Antenna module and network device

Abstract

Embodiments of this application provide an antenna module and a network device, to make strengths of the antenna module drop sharply in all directions around a "main lobe", and suppress interference between adjacent network devices. The antenna module includes N first elements, a first feed network, a reflector, and a first substrate, where N is any integer greater than 1, the first substrate and the reflector are sequentially arranged in a direction perpendicular to the first substrate, the first substrate fastens the N first elements and the first feed network, the first feed network is connected to each first element, the N first elements are sequentially arranged end-to-end on a surface of the first substrate, and when the first feed network feeds the N first elements, currents flowing through different first elements all flow in a same direction.

Description

ANTENNA MODULE AND NETWORK DEVICE

[0001] This application claims priority to China Patent Application No. 202410309815.1, filed with the China National Intellectual Property Administration on March 15, 2024 and entitled "ANTENNA MODULE AND NETWORK DEVICE", which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] This application relates to the field of communication technologies, and in particular, to an antenna module and a network device.BACKGROUND

[0003] A wireless access point (access point, AP) may provide wide signal coverage by using an omnidirectional antenna, to meet a communication capacity requirement. However, when a distance between two APs that operate at a same frequency or adjacent frequencies is small, signals interfere with each other, and consequently communication quality deteriorates.

[0004] The conventional technology provides an array antenna. A beam formed by the array antenna exhibits a sharp and concentrated main lobe, and beam gains drop rapidly in other directions around the main lobe. In this case, the gains drop sharply in all directions around the main lobe. That the gains drop sharply in all the directions means that, when the array antenna transmits or receives electromagnetic waves in the other directions around the main lobe, the gains of the beam of the array antenna in all the directions can drop rapidly. This feature enables the array antenna to transmit energy directionally to a specific target area (that is, a main lobe coverage area) more effectively, while mitigating interference to a non-target area (that is, an area outside the main lobe coverage area).

[0005] The array antenna includes a plurality of antenna elements, and the feature that the beam gains of the array antenna drop sharply in all the directions is implemented by adjusting an amplitude and a phase of each antenna element. However, an array design increases complexity of implementing sharp drops for the beam in all the directions.SUMMARY

[0006] Embodiments of this application provide an antenna module and a network device, to make gains of the antenna module drop sharply in all directions around a main lobe, and suppress interference between adjacent network devices.

[0007] According to a first aspect, an embodiment of this application provides an antenna module, including N first elements, a first feed network, a reflector, and a first substrate, where N is any integer greater than 1, the first substrate and the reflector are sequentially arranged in a direction perpendicular to the first substrate, the first substrate fastens the N first elements and the first feed network, the first feed network is connected to each first element, the N first elements are sequentially arranged end-to-end on a surface of the first substrate, and the N first elements sequentially arranged end-to-end can form a regular shape. That the N first elements are sequentially arranged end-to-end means that the N first elements are arranged in a specific sequence, where a head of each first element faces a tail of a previous first element, and there is a specific gap therebetween. The regular shape may be a shape having definite, clear, and recognizable geometric features, for example, a circle, an ellipse, or any polygon. When the first feed network feeds the N first elements, currents flowing through the N first elements form a co-directional loop current, and specifically currents flowing through different first elements all flow in a same direction. For example, the currents flowing through the different first elements all flow in a clockwise direction, or all flow in a counterclockwise direction.

[0008] According to this aspect, when the currents flowing through the N first elements form the co-directional loop current and under the mirror effect of the reflector, a beam of the antenna module is a conical beam. The conical beam has a main lobe coverage area and a side lobe coverage area. A concentrated and uniform gain is achieved within the main lobe coverage area, whereas gains drop sharply in all directions within the side lobe coverage area. Because the gains drop sharply in all the directions within the side lobe coverage area, signal gains of the antenna module within the side lobe coverage area are reduced to a minimum, to effectively suppress interference to other antenna modules. Even if two antenna modules operate at a same frequency or adjacent frequencies and are close to each other, because gains of both the antenna modules can drop sharply in all the directions within the side lobe coverage area, isolation between the two antenna modules is improved, and interference between the two antenna modules is effectively suppressed. This improves concurrent throughput performance of a plurality of antenna modules, and helps enhance communication quality. Because the gains of the antenna module shown in this aspect can drop sharply in all the directions within the side lobe coverage area, interference suppression can be implemented between the plurality of antenna modules regardless of placement locations. For example, the plurality of antenna modules are arranged in a linear or curved shape. For another example, the plurality of antenna modules are arranged in a honeycomb shape.

[0009] According to the first aspect, in an optional implementation, each first element includes a first radiation arm and a second radiation arm, N first radiation arms are located on a first surface of the first substrate, N second radiation arms are located on a second surface of the first substrate, the first surface, the second surface, and the reflector are sequentially arranged in the direction perpendicular to the first substrate, the N first radiation arms are sequentially arranged end-to-end to form a regular shape, and the N second radiation arms are sequentially arranged end-to-end to form a regular shape. This implementation effectively ensures that when the first feed network feeds the N first elements, the currents flowing through the N first elements form the co-directional loop current, thereby ensuring that the beam of the antenna module is a conical beam.

[0010] According to the first aspect, in an optional implementation, at least one of the first elements has a circumcircle, there is a first distance between a center of the circumcircle and a phase center of at least one of the first element that is used to form the circumcircle, and the first distance is a first specified multiple of an operating wavelength of the antenna module, where the first specified multiple is any value within a range of 0.4 to 0.75. Each of the N first elements is inscribed in the circumcircle. Alternatively, some of the N first elements are inscribed in the circumcircle. In this implementation, when there is a first distance between the center of the circumcircle and a phase center of the first element that is used to form the circumcircle, and the first distance is the first specified multiple of the operating wavelength of the antenna module, sharp gain drops are effectively implemented within the side lobe coverage area. In addition, when the first distance has different values within the range of 0.4 to 0.75, the antenna module can have different sizes. This improves flexibility of selecting a size of the antenna module.

[0011] According to the first aspect, in an optional implementation, the first distance is 0.6 times the operating wavelength of the antenna module. In this implementation, an effect of sharp gain drops implemented within the side lobe coverage area of the antenna module is optimum, and interference suppression is maximized.

[0012] According to the first aspect, in an optional implementation, the regular shape is a circle, an ellipse, or a polygon, each first radiation arm is in the shape of a square, a rectangle, or an arc, and each second radiation arm is in the shape of a square, a rectangle, or an arc. This implementation effectively ensures that when the first feed network feeds the N first elements, the currents flowing through the N first elements form the co-directional loop current, thereby ensuring that the beam of the antenna module is a conical beam.

[0013] According to the first aspect, in an optional implementation, the first feed network includes N first microstrips, a power splitter, N second microstrips, and a ground module, a first end of the first microstrip is connected to the first radiation arm, a second end of the first microstrip is connected to the power splitter, a first end of the second microstrip is connected to the second radiation arm, and a second end of the second microstrip is connected to the ground module. This implementation ensures that the first feed network can successfully feed the N first elements, so that the currents flowing through the N first elements form the co-directional loop current.

[0014] According to the first aspect, in an optional implementation, a target radiation arm is connected to a target microstrip, an absolute value of an included angle between the target radiation arm and the target microstrip is greater than 80 degrees and less than 100 degrees, the target radiation arm is one of the N first radiation arms or the N second radiation arms, and the target microstrip is one of the N first microstrips or the N second microstrips. In this implementation, the absolute value of the included angle between the target radiation arm and the target microstrip is greater than 80 degrees and less than 100 degrees, so that the antenna module can achieve horizontal polarization.

[0015] According to the first aspect, in an optional implementation, the target radiation arm is perpendicular to the target microstrip. In this implementation, when the target radiation arm is perpendicular to the target microstrip, the antenna module can achieve horizontal polarization.

[0016] According to the first aspect, in an optional implementation, each first element has a first orthographic projection on the first substrate, the reflector has a second orthographic projection on the first substrate, and the first orthographic projection is located within the second orthographic projection. In this implementation, when each first orthographic projection is located within a coverage area of the second orthographic projection, the reflector can perform mirror reflection on a part of beams of the antenna module, to form a conical beam.

