WAVEGUIDE AND COMMUNICATION SYSTEM

Abstract

 This application provides a waveguide and a communication system. The waveguide may include a base, and a first waveguide cavity, a second waveguide cavity, and a connection structure are provided inside the base. The base has a first surface and a second surface, a first port is provided on the first surface, a second port and a third port are provided on the second surface, the first port and the second port separately communicate with the first waveguide cavity, the third port communicates with the second waveguide cavity, and the second waveguide cavity communicates with the first waveguide cavity through the connection structure. An area of a first cross section of the first waveguide cavity is greater than an area of a second cross section of the first waveguide cavity, the second cross section is located between the connection structure and the second port, and the first cross section is farther away from the second port than the second cross section. In this application, an original signal that enters the waveguide can be branched into a first branch signal and a second branch signal, and a power difference and a phase difference between the first branch signal and the second branch signal can be adjusted, so that the power difference meets a power difference requirement, and the phase difference meets a phase difference requirement.

Description

[0001] This application claims priority to Chinese Patent Application No. 202211272215.X, filed with the China National Intellectual Property Administration on October 18, 2022 and entitled "WAVEGUIDE AND COMMUNICATION SYSTEM", 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 a waveguide and a communication system.

BACKGROUND

[0003] A communication system generally includes an antenna, a signal processor, and a waveguide connected between the antenna and the signal processor. The antenna may include a plurality of feeds, and each feed transmits a received signal to the signal processor through the waveguide. After processing the signal, the signal processor sends a processed signal to the waveguide. The waveguide divides the received signal into a plurality of branch signals, and sends the plurality of branch signals to the plurality of feeds. The feeds radiate the signals.

[0004] In a related technology, the plurality of branch signals output by the waveguide include a first branch signal and a plurality of second branch signals. The waveguide may adjust power of the second branch signal, to obtain a specific power difference between the first branch signal and the second branch signal. Because there is a specific relationship between a phase difference and the power difference between the first branch signal and the second branch signal, a specific phase difference is obtained during power adjustment, but the phase difference usually does not meet a phase difference requirement. Therefore, during actual use, a connection waveguide usually needs to be additionally installed between the waveguide and the antenna, to meet the phase difference requirement. However, the additionally installed connection waveguide affects the power difference, and consequently, the power difference does not meet a power difference requirement.

SUMMARY

[0005] This application provides a waveguide and a communication system, to branch an original signal that enters the waveguide into a first branch signal and a second branch signal and adjust a power difference between the first branch signal and the second branch signal, so that a power difference meets a power difference requirement. In addition, a phase difference between the first branch signal and the second branch signal is adjusted, so that the phase difference meets a phase difference requirement.

[0006] According to a first aspect, this application provides a waveguide, and the waveguide may be used in a communication system. Specifically, the waveguide may be used in a communication system that backhauls a signal from a base station to a relay station. In addition to the waveguide, the communication system may further include an antenna and a signal processor, and the waveguide is connected between the antenna and the signal processor. The antenna may include a primary reflector, a secondary reflector, and a first feed and a second feed that are located between the primary reflector and the secondary reflector. The secondary reflector receives the signal backhauled by the base station. The signal is sent to the primary reflector after passing through the first feed and the second feed, and then passes through the waveguide and is transmitted to the signal processor. After the signal processor processes all the received signals, the signals pass through the waveguide and are transmitted to the antenna. The signals are radiated through the antenna.

[0007] The waveguide may include a base, and a first waveguide cavity, a second waveguide cavity, and a connection structure are provided inside the base. The base has a first surface and a second surface, a first port is provided on the first surface, a second port and a third port are provided on the second surface, the first port and the second port separately communicate with the first waveguide cavity, the third port communicates with the second waveguide cavity, and the second waveguide cavity communicates with the first waveguide cavity through the connection structure. An area of a first cross section of the first waveguide cavity is greater than an area of a second cross section of the first waveguide cavity, the second cross section is located between the connection structure and the second port, and the first cross section is farther away from the second port than the second cross section. It may be understood that, it is assumed that the first waveguide cavity extends along a third direction. In this case, both the first cross section and the second cross section are perpendicular to the third direction. Both the first cross section and the second cross section may be rectangles. Cross sections of the connection structure and the second waveguide cavity may also be rectangles.

