Antenna system and communication device

Abstract

Embodiments of this application disclose an antenna system and a communication device. The antenna system includes a first antenna and a second antenna. The first antenna includes: a feed, configured to emit an electromagnetic wave; a first reflector, where a reflective surface of the first reflector faces the feed, and the first reflector is configured to reflect the electromagnetic wave emitted by the feed; and a second reflector, where the feed is located between the second reflector and the first reflector, the feed is disposed close to a reflective surface of the second reflector, and the second reflector is configured to reflect the electromagnetic wave reflected by the first reflector. The second antenna includes an optical fiber and a lens assembly connected to the optical fiber, the first reflector includes a first through hole, the optical fiber passes through the first through hole for ease of mounting, and the lens assembly is located on a side that is of the first reflector and that is away from the second reflector. The first antenna and the second antenna may share an aperture of the second reflector, occupying less space. In addition, the two antennas are used together in a hybrid network, achieving channel complementarity and improving communication performance.

Description

[0001] This application claims priority to Chinese Patent Application No. 202310313243.X, filed with the China National Intellectual Property Administration on March 20, 2023 and entitled "ANTENNA SYSTEM AND COMMUNICATION DEVICE", which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] Embodiments of this application relate to the antenna field, and in particular, to an antenna system and a communication device.BACKGROUND

[0003] Currently, millimeter-wave antennas are widely used in the field of wireless communication, with millimeter wave bands emerging as main frequency bands for microwave backhaul. However, millimeter waves experience more severe atmospheric attenuation. This affects a communication distance of a backhaul link.

[0004] Optical wireless exhibits stronger resistance to rain-induced attenuation while the millimeter waves demonstrate enhanced resilience against fog and snow-related attenuation.

[0005] Therefore, integrating millimeter-wave antennas with optical antennas in hybrid networking enables complementary channel, thereby improving communication performance of long-distance wireless backhaul.

[0006] At present, there are some solutions for hybrid networking of millimeter waves and optical wireless. As shown in FIG. 2, a communication device 002 includes a millimeter-wave antenna and an optical antenna.

[0007] The millimeter-wave antenna includes a millimeter-wave feed 10 and a reflective surface 11 arranged sequentially along the x-axis.

[0008] The optical antenna includes a dielectric dichroic mirror 12, a lens assembly 14, and an optical wireless source 13 arranged sequentially along the x-axis.

[0009] Millimeter waves emitted from the millimeter-wave feed 10 are reflected by the reflective surface 11 and then transmitted outward along the x-axis. Wireless light emitted by the optical wireless source 13 is transmitted to the dielectric dichroic mirror 12 through the lens assembly 14 and the reflective surface 11, is reflected by the dielectric dichroic mirror 12 and then reflected by the reflective surface 11, and finally is transmitted outward along the x-axis.

[0010] However, due to the front placement of the millimeter-wave feed, feed loss of the millimeter-wave feed and feeder blockage significantly affect antenna gain. Besides, the millimeter wave and the wireless light share the reflective surface 11, but it is difficult for the reflective surface 11 to reflect the millimeter wave and the wireless light at the same time.

[0011] Both the millimeter-wave antenna and the optical antenna are separately deployed, which requires separate installations and alignments. In addition, device sizes are large, and tower rental and mounting costs are high, making widespread implementation challenging.SUMMARY

[0012] Embodiments of this application provide an antenna system and a communication device, to resolve difficulty in assembly of a millimeter-wave antenna and an optical antenna.

[0013] To achieve the foregoing objective, the following technical solutions are used in this application. According to a first aspect, an antenna system is provided, including a first antenna and a second antenna. The first antenna includes: a feed, where the feed is configured to emit an electromagnetic wave; a first reflector, where a reflective surface of the first reflector faces the feed, and the first reflector is configured to reflect the electromagnetic wave emitted by the feed; and a second reflector, where the feed is located between the second reflector and the first reflector, the feed is disposed close to a reflective surface of the second reflector, and the second reflector is configured to reflect the electromagnetic wave reflected by the first reflector. The second antenna includes an optical fiber and a lens assembly connected to the optical fiber, the first reflector includes a first through hole, the optical fiber passes through the first through hole, and the lens assembly is located on a side that is of the first reflector and that is away from the second reflector. Therefore, the first antenna is a reflector antenna, and the second antenna is an optical antenna. The electromagnetic wave emitted by the feed of the first antenna is transmitted outward after passing through the first reflector and the second reflector sequentially. An aperture of the millimeter-wave antenna may be a circular ring enclosed by an edge of the second reflector and an edge of the first reflector. In other words, no millimeter wave is transmitted from the aperture of the first reflector. The optical fiber of the optical antenna passes through the first reflector, and wireless light is transmitted from the center of the first reflector, and then transmitted outward through the lens assembly. The lens assembly is opposite to the first reflector, so that the wireless light is in a dielectric lens (that is, within a range of the aperture of the first reflector). In other words, an aperture of an optical antenna may be a circle enclosed by an edge of the dielectric lens. Therefore, the optical fiber passes through the through hole of the first reflector, to facilitate mounting and alignment. In addition, the first antenna and the second antenna may share an aperture of the second reflector, and occupy less space. This helps reduce a device size, and can implement large-scale deployment. Moreover, interference between the first antenna and the second antenna is small, and antenna efficiency is improved. In addition, hybrid networking of the millimeter-wave antenna and the optical antenna can implement channel complementarity, and improve communication performance of long-distance wireless backhaul.