[0017] According to the first aspect, in an optional implementation, there is a target distance between the first substrate and the reflector, the target distance is a specified distance multiple of the operating wavelength of the antenna module, and the specified distance multiple is any value from 0.07 to 0.5. In this implementation, when the target distance is the specified distance multiple of the operating wavelength of the antenna module, a gain of an electromagnetic wave radiated by the antenna module within the main lobe coverage area is greater than a gain of an electromagnetic wave radiated within the side lobe coverage area, so that a signal strength within the main lobe coverage area is improved. In addition, because an effect of sharp gain drops is omnidirectional within the side lobe coverage area, an interference suppression capability of the side lobe is improved. When the target distance h is the specified distance multiple of the operating wavelength λ of the antenna module, different values of the target distance h can make the antenna module have different effects of sharp gain drops within the side lobe coverage area. Therefore, values of the target distance h can be correspondingly set based on different requirements of the antenna module for the effects of sharp gain drops within the side lobe coverage area.

[0018] According to the first aspect, in an optional implementation, the antenna module further includes a second substrate, a second feed network, and M second elements, M is any integer greater than 1, the second substrate, the first substrate, and the reflector are sequentially arranged or the first substrate, the second substrate, and the reflector are sequentially arranged in the direction perpendicular to the first substrate, the second substrate fastens the M second elements and the second feed network, the second feed network is connected to each second element, the M second elements are sequentially arranged end-to-end on a surface of the second substrate to form a regular shape, and when the second feed network feeds the M second elements, currents flowing through the M second elements form a co-directional loop current. In this implementation, in the antenna module, beam shapes of the N first elements are different from those of the M second elements. In this case, if only the N first elements are fed, only the M second elements are fed, or the N first elements and the M second elements are separately fed, the antenna module has different beam shapes. Therefore, corresponding elements can be fed based on different application scenarios of the antenna module, to adapt to different application scenarios and meet requirements for different beam shapes.

[0019] According to the first aspect, in an optional implementation, at least one of the first elements has a first circumcircle, there is a first distance between a center of the first circumcircle and a phase center of at least one of the first element that is used to form the first circumcircle, at least one of the second elements has a second circumcircle, there is a second distance between a center of the second circumcircle and a phase center of at least one of the second element that is used to form the second circumcircle, and the first distance is not equal to the second distance. In this implementation, the first distance is not equal to the second distance, so that the beam shapes of the N first elements are different from those of the M second elements.

[0020] According to the first aspect, in an optional implementation, the first distance is any value within the range of 0.4 to 0.75 times the operating wavelength of the antenna module, and the second distance is any value outside the range of 0.4 to 0.75 times the operating wavelength of the antenna module. In this implementation, different elements can be fed based on different operating scenarios of the antenna module. For example, if two adjacent antenna modules are close to each other, only the N first elements are fed, to suppress interference to other antenna modules. For another example, if two antenna modules are far away from each other, and no co-frequency or adjacent-frequency interference occurs, power may be supplied to only the M second elements, to expand a coverage area of the antenna module's gain.

[0021] According to a second aspect, an embodiment of this application provides a network device. The network device includes a baseband module, a radio frequency module, and the antenna module according to any one of the implementations of the first aspect, the radio frequency module includes a transmitter and / or a receiver, and the antenna module includes a transmit antenna and / or a receive antenna. The baseband module is configured to send a first digital signal to the transmitter, the radio frequency module is configured to convert the first digital signal into a first radio frequency signal, and the transmit antenna is configured to convert the first radio frequency signal into a first electromagnetic wave and radiate the first electromagnetic wave; and / or the receive antenna is configured to receive a second electromagnetic wave and convert the second electromagnetic wave into a second radio frequency signal, and the receiver is configured to convert the second radio frequency signal into a second digital signal and send the second digital signal to the baseband module.

[0022] According to a third aspect, an embodiment of this application provides a communication system. The communication system includes a plurality of network devices. For descriptions of a structure of the network device, refer to the second aspect. Details are not described again.

[0023] According to a fourth aspect, an embodiment of this application provides a communication system. The communication system includes a plurality of network devices and a plurality of terminals connected to the network devices. For descriptions of a structure of the network device, refer to the second aspect. Details are not described again.BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1 is an example diagram of a communication system;

[0025] FIG. 2 is an example diagram of an embodiment of a structure of a network device according to this application;

[0026] FIG. 3 is an example diagram of an embodiment of an overall structure of an antenna module according to this application;

[0027] FIG. 4 is an example diagram of different quantities of first elements included in the antenna module shown in FIG. 3;

[0028] FIG. 5 shows various example diagrams of regular shapes formed by sequentially arranging N first elements end-to-end according to this application;

[0029] FIG. 6 is a side view of the antenna module shown in FIG. 3;

[0030] FIG. 7 is an example diagram of a partial structure of the antenna module shown in FIG. 3;

[0031] FIG. 8 is an example diagram of a top-view structure shown in FIG. 7;

[0032] FIG. 9 is an example diagram of a bottom-view structure shown in FIG. 3;

[0033] FIG. 10 is a diagram of a connection example shown in FIG. 8;

[0034] FIG. 11 is a diagram of a connection example shown in FIG. 9;

[0035] FIG. 12 is an example diagram of feeding of the antenna module shown in FIG. 3;

[0036] FIG. 13a is an example antenna radiation pattern of the antenna module shown in FIG. 3 that does not include a reflector;

[0037] FIG. 13b is an example three-dimensional antenna radiation pattern of FIG. 13a;

[0038] FIG. 14a is an example antenna radiation pattern of the antenna module shown in FIG. 3 that includes a reflector;

[0039] FIG. 14b is an example three-dimensional antenna radiation pattern of FIG. 14a;

[0040] FIG. 14c is an example diagram of a circumcircle of N first elements according to this application;

[0041] FIG. 15a is an example corresponding antenna radiation pattern when a first distance for the antenna module shown in FIG. 3 is not a first specified multiple of an operating wavelength of the antenna module;

[0042] FIG. 15b is an example corresponding antenna radiation pattern when a first distance for the antenna module shown in FIG. 3 is a first specified multiple of an operating wavelength of the antenna module;

[0043] FIG. 16a is an example antenna radiation pattern of the antenna module shown in FIG. 3 at different first distances;

[0044] FIG. 16b is another example antenna radiation pattern of the antenna module shown in FIG. 3 at different first distances;

[0045] FIG. 17 is example three-dimensional antenna radiation patterns of the antenna module shown in FIG. 3 at a first distance d of 1.2λ;

[0046] FIG. 18 is an example antenna radiation pattern of the antenna module shown in FIG. 3 at different target distances;

[0047] FIG. 19 is an example diagram of an embodiment of a top-view structure of an antenna module according to this application;

[0048] FIG. 20 is an example antenna radiation pattern of the antenna module shown in FIG. 19 on a horizontal cross-sectional plane;

[0049] FIG. 21 is an example three-dimensional antenna radiation pattern of the antenna module shown in FIG. 19;

[0050] FIG. 22 is another example diagram of an embodiment of a top-view structure of an antenna module according to this application; and

[0051] FIG. 23 is an example diagram of a side-view structure of the antenna module shown in FIG. 22.DESCRIPTION OF EMBODIMENTS

[0052] A communication system to which an embodiment of this application is applied is described with reference to FIG. 1. FIG. 1 is an example diagram of a communication system. In this example, a plurality of APs and a plurality of terminals are included. For example, the plurality of APs include an AP 101 and an AP 111, and the plurality of terminals include a plurality of terminals 102 all connected to the AP 101 and a plurality of terminals 112 all connected to the AP 111. In this example, each AP is a ceiling-mounted AP. For example, the AP 101 and the AP 111 are mounted on a ceiling to serve as wireless access points. A type of the AP is not limited in this example. A type of the communication system is not limited in this example. For example, the communication system includes an access point controller (access point controller, AC) connected to the plurality of APs. For another example, the type of the communication system is fiber to the room (fiber to the room, FTTR), and in this case, each AP serves as a secondary gateway and may be connected to each terminal through wireless fidelity (wireless fidelity, WiFi). For still another example, the type of the communication system is a power line communication (power line communication network, PLC) network, and in this case, each AP serves as a PLC gateway in PLC and is connected to each terminal. For yet another example, the type of the communication system is a wireless mesh network (wireless mesh network, Mesh). The APs may be connected to the terminals through Wi-Fi, or through near field communication (near field communication, NFC), infrared, Bluetooth, ZigBee (ZigBee), or the like. This is not specifically limited.