[0008] When the waveguide is used in the communication system, the first port is configured to connect to the signal processor, both the second port and the third port are configured to connect to the antenna, the second port is connected to the first feed, and the third port is connected to the second feed. After entering the first waveguide cavity from the first port, an initial signal sent by the signal processor is branched into at least two branch signals, namely a first branch signal and a second branch signal, when passing through the connection structure in a process of being transmitted forward in the first waveguide cavity. The first branch signal continues to be transmitted forward in the first waveguide cavity, and is transmitted to the first feed in the antenna through the second port. The second branch signal is transmitted to the second waveguide cavity after passing through the connection structure, is transmitted forward in the second waveguide cavity to the third port, and is transmitted to the second feed in the antenna through the third port. After the second branch signal passes through the connection structure and enters the second waveguide cavity, power of the second branch signal changes. However, the original signal and the first branch signal obtained through branching are always transmitted in the first waveguide cavity, and therefore, power of the original signal and the first branch signal almost does not change. Therefore, a power difference exists between the power of the second branch signal output from the third port and the power of the first branch signal output from the second port. In addition, a cross-sectional area of the connection structure may be adjusted, to adjust the power difference.

[0009] In addition, because the area of the first cross section of the first waveguide cavity is greater than the area of the second cross section, and the first cross section is farther away from the second port than the second cross section, a partial region of the first waveguide cavity is in a tapered shape in a direction from the first port to the second port. In this way, a structure in the tapered shape can provide specific impedance for the branch signal transmitted in the first waveguide cavity, so that the impedance provided by the first waveguide cavity for the first branch signal is different from impedance provided by the second waveguide cavity for the second branch signal. In this way, a difference exists between a phase of the first branch signal output from the second port and a phase of the second branch signal output from the third port. In other words, in this application, a phase difference can exist between the first branch signal and the second branch signal. In addition, a difference between the area of the first cross section and the area of the second cross section may be adjusted, to adjust a value of the phase difference. In this application, the power difference and the phase difference between the first branch signal and the second branch signal can be separately adjusted, so that the power difference meets a power difference requirement, and the phase difference meets a phase difference requirement.

[0010] In some embodiments, the area of the second cross section is less than an area of an end face that is of the first waveguide cavity and that is at the second port. Because the second cross section is located between the second port and the connection structure, when the area of the second cross section is less than the area of the end face that is of the first waveguide cavity and that is at the second port, the first waveguide cavity is in a flared shape from the second cross section to the second port. For the first waveguide cavity, the part from the first cross section to the second cross section is in the tapered shape, and the part from the second cross section to the second port is in the tapered shape. Therefore, an area of a cross section of the first waveguide cavity first decreases and then increases. Because the first port needs to be connected to a waveguide connector of the signal processor, and the second port also needs to be connected to a waveguide connector of the first feed of the antenna, the waveguide connector is usually in a standard fixed size. When the area of the cross section of the first waveguide cavity first decreases and then increases, areas of the first port and the second port that are located at two ends of the first waveguide cavity can be the same. More specifically, the first port and the second port can be set to be in a same shape and size, to facilitate better use of the waveguide in a standard size connector of the waveguide.

[0011] In some embodiments, a size of the first cross section in the first direction is greater than a size of the second cross section in the first direction, and a size of the first cross section in the second direction is the same as a size of the second cross section in the second direction. It may be understood that the first direction is perpendicular to the third direction. The first direction may be a width direction of the cross section of the first waveguide cavity, and the second direction may be a length direction of the cross section of the first waveguide cavity. In this way, the size of the first cross section in the first direction may be set to be greater than the size of the second cross section in the first direction, so that the area of the first cross section is greater than the area of the second cross section. When the size of the first cross section in the second direction is the same as the size of the second cross section in the second direction, a cavity surface that is on the first waveguide cavity and that is perpendicular to the second direction may be a plane as a whole, and distances between the plane and a center line of the first waveguide cavity are the same. In this way, a processing difficulty of the cavity surface of the first waveguide cavity can be reduced.

[0012] In some other embodiments, the size of the first cross section in the second direction is greater than the size of the second cross section in the second direction, and the size of the first cross section in the first direction is the same as the size of the second cross section in the first direction. The second direction is perpendicular to the first direction, and the second direction is also perpendicular to the third direction. The second direction may be the length direction of the cross section of first waveguide cavity.

[0013] In some other embodiments, the size of the first cross section in the first direction is greater than the size of the second cross section in the first direction, and the size of the first cross section in the second direction is greater than the size of the second cross section in the second direction.