[0014] In an optional implementation, a focal trajectory of the first reflector is a circular ring, and the circular ring is perpendicular to an axis of the first antenna. Therefore, the first antenna is an annular focus antenna, so that blocking of the electromagnetic wave reflected by the second reflector by the first reflector can be reduced, and reflection of the feed by the first reflector can also be reduced, so that the feed and the first reflector can be designed to be very close to each other. This helps reduce a side lobe and a voltage standing wave ratio of the antenna and improve the antenna efficiency.

[0015] In an optional implementation, the first through hole is positioned at the center of the first reflector. Therefore, the optical fiber can be located at the center of the first reflector, and the first reflector is used as the aperture of the optical antenna, so that aperture efficiency is improved.

[0016] In an optional implementation, the feed includes a waveguide tube and a feed horn, and the optical fiber passes through the waveguide tube and the feed horn. Therefore, a structure in which the first antenna and the second antenna are coaxial is implemented, wireless light alignment can be assisted, and mounting difficulty and time costs are reduced. This helps promote large-scale commercial use of a hybrid networking product.

[0017] In an optional implementation, the waveguide tube includes a first waveguide, a second waveguide, and a combining end of the first waveguide and a second waveguide, an end of the first waveguide and an end of the second waveguide are connected to the combining end, and the optical fiber enters the waveguide tube through the combining end. Therefore, differential feeding can be implemented by using the first waveguide and the second waveguide, and the optical fiber may pass through a gap between the first waveguide and the second waveguide to enter the combining end of the first waveguide and the second waveguide. There is no need to provide an additional opening for introducing the optical fiber on the waveguide, so that production costs are reduced.

[0018] In an optional implementation, the waveguide tube further includes a third waveguide and a fourth waveguide, an end of the third waveguide and an end of the fourth waveguide are connected to the combining end, and polarization directions of the third waveguide and the fourth waveguide are orthogonal to polarization directions of the first waveguide and the second waveguide. Therefore, the third waveguide and the fourth waveguide are disposed, so that dual polarization of the antenna can be implemented, and less space is occupied by a dual-polarized antenna.

[0019] In an optional implementation, a metal tube is further included. The metal tube is disposed in the feed, one end is connected to a port of the combining end, the other end is connected to the first reflector, and the optical fiber passes through the metal tube. Therefore, the metal tube can provide support for the first reflector, and can further reduce leakage of a millimeter wave, and reduce impact of an optical fiber transmission line on millimeter-wave radiation.

[0020] In an optional implementation, the metal tube and the first antenna are disposed coaxially. Therefore, a structure in which the first antenna and the second antenna are coaxial is implemented, the wireless light alignment can be assisted, and the mounting difficulty and the time costs are reduced. This helps promote the large-scale commercial use of the hybrid networking product.

[0021] In an optional implementation, the combining end of the first waveguide and the second waveguide is provided with a step structure, and a step surface of the step structure is perpendicular to the axis of the first antenna. Therefore, the step structure is disposed, so that the impact of the optical fiber on a transmission mode of the millimeter-wave antenna and distortion of a radiation beam can be reduced.

[0022] In an optional implementation, a material of the step structure includes metal. Therefore, performance of the step structure can be improved, and the impact on the transmission mode of the millimeter-wave antenna can be better reduced.

[0023] In an optional implementation, the lens assembly and the first antenna are disposed coaxially. Therefore, the lens assembly, that is, the optical antenna, can better reuse the aperture of the first reflector, the interference between the first antenna and the second antenna is small, and the antenna efficiency is improved.

[0024] In an optional implementation, an aperture of the lens assembly is smaller than or equal to the aperture of the first reflector. Therefore, isolation between the first antenna and the second antenna is improved, the mutual interference between the first antenna and the second antenna can be further reduced, and the antenna efficiency is improved.

[0025] In an optional implementation, a transceiver is further included, where both the feed and the optical fiber are connected to the transceiver. Therefore, the electromagnetic wave and the wireless light can be received and transmitted by using the transceiver.

[0026] In an optional implementation, the second reflector includes a second through hole, where the transceiver is located in the second through hole. Therefore, the transceiver is disposed in the through hole of the second reflector, so that the transceiver can occupy less space.

[0027] In an optional implementation, the second through hole is positioned at the center of the second reflector. Therefore, the feed and the optical fiber can be coaxial, the wireless light alignment can be assisted, and the mounting difficulty and the time costs are reduced. This helps promote the large-scale commercial use of the hybrid networking product.

[0028] In an optional implementation, the first antenna is a millimeter-wave antenna. Therefore, channel attenuation resistance of the millimeter-wave antenna and the optical antenna varies in different environments, so that hybrid networking of the millimeter-wave antenna and the optical antenna can implement the channel complementarity, and improve the communication performance of the antenna.

[0029] In an optional implementation, the lens assembly includes the dielectric lens, and the dielectric lens is disposed on a side that is of the optical fiber and that is away from the first reflector. Therefore, the dielectric lens may be used as the optical antenna.