[0053] The AP is configured to provide wireless access services for the plurality of terminals connected to the AP. For example, the AP 101 provides wireless access for the plurality of terminals 102 located within a first coverage area. Specifically, in this example, the AP 1 is a ceiling-mounted AP. In this case, the AP 101 provides strong electromagnetic wave coverage within the first coverage area. The first coverage area includes a range in which an included angle between a direction of radiating electromagnetic waves (or a direction of receiving electromagnetic waves) by the AP 1 and a target axis is from 0 degrees to 60 degrees. The first coverage area further includes a range in which an included angle between a direction of radiating electromagnetic waves (or a direction of receiving electromagnetic waves) by the AP 1 and the target axis is from 300 degrees to 360 degrees. The AP 101 is mounted on a ceiling, and the target axis is perpendicular to a direction of the ceiling. For another example, electromagnetic waves radiated (or received) by the AP 1 have a strongest gain in a direction of the target axis, and have relatively weak gains in other directions. For still another example, the AP 111 provides wireless access for the plurality of terminals 112 located within a second coverage area. For descriptions of the second coverage area of the AP 111, refer to the descriptions of the first coverage area of the AP 101. Details are not described again. In a high-density deployment scenario, the AP is generally disposed at a height of 3 meters to 5 meters (m), and a radius of a coverage area may reach 5 m to 8 m. In this scenario, there are usually a large quantity of users per unit area. Therefore, a wide-angle omnidirectional antenna may be used in the AP for signal coverage, to ensure communication capacity. However, because a quantity of channels is limited, a distance between APs that operate at a same frequency or adjacent frequencies is usually small. In this case, signal interference exists between APs that operate at a same frequency or adjacent frequencies. For example, the adjacent AP 101 and AP 111 operate at a same frequency or adjacent frequencies, and consequently signal interference exists between the AP 101 and the AP 111. Based on this, an embodiment of this application provides an antenna module used for an AP, to change radio signal coverage of the AP. In this case, signal gains of the AP 101 outside the first coverage area are reduced to a minimum, and signal gains of the AP 111 outside the second coverage area are reduced to the minimum. This effectively suppresses mutual interference between the AP 101 and the AP 111, and improves an interference suppression capability of the AP, thereby mitigating signal interference between APs that operate at a same frequency or adjacent frequencies. The AP may be a base station, a router, a switch, or another network device, and the terminal may be a mobile phone, a computer, a tablet computer, a wearable device, or the like. In addition, the descriptions of the AP and the terminal in FIG. 1 are an optional example, and do not constitute any limitation on quantities and types of the AP and the terminal in application scenarios provided in embodiments of this application.

[0054] FIG. 2 is an example diagram of an embodiment of a structure of a network device according to this application. For example, the AP in FIG. 1 may be implemented by the network device shown in FIG. 2. The network device includes a processor 201, a communication bus 202, a memory 203, a radio frequency module 204, an antenna module 205, and a baseband module 206. The processor 201 may include one or more chips, or one or more integrated circuits. For another example, the processor 201 may include one or more of the following: one or more neural processing units (neural processing units, NPUs), an optical digital signal processor (optical digital signal processor, oDSP), a field-programmable gate array (field-programmable gate array, FPGA), an application-specific integrated circuit (application-specific integrated circuit, ASIC), a system on chip (system on chip, SoC), a central processing unit (central processing unit, CPU), a network processor (network processor, NP), a microcontroller (microcontroller unit, MCU), a programmable logic device (programmable logic device, PLD), a network interface card chip, a memory interface chip, or another integrated chip. Details are not described. The communication bus 202 may include a path for transmitting information between the components. The memory 203 may be a read-only memory (read-only memory, ROM), a random access memory (random access memory, RAM), or another type of storage device, or may be an electrically erasable programmable read-only memory (electrically-erasable programmable read-only memory, EEPROM), an optical disc, a magnetic disk, another magnetic storage device, or any other medium that can be used to carry or store expected program code in a form of instructions or a data structure and can be accessed by a computer. The memory 203 may exist independently and is connected to the processor 201. Alternatively, the memory 203 may be integrated with the processor 201. The radio frequency module 204 and the antenna module 205 are configured to cooperate in sending and receiving radio frequency signals. The antenna module 205 is the antenna module provided in embodiments of this application. For a structure of the antenna module, refer to related descriptions in subsequent embodiments. The baseband module 206 is configured to process a received radio signal or a to-be-sent radio signal. Specifically, the network device includes P transmit channels and J receive channels, where P is any integer greater than or equal to 1, and J is any integer greater than or equal to 1. Each of the J receive channels includes one receiver in the radio frequency module 204 and one receive antenna in the antenna module 205. Each of the P transmit channels includes one transmitter in the radio frequency module 204 and one transmit antenna in the antenna module 205. For example, the baseband module 206 sends a first digital signal to the transmit channel. The transmitter in the radio frequency module 204 is configured to: convert the first digital signal into a first radio frequency signal, and process the first radio frequency signal to obtain a processed first radio frequency signal. The transmitter may include components such as a switch, a filter (filter), a power amplifier (power amplifier, PA), a low noise amplifier (low noise amplifier, LNA), an antenna tuner, or a phase shifter. The transmit antenna in the antenna module 205 is configured to convert the first radio frequency signal into an electromagnetic wave and radiate the electromagnetic wave. For another example, the receive antenna in the antenna module 205 receives an electromagnetic wave, and converts the electromagnetic wave into a second radio frequency signal. The receiver in the radio frequency module 204 processes the second radio frequency signal to obtain a processed second radio frequency signal, and converts the processed second radio frequency signal into a second digital signal. For descriptions of components included in the receiver and processing, refer to the descriptions of the components included in the transmitter and processing. Details are not described again. The receiver sends the second digital signal to the baseband module 206, and the baseband module 206 performs digital processing on the second digital signal.

[0055] The structure of the antenna module provided in embodiments of this application is described based on FIG. 1 and FIG. 2. FIG. 3 is an example diagram of an overall structure of an antenna module according to an embodiment of this application. The antenna module 300 shown in this embodiment includes a reflector 301, a first substrate 302, a first feed network 304, and N first elements 305. In this embodiment, that the first substrate 302 is a printed circuit board (printed circuit board, PCB) is used as an example, and does not constitute any limitation. The first substrate 302 may be any type of substrate that can support and fasten the first feed network 304 and the N first elements 305, for example, a plastic substrate or a ceramic substrate. In this embodiment, an example is used in which the N first elements 305 are distributed along an edge of the first substrate 302, that is, the N first elements are located in an edge region of the first substrate 302. It should be noted that, locations of the N first elements 305 on a surface of the first substrate are not limited in this embodiment, provided that the N first elements 305 are sequentially arranged end-to-end to form a regular shape.

[0056] That the N first elements 305 are sequentially arranged end-to-end means that the plurality of first elements 305 are arranged in a specific sequence, where a head of each first element 305 faces a tail of a previous first element 305, and there is a specific gap therebetween. A specific type of the regular shape formed by sequentially arranging the N first elements end-to-end is not limited in this embodiment. For example, the regular shape may be a circle. A specific value of N is not limited in this embodiment, provided that N is any integer equal or greater than 2. For example, N may be an even number or an odd number. FIG. 4 is an example diagram of different quantities of first elements included in the antenna module shown in FIG. 3. In examples shown in FIG. 4, the N first elements 305 are sequentially arranged end-to-end to form circles. In an example 1, the antenna module includes two first elements. In an example 2, the antenna module includes three first elements. In an example 3, the antenna module includes four first elements. In an example 4, the antenna module includes five first elements. In an example 5, the antenna module includes six first elements. In an example 6, the antenna module includes eight first elements. In an example 7, the antenna module includes 12 first elements, and so on.

