / off switch 313 of the split-ring resonator 311 are disconnected. At this time, the reflection characteristics of the closed central loop 312 are stronger, and the metamaterial structure 300 is in the reflection state. At this time, the metamaterial structure 300 generates a stopband, the transmission coefficient is low, the reflection coefficient is close to 0 dB, and the metamaterial structure 300 exhibits strong reflection characteristics. When the power on / off switch 313 is in the on state, both sides of the power on / off switch 313 of the split-ring resonator 311 are electrically connected, the reflection characteristics of the closed central loop 312 are weaker, the metamaterial structure 300 is in the transmission state, the stopband of the metamaterial structure 300 disappears, and a passband with significantly improved transmission level is generated. At this time, the transmission coefficient of the metamaterial structure 300 is close to 0 dB, the reflection coefficient is low, and the metamaterial structure 300 exhibits strong transmission characteristics.

[0032] It should be noted that when the power on / off switch 313 is turned on, the current flowing in the circuit formed by the split-ring resonator 311 is direct current, that is, the power on / off switch 313 is electrically connected to the DC power supply.

[0033] Optionally, the substrates 316 of the respective metamaterial structures 300 are connected end to end in sequence to enclose the above-mentioned accommodation space. The split-ring resonator 311 and the closed central loop 312 can be provided on the inner surface of the substrate 316, that is, the split-ring resonator 311 and the closed central loop 312 can be provided on the inner side wall of the accommodation space. At this time, the connection structure for connecting the respective substrates 316 will be located on the outer surface of the substrate 316, which results in poor aesthetics of the beamforming antenna. Therefore, in other alternative embodiments, the split-ring resonator 311 and the closed central loop 312 are provided on the outer surface of the substrate 316. At this time, the connection structure for connecting the respective substrates 316 will be located on the inner surface of the substrate 316 for hiding, which is beneficial to improving the aesthetics of the beamforming antenna.

[0034] In an alternative embodiment, the central axis of the closed central ring 312 coincides with the central axis of the open resonant ring 311. At this time, the distances between the outer peripheral surface of the closed central ring 312 and the inner peripheral surface of the open resonant ring 311 are equal at various positions, so that the energy distribution coupled from the open resonant ring 311 to the closed central ring 312 is more uniform. Of course, the central axis of the closed central ring 312 and the central axis of the open resonant ring 311 may also be arranged offset.

[0035] Optionally, the closed central ring 312 may be a triangular structure, a rectangular structure, etc. Since the curvature at the connection of adjacent sides of such a structure is relatively large and the characteristic impedance fluctuates greatly, the energy loss of electromagnetic waves is relatively large. Based on this, in another embodiment, the closed central ring 312 is a circular ring. Since the circular ring is relatively smooth and its curvature is equal everywhere, it is beneficial to reduce the energy loss of electromagnetic waves, thereby improving the radiation performance of the radiator 200.

[0036] In yet another alternative embodiment, the open resonant ring 311 includes a first portion 311a and a second portion 311b which are spaced apart. The first portion 311a and the second portion 311b are arranged opposite to each other, and power-on and power-off switches 313 are provided on both the first portion 311a and the second portion 311b. Optionally, both the first portion 311a and the second portion 311b may be bent structures. Since the curvature at the bent portion is relatively large, the energy loss of electromagnetic waves on the first portion 311a and the second portion 311b will be relatively large at this time. Therefore, in other embodiments, both the first portion 311a and the second portion 311b include arc segments 311a1, that is, both the first portion 311a and the second portion 311b are arc-shaped structures. The power-on and power-off switch 313 is provided on the arc segment 311a1. The closed central ring 312 is located between the arc segment 311a1 of the first portion 311a and the arc segment 311a1 of the second portion 311b. The arc segments 311a1 of the first portion 311a and the arc segments 311a1 of the second portion 311b are spaced apart on the same circumference. Since the arc segment 311a1 is relatively smooth and the curvature of the arc segment 311a1 is equal everywhere, the energy loss of electromagnetic waves on the arc segment 311a1 is relatively small, which is beneficial to improving the radiation performance of the radiator 200.

[0037] It should be noted that the power-on and power-off switch 313 provided on the first portion 311a and the power-on and power-off switch 313 provided on the second portion 311b need to be turned on simultaneously.