[0030] In an optional implementation, the lens assembly further includes a fiber-optic beam expander, the fiber-optic beam expander is located between the first reflector and the dielectric lens, the fiber-optic beam expander is connected to the optical fiber, and the dielectric lens is disposed on a light-emitting side of the fiber-optic beam expander. Therefore, the fiber-optic beam expander may expand a beam of the wireless light emitted by the optical fiber.

[0031] According to a second aspect, a communication device is provided. The communication device includes the foregoing antenna system. Therefore, the communication device uses the foregoing antenna, so that mounting difficulty can be reduced.

[0032] In an optional implementation, the communication device is a wireless backhaul base station. Therefore, the antenna is used in a wireless backhaul node, so that channel complementarity can be implemented, and communication performance of long-distance wireless backhaul can be improved.BRIEF DESCRIPTION OF DRAWINGS

[0033] FIG. 1 is a diagram of a structure of a communication system; FIG. 2 is a diagram of a structure of a communication device; FIG. 3 is a diagram of a structure of another communication device; FIG. 4 is a diagram of an operating state of the communication device in FIG. 3; FIG. 5 is a diagram of a structure of an antenna system according to an embodiment of this application; FIG. 6 is a diagram of a structure of a communication device in FIG. 5; FIG. 7 is a diagram of a structure of another antenna system according to an embodiment of this application; FIG. 8 is a partially enlarged view at position 1002 in FIG. 7; FIG. 9 is a three-dimensional diagram at position 1002 in FIG. 7; FIG. 10 is a diagram of a structure of another antenna system according to an embodiment of this application; FIG. 11 is a partially enlarged view at position 1002 in FIG. 10; FIG. 12 is a three-dimensional diagram at position 1002 in FIG. 10; FIG. 13 is another partially enlarged view at position 1002 in FIG. 10; and FIG. 14 is another three-dimensional diagram at position 1002 in FIG. 10. DESCRIPTION OF EMBODIMENTS

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following further describes this application in detail with reference to the accompanying drawings.

[0035] Terms such as "first" and "second" mentioned below are merely intended for a purpose of description, and shall not be understood as an indication or implication of relative importance or implicit indication of a quantity of indicated technical features. Therefore, a feature limited by "first", "second", or the like may explicitly or implicitly include one or more features. In the descriptions of this application, unless otherwise stated, "a plurality of" means two or more.

[0036] In addition, in this application, orientation terms such as "upper", and "lower" are defined relative to an illustrative orientation of a component in the accompanying drawings. It should be understood that these directional terms are relative concepts and are used for relative description and clarification, and may vary accordingly depending on a change in orientations in which components are placed in the accompanying drawings.

[0037] The following describes terms that may appear in embodiments of this application.

[0038] Cassegrain antenna: The Cassegrain antenna includes a second reflector, a first reflector, and a radiation source. The second reflector is a paraboloid of revolution, and the first reflector is a hyperboloid of revolution. In structure, one focus of the hyperbolic surface coincides with a focus of the parabolic surface, a focal axis of the hyperbolic surface coincides with a focal axis of the parabolic surface, and the radiation source is located on the other focus of the hyperbolic surface. The first reflector may reflect an electromagnetic wave emitted by the radiation source once, to reflect the electromagnetic wave to the second reflector, and then a plane wave beam in a corresponding direction is obtained by reflecting the electromagnetic wave by the second reflector, to implement directional transmission.

[0039] Annular focus antenna: A second reflector of the annular focus antenna is a paraboloid of revolution, a busbar of the first reflector is an ellipse or a hyperbola, and a focal trajectory of the annular focus antenna is a circular ring.

[0040] FIG. 1 is a diagram of a communication system according to an embodiment of this application. As shown in FIG. 1, the communication system includes a context-aware sensor (context-aware sensor) 001 and a communication device 002.

[0041] The context-aware sensor 001 is configured to obtain environment information, for example, may determine a foggy, rainy, or snowy environment.

[0042] An embodiment of this application further provides a communication device. The communication device may include at least one transmitter device and at least one receiver device.

[0043] The transmitter device is configured to emit an electromagnetic wave. The transmitter device may be an evolved NodeB (evolved NodeB, eNB), a radio network controller (radio network controller, RNC), a NodeB (NodeB, NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home base station (for example, a home evolved NodeB, or a home NodeB, HNB), a baseband unit (baseband unit, BBU), an access point (access point, AP) in a wireless fidelity (wireless fidelity, Wi-Fi) system, a wireless relay node, a wireless backhaul node, a transmission point (transmission point, TP), a transmission and reception point (transmission and reception point, TRP), or the like, or may be a gNB or a transmission point (TRP or TP) in a 5G system such as an NR (new radio, new radio) system, an antenna panel or a group of antenna panels of a base station in a 5G system, or the like. These are not exhaustive.