[0057] The foregoing uses an example in which the regular shape is a circle, and no limitation is imposed. For example, FIG. 5 is various example diagrams of regular shapes formed by sequentially arranging N first elements end-to-end according to this application. In an example 1 shown in FIG. 5, N=3, and a regular shape formed by sequentially arranging the N first elements 305 is a triangle. In an example 2, N=4, and a regular shape formed by sequentially arranging the N first elements 305 is a square. In an example 3, N=5, and a regular shape formed by sequentially arranging the N first elements 305 is a pentagon. In an example 4, N=6, and a regular shape formed by sequentially arranging the N first elements 305 is a hexagon. In an example 5, N=9, and a regular shape formed by sequentially arranging the N first elements 305 is nonagon, and so on. Details are not described.

[0058] The first feed network 304 shown in this embodiment is connected to the N first elements 305. In this case, with reference to FIG. 2, the first feed network 304 receives the first radio frequency signal from the transmitter in the radio frequency module 204, and sends the first radio frequency signal to the first elements 305. The first elements 305 receive the second radio frequency signal, the first elements 305 send the second radio frequency signal to the feed network 304, and the feed network 304 sends the second radio frequency signal to the receiver in the radio frequency module 204.

[0059] Each first element shown in this embodiment is a dipole element. For a structure of each first element, refer to FIG. 6. FIG. 6 is a side view of the antenna module shown in FIG. 3. The substrate 302 shown in this embodiment includes a first surface 611 and a second surface 612. The first surface 611 and the second surface 612 are two surfaces whose locations face away from each other on the first substrate 302. For example, the first substrate 302 is parallel to a plane XY, the plane XY includes a direction X and a direction Y, the direction X is perpendicular to the direction Y, and a direction Z is perpendicular to the plane XY. In this case, the first surface 611 and the second surface 612 are sequentially arranged along the direction Z. Along the direction Z, the location of the second surface 612 is opposite to that of the reflector 301, and there is a target distance h between the second surface 612 and the reflector 301. The location of the first surface 611 faces away from that of the reflector 301. Each first element includes a first radiation arm 601 and a second radiation arm 602. Optionally, for a first radiation arm 601 and a second radiation arm 602 included in one first element, an orthographic projection of the first radiation arm 601 on the reflector 301 at least partially overlaps an orthographic projection of the second radiation arm 602 on the reflector 301. The orthographic projection of the first radiation arm 601 on the reflector 301 is an orthographic projection formed on the reflector 301 by projecting the first radiation arm 601 by using a plurality of parallel projection lines that are perpendicular to the reflector 301 (for example, along the direction Z). For descriptions of the orthographic projection of the second radiation arm 602, refer to the descriptions of the orthographic projection of the first radiation arm 601. Details are not described again. Because the location of the second surface 612 of the substrate 302 shown in this embodiment is opposite to that of the reflector 301, a target gap is formed between the second surface 612 and the reflector 301, and N second radiation arms 602 are located in the target gap.

[0060] Refer now to FIG. 7, FIG. 8, and FIG. 9. FIG. 7 is an example diagram of a partial structure of the antenna module shown in FIG. 3, FIG. 8 is an example diagram of a top-view structure shown in FIG. 7, and FIG. 9 is an example diagram of a bottom-view structure shown in FIG. 3. N first radiation arms 601 are distributed on the first surface 611, and the N second radiation arms 602 are distributed on the second surface 612. The first feed network shown in this embodiment includes N first microstrips 701, a power splitter 702, N second microstrips 801, and a ground module 802. The N first microstrips 701 and the power splitter 702 are located on the first surface 611 of the first substrate. A first end of the first microstrip 701 is connected to the first radiation arm 601, and a second end of the first microstrip 701 is connected to the power splitter 702. The power splitter 702 shown in this embodiment is located in a central area of the first surface 611. The N second microstrips 801 and the ground module 802 are located on the second surface 612 of the first substrate. A first end of the second microstrip 801 is connected to the second radiation arm 602, and a second end of the second microstrip 801 is connected to the ground module 802. The ground module 802 generally refers to a ground conductive plate in a microstrip structure. The ground module 802 provides a stable reference potential for the microstrip, which helps maintain stable transmission of signals. In addition, the ground plane is capable of shielding and mitigating electromagnetic interference. A specific quantity of power splitters 702 is not limited in this embodiment. With reference to FIG. 10 and FIG. 11, FIG. 10 is a diagram of a connection example shown in FIG. 8, and FIG. 11 is a diagram of a connection example shown in FIG. 9. The radio frequency module and the antenna module of the network device are connected to each other through a coaxial cable 1100. The coaxial cable 1100 has an inner conductor 1000 and an outer conductor. The outer conductor of the coaxial cable 1100 is connected to the ground module 802, and therefore the outer conductor of the coaxial cable 1100 and the ground module 802 jointly serve as the ground of the antenna module. The inner conductor 1000 of the coaxial cable 1100 is connected to the power splitter 702. For example, a radio frequency signal is emitted by the antenna module. The radio frequency module transmits the radio frequency signal to the power splitter 702 via the inner conductor 1000 of the coaxial cable 1100, and the power splitter 702 divides energy of one radio frequency signal into a plurality of radio frequency signals for output. A quantity of power splitters 702 is not limited in this embodiment. For example, if a value of N is 12, the power splitter 702 includes two types of power splitters: a one-to-four power splitter, and a one-to-three power splitter. An input port of the one-to-four power splitter is connected to the inner conductor 1000 of the coaxial cable 1100, each output port of the one-to-four power splitter is connected to an input port of one one-to-three power splitter, and three output ports of the one-to-three power splitter are respectively connected to three first radiation arms. In this case, when receiving a radio frequency signal A, the one-to-four power splitter divides energy of the radio frequency signal into radio frequency signals A1, A2, A3, and A4, and sends the radio frequency signals A1, A2, A3, and A4 to one-to-three power splitters, respectively. Each one-to-three power splitter divides energy of each of the radio frequency signals A1, A2, A3, and A4 into radio frequency signals B1, B2, and B3, and transmits the radio frequency signals B1, B2, and B3 to three first radiation arms, respectively.

[0061] It can be understood that, each of the N first elements is connected to the first feed network, and when the first feed network feeds the N first elements, currents flowing through the N first elements form a co-directional loop current. When the currents flowing through the N first elements form the co-directional loop current, it means that in the N first elements, currents flowing through different first elements all flow in a same direction. For example, the currents flowing through the different first elements all flow in a clockwise direction, or the currents flowing through the different first elements all flow in a counterclockwise direction. Refer to FIG. 12. FIG. 12 is an example diagram of feeding of the antenna module shown in FIG. 3. That the currents flowing through the N first elements form the co-directional loop current means that, when the first feed network feeds the N first elements, the currents flowing through the different first elements all flow in a clockwise direction, so that the currents flowing through the N first elements form a co-directional loop current 1201. A flow direction of the co-directional loop current 1201 may be clockwise (for example, as shown in FIG. 12) or counterclockwise. Alternatively, a plurality of cycles may be involved, where flow directions are clockwise in some cycles and counterclockwise in other cycles. This is not specifically limited. The N first elements shown in this embodiment form the co-directional loop current during feeding. This helps improve a radiation capability in a coverage area, and improve efficiency and a gain of the antenna.