[0038] Optionally, the power-on / off switches 313 provided on the first part 311a and the power-on / off switches 313 provided on the second part 311b can be centrally controlled by a control member for the convenience of user operation. Additionally, it should be noted that the control member is provided in one-to-one correspondence with the metamaterial structure 300, that is, one control member controls multiple power-on / off switches 313 provided on one metamaterial structure 300.

[0039] Optionally, the number of the metamaterial units 310 can be one; or, in other embodiments, at least one metamaterial unit 310 includes a first metamaterial unit 314 and a second metamaterial unit 315 arranged in sequence along the axial direction of the accommodation space. The substrate 316 of the first metamaterial unit 314 is connected to the substrate 316 of the second metamaterial unit 315, and the split ring resonator 311 of the first metamaterial unit 314 is connected to the split ring resonator 311 of the second metamaterial unit 315. When the metamaterial structure 300 is in a reflection state, the number of the metamaterial units 310 is multiple, which is beneficial to improving the reflection performance of the metamaterial structure 300; similarly, when the metamaterial structure 300 is in a transmission state, the number of the metamaterial units 310 is multiple, which is beneficial to improving the transmission performance of the metamaterial structure 300, so that more electromagnetic waves radiated by the radiator 200 can be radiated out, thereby improving the radiation performance of the radiator 200. Of course, at least one metamaterial unit 310 may further include a third metamaterial unit, a fourth metamaterial unit, etc., which can be set according to actual needs, and the embodiments of the present application do not make specific limitations thereto.

[0040] Optionally, the arc segments 311a1 of the split ring resonators 311 of adjacent metamaterial units 310 can be directly connected. At this time, the connection area between the two is small, the stability is poor, and it is not convenient for the fabrication of the metamaterial structure 300. Based on this, in a further optional embodiment, both the first part 311a and the second part 311b further include a first straight segment 311a2 and a second straight segment 311a3. The arc segment 311a1 is connected between the first straight segment 311a2 and the second straight segment 311a3, and both the first straight segment 311a2 and the second straight segment 311a3 are connected to the split ring resonators 311 of adjacent metamaterial units 310, thereby increasing the connection area between the split ring resonators 311 of adjacent metamaterial units 310. This can not only improve the connection stability between the split ring resonators 311 of adjacent metamaterial units 310, but also facilitate the fabrication of the split ring resonators 311 of the metamaterial structure 300.

[0041] Optionally, the power on / off switch 313 can be disposed at the end of the arc segment 311a1. In this case, when the power on / off switch 313 is in the off state, the lengths of the arc segment 311a1 on both sides of the power on / off switch 313 are different, and the electromagnetic wave energy distribution on the arc segment 311a1 is uneven, which will affect the reflection / transmission characteristics of the metamaterial structure 300. Therefore, in other embodiments, the power on / off switch 313 is disposed in the middle region of the arc segment 311a1. The power on / off switches 313 of the arc segment 311a1 of the first part 311a and the power on / off switches 313 of the arc segment 311a1 of the second part 311b are respectively located on both sides of the central axis of the split ring resonator 311, that is, the split ring resonator 311 can have an axisymmetric structure. When the power on / off switch 313 is in the off state, the lengths of the arc segment 311a1 on both sides of the power on / off switch 313 are equal. At this time, the electromagnetic wave energy on the arc segment 311a1 is evenly distributed, which is beneficial to improving the reflection / transmission characteristics of the metamaterial structure 300, so that more electromagnetic waves are reflected, thereby improving the radiation performance of the beamforming antenna.