[0044] The receiver device is configured to receive an electromagnetic wave. The transmitter device may be an evolved NodeB, a radio network controller, a NodeB, a base station controller, a base transceiver station, a home base station, a baseband unit, an access point in a wireless fidelity system, a wireless relay node, a wireless backhaul node, a transmission point, a transmission and reception point, or the like, may be a gNB or a transmission point in a 5G system such as an NR system, an antenna panel or a group of antenna panels of a base station in a 5G system, or the like, or may be user equipment (user equipment, UE), a mobile station, a remote station, and the like. The receiver device is a network device having a wireless receiving function. A terminal may be deployed on land, including an indoor or outdoor terminal, a handheld terminal, a wearable terminal, or a vehicle-mounted terminal, may be deployed on water (for example, a ship), or may be deployed in air (for example, an airplane, a balloon, and a satellite). The terminal may be specifically a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiver function, a virtual reality (virtual reality, VR) terminal device, an augmented reality (augmented reality, AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in telemedicine (remote medical), a wireless terminal in a smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in a smart city (smart city), a wireless terminal in a smart home (smart home), or the like. These are not exhaustive.

[0045] The communication device may include an antenna system. The antenna system is configured to: emit or receive an electromagnetic wave. In an embodiment, the communication device may be a ground station (Ground Station), which is a component of a satellite system or a space system. In other words, the communication device is a ground device that is disposed on the earth for space communication, for example, a ground device that is disposed on the earth surface (including ships and aircraft) for artificial satellite communication. During operation, the communication device can transmit a signal to a satellite or receive a signal transmitted by a satellite.

[0046] In another embodiment, the communication device may be a base station, and is used for wireless backhaul (backhaul). In other words, the communication device completes data communication between the base station and a core network. A wireless backhaul technology includes a microwave transmission technology and a wireless optical backhaul technology. The communication device may be used in a wireless backhaul communication system. The wireless backhaul communication system generally includes at least one base station, and each base station provides a service for a plurality of terminals. A specific base station (for example, a base station A) in the at least one base station is connected to the core network in a wired / wireless manner, and another base station is connected to the core network through the base station A.

[0047] Impact of a foggy, rainy, or snowy environment varies on transmission links of different antennas.

[0048] For example, impact of fog on attenuation of free-space optical communication (Free Space Optical Communications, FSO) links is far greater than impact on electromagnetic frequency (Radio Frequency, RF) communication.

[0049] When a frequency of an electromagnetic wave is greater than 40 GHz, impact of rain on attenuation of electromagnetic wave transmission links is far greater than impact on attenuation of the free-space optical communication links.

[0050] When the frequency of the electromagnetic wave is less than 100 GHz, impact of snow on attenuation of the electromagnetic wave transmission link is far less than impact on attenuation of the free-space optical communication link.

[0051] Therefore, an embodiment of this application provides an antenna system. Hybrid networking is performed on an electromagnetic wave 003 and free space optical 004, to implement channel complementarity and improve long-distance wireless communication performance.

[0052] In some embodiments of this application, a communication device 002 includes a millimeter-wave antenna and an optical antenna. The millimeter-wave antenna is configured to: receive and emit an electromagnetic wave, to implement the electromagnetic wave transmission, and the optical antenna is configured to receive and emit wireless light, to implement the free space optical communication.

[0053] The communication device 002 may control, based on environment information obtained by the context-aware sensor 001, the millimeter-wave antenna and the optical antenna to operate.

[0054] FIG. 3 is a diagram of a structure of another communication device. As shown in FIG. 3, the communication device 002 includes a millimeter-wave antenna and an optical antenna.

[0055] In some embodiments of this application, the millimeter-wave antenna is a Cassegrain antenna, and includes a feed 100, a second reflector 101, a first reflector 102, and a support tube 103.

[0056] In some embodiments, as shown in FIG. 4, a reflective surface of the second reflector 101 is a paraboloid of revolution, a reflective surface of the first reflector 102 is a hyperboloid of revolution, and the reflective surface of the second reflector 101 is opposite to the reflective surface of the first reflector 102. The feed 100 is designed with a hollow metal waveguide tube, so that a transmitted electromagnetic wave can be completely confined within the metal tube. The feed 100 (waveguide tube) passes through the second reflector 101 and is opposite to the first reflector 102. In addition, the feed 100 is connected to the first reflector 102 through the support tube 103.

[0057] FIG. 4 is a diagram of an operating state of the millimeter-wave antenna in FIG. 3. As shown in FIG. 4, during operation, an electromagnetic wave emitted by the feed 100 is reflected by the first reflector 102 to the second reflector 101, and is transmitted outward along the +x axis after being reflected by the second reflector.

[0058] The optical antenna includes an optical fiber 200 and a lens assembly 14 connected to the optical fiber 200. The optical fiber 200 passes through the feed 100. The optical fiber 200 passes through the waveguide tube (feed 100) and the support tube 103.

[0059] Wireless light transmitted by the optical fiber 200 is transmitted outward through the lens assembly 14 along the +x axis.

[0060] However, the Cassegrain antenna is an antenna system with two reflective surfaces, and the first reflector 102, the feed 100, and the support tube 103 block the second reflector. As a result, a sidelobe level of the Cassegrain antenna is increased, and a gain of the Cassegrain antenna is reduced.

[0061] In addition, a solution in which the millimeter-wave waveguide and the optical fiber are coaxial affects fundamental mode transmission. Consequently, a bandwidth of the feed is compressed to less than 2%, and antenna aperture efficiency is only 26% due to radiation distortion of the feed and structural damage to the first reflector.