[0062] When the currents flowing through the N first elements form the co-directional loop current, for radiation of the antenna module, refer to FIG. 13a and FIG. 13b. FIG. 13a is an example antenna radiation pattern of the antenna module shown in FIG. 3 that does not include a reflector, and FIG. 13b is an example three-dimensional antenna radiation pattern of FIG. 13a. An antenna radiation pattern, also referred to as an antenna pattern or a far-field pattern, is a three-dimensional spatial variable pattern used to describe variation of a field or power with an angle θ in a spherical coordinate system. Radiation characteristics of the antenna module in various spatial directions can be learned by using the radiation pattern. Specifically, a primary maximum radiation area of the N first elements is referred to as a "main lobe", and a secondary maximum radiation area is referred to as a "lobe" or a "side lobe". The main lobe usually points in a direction in which antenna radiation energy of the N first elements is most concentrated, whereas the side lobe may cause interference to other network devices. The N first elements shown in this embodiment have a most concentrated radiation capability from 0 degrees to 60 degrees, 120 degrees to 180 degrees, 180 degrees to 240 degrees, and 300 degrees to 360 degrees. The angle is an included angle between a direction of radiating electromagnetic waves (or a direction of receiving electromagnetic waves) by the first element and a target axis. If the AP is a ceiling-mounted AP, the AP is mounted on a ceiling, and the target axis is perpendicular to a direction of the ceiling. For another example, in the example three-dimensional pattern, the antenna radiation pattern exhibits a strongest radiation or receiving capability in a direction of the target axis, and exhibits relatively weak radiation or receiving capabilities in other directions. It can be understood that the target axis is parallel to a direction Z. In this case, the main lobe is located within ranges of 0 degrees to 60 degrees, 120 degrees to 180 degrees, 180 degrees to 240 degrees, and 300 degrees to 360 degrees. The antenna module shown in this embodiment can implement omnidirectional gain coverage within a main lobe coverage area. Implementing omnidirectional gain coverage within the main lobe coverage area means that the antenna module can transmit or receive electromagnetic waves in a state of a uniform gain within the coverage areas from 0 degrees to 60 degrees, 120 degrees to 180 degrees, 180 degrees to 240 degrees, and 300 degrees to 360 degrees. FIG. 13a is an example radiation pattern of the three-dimensional radiation pattern shown in FIG. 13b on a first cross-sectional plane, where the first cross-sectional plane includes the direction Z and a direction X. Alternatively, FIG. 13a is an example radiation pattern of the three-dimensional radiation pattern shown in FIG. 13b on a second cross-sectional plane, where the second cross-sectional plane includes the direction Z and a direction Y. Neither a specific orientation of the direction X nor a specific orientation of the direction Y is limited in this embodiment, provided that the direction Z is perpendicular to a plane XY (a plane including the direction X and the direction Y).

[0063] A function of the reflector shown in this embodiment is to change the radiation pattern shown in FIG. 13a to a radiation pattern shown in FIG. 14a, and change the radiation pattern shown in FIG. 13b to a radiation pattern shown in FIG. 14b. FIG. 14a is an example antenna radiation pattern of the antenna module shown in FIG. 3 that includes a reflector, and FIG. 14b is an example three-dimensional antenna radiation pattern of FIG. 14a. The reflector 301 has a mirror effect. Specifically, the three-dimensional radiation pattern shown in FIG. 13b includes a first radiation area 1310 (ranging from 0 degrees to 90 degrees and 270 degrees to 360 degrees) and a second radiation area 1311 (ranging from 90 degrees to 180 degrees and 180 degrees to 270 degrees). An example in which the antenna module radiates electromagnetic waves is used. A radiation pattern formed in space by a plurality of first electromagnetic waves radiated by the antenna module is shown in the first radiation area 1310, and a radiation pattern formed in space by a plurality of second electromagnetic waves radiated by the antenna module is shown in the second radiation area 1311. The mirror effect of the reflector 301 means that, when the plurality of second electromagnetic waves emitted by the antenna module strike the reflector 301, the plurality of second electromagnetic waves are reflected by the reflector 301, and the reflected second electromagnetic waves are superimposed with the first electromagnetic wave in space, thereby forming the radiation patterns shown in FIG. 14a and FIG. 14b. Due to the mirror effect of the reflector 301, the main lobe coverage area of the antenna module is concentrated within ranges of 0 degrees to 60 degrees and 300 degrees to 360 degrees. This satisfies an application requirement of the ceiling-mounted AP. With reference to FIG. 1, the first coverage area of the AP 101 ranges from 0 degrees to 60 degrees and 300 degrees to 360 degrees.

[0064] In the antenna module shown in this embodiment, to suppress interference between different APs, gains of the N first elements can drop sharply in all directions within a side lobe coverage area. With reference to FIG. 14a and FIG. 14b, the side lobe coverage area is from 60 degrees to 90 degrees and 270 degrees to 300 degrees. That the gains drop sharply in all the directions within the side lobe coverage area means that the N first elements transmit or receive electromagnetic waves in a state of sharp gain drops in all the directions within the side lobe coverage area. It can be learned that, a gain of an electromagnetic wave radiated by the N first elements within the main lobe coverage area is greater than a gain of an electromagnetic wave radiated within the side lobe coverage area, so that a signal strength within the main lobe coverage area is improved. In addition, because an effect of sharp gain drops is omnidirectional within the side lobe coverage area, an interference suppression capability of the side lobe is improved. In this way, the N first elements forming the co-directional loop current can effectively suppress electromagnetic interference to a same frequency or adjacent frequencies, and improve concurrent throughput performance of a plurality of network devices in the communication system. It should be noted that the descriptions of the main lobe and side lobe coverage angles in this embodiment are an optional example, and do not constitute any limitation.

[0065] Based on a radiation condition of the antenna module within the main lobe coverage area and a radiation condition of the antenna module within the side lobe coverage area, electromagnetic waves radiated or received by the antenna module form a conical beam, which features sharp drops in beam gains (that is, sharp gain drops in all the directions within the side lobe coverage area) and an omnidirectional uniform radiation capability (that is, a gain is concentrated and uniform within the main lobe coverage area). It can be understood that, when the communication system includes a plurality of network devices, even if the plurality of network devices are placed side by side in close proximity, because electromagnetic waves corresponding to antenna modules of the network devices exhibit a conical beam, gains drop sharply in a lateral direction (that is, within the side lobe coverage area), and mutual coupling between antenna modules of different network devices decreases accordingly. This improves isolation between the antenna modules of the different network devices, helps enhance communication quality of the communication system, and improves multiple-input multiple-output (multiple-input multiple-output, MIMO) throughput performance. A type of the element included in the antenna module is not limited in this embodiment. For example, the type of the element may alternatively be a mu-negative antenna (mu-negative antenna, MNG), an Alford loop antenna (Alford loop antenna, Alford), a loop antenna, a square loop antenna, or the like.

[0066] In the foregoing example, each of the N first elements is in a first arc shape, the edge of the first substrate is in a second arc shape, and the first arc shape is conformal to the second arc shape. That the first arc-shaped structure is conformal to the second arc-shaped structure means that a curvature direction of the first arc-shaped structure is consistent with that of the second arc-shaped structure. A shape of the first element is not limited in this embodiment. For example, the first element may alternatively be of a square structure, a rectangular structure, or the like. This is not specifically limited, provided that the N first elements form the co-directional loop current during feeding.

[0067] In the foregoing embodiment, a target radiation arm is connected to a target microstrip, and the target radiation arm is perpendicular to the target microstrip. The target radiation arm is one of the N first radiation arms or the N second radiation arms, and the target microstrip is one of the N first microstrips or the N second microstrips. For example, as shown in FIG. 10, the target radiation arm is the first radiation arm 601, the target microstrip is the first microstrip 701, and the first radiation arm 601 and the first microstrip 701 are connected to each other and are perpendicular to each other. It should be noted that an angle between the first radiation arm 601 and the first microstrip 701 is not limited in this embodiment, provided that the first radiation arm 601 is perpendicular to or approximately perpendicular to the first microstrip 701. In this case, an absolute value of the included angle between the first radiation arm 601 and the first microstrip 701 is within a preset angle range, where the preset angle range may be greater than 80 degrees and less than 100 degrees. For another example, as shown in FIG. 11, the target radiation arm is the second radiation arm 602, the target microstrip is the second microstrip 801, and the second radiation arm 602 and the second microstrip 801 are connected to each other and are perpendicular to each other. It should be noted that an angle between the second radiation arm 602 and the second microstrip 801 is not limited in this embodiment, provided that the second radiation arm 602 is perpendicular to or approximately perpendicular to the second microstrip 801. In this case, an absolute value of the included angle between the second radiation arm 602 and the second microstrip 801 is within a preset angle range, where the preset angle range may be greater than 80 degrees and less than 100 degrees. When the target radiation arm is perpendicular to the target microstrip, the antenna module can generate horizontal polarization.