[0042] Optionally, the frequency of the beamforming antenna can be adjusted by adjusting the size (such as length) of the radiator 200; or, in another alternative embodiment, both the split ring resonator 311 and the closed central ring 312 are frequency adjustable structures. Optionally, by adjusting the widths of the split ring resonator 311 and the closed central ring 312, the impedance matching of the beamforming antenna is adjusted, thereby adjusting the frequency range of the beamforming antenna; or, by adjusting the lengths of the split ring resonator 311 and the closed central ring 312, the frequency range of the beamforming antenna is adjusted. Further optionally, the widths and lengths of the split ring resonator 311 and the closed central ring 312 can be adjusted simultaneously to make the frequency adjustable range of the beamforming antenna wider. For example: the frequency range of the beamforming antenna is 5.15 - 5.85 GHz. When the power on / off switch 313 is in the off state, the metamaterial structure 300 generates a stopband in the frequency range of 5.15 - 5.85 GHz. The transmission coefficient of the metamaterial structure 300 is lower than -12 dB, and the reflection coefficient is close to 0 dB. The metamaterial structure 300 has strong reflectivity; when the power on / off switch 313 is in the on state, the metamaterial structure 300 generates a passband in the frequency range of 5.15 - 5.85 GHz. The transmission coefficient of the metamaterial structure 300 is close to 0 dB, and the reflection coefficient is lower than -9 dB. The metamaterial structure 300 has strong transmission characteristics. When electromagnetic waves in other frequency ranges are required, the widths and / or lengths of the split ring resonator 311 and the closed central ring 312 can be adjusted to adjust the passband frequency range and stopband frequency range of the metamaterial structure 300, so as to meet the actual use requirements. In this case, the requirements for the setting of the radiator 200 are relatively low, and the radiator 200 can be any radiator with omnidirectional radiation performance, thereby greatly reducing the manufacturing difficulty of the radiator 200.

[0043] In an alternative embodiment, when the number of the metamaterial structures 300 in the reflection state is at least two, that is, other metamaterial structures 300 are in the transmission state, at least two adjacent metamaterial structures 300 in the reflection state are arranged adjacent to each other. Correspondingly, other metamaterial structures 300 in the transmission state are also arranged adjacent to each other. At this time, the metamaterial structures 300 in the reflection state are connected in sequence to form a larger reflecting surface, so as to better gather the electromagnetic waves radiated by the radiator 200 to the direction where the metamaterial structures 300 in the transmission state are located, thereby improving the radiation performance of the directional beam. Of course, when the number of the metamaterial structures 300 in the reflection state is at least two, the metamaterial structures 300 in the reflection state and the metamaterial structures 300 in the transmission state can also be arranged alternately. At this time, the electromagnetic waves radiated by the radiator 200 are divided into at least two directional beams, and the performance of each directional beam is worse than that of a directional beam formed after at least two adjacent metamaterial structures 300 in the reflection state are arranged adjacent to each other.

[0044] In an alternative embodiment, when at least one metamaterial structure 300 is in the reflection state, the beamforming antenna is a directional antenna; when all the metamaterial structures 300 are in the transmission state, the beamforming antenna is an omnidirectional antenna. In this solution, by controlling the state of the metamaterial structure 300, the beamforming antenna can be flexibly switched to a directional antenna or an omnidirectional antenna to meet the actual usage requirements, avoiding separately setting different directional antennas and omnidirectional antennas, thereby saving costs.

[0045] Optionally, at least two of the metamaterial structures 300 can be plate structures, and the accommodation space surrounded by at least two of the metamaterial structures 300 can be in a triangular prism structure, a quadrangular prism structure, etc. At this time, the number of the metamaterial structures 300 is small, and the curvature of the connection of the substrates 316 of the adjacent metamaterial structures 300 is large. When at least two of the metamaterial structures 300 are in the reflection state and are arranged adjacent to each other, the reflecting surface formed by the at least two of the metamaterial structures 300 easily causes electromagnetic wave leakage. Based on this, in an alternative embodiment, the accommodation space surrounded by at least two of the metamaterial structures 300 can be in a hexagonal prism structure. At this time, the number of the metamaterial structures 300 is large to reduce the curvature of the connection of the substrates 316 of the adjacent metamaterial structures 300. When at least two of the metamaterial structures 300 are in the reflection state and are arranged adjacent to each other, the continuity of the reflecting surface formed by the at least two of the metamaterial structures 300 is good, which can avoid electromagnetic wave leakage, thereby improving the beam performance of the antenna. Of course, the accommodation space surrounded by at least two of the metamaterial structures 300 can also be an octagonal prism structure, a decagonal prism structure, etc., and the embodiments of the present application do not make specific limitations thereto. It should be noted that when the number of the metamaterial structures 300 is large, the manufacturing cost and power consumption of the antenna will be increased. Therefore, in actual applications, the metamaterial structures 300 can be avoided from being set too many.