[0062] An antenna aperture is a parameter indicating efficiency of an antenna in receiving waves. The antenna aperture refers to an area perpendicular to a direction of an incident electromagnetic wave that effectively intercepts energy of the incident electromagnetic wave. For example, in the antenna shown in FIG. 4, an aperture of the millimeter-wave antenna may be a circle formed by edges of the second reflector 101.

[0063] In view of this, an embodiment of this application provides an improved antenna system.

[0064] FIG. 5 is a diagram of a structure of an antenna system according to an embodiment of this application. As shown in FIG. 5, the antenna system includes a transceiver 1001 and a first antenna and a second antenna that are connected to the transceiver 1001, and the first antenna and the second antenna share an aperture.

[0065] In an embodiment, the first antenna is a millimeter-wave antenna, and is configured to: emit and receive a millimeter wave. The second antenna is an optical antenna, and is configured to: emit and receive wireless light.

[0066] The transceiver 1001 is configured to: receive or emit an electromagnetic wave through the first antenna, and receive or emit wireless light through the second antenna.

[0067] The first antenna includes a second reflector 1004, a feed 1002, and a first reflector 1005 that are sequentially arranged along the +z axis. The feed 1002 is located between the second reflector 1004 and the first reflector 1005.

[0068] The second reflector 1004 includes a first surface and a second surface that are opposite to each other, and the first reflector 1005 includes a first surface and a second surface that are opposite to each other. The first surface of the second reflector 1004 is opposite to the second surface of the first reflector 1005.

[0069] In some embodiments, the first surface of the second reflector 1004 may be used as a reflective surface of the second reflector 1004, and the second surface of the first reflector 1005 may be used as a reflective surface of the first reflector 1005.

[0070] As shown in FIG. 6, during operation of the first antenna, the feed 1002 emits an electromagnetic wave to the first reflector 1005, the first reflector 1005 may reflect, to the second reflector 1004, the electromagnetic wave generated by the feed 1002, and the second reflector 1004 may reflect the electromagnetic wave reflected by the first reflector 1005, so that the electromagnetic wave is transmitted outward along the +z axis.

[0071] The second antenna includes an optical fiber 1003 and a lens assembly that are sequentially arranged along the +z axis. The lens assembly is connected to the optical fiber 1003.

[0072] In an embodiment, the lens assembly includes a fiber-optic beam expander 1006 and a dielectric lens 1007 that are sequentially arranged along the +z axis. The fiber-optic beam expander 1006 is located between the optical fiber 1003 and the dielectric lens 1007, the fiber-optic beam expander 1006 is connected to the optical fiber 1003, and the dielectric lens 1007 is disposed on a light-emitting side of the fiber-optic beam expander 1006.

[0073] In some embodiments of this application, the first reflector 1005 includes a first through hole, the optical fiber 1003 passes through the first through hole, and the lens assembly is located on a side that is of the first reflector 1005 and that is away from the second reflector 1004. In an embodiment, the first through hole is positioned at the center of the first reflector. Therefore, the optical fiber can be located at the center of the first reflector, and the first reflector is used as an aperture of the optical antenna, so that aperture efficiency is improved.

[0074] In an embodiment, the fiber-optic beam expander 1006 can change a diameter and a divergence angle of a light beam. A light beam emitted from the optical fiber has a specific divergence angle, and the light beam may be changed to a collimated (parallel) light beam through adjustment using the fiber-optic beam expander 1006.

[0075] The dielectric lens 1007 is configured to adjust a light ray emitted by the fiber-optic beam expander 1006, for example, control and change a direction or a width of a light beam, focusing, and defocusing.

[0076] As shown in FIG. 6, during operation of the second antenna, wireless light emitted by the optical fiber 1003 is irradiated to the dielectric lens 1007 through the fiber-optic beam expander 1006, so that the wireless light is transmitted outward along the +z axis.

[0077] Therefore, the first antenna is a reflector antenna, and the second antenna is an optical antenna. The electromagnetic wave emitted by the feed of the first antenna is transmitted outward after passing through the first reflector and the second reflector sequentially. The optical fiber of the second antenna passes through the first reflector, and wireless light is transmitted from the center of the first reflector, and then transmitted outward through the lens assembly. The aperture of the first antenna may be a circular ring enclosed by an edge of the second reflector and an edge of the first reflector. In other words, no millimeter wave is transmitted from an aperture of the first reflector.

[0078] The optical fiber of the second antenna passes through the first reflector, and the wireless light is transmitted from the center of the first reflector, and then transmitted outward through the lens assembly. The lens assembly is opposite to the first reflector, so that the wireless light is transmitted through the dielectric lens (that is, within a range of the aperture of the first reflector). In other words, an aperture of the optical antenna may be a circle enclosed by an edge of the dielectric lens. Therefore, the optical fiber passes through the through hole of the first reflector, to facilitate mounting and alignment. In addition, the first antenna and the second antenna may share an aperture of the second reflector, and occupy small space. This helps reduce a device size, and can implement large-scale deployment.

[0079] In addition, hybrid networking of the millimeter-wave antenna and the optical antenna can implement channel complementarity, and improve communication performance of long-distance wireless backhaul.

[0080] In some embodiments of this application, the second reflector includes a second through hole, where the transceiver 1001 is located in the second through hole. In an embodiment, the second through hole is positioned at the center of the second reflector.