[0014] In some embodiments, the size of the second cross section in the first direction is less than a size of the end face in the first direction, the size of the second cross section in the second direction is the same as a size of the end face in the second direction, and the second direction is perpendicular to the first direction. In this way, the size of the second cross section in the first direction may be set to be less than the size of the end face in the first direction, so that the area of the second cross section is less than the area of the end face. When the size of the second cross section in the second direction is the same as the size of the end face in the second direction, the cavity surface that is on the first waveguide cavity and that is perpendicular to the second direction may be a plane as a whole, and distances between the plane and the center line of the first waveguide cavity are the same. In this way, a processing difficulty of the cavity surface of the first waveguide cavity can be reduced.

[0015] In some other embodiments, the size of the second cross section in the second direction is less than the size of the end face in the second direction, and the size of the second cross section in the first direction is the same as the size of the end face in the first direction.

[0016] In some other embodiments, the size of the second cross section in the first direction is less than the size of the end face in the first direction, and the size of the second cross section in the second direction is less than the size of the end face in the second direction.

[0017] In some embodiments, the first waveguide cavity includes a first cavity segment and a second cavity segment that is close to the second port, the first cavity segment is connected to one end that is of the second cavity segment and that is away from the second port, and a cross-sectional area of the first cavity segment gradually decreases from one end away from the second port to one end close to the second port. In this way, the first cavity segment is gradually tapered from the end away from the second port to the end close to the second port, and the cross-sectional area changes gradually instead of changing suddenly, so that a problem of an energy loss of a signal caused by a sudden change of the cross-sectional area can be avoided.

[0018] In some embodiments, a cross-sectional area of the second cavity segment gradually increases from one end away from the second port to one end close to the second port. In this way, the second cavity segment is in a flared shape from one end away from the second port to one end close to the second port, and the cross-sectional area changes gradually instead of changing suddenly, so that a problem of an energy loss of a signal caused by a sudden change of the cross-sectional area can be avoided.

[0019] In some embodiments, at least one cavity surface of the first cavity segment is inclined toward a center line of the first cavity segment; and/or at least one cavity surface of the second cavity segment is inclined toward a center line of the second cavity segment. The first cavity segment may include four cavity surfaces that are connected end to end and that enclose a closed shape. Among the four cavity surfaces, one cavity surface is inclined toward the center line of the first cavity segment, or two cavity surfaces are inclined toward the center line of the first cavity segment, or three cavity surfaces are inclined toward the center line of the first cavity segment, or four cavity surfaces are inclined toward the center line of the first cavity segment, and the cavity surface inclined toward the center line of the first cavity segment may be a plane. In this way, the cavity surface inclined toward the center line of the first cavity segment can better provide impedance for the first branch signal.

[0020] In some embodiments, at least one cavity surface of the first cavity segment is a stepped surface; and/or at least one cavity surface of the second cavity segment is a stepped surface. In this way, the stepped surface of the first cavity segment can provide impedance for the first branch signal transmitted in the first cavity segment.

[0021] In some embodiments, a cut-off surface further exists inside the base, the second waveguide cavity extends to the cut-off surface in a direction away from the third port, and a projection of the cut-off surface onto a cavity surface of the first waveguide cavity is located between the first port and the connection structure; and the waveguide further includes an impedance matching structure that protrudes from a cavity surface of the second waveguide cavity, the impedance matching structure is opposite to the connection structure, the impedance matching structure includes a first convex part disposed on the cavity surface of the second waveguide cavity and a second convex part disposed on the first convex part, a size of the second convex part in a third direction is less than a size of the first convex part in the third direction, and the third direction is an extension direction of the first waveguide cavity. Because the projection of the cut-off surface onto the cavity surface of the first waveguide cavity is located between the first port and the connection structure, the connection structure is located between the cut-off surface in the second waveguide cavity and the third port. In other words, a first part of the second waveguide cavity is located on one side of the connection structure, and a second part of the second waveguide cavity is located on the other side of the connection structure. After the second branch signal enters the second waveguide cavity from the connection structure, a part of the second branch signal enters the first part of the second waveguide cavity from one side of the connection structure and is transmitted to the cut-off surface, and the other part of the second branch signal enters the second part of the second waveguide cavity from the other side of the connection structure and is output from the third port. The cut-off surface provides impedance for the part of the second branch signal that enters the first part of the second waveguide cavity and is transmitted to the cut-off surface, so that the second branch signal is in a high impedance state. In this way, no additional matching load needs to be connected for the second branch signal, so that a structure of the waveguide can be simplified, and costs of the communication system can be reduced.