[0046] Optionally, when the accommodation space surrounded by at least two metamaterial structures 300 is in a hexagonal prism structure, at this time, the at least two metamaterial structures 300 include a first metamaterial structure 320, a second metamaterial structure 330, a third metamaterial structure 340, a fourth metamaterial structure 350, a fifth metamaterial structure 360, and a sixth metamaterial structure 370 that are connected end to end in sequence. During the actual application of the beamforming antenna disclosed in the present application, the on-off switches 313 on the split ring resonators 311 of each metamaterial structure 300 can be switched in the clockwise direction. For example, the first metamaterial structure 320, the second metamaterial structure 330, and the third metamaterial structure 340 are controlled in sequence, the second metamaterial structure 330, the third metamaterial structure 340, and the fourth metamaterial structure 350, the third metamaterial structure 340, the fourth metamaterial structure 350, and the fifth metamaterial structure 360, the fourth metamaterial structure 350, the fifth metamaterial structure 360, and the sixth metamaterial structure 370, the fifth metamaterial structure 360, the sixth metamaterial structure 370, and the first metamaterial structure 320, and the sixth metamaterial structure 370, the first metamaterial structure 320, and the second metamaterial structure 330. The on-off switches 313 on the split ring resonators 311 of the metamaterial structures 300 are turned on, so that the directional beam is sequentially switched along the orientations where the second metamaterial structure 330, the third metamaterial structure 340, the fourth metamaterial structure 350, the fifth metamaterial structure 360, the sixth metamaterial structure 370, and the first metamaterial structure 320 are located, thereby realizing beamforming within 360°. Of course, only the on-off switches 313 on the split ring resonators 311 of two metamaterial structures 300 can be turned on and switched in sequence in the clockwise direction; or, the on-off switches 313 on the split ring resonators 311 of four metamaterial structures 300 can be turned on and switched in sequence in the clockwise direction. Optionally, the on-off switches 313 on the split ring resonators 311 of the metamaterial structures 300 in the above embodiments can also be switched in the counterclockwise direction, and the embodiments of the present application do not make specific limitations on this.

[0047] Optionally, the radiator 200 can be arranged close to any one of the metamaterial structures 300. At this time, the distances between the radiator 200 and the respective metamaterial structures 300 are not equal. Accordingly, the electromagnetic wave energy coupled by the radiator 200 to the respective metamaterial structures 300 is also not equal. In view of this, in other embodiments, the radiator 200 is located at the center of the accommodation space. At this time, the distances between the radiator 200 and the respective metamaterial structures 300 are equal. Accordingly, the electromagnetic wave energy coupled by the radiator 200 to the respective metamaterial structures 300 is also equal, so that the performance of the beamforming antenna in any azimuth is relatively uniform.

[0048] Optionally, the radiator 200 is a dipole antenna, which has the characteristics of strong directivity, good anti-interference performance, small antenna size, multiple polarization modes and suitability for multiple application scenarios. Of course, the radiator 200 can also be other types of omnidirectional or quasi-omnidirectional antennas, such as loop antennas, microstrip patch antennas, etc. The embodiments of the present application do not make specific limitations on this.

[0049] Based on the beamforming antenna disclosed in the present application, referring to Figure 7 and Figure 8 it can be known that the radiator 200 is less than -10 dB in the range of 5.15 - 5.85 GHz, the antenna gain is 2 dB, and it has good omnidirectionality.

[0050] Referring to Figures 9 to 11 it can be known that the beamforming antenna is less than -15 dB in the range of 5.15 - 5.85 GHz, the gain reaches more than 5.5 dB. By switching the on-off switch 313 between the on state and the off state, the beamforming antenna can achieve beamforming in a 360° range; when all the on-off switches 313 are turned on, the beamforming antenna switches from directional radiation to omnidirectional radiation, and can achieve flexible switching between an omnidirectional antenna and a directional antenna, and the non-circularity is less than 3 dB. Therefore, through the designed metamaterial structure 300 of the present application, not only the problems of large size and high cost of traditional beamforming antennas are solved, but also 360° beam full coverage can be achieved, the non-circularity is less than 3 dB, and it has universality and can be widely applied to common omnidirectional and quasi-omnidirectional antennas.