[0081] Therefore, the transceiver 1001 is disposed in the through hole of the second reflector, so that the transceiver 1001 can occupy less space. The second through hole is provided at the center of the second reflector 1004, so that the feed and the optical fiber can be coaxial, wireless light alignment can be assisted, and mounting difficulty and time costs are reduced. This helps promote large-scale commercial use of a hybrid networking product.

[0082] In an embodiment, the first antenna is an annular focus antenna. For example, a focal trajectory of the first reflector is a circular ring, and the circular ring is perpendicular to an axis of the first antenna. Therefore, the first antenna is an annular focus antenna, so that blocking of an electromagnetic wave reflected by the second reflector by the first reflector can be reduced, and reflection of the feed by the first reflector can also be reduced, so that the feed and the first reflector can be designed to be very close to each other. This helps reduce a side lobe and a voltage standing wave ratio of the antenna and improve antenna efficiency.

[0083] In an embodiment, the circular ring formed by the focal trajectory of the first reflector is greater than or equal to the aperture of the first reflector. The aperture of the first reflector may be a circular ring enclosed by the edge of the first reflector. Therefore, the blocking of the electromagnetic wave reflected by the second reflector by the first reflector can be reduced.

[0084] The following describes a structure of the first antenna with reference to FIG. 6. As shown in FIG. 6, the reflective surface of the second reflector 1004 is a partially paraboloid of revolution, the reflective surface of the first reflector 1005 is formed by rotating an elliptical arc CB around an axis OC of the second reflector for a cycle, and the feed 1002 is located on a focus M of an ellipsoidal surface. A wave radiated by the feed 1002 is reflected by the first reflector 1005 and then converges on another focus of the ellipsoidal surface. A focus of the first reflector 1005 is a focus of a parabolic surface OD. Therefore, the electromagnetic wave reflected by the second reflector 1004 is transmitted outward in parallel. The focus of the first reflector 1005 forms a circular ring perpendicular to an antenna axis. Therefore, the antenna is referred to as an annular focus antenna. A design of the annular focus antenna can reduce the blocking of the electromagnetic wave by the first reflector 1005, and can also reduce the reflection of the feed 1002 by the first reflector 1005, so that the feed 1002 and the first reflector 1005 can be designed to be very close to each other. This helps reduce a side lobe and a voltage standing wave ratio of the antenna at a wide frequency band and improve the antenna efficiency.

[0085] In the annular focus antenna, no electromagnetic wave is transmitted from an XOY region in which the first reflector 1005 is located. In this embodiment of this application, the second antenna is disposed on a side that is of the first reflector 1005 and that is away from the second reflector 1004, so that the second antenna can reuse an aperture of a region in which the second reflector 1004 is opposite to the first reflector 1005, mutual interference between the wireless light emitted by the second antenna and an electromagnetic wave emitted by the annular focus antenna is reduced, and the antenna efficiency is further improved.

[0086] Therefore, the first antenna is an annular focus antenna, so that the blocking of the electromagnetic wave reflected by the second reflector by the first reflector can be reduced, and the reflection of the feed by the first reflector can also be reduced, so that the feed and the first reflector can be designed to be very close to each other. This helps reduce the side lobe and the voltage standing wave ratio of the antenna and improve the antenna efficiency.

[0087] An antenna aperture is a parameter indicating efficiency of an antenna in receiving a wave, and refers to an area that is perpendicular to a direction of an incident electromagnetic wave and that effectively intercepts energy of the incident electromagnetic wave. For example, in the antenna shown in FIG. 6, the aperture of the first antenna may be the circular ring enclosed by the edge of the second reflector 1004 and the edge of the first reflector 1005, and the aperture of the optical antenna may be the circle enclosed by the edge of the dielectric lens 1007.

[0088] In some embodiments, the lens assembly and the first antenna are disposed coaxially. Therefore, the lens assembly, that is, the second antenna, can better reuse the aperture of the first reflector, interference between the first antenna and the second antenna is small, and the antenna efficiency is improved.

[0089] The aperture of the second antenna is smaller than or equal to the aperture of the first reflector 1005.

[0090] Therefore, the mutual interference between the first antenna and the second antenna can be further reduced, and the antenna efficiency is improved.

[0091] A feeding manner of the annular focus antenna is not limited in this embodiment of this application. In some other embodiments, the annular focus antenna uses a differential feeding manner. For example, as shown in 1002 in FIG. 7, the transceiver 1001 is connected to the feed 1002 through a waveguide 1008. In an embodiment, the waveguide 1008 is, for example, a hollow metal waveguide tube, so that a transmitted electromagnetic wave can be completely confined within the metal tube. This is also referred to as a closed waveguide.

[0092] FIG. 8 is an enlarged view at position 1002 in FIG. 7. FIG. 9 is a three-dimensional diagram at position 1002 in FIG. 7. As shown in FIG. 8 and FIG. 9, the feed 1002 includes: a feed horn 10021, a first waveguide 10081, a second waveguide 10082, and a combining end 10083 connected to the first waveguide 10081 and the second waveguide 10082. A gap is provided between the first waveguide 10081 and the second waveguide 10082, and the optical fiber may pass through the gap to enter the combining end 10083 of the first waveguide 10081 and the second waveguide 10082, enter the feed horn 10021 through the combining end 10083, and finally exit through the first reflector 1005.