[0068] The following specifically describes how the antenna module forms the conical beam shown above. All of the N first elements shown in this embodiment have a same circumcircle, and in this case, vertices of all the first elements are inscribed in the circumcircle. For another example, some first elements have a same circumcircle, and in this case, vertices of the some first elements are inscribed in the circumcircle. For example, as shown in FIG. 14c, FIG. 14c is an example diagram of a circumcircle of N first elements according to this application. If the N first elements 1401 are sequentially arranged end-to-end to form a triangle, vertices of all the first elements 1401 are inscribed in the circumcircle 1400. To form a conical beam, there is a first distance d between a center of the circumcircle and a phase center of the first element. The phase center of the first element is a center of an equivalent radiation source of electromagnetic waves radiated after the first element is fed, namely, an equivalent source point. A specific location of the phase center of the first element is related to a shape, a feeding location, and the like of the first element. The first elements are inscribed in the circumcircle, and in the example shown in FIG. 14c, the first elements are the first elements 1401 included in the antenna module. To form a conical beam, the first distance d is a first specified multiple of an operating wavelength λ of the antenna module, where the first specified multiple is any value within a range of 0.4 to 0.75. In the foregoing example, all the first elements are inscribed in the circumcircle formed by the N first elements. In other examples, some of the N first elements are alternatively inscribed in the circumcircle. For example, the N first elements include a first element L1, a first element L2, a first element L3, and a first element L4. The first element L1, the first element L2, and the first element L3 can form one circumcircle. If there is a first distance d1 between a center of the circumcircle and a phase center of the first element L1, and the first distance d1 is a first specified multiple of the operating wavelength λ of the antenna module, gains of electromagnetic waves radiated by the first element L1 can drop sharply within the side lobe coverage area. In other words, the gains of the electromagnetic waves radiated by the first element L1 drop sharply from 60 degrees to 90 degrees and 270 degrees to 300 degrees. If there is a first distance d2 between the center of the circumcircle and a phase center of the first element L2, and the first distance d2 is a first specified multiple of the operating wavelength λ of the antenna module but the first distance d1 is not equal to the first distance d2, because the first distance d2 is also the first specified multiple of the operating wavelength λ of the antenna module, gains of electromagnetic waves radiated by the first element L2 can drop sharply within the side lobe coverage area. In other words, the gains of the electromagnetic waves radiated by the first element L2 drop sharply from 60 degrees to 90 degrees and 270 degrees to 300 degrees. If there is a first distance d3 between the center of the circumcircle and a phase center of the first element L3, and the first distance d3 is not a first specified multiple of the operating wavelength λ of the antenna module, gains of electromagnetic waves radiated by the first element L3 cannot drop sharply within the side lobe coverage area.

[0069] FIG. 15a is an example corresponding antenna radiation pattern when a first distance for the antenna module shown in FIG. 3 is not a first specified multiple of an operating wavelength of the antenna module. In the example shown in FIG. 15a, when the first distance d is 0.25λ, the radiation pattern of the antenna module is shown in 1501, where λ is the operating wavelength of the antenna module. It can be understood that in the example shown in FIG. 15a, the first distance d is not a first specified multiple of the operating wavelength λ (that is, 0.25 is not within the range of 0.4 to 0.75). FIG. 15b is an example corresponding antenna radiation pattern when a first distance for the antenna module shown in FIG. 3 is a first specified multiple of an operating wavelength of the antenna module. In the example shown in FIG. 15b, when the first distance d is 0.5λ, the radiation pattern of the antenna module is shown in 1502. It can be understood that in the example shown in FIG. 15b, the first distance d is a first specified multiple of the operating wavelength λ (that is, 0.5 is within the range of 0.4 to 0.75). With reference to FIG. 15a and FIG. 15b, in comparison with FIG. 15a, a sharp amplitude drop characteristic in a side lobe direction (that is, from 60 degrees to 90 degrees, 90 degrees to 120 degrees, 240 degrees to 270 degrees, and 270 degrees to 300 degrees) is improved in FIG. 15b. In addition, when the first distance d for the antenna module is a first specified multiple (that is, 0.4 to 0.75) of the operating wavelength λ of the antenna module, a gain of an electromagnetic wave radiated by the antenna module within the main lobe coverage area is greater than a gain of an electromagnetic wave radiated within the side lobe coverage area. For descriptions of the main lobe and side lobe coverage areas, refer to the foregoing embodiments. Details are not described again. It can be understood that the antenna module shown in this embodiment effectively improves a signal strength within the main lobe coverage area. In addition, because an effect of sharp gain drops is omnidirectional within the side lobe coverage area, an interference suppression capability of the side lobe is improved.

[0070] FIG. 16a is an example antenna radiation pattern of the antenna module shown in FIG. 3 at different first distances, and FIG. 16b is another example antenna radiation pattern of the antenna module shown in FIG. 3 at different first distances. For details, refer to Table 1:Table 1First distance dCorresponding radiation patternFirst distance d=0.4λA radiation pattern of the antenna module is shown in 1601 in FIG. 16a.First distance d=0.45λA radiation pattern of the antenna module is shown in 1602 in FIG. 16a.First distance d=0.5λA radiation pattern of the antenna module is shown in 1603 in FIG. 16a.First distance d=0.55λA radiation pattern of the antenna module is shown in 1604 in FIG. 16a.First distance d=0.6λA radiation pattern of the antenna module is shown in 1611 in FIG. 16b.First distance d=0.65λA radiation pattern of the antenna module is shown in 1612 in FIG. 16b.First distance d=0.7λA radiation pattern of the antenna module is shown in 1613 in FIG. 16b.First distance d=0.75λA radiation pattern of the antenna module is shown in 1614 in FIG. 16b. 

[0071] In FIG. 16a and FIG. 16b, an example in which no reflector is disposed on the antenna module is used. It can be learned that, when the first distance d for the antenna module is a first specified multiple (that is, 0.4 to 0.75) of the operating wavelength λ of the antenna module, a gain of an electromagnetic wave radiated by the antenna module within the main lobe coverage area (that is, from 0 degrees to 60 degrees, 300 degrees to 360 degrees, and 120 degrees to 240 degrees) is greater than a gain of an electromagnetic wave radiated in the side lobe direction (that is, from 60 degrees to 120 degrees and 240 degrees to 300 degrees), so that a signal strength within the main lobe coverage area is improved. In addition, because an effect of sharp gain drops is omnidirectional within the side lobe coverage area, an interference suppression capability of the side lobe is improved. When the first distance d is the first specified multiple of the operating wavelength λ of the antenna module, different values of the first distance d can make the antenna module have different sizes. This improves flexibility of selecting a size of the antenna module. With reference to FIG. 16a and FIG. 16b, it can be learned that, when the radiation pattern 1611 (that is, the first distance d=0.6λ) is used, an effect of sharp gain drops implemented within the side lobe coverage area of the antenna module is optimum. Therefore, a target distance d for the antenna module shown in this embodiment may be 0.6λ.