[0022] In some embodiments, a distance between a center of the third port and a center of the second port is greater than a distance between a center of a cross section that is of the second waveguide cavity and that is taken along a plane and a center of a cross section that is of the first waveguide cavity and that is taken along the plane, and the plane is located between the connection structure and the second port. There is usually a large gap between a center of the first feed and a center of the second feed in the antenna. When both the first waveguide cavity and the second waveguide cavity in the waveguide are in a standard waveguide cavity size, a size of the second port is the same as a size of the third port. In this case, a distance between the center of the first feed and the center of the second feed is greater than a sum of a distance from the center of the second port to an edge of the second port and a distance from the center of the third port to an edge of the third port. When the distance between the center of the third port and the center of the second port is greater than the distance between the center of the cross section that is of the second waveguide cavity and that is taken along the plane and the center of the cross section that is of the first waveguide cavity and that is taken along the same plane, the distance between the center of the third port and the center of the second port is greater than the sum of the distance between the center of the second port and the edge of the second port and the distance between the center of the third port and the edge of the third port. In this way, the distance between the center of the third port and the center of the second port can match the distance between the center of the first feed and the center of the second feed, and there is no need to additionally install a connection waveguide on the second port and the third port to match the two distances. This can further simplify the structure of the communication system and reduce the costs.

[0023] In some embodiments, one end that is of at least a part of a cavity segment of the second waveguide cavity and that is close to the third port is inclined toward a direction away from the first waveguide cavity. In this way, a distance between the center line of the first waveguide cavity and the end that is of the at least a part of the cavity segment of the second waveguide cavity and that is close to the third port is greater than a distance between the center line of the first waveguide cavity and one end that is of the at least a part of the cavity segment of the second waveguide cavity and that is away from the third port, to facilitate matching of the distance between the center of the second port and the center of the third port and the distance between the center of the first feed and the center of the second feed.

[0024] In some embodiments, the second waveguide cavity includes a third cavity segment close to the third port and a fourth cavity segment connected to one end that is of the third cavity segment and that faces away from the third port, one end that is of the fourth cavity segment and that is close to the third cavity segment is inclined toward the direction away from the first waveguide cavity, and an extension direction of the third cavity segment is the same as the extension direction of the first waveguide cavity. In this way, it can be ensured that the distance between the center of the second port and the center of the third port matches the distance between the center of the first feed and the center of the second feed, and a sudden change position of a connection between the third cavity segment and the fourth cavity segment can be located inside the waveguide. In this way, when a phase difference and a power difference are set, impact of the sudden change position of the connection between the third cavity segment and the fourth cavity segment can be fully taken into account, so that a power difference and a phase difference between the first branch signal and the second branch signal that are output from the waveguide are consistent with a power difference and a phase difference between the first branch signal and the second branch signal that enter the antenna.

[0025] In some other embodiments, the center line of the second waveguide cavity is a straight line, and an included angle exists between an extension line of the center line of the second waveguide cavity and an extension line of the center line of the first waveguide cavity.

[0026] In some embodiments, the first surface is opposite to the second surface. Because the first port is located on the first surface, and the second port is located on the second surface, when the first surface is opposite to the second surface, the first port and the second port may be disposed opposite to each other. In other words, the center of the first port and the center of the second port are located in a same straight line. In this way, the center line of the first waveguide cavity is a straight line. This can reduce a problem of an energy loss of the first branch signal caused by bending of the first waveguide cavity.

[0027] In some embodiments, there are at least two second waveguide cavities, there are at least two connection structures, and the at least two second waveguide cavities are respectively connected to the first waveguide cavity through the at least two connection structures. In this way, a quantity of second waveguide cavities may be the same as a quantity of feeds in the antenna. When the feed includes the first feed and two second feeds, there may be two second waveguide cavities, and the first waveguide cavity is connected to the first feed through the second port, and the two second waveguide cavities are respectively connected to the two second feeds through respective second ports.

[0028] In some embodiments, the at least two second waveguide cavities are arranged around the first waveguide cavity in an array with the first waveguide cavity as a center. A plurality of second feeds in the antenna are arranged around the first feed in an array with the first feed as a center. In this way, the second waveguide cavity can be directly connected to the second feed through the third port, and no other connection waveguide needs to be additionally installed.

[0029] According to a second aspect, this application provides a communication system. The communication system includes an antenna, a signal processor, and the waveguide according to any one of the foregoing implementations, and the waveguide is connected between the antenna and the signal processor. The communication system can achieve all effect of the foregoing waveguide.