[0051] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all belong to the protection scope of the present application.

Claims

1. An antenna, characterized in that, It includes a radiator (200) and at least two metamaterial structures (300). The at least two metamaterial structures (300) are connected end to end in sequence to enclose an accommodation space, and the radiator (200) is arranged in the accommodation space. The radiator (200) has a feeding port (210). The metamaterial structure (300) can be switched between a reflection state and a transmission state. When the metamaterial structure (300) is in the reflection state, the metamaterial structure (300) can reflect the electromagnetic wave radiated by the radiator (200); when the metamaterial structure (300) is in the transmission state, the electromagnetic wave radiated by the radiator (200) can pass through the metamaterial structure (300).

2. The antenna according to claim 1, characterized in that, The metamaterial structure (300) includes at least one metamaterial unit (310). The metamaterial unit (310) includes a substrate (316), and a split ring resonator (311) and a closed central ring (312) that are spaced apart and arranged on the substrate (316). The split ring resonator (311) is sleeved outside the closed central ring (312). The split ring resonator (311) is provided with a power on / off switch (313), and the power on / off switch (313) can control the metamaterial structure (300) to switch between the reflection state and the transmission state. When the power on / off switch (313) is closed, the metamaterial structure (300) is in the reflection state; when the power on / off switch (313) is turned on, the metamaterial structure (300) is in the transmission state.

3. The antenna according to claim 2, characterized in that, The central axis of the closed central ring (312) coincides with the central axis of the split ring resonator (311).

4. The antenna according to claim 2, characterized in that, The closed central ring (312) is a circular ring.

5. The antenna according to claim 2, characterized in that, The split ring resonator (311) includes a first part (311a) and a second part (311b) that are spaced apart. The first part (311a) and the second part (311b) are arranged opposite to each other. Both the first part (311a) and the second part (311b) are provided with the power on / off switch (313). Both the first part (311a) and the second part (311b) include an arc segment (311a1). The closed central ring (312) is located between the arc segment (311a1) of the first part (311a) and the arc segment (311a1) of the second part (311b). The arc segment (311a1) of the first part (311a) and the arc segment (311a1) of the second part (311b) are spaced apart on the same circumference.

6. The antenna according to claim 5, characterized in that, The at least one metamaterial unit (310) includes a first metamaterial unit (314) and a second metamaterial unit (315) arranged in sequence along the axial direction of the accommodation space. The substrate (316) of the first metamaterial unit (314) is connected to the substrate (316) of the second metamaterial unit (315), and the split-ring resonator (311) of the first metamaterial unit (314) is connected to the split-ring resonator (311) of the second metamaterial unit (315).

7. The antenna according to claim 6, characterized in that, Both the first part (311a) and the second part (311b) further include a first straight segment (311a2) and a second straight segment (311a3). The arc segment (311a1) is connected between the first straight segment (311a2) and the second straight segment (311a3). Both the first straight segment (311a2) and the second straight segment (311a3) are connected to the split-ring resonator (311) of the adjacent metamaterial unit (310).

8. The antenna according to claim 5, characterized in that, A power on / off switch (313) is arranged in the middle area of the arc segment (311a1). The power on / off switch (313) of the arc segment (311a1) of the first part (311a) and the power on / off switch (313) of the arc segment (311a1) of the second part (311b) are respectively located on both sides of the central axis of the split-ring resonator (311).

9. The antenna according to claim 2, characterized in that, Both the split-ring resonator (311) and the closed central ring (312) are frequency tunable structures.

10. The antenna according to claim 1, characterized in that, When the number of the metamaterial structures (300) in the reflection state is at least two, the at least two metamaterial structures (300) in the reflection state are arranged adjacent to each other.

11. The antenna according to claim 1, characterized in that, When at least one of the metamaterial structures (300) is in the reflection state, the beamforming antenna is a directional antenna; when each of the metamaterial structures (300) is in the transmission state, the beamforming antenna is an omnidirectional antenna.

12. The antenna according to claim 1, characterized in that, The accommodation space has a hexagonal prism structure.

13. The antenna according to claim 1, characterized in that, The radiator (200) is located at the center of the accommodation space, and the radiator (200) is a dipole antenna.

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