[0072] FIG. 17 is example three-dimensional antenna radiation patterns of the antenna module shown in FIG. 3 at a first distance d of 0.6λ. An example three-dimensional antenna radiation pattern 1701 shown in FIG. 17 is a three-dimensional antenna radiation pattern in which a target distance d is 0.6λ and the antenna module does not include a reflector. An example three-dimensional antenna radiation pattern 1702 shown in FIG. 17 is a three-dimensional antenna radiation pattern in which a target distance d is 0.6λ and the antenna module includes a reflector. For descriptions of a function of the reflector, refer to the foregoing embodiments. Details are not described again. With reference to FIG. 14a and FIG. 14b, it can be learned that the gain of the electromagnetic wave of the antenna module within the first coverage area (that is, from 0 degrees to 60 degrees and 300 degrees to 360 degrees) is strong, whereas an effect of sharp gain drops is omnidirectional within the side lobe coverage area, so that an interference suppression capability of the side lobe is improved, and therefore gains of electromagnetic waves outside the first coverage area are weak. This effectively suppresses electromagnetic interference to a same frequency or adjacent frequencies, and improves concurrent throughput performance of a plurality of network devices in the communication system.

[0073] In this embodiment, the N first elements have first orthographic projections on the first substrate, and the reflector has a second orthographic projection on the first substrate. Specifically, the first elements and the reflector are projected by using a plurality of parallel projection lines that are perpendicular to the first substrate, to form the first orthographic projections and the second orthographic projection on the first substrate. In this case, the N first elements form N first orthographic projections on the substrate. Each of the N first orthographic projections is located within the second orthographic projection. In this way, a reflection effect of the reflector 301 on electromagnetic waves emitted by the second radiation arms is effectively achieved, to ensure that the electromagnetic waves radiated by the N first elements can cover a corresponding coverage area. There is a target distance h between the second surface of the first substrate and the reflector that are shown in this embodiment, the target distance h is a specified distance multiple of the operating wavelength of the antenna module, and the specified distance multiple is any value from 0.07 to 0.5. FIG. 18 is an example antenna radiation pattern of the antenna module shown in FIG. 3 at different target distances. For details, refer to Table 2:Table 2Target distance hCorresponding antenna radiation patternTarget distance h=0.125An antenna radiation pattern is shown in 1801.Target distance h=0.25An antenna radiation pattern is shown in 1802.Target distance h=0.375An antenna radiation pattern is shown in 1803.Target distance h=0.5An antenna radiation pattern is shown in 1804. 

[0074] It can be understood that, when the target distance is the specified distance multiple of the operating wavelength of the antenna module, a gain of an electromagnetic wave radiated by the antenna module within the main lobe coverage area is greater than a gain of an electromagnetic wave radiated within the side lobe coverage area, so that a signal strength within the main lobe coverage area is improved. In addition, because an effect of sharp gain drops is omnidirectional within the side lobe coverage area, an interference suppression capability of the side lobe is improved. When the target distance h is the specified distance multiple of the operating wavelength λ of the antenna module, different values of the target distance h can make the antenna module have different effects of sharp gain drops within the side lobe coverage area. Therefore, values of the target distance h can be correspondingly set based on different requirements of the antenna module for the effects of sharp gain drops within the side lobe coverage area.

[0075] In the foregoing embodiment, that different first distances d are equal for the N first elements is used as an example. In the following embodiment, there are different first distances for the N first elements. FIG. 19 is an example diagram of an embodiment of a top-view structure of an antenna module according to this application. The antenna module 1900 shown in this embodiment includes a reflector 1901, a first substrate 1902, a first feed network, and N first elements. For descriptions of the reflector 1901, the first substrate 1902, and the first feed network shown in this embodiment, refer to the corresponding descriptions in the foregoing embodiments. Details are not described again. In this embodiment, a value of N is 4. In this case, the antenna module 1900 shown in this embodiment includes four first elements, and the four first elements are sequentially arranged end-to-end to form a rectangular structure. In this case, the N first elements specifically include a first element 1911, a first element 1912, a first element 1913, and a first element 1914. The four first elements shown in this embodiment form two circumcircles. Specifically, the first element 1912 and the first element 1914 form a circumcircle C1, where first distances between the first element 1912 and a center of the circumcircle C1 and between the first element 1914 and the center of the circumcircle C1 are d1. The first element 1911 and the first element 1913 form a circumcircle C2, where first distances between the first element 1911 and a center of the circumcircle C2 and between the first element 1913 and the center of the circumcircle C2 are d2. The first distances d1 are along a direction Y, the first distances d2 are along a direction X, and the first substrate 1902 is parallel to a plane XY. The first distance d1 shown in this embodiment is not equal to the first distance d2. For descriptions of the first distance d1 and the first distance d2, refer to the descriptions of the first distance d shown in the foregoing embodiments. Details are not described again. For descriptions of a co-directional loop current formed by the four first elements in this embodiment, refer to the foregoing embodiments. Details are not described again. In this embodiment, an example is used in which the first distance d1 is not a first specified multiple of an operating wavelength of the antenna module and the first distance d2 is a first specified multiple of the operating wavelength of the antenna module. Specifically, for example, the first distance d1=0.25, and the first distance d2=0.5. For descriptions of the first specified multiple, refer to the foregoing embodiments. Details are not described again. Refer now to FIG. 20 and FIG. 21. FIG. 20 is an example antenna radiation pattern of the antenna module shown in FIG. 19 on a horizontal cross-sectional plane. FIG. 21 is an example three-dimensional antenna radiation pattern of the antenna module shown in FIG. 19. Because the first distance d2 is a first specified multiple of the operating wavelength of the antenna module, and the first distance d2 is a length along the direction X, electromagnetic waves emitted by the antenna module have an effect of sharp gain drops in the direction X. In this embodiment, a degree of sharp gain drops in the direction X may be adjusted by adjusting a value of the first distance d2. Because the first distance d1 is not a first multiple of the operating wavelength of the antenna, and the first distance d1 is a length along the direction Y, electromagnetic waves emitted by the antenna module have an effect of gain enhancement in the direction Y. It can be understood that the antenna module shown in this embodiment can implement an effect of sharp gain drops or gain enhancement by adjusting values of different first distances. In this embodiment, a degree of gain enhancement in the direction Y may be adjusted by adjusting a value of the first distance d1. In this embodiment, that the N first elements are arranged around to form a rectangle is used as an example, and does not constitute any limitation. The N first elements may form any type of shape, for example, a circle, an ellipse, or a polygon. A shape of each first element is not limited in this embodiment. For example, the first element may be in the shape of a rectangle or an arc. This is not specifically limited.

[0076] In the foregoing embodiment, that the antenna module includes one substrate (that is, the first substrate) is used as an example. An antenna module shown in this embodiment includes K substrates, where K is any integer greater than or equal to 2. FIG. 22 is another example diagram of a top-view structure of an antenna module according to an embodiment of this application, and FIG. 23 is an example diagram of a side-view structure of the antenna module shown in FIG. 22. In this embodiment, that a value of K is 3 is used as an example. It should be noted that the value of K is not limited in this embodiment.

[0077] The antenna module shown in this embodiment includes the K substrates, and when K is equal to 3, the antenna module includes three substrates: a first substrate 2201, a second substrate 2202, and a third substrate 2203. The antenna module further includes three feed networks: a first feed network, a second feed network, and a third feed network. The first substrate 2201 is configured to connect to a first element array, the first element array includes N first elements 2211, and the first feed network is connected to the N first elements 2211 and is configured to feed the N first elements 2211, so that the N first elements 2211 form a co-directional loop current. For descriptions of the N first elements 2211 and the first feed network, refer to the foregoing embodiments. Details are not described again. The second substrate 2202 is configured to connect to a second element array, the second element array includes M second elements 2212, and the second feed network is connected to the M second elements 2212 and is configured to feed the M second elements 2212, so that the M second elements 2212 form a co-directional loop current. For descriptions of the M second elements 2212, refer to the descriptions of the N first elements 2211. For descriptions of the second feed network and the second substrate, refer to the descriptions of the first feed network and the first substrate. Details are not described again. The third substrate 2203 is configured to connect to a third element array, the third element array includes L third elements 2213, and the third feed network is connected to the L third elements 2213 and is configured to feed the L third elements 2213, so that the L third elements 2213 form a co-directional loop current. For descriptions of the L third elements 2213, refer to the descriptions of the N first elements 2211. For descriptions of the third feed network and the third substrate, refer to the descriptions of the first feed network and the first substrate. Details are not described again. N, M, and L shown in this embodiment are all any integers greater than 1. In this embodiment, the first substrate 2201, the second substrate 2202, the third substrate 2203, and a reflector 2300 are sequentially arranged along a direction Z. In addition, there is a gap between the first substrate 2201 and the second substrate 2202, and there is a gap between the third substrate 2203 and the reflector 2300. For example, the first substrate 2201 and the second substrate 2202 may be supported and fastened by using a support member located between the first substrate 2201 and the second substrate 2202. For another example, the third substrate 2203 and the reflector 2300 may be supported and fastened by using a support member located between the third substrate 2203 and the reflector 2300. It should be noted that connection manners between different substrates and between a substrate and the reflector are not limited in this embodiment. For descriptions of the reflector 2300, refer to the foregoing embodiments. Details are not described again. In this case, the second substrate 2202 is located between the first substrate 2201 and the third substrate 2203, and the third substrate 2203 is located between the second substrate 2202 and the reflector 2300. In this embodiment, an example is used in which a diameter of a circle formed by the first element array, a diameter of a circle formed by the second element array, and a diameter of a circle formed by the third element array increase in ascending order. It should be noted that a magnitude relationship between the diameter of the circle formed by the first element array, the diameter of the circle formed by the second element array, and the diameter of the circle formed by the third element array is not limited in this embodiment.