BRIEF DESCRIPTION OF DRAWINGS

[0030] To describe technical solutions in embodiments of this application more clearly, the following briefly describes the accompanying drawings for describing embodiments of this application. It is clear that the accompanying drawings in the following descriptions show merely some embodiments of this application, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

FIG. 1 is a diagram of an application scenario according to an embodiment of this application;

FIG. 2 is a diagram of a structure of a communication system according to an embodiment of this application;

FIG. 3 is a diagram of a structure of a waveguide in a related technology;

FIG. 4 is a diagram of a structure of a waveguide at a first angle of view according to a first embodiment of this application;

FIG. 5 is a diagram of a structure of the waveguide shown in FIG. 4 at a second angle of view;

FIG. 6 is a diagram of a structure of the waveguide shown in FIG. 4 at a third angle of view;

FIG. 7 is a half-sectional view of the waveguide shown in FIG. 4;

FIG. 8 is a partial enlarged diagram of A in FIG. 7;

FIG. 9 is a diagram of a cross section of a waveguide according to a second embodiment of this application;

FIG. 10 is a diagram of a cross section of a waveguide according to a third embodiment of this application;

FIG. 11 is a diagram of a cross section of a waveguide according to a fourth embodiment of this application;

FIG. 12 is a diagram of a cross section of a waveguide according to a fifth embodiment of this application; and

FIG. 13 is a diagram of a cross section of a waveguide according to a sixth embodiment of this application.

[0031] Reference numerals: 11: base station; 12: communication system; 13: repeater; 14: antenna; 141: primary reflector; 142: secondary reflector; 143: feed; 1431: first feed; 1432: second feed; 1433: third feed; 15: signal processor; 16: signal processing apparatus; 20: waveguide; 21: base; 2111: first input port; 2112: second input port; 2113: third input port; 2121: first output port; 2122: second output port; 2123: third output port; 211: body; 212: first boss; 2120: first installation hole; 213: second boss; 2130: second installation hole; 214: first surface; 2141: first port; 215: second surface; 2152: second port; 2153: third port; 2154: fourth port; 22: first waveguide cavity; 221: fifth cavity segment; 222: first cavity segment; 223: second cavity segment; 224: first cavity surface; 225: second cavity surface; 23: second waveguide cavity; 231: sixth cavity segment; 232: fourth cavity segment; 233: third cavity segment; 24: third waveguide cavity; 241: seventh cavity segment; 242: ninth cavity segment; 243: eighth cavity segment; 25: connection structure; 251: first connection structure; 252: second connection structure; 26: cut-off surface; 261: first cut-off surface; 262: second cut-off surface; 27: first impedance matching structure; 271: first convex part; 272: second convex part; 28: second impedance matching structure.

DESCRIPTION OF EMBODIMENTS

[0032] The following clearly and completely describes the technical solutions in embodiments of this application with reference to the accompanying drawings in embodiments of this application. It is clear that the described embodiments are some but not all of embodiments of this application. All other embodiments obtained by a person of ordinary skill in the art based on embodiments of this application without creative efforts shall fall within the protection scope of this application.

[0033] The term "and/or" in this specification describes only an association relationship for describing associated objects and represents that three relationships may exist. For example, A and/or B may represent the following three cases: Only A exists, both A and B exist, and only B exists.

[0034] In this specification and claims in embodiments of this application, the terms "first", "second", and the like are intended to distinguish between different objects, but are not used to describe a particular order of the objects. For example, a first target object, a second target object, and the like are used for distinguishing between different target objects, but are not used for describing a specific order of the target objects.

[0035] In embodiments of this application, the word such as "example" or "for example" is used to represent an example, an illustration, or a description. Any embodiment or design solution described as an "example" or "for example" in embodiments of this application should not be explained as being more preferred or having more advantages than another embodiment or design solution. Exactly, use of the term "example", "for example", or the like is intended to present a related concept in a specific manner.

[0036] In descriptions of embodiments of this application, unless otherwise stated, "plurality of" means two or more. For example, a plurality of processing units mean two or more processing units, and a plurality of systems mean two or more systems.

[0037] Microwave is an electromagnetic wave, and a frequency range of microwave is 300 MHz to 300 GHz. E-band (E waveband) microwave is a type of microwave, and a frequency range of E-band microwave includes 71 GHz to 76 GHz and 81 GHz to 86 GHz. E-band microwave is a type of microwave that is often used in a process in which a signal from a base station is backhauled to a repeater or a central station. The base station may backhaul the signal to the repeater 13 or the central station in a point-to-point communication manner. In actual station deployment, that is, as shown in FIG. 1, when a communication system 12 is deployed between the base station 11 and the repeater 13, a quantity of communication systems 12 between the base station 11 and the relay station 13 may be determined based on a distance between the base station 11 and the relay station 13 and a signal transmission distance of the communication system 12. For example, as shown in FIG. 1, two communication systems 12 are deployed between the base station 11 and the relay station 13, and the base station 11 backhauls a signal that needs to be backhauled to the relay station 13 through the two communication systems 12 in sequence.