[0093] The first waveguide 10081 includes a first end and a second end that are opposite to each other, the second waveguide 10082 includes a first end and a second end that are opposite to each other, the first end of the first waveguide 10081 and the first end of the second waveguide 10082 are connected to the combining end 10083, and the second end of the first waveguide 10081 and the second end of the second waveguide 10082 are connected to the transceiver 1001 through a waveguide tube.

[0094] Therefore, the optical fiber and the waveguide 1008 can be coaxial, the wireless light alignment can be assisted, and the mounting difficulty and the time costs are reduced. This helps promote large-scale commercial use of a hybrid networking product using wireless light and an electromagnetic wave.

[0095] To reduce impact of coaxiality of the optical fiber 1003 and the differential feeding waveguide 1008 on fundamental mode transmission, as shown in FIG. 8 and FIG. 9, a step structure 10084 is further provided at the combining end 10083 of the first waveguide 10081 and the second waveguide 10082. In an embodiment, a step surface of the step structure 10084 is perpendicular to the axis of the first antenna.

[0096] In an embodiment, the step structure 10084 includes a boss.

[0097] In an embodiment, a material of the boss includes metal.

[0098] The boss is formed at the combining end 10083, and the boss may be of a solid structure or a hollow structure. In this embodiment, the optical fiber 1003 needs to pass through the combining end 10083. Therefore, the boss may be made into the hollow structure.

[0099] The step structure 10084 may reduce impact of the optical fiber 1003 on a transmission mode, and reduce distortion of a radiation beam.

[0100] In some embodiments of this application, as shown in FIG. 10, a metal tube 1009 may be further disposed in the feed 1002, so that one end of the metal tube 1009 is connected to a port of the combining end, the other end of the metal tube 1009 is connected to the first reflector 1005, and the optical fiber 1003 passes through the metal tube 1009.

[0101] Therefore, the metal tube 1009 can be configured to accommodate the optical fiber 1003, and can also provide support for the first reflector 1005, so that there is no need to dispose another support rod, and less space is used.

[0102] The metal tube may further reduce impact of an optical fiber transmission line on millimeter-wave radiation, and reduce millimeter-wave energy leakage.

[0103] FIG. 11 is a partially enlarged view at position 1002 in FIG. 10. FIG. 12 is a three-dimensional diagram at position 1002 in FIG. 10. As shown in FIG. 11 and FIG. 12, the feed 1002 includes the feed horn 10021, the first waveguide 10081, the second waveguide 10082, the combining end 10083 connected to the first waveguide 10081 and the second waveguide 10082, and the gap is provided between the first waveguide 10081 and the second waveguide 10082.

[0104] In addition, the metal tube 1009 is further disposed in the feed 1002, the metal tube 1009 passes through the feed 1002, the end of the metal tube 1009 is connected to the port of the combining end, and the other end of the metal tube 1009 is connected to the first reflector 1005. The optical fiber may pass through the gap between the first waveguide 10081 and the second waveguide 10082 to enter the end of the metal tube 1009 and exit from the other end of the metal tube 1009.

[0105] Therefore, the metal tube can provide support for the first reflector, and can further reduce leakage of a millimeter wave, and reduce the impact of the optical fiber transmission line on the millimeter-wave radiation.

[0106] In an embodiment, the metal tube 1009 and the first antenna are disposed coaxially.

[0107] Therefore, the optical fiber and the metal tube can be coaxial, the wireless light alignment can be assisted, and the mounting difficulty and the time costs are reduced. This helps promote the large-scale commercial use of the hybrid networking product.

[0108] To reduce the impact of the coaxiality of the optical fiber 1003 and the differential feeding waveguide 1008 on the fundamental mode transmission, as shown in FIG. 8 and FIG. 9, the step structure 10084 is further provided at the combining end 10083 of the first waveguide 10081 and the second waveguide 10082. In an embodiment, the step structure 10084 includes a plurality of bosses.

[0109] The step structure 10084 may be a plurality of bosses formed around the metal tube, and the boss is, for example, of a solid metal structure.

[0110] The step structure 10084 may reduce the impact of the optical fiber 1003 on the transmission mode, and reduce the distortion of the radiation beam.

[0111] In some embodiments of this application, the first antenna is a dual-polarized antenna. FIG. 13 is another partially enlarged view at position 1002 in FIG. 10. FIG. 14 is another three-dimensional diagram at position 1002 in FIG. 10. As shown in FIG. 13 and FIG. 14, the feed 1002 further includes a third waveguide 10085 and a fourth waveguide 10086. An end of the third waveguide 10085 and an end of the fourth waveguide 10086 are connected to the combining end 10083, and polarization directions of the third waveguide 10085 and the fourth waveguide 10086 are orthogonal to polarization directions of the first waveguide 10081 and the second waveguide 10082.

[0112] In some embodiments, the first waveguide 10081 and the second waveguide 10082 are horizontally polarized waveguides, and the third waveguide 10085 and the fourth waveguide 10086 are vertically polarized waveguides.

[0113] Therefore, the third waveguide and the fourth waveguide are disposed, so that dual polarization of the antenna can be implemented, and less space is occupied by the dual-polarized antenna.