[0078] Optionally, the first element array shown in this embodiment has a first distance d1. For descriptions of the first distance d1, refer to the foregoing embodiments. Details are not described again. The second element array has a second distance d2, and the third element array has a third distance d3. For descriptions of the second distance d2 and the third distance d3, refer to the descriptions of the first distance d1. Details are not described again. Any two of the first distance d1, the second distance d2, and the third distance d3 are different from each other. In addition, in the first distance d1, the second distance d2, and the third distance d3, only the first distance is a first specified multiple of an operating wavelength of the antenna module, where the first specified multiple is any value from 0.4 to 0.75. Neither the second distance d2 nor the third distance d3 is the operating wavelength of the antenna module. For example, the second distance d2 is less than 0.4 times the operating wavelength of the antenna module, and the third distance d3 is greater than 0.75 times the operating wavelength of the antenna module. In this embodiment, different element arrays can be made to operate based on specific application scenarios of the antenna module. For example, if a network device is far away from a surrounding network device, and no co-frequency or adjacent-frequency interference occurs, power may be supplied to the second element array and the third element array, to expand a coverage area of the antenna module's gain. If a network device is close to a surrounding network device, and co-frequency or adjacent-frequency interference occurs, sharp gain drops in all directions need to be implemented within a side lobe coverage area. In this case, only the first element array is fed, and power is not supplied to the second element array and the third element array. In this embodiment, that the first element array is located at a topmost layer of the three element arrays is used as an example. In another example, the first element array may alternatively be located at a bottommost layer of the three element arrays. For another example, the first element array may be located at an intermediate layer of the three element arrays. This is not specifically limited.

[0079] An embodiment of this application provides a network device. The network device includes the antenna module shown in the foregoing embodiments. For descriptions of a structure of the network device, refer to the corresponding descriptions in FIG. 2. Details are not described again.

[0080] An embodiment of this application provides a communication system. The communication system includes a plurality of network devices. For descriptions of a structure of the network device, refer to the corresponding descriptions in FIG. 2. Details are not described again.

[0081] An embodiment of this application provides a communication system. The communication system includes a plurality of network devices and a plurality of terminals connected to the network devices. For descriptions of the communication system, refer to the corresponding descriptions in FIG. 1. Details are not described again.

[0082] 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 readily figured out by a person skilled in the art 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 module, comprising N first elements, a first feed network, a reflector, and a first substrate, wherein N is any integer greater than 1, the first substrate and the reflector are sequentially arranged in a direction perpendicular to the first substrate, the first substrate fastens the N first elements and the first feed network, the first feed network is connected to each first element, the N first elements are sequentially arranged end-to-end on a surface of the first substrate, and when the first feed network feeds the N first elements, currents flowing through different first elements all flow in a same direction. 2. The antenna module according to claim 1, wherein the currents flowing through the different first elements all flow in a clockwise direction, or all flow in a counterclockwise direction. 3. The antenna module according to claim 1 or 2, wherein each first element comprises a first radiation arm and a second radiation arm, N first radiation arms are located on a first surface of the first substrate, N second radiation arms are located on a second surface of the first substrate, the first surface, the second surface, and the reflector are sequentially arranged in the direction perpendicular to the first substrate, the N first radiation arms are sequentially arranged end-to-end, and the N second radiation arms are sequentially arranged end-to-end.

4. The antenna module according to any one of claims 1 to 3, wherein at least one of the first elements has a circumcircle, there is a first distance between a center of the circumcircle and a phase center of at least one of the first element that is used to form the circumcircle, and the first distance is any value within a range of 0.4 to 0.75 times an operating wavelength of the antenna module.

5. The antenna module according to claim 3, wherein the first feed network comprises N first microstrips, a power splitter, N second microstrips, and a ground module, a first end of the first microstrip is connected to the first radiation arm, a second end of the first microstrip is connected to the power splitter, a first end of the second microstrip is connected to the second radiation arm, and a second end of the second microstrip is connected to the ground module.

6. The antenna module according to claim 5, wherein a target radiation arm is connected to a target microstrip, an absolute value of an included angle between the target radiation arm and the target microstrip is greater than 80 degrees and less than 100 degrees, the target radiation arm is one of the N first radiation arms or the N second radiation arms, and the target microstrip is one of the N first microstrips or the N second microstrips.

7. The antenna module according to claim 6, wherein the target radiation arm is perpendicular to the target microstrip.

8. The antenna module according to any one of claims 1 to 7, wherein each first element has a first orthographic projection on the first substrate, the reflector has a second orthographic projection on the first substrate, and the first orthographic projection is located within the second orthographic projection.

9. The antenna module according to any one of claims 1 to 8, wherein there is a target distance between the first substrate and the reflector, the target distance is a specified distance multiple of the operating wavelength of the antenna module, and the specified distance multiple is any value from 0.07 to 0.5.

10. The antenna module according to any one of claims 1 to 9, wherein the antenna module further comprises a second substrate, a second feed network, and M second elements, M is any integer greater than 1, the second substrate, the first substrate, and the reflector are sequentially arranged or the first substrate, the second substrate, and the reflector are sequentially arranged in the direction perpendicular to the first substrate, the second substrate fastens the M second elements and the second feed network, the second feed network is connected to each second element, the M second elements are sequentially arranged end-to-end on a surface of the second substrate, and when the second feed network feeds the M second elements, currents flowing through the M second elements form a co-directional loop current.

11. The antenna module according to claim 10, wherein at least one of the first elements has a first circumcircle, there is a first distance between a center of the first circumcircle and a phase center of at least one of the first element that is used to form the first circumcircle, at least one of the second elements has a second circumcircle, there is a second distance between a center of the second circumcircle and a phase center of at least one of the second element that is used to form the second circumcircle, and the first distance is not equal to the second distance.

12. The antenna module according to claim 11, wherein the first distance is any value within the range of 0.4 to 0.75 times the operating wavelength of the antenna module, and the second distance is any value outside the range of 0.4 to 0.75 times the operating wavelength of the antenna module.

13. A network device, wherein the network device comprises a baseband module, a radio frequency module, and the antenna module according to any one of claims 1 to 12, the radio frequency module comprises a transmitter and / or a receiver, and the antenna module comprises a transmit antenna and / or a receive antenna;the baseband module is configured to send a first digital signal to the transmitter, the radio frequency module is configured to convert the first digital signal into a first radio frequency signal, and the transmit antenna is configured to convert the first radio frequency signal into a first electromagnetic wave and radiate the first electromagnetic wave; and / orthe receive antenna is configured to receive a second electromagnetic wave and convert the second electromagnetic wave into a second radio frequency signal, and the receiver is configured to convert the second radio frequency signal into a second digital signal and send the second digital signal to the baseband module.

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