[0038] As shown in FIG. 2, the communication system 12 usually includes an antenna 14 and a signal processor 15. The antenna 14 is mainly a high-gain parabolic antenna. During actual use, there is usually a problem of interference between the antenna and the communication system 12. Therefore, a pattern of the parabolic antenna is required to have a feature of a low side lobe. The signal processor 15 may be an E-band device.

[0039] As shown in FIG. 2, the antenna 14 may include a primary reflector 141, a secondary reflector 142, and a plurality of feeds 143 located between the primary reflector 141 and the secondary reflector 142. For ease of description, the plurality of feeds 143 include a first feed 1431, a second feed 1432, and a third feed 1433. The primary reflector 141 receives a signal backhauled by the base station 11, and reflects the signal to the secondary reflector 142. The secondary reflector 142 reflects the signal to the first feed 1431, the second feed 1432, and the third feed 1433, and then the signal is transmitted to the signal processor 15. The signal processor 15 processes all the received signals, and then transmits processed signals to the antenna 14. The antenna 14 radiates the signals.

[0040] A structure of the feed 143, the primary reflector 141, and the secondary reflector 142 is usually optimized for implementation, so that the antenna 14 has the feature of a low side lobe. However, after optimization, performance of a low side lobe of the antenna 14 is still poor. Therefore, as shown in FIG. 2, a signal processing apparatus 16 may be further added between the antenna 14 and the signal processor 15, and power and a phase of a signal are adjusted, so that an electromagnetic field is superimposed at a spatial location. This increases or decreases energy in a required direction, to implement good performance of a low side lobe. The signal processing apparatus 16 may be an active signal processing apparatus 16, or may be a passive signal processing apparatus 16. When the active signal processing apparatus 16 is used, the active signal processing apparatus 16 may include active devices such as a frequency modulator and a phase shifter, to branch an original signal received from the signal processor 15 into a plurality of branch signals, and process each branch signal by using the frequency modulator, so that a power difference exists between one branch signal and another branch signal. In addition, each branch signal is processed by using the phase shifter, so that a phase difference exists between one branch signal and another branch signal. An advantage of the active signal processing apparatus 16 is flexible implementation of a required amplitude-phase weight value, but a disadvantage of the active signal processing apparatus is high costs.

[0041] The passive signal processing apparatus 16 may be, for example, a waveguide 20 shown in FIG. 3, has no power supply, is mainly configured to branch a signal sent by the signal processor 15 into a plurality of branch signals, and adjust power and phases of some branch signals in the plurality of branch signals, so that a power difference and a phase difference exist between one branch signal and another branch signal. Because costs of the passive signal processing apparatus are low, the passive signal processing apparatus is widely used.

[0042] In a related technology, as shown in FIG. 3, the waveguide 20 includes a base 21, and a first input port 2111, a second input port 2112, and a third input port 2113 that are located on two sides of the first input port 2111, a first output port 2121 that communicates with the first input port 2111, a second output port 2122 that communicates with the second input port 2112, and a third output port 2123 that communicates with the third input port 2113 are provided on a surface of the base 21. The first input port 2111 is configured to connect to the signal processor 15, and the first output port 2121, the second output port 2122, and the third output port 2123 are respectively configured to connect to the first feed 1431, the second feed 1432, and the third feed 1433 in the antenna 14. The second input port 2112 and the third input port 2113 are separately connected to an external matching waveguide 20, and standard matching loads of corresponding frequency bands may be transmitted to the second input port 2112 and the third input port 2113 through the matching waveguide 20.

[0043] As shown in FIG. 3, a first waveguide cavity 22, a second waveguide cavity 23, and a third waveguide cavity 24 are provided inside the base 21, two ends of the first waveguide cavity 22 respectively communicate with the first input port 2111 and the first output port 2121, two ends of the second waveguide cavity 23 respectively communicate with the second input port 2112 and the second output port 2122, and two ends of the third waveguide cavity 24 respectively communicate with the third input port and the third output port 2123. The second waveguide cavity 23 and the third waveguide cavity 24 separately communicate with the first waveguide cavity 22. It may be understood that, in FIG. 3, a dashed line represents a contour line that is located inside the base 21 but is blocked by an entity and cannot be seen from the outside.