[0114] An antenna system provided in an embodiment of this application includes a first antenna and a second antenna. The first antenna may be a reflector antenna. In some embodiments of this application, the reflector antenna is an annular focus antenna, and includes a second reflector, a feed, and a first reflector. An electromagnetic wave emitted by the feed of the first antenna is transmitted outward after passing through the first reflector and the second reflector sequentially. An aperture of the first antenna may be a circular ring enclosed by an edge of the second reflector and an edge of the first reflector. In other words, no millimeter wave is transmitted from the aperture of the first reflector.

[0115] An optical fiber of the second antenna passes through the first reflector, and wireless light is transmitted from the center of the first reflector, and then transmitted outward through a lens assembly. The lens assembly is opposite to the first reflector, so that the wireless light is in a dielectric lens (that is, within a range of the aperture of the first reflector). In other words, an aperture of an optical antenna may be a circle enclosed by an edge of the dielectric lens. Therefore, the optical fiber passes through a through hole of the first reflector, to facilitate mounting and alignment. In addition, the first antenna and the second antenna may share an aperture of the second reflector, and occupy small space. This helps reduce a device size, and can implement large-scale deployment.

[0116] In addition, the first antenna is configured to: emit and receive a millimeter wave. The second antenna includes the optical fiber and the lens assembly connected to the optical fiber, and the second antenna is configured to: emit and receive wireless light. The wireless light has an advantage of stronger resistance to rain attenuation, and the millimeter wave has stronger resistance to fog attenuation and snow attenuation. Hybrid networking of the first antenna and the second antenna can implement channel complementarity, and improve communication performance of long-distance wireless backhaul.

[0117] The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

1. An antenna system, comprising a first antenna and a second antenna, wherein the first antenna comprises: a feed, wherein the feed is configured to emit an electromagnetic wave; a first reflector, wherein a reflective surface of the first reflector faces the feed, and the first reflector is configured to reflect the electromagnetic wave emitted by the feed; and a second reflector, wherein the feed is located between the second reflector and the first reflector, the feed is disposed close to a reflective surface of the second reflector, and the second reflector is configured to reflect the electromagnetic wave reflected by the first reflector; and the second antenna comprises an optical fiber and a lens assembly connected to the optical fiber, the first reflector comprises a first through hole, the optical fiber passes through the first through hole, and the lens assembly is located on a side that is of the first reflector and that is away from the second reflector.

2. The antenna system according to claim 1, wherein a focal trajectory of the reflective surface of the first reflector is a circular ring, and the circular ring is perpendicular to an axis of the first antenna.

3. The antenna system according to claim 1 or 2, wherein the first through hole is positioned at the center of the first reflector.

4. The antenna system according to any one of claims 1 to 3, wherein the feed comprises a waveguide tube and a feed horn, and the optical fiber passes through the waveguide tube and the feed horn.

5. The antenna system according to claim 4, wherein the waveguide tube comprises a first waveguide, a second waveguide, and a combining end, both an end of the first waveguide and an end of the second waveguide are connected to the combining end, and the optical fiber enters the feed horn through the combining end.

6. The antenna system according to claim 5, wherein the waveguide tube further comprises a third waveguide and a fourth waveguide, an end of the third waveguide and an end of the fourth waveguide are connected to the combining end, and polarization directions of the third waveguide and the fourth waveguide are orthogonal to polarization directions of the first waveguide and the second waveguide.

7. The antenna system according to claim 5 or 6, further comprising a metal tube, wherein the metal tube passes through the feed, one end of the metal tube is connected to a port of the combining end, the other end of the metal tube is connected to the first reflector, and the optical fiber passes through the metal tube.

8. The antenna system according to claim 7, wherein the metal tube and the first antenna are disposed coaxially.

9. The antenna system according to any one of claims 5 to 8, wherein the combining end is provided with a step structure, and a step surface of the step structure is perpendicular to the axis of the first antenna.

10. The antenna system according to claim 9, wherein a material of the step structure comprises metal.

11. The antenna system according to any one of claims 1 to 10, wherein the lens assembly and the first antenna are disposed coaxially.

12. The antenna system according to claim 11, wherein an aperture of the lens assembly is smaller than or equal to an aperture of the first reflector.

13. The antenna system according to any one of claims 1 to 12, further comprising a transceiver, wherein both the feed and the optical fiber are connected to the transceiver.

14. The antenna system according to claim 13, wherein the second reflector comprises a second through hole, and the transceiver is located in the second through hole.

15. The antenna system according to claim 14, wherein the second through hole is positioned at the center of the second reflector.

16. The antenna system according to any one of claims 1 to 15, wherein the lens assembly comprises a dielectric lens, and the dielectric lens is disposed on a side that is of the optical fiber and that is away from the first reflector.

17. The antenna system according to claim 16, wherein the lens assembly further comprises a fiber-optic beam expander, the fiber-optic beam expander is located between the first reflector and the dielectric lens, the fiber-optic beam expander is connected to the optical fiber, and the dielectric lens is disposed on a light-emitting side of the fiber-optic beam expander.

18. The antenna system according to any one of claims 1 to 17, wherein the first antenna is a millimeter-wave antenna.

19. A communication device, wherein the communication device comprises the antenna system according to any one of claims 1 to 17.

20. The communication device according to claim 19, wherein the communication device is a wireless backhaul base station.

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