[0044] After entering the first waveguide cavity 22 from the first input port 2111, the initial signal sent by the signal processor 15 is branched into three branch signals, namely a first branch signal, a second branch signal, and a third branch signal. The first branch signal continues to be transmitted forward in the first waveguide cavity 22, and is transmitted to the first feed 1431 from the first output port 2121. The second branch signal enters the second waveguide cavity 23, is coupled to the standard matching load connected from the second input port 2112, and is transmitted to the second feed 1432 from the second output port 2122. The third branch signal enters the third waveguide cavity 24, is coupled to the standard matching load connected from the third input port 2113, and is transmitted to the third feed 1433 from the third output port 2123. After the second branch signal is obtained through branching of the initial signal and then enters the second waveguide cavity 23 through the first waveguide cavity 22, a power difference and a phase difference are generated between the second branch signal and the first branch signal in a process of transmission in the second waveguide cavity 23. After the third branch signal is obtained through branching of the initial signal and then enters the third waveguide cavity 24 through the first waveguide cavity 22, a power difference and a phase difference are generated between the third branch signal and the first branch signal in a process of transmission in the third waveguide cavity 24.

[0045] In a related technology, the waveguide 20 may adjust a size of a connection part between the first waveguide cavity 22 and the second waveguide cavity 23, so that power of the second branch signal is adjusted, to obtain a specific power difference between the first branch signal and the second branch signal. In addition, the waveguide 20 may adjust a size of a connection part between the first waveguide cavity 22 and the third waveguide cavity 24, so that power of the third branch signal is adjusted, to obtain a specific power difference between the first branch signal and the third branch signal. Because there is a specific relationship between a phase difference and a power difference between two signals, a specific phase difference is obtained during power adjustment, but the phase difference usually does not meet a phase difference requirement. Therefore, during actual use, a connection waveguide usually needs to be additionally installed between the waveguide 20 and the antenna 14, to meet the phase difference requirement. However, the additionally installed connection waveguide affects the power difference, and consequently, the power difference does not meet a power difference requirement.

[0046] In view of this, as shown in FIG. 4, an embodiment of this application provides a waveguide 20. The waveguide 20 may include a base 21. The base 21 includes a body 211, and a first boss 212 and a second boss 213 shown in FIG. 5 that are fastened to two ends of the body 211. A plurality of first installation holes 2120 are provided on the first boss 212, and the plurality of first installation holes 2120 are configured to be fastened to the signal processor 15 shown in FIG. 2. As shown in FIG. 5, a plurality of second installation holes 2130 are further provided at one end that is of the body 211 and that is fastened to the second boss 213, and the plurality of second installation holes 2130 are configured to be fastened to the antenna 14 shown in FIG. 2.

[0047] For ease of description, as shown in FIG. 4, three directions, namely an X direction (a first direction), a Y direction (a second direction), and a Z direction (a third direction) may be defined. The Z direction is a length direction of the waveguide 20, the X direction is a width direction of the waveguide 20, and the Y direction is a height direction of the waveguide 20.

[0048] As shown in FIG. 6, the base 21 has a first surface 214 and a second surface 215 that are opposite to each other. The first surface 214 is located on the first boss 212, and the second surface 215 is located on the second boss 213. As shown in FIG. 4, a first port 2141 is provided on the first surface 214. As shown in FIG. 5, a second port 2152, a third port 2153, and a fourth port 2154 are provided on the second surface 215. The first port 2141, the second port 2152, the third port 2153, and the fourth port 2154 have a same shape and size. When the waveguide 20 is used in the communication system 12, the waveguide 20 may be fastened to the signal processor 15 through the plurality of first installation holes 2120 on the first boss 212, and the first port 2141 is connected to the signal processor 15 through a waveguide connector. The waveguide 20 may be fastened to the antenna 14 through the plurality of second installation holes 2130, and the second port 2152, the third port 2153, and the fourth port 2154 are respectively connected to the first feed 1431, the second feed 1432, and the third feed 1433 of the antenna 14 through three waveguide connectors.

[0049] As shown in FIG. 6, the first port 2141 is opposite to the second port 2152. In other words, a center of the first port 2141 and a center of the second port 2152 are located in a same straight line.

[0050] As shown in FIG. 2, the second feed 1432 and the third feed 1433 are distributed on two sides of the first feed 1431. In other words, the second feed 1432, the first feed 1431, and the third feed 1433 are arranged along the X direction. Therefore, as shown in FIG. 5, the third port 2153 and the fourth port 2154 may be distributed on two sides of the second port 2152, to simplify a structure of a connector of the waveguide 20 and a structure of a connection device between the waveguide 20 and the antenna 14.

[0051] As shown in FIG. 7, a first waveguide cavity 22, a second waveguide cavity 23, a third waveguide cavity 24, and two connection structures 25 are provided inside the base 21. In this embodiment, shapes of cross sections of the first waveguide cavity 22, the second waveguide cavity 23, the third waveguide cavity 24, and the two connection structures 25 may all be rectangles. A cross section of the first waveguide cavity 22 may be a cross section that is of the first waveguide cavity 22 and that is taken along a surface perpendicular to the Z direction.

[0052] As shown in FIG. 7, the second waveguide cavity 23 and the third waveguide cavity 24 respectively communicate with the first waveguide cavity 22 through the two connection structures 25, and the second waveguide cavity 23 and the third waveguide cavity 24 are respectively located on two sides of the first waveguide cavity 22. For ease of description, the two connection structures 25 are respectively named a first connection structure 251 and a second connection structure 252, the first connection structure 251 is connected between the first waveguide cavity 22 and the second waveguide cavity 23, and the second connection structure 252 is connected between the first waveguide cavity 22 and the third waveguide cavity 24.

[0053] As shown in FIG. 7, the first port 2141 and the second port 2152 respectively communicate with two ends of the first waveguide cavity 22, the third port 2153 communicates with the second waveguide cavity 23, and the fourth port 2154 communicates with the third waveguide cavity 24. After entering the first waveguide cavity 22 from the first port 2141, the initial signal sent by the signal processor 15 is branched into three branch signals, namely the first branch signal, the second branch signal, and the third branch signal, when passing through the first connection structure 251 and the second connection structure 252 in a process of being transmitted forward in the first waveguide cavity 22. The first branch signal continues to be transmitted forward in the first waveguide cavity 22, and is transmitted to the first feed 1431 in the antenna 14 through the second port 2152. The second branch signal is transmitted to the second waveguide cavity 23 after passing through the first connection structure 251, is transmitted forward in the second waveguide cavity 23 to the third port 2153, and is transmitted to the second feed 1432 in the antenna 14 through the third port 2153. The third branch signal is transmitted to the third waveguide cavity 24 after passing through the second connection structure 252, is transmitted forward in the third waveguide cavity 24 to the fourth port 2154, and is transmitted to the third feed 1433 in the antenna 14 through the fourth port 2154.

[0054] After the second branch signal passes through the first connection structure 251 and enters the second waveguide cavity 23, power of the second branch signal changes. After the third branch signal passes through the second connection structure 252 and enters the third waveguide cavity 24, power of the third branch signal also changes. The first branch signal obtained through branching is consistently transmitted in the first waveguide cavity 22, and power of the first branch signal almost does not change. Therefore, a power difference exists between the power of the second branch signal output from the third port 2153 and the power of the first branch signal output from the second port 2152, and a power difference exists between the power of the third branch signal output from the fourth port 2154 and the power of the first branch signal output from the second port 2152. In addition, a cross-sectional area of the first connection structure 251 may be adjusted, to adjust a value of the power difference between the second branch signal and the first branch signal, and a cross-sectional area of the second connection structure 252 may be adjusted, to adjust a value of the power difference between the third branch signal and the first branch signal.

[0055] A dash-dot line in the middle of FIG. 7 represents a center line a1 of the first waveguide cavity. As shown in FIG. 7, the center line a1 of the first waveguide cavity 22 may be a straight line, and the first waveguide cavity 22 extends along the Z direction. In this way, a problem of an energy loss of the first branch signal caused by bending of the first waveguide cavity 22 can be reduced.

[0056] As shown in FIG. 7, the first waveguide cavity 22 includes a fifth cavity segment 221 close to the first port 2141, a second cavity segment 223 close to the second port 2152, and a first cavity segment 222 located between the fifth cavity segment 221 and the second cavity segment 223. Both the first connection structure 251 and the second connection structure 252 are connected to the fifth cavity segment 221. After entering the first waveguide cavity 22 from the first port 2141, the initial signal sent by the signal processor 15 first enters the fifth cavity segment 221, and then is branched into the first branch signal, the second branch signal, and the third branch signal when passing through the first connection structure 251 and the second connection structure 252, and the first branch signal continues to be transmitted forward in the fifth cavity segment 221, successively enters the first cavity segment 222 and the second cavity segment 223, and then is output from the second port 2152.

[0057] Cross-sectional areas of the fifth cavity segment 221 are the same. As shown in FIG. 7, an area of a first cross section of the first cavity segment 222 is greater than an area of a second cross section of the first cavity segment 222. The second cross section is located between the connection structure 25 and the second port 2152, and the first cross section is farther away from the second port 2152 than the second cross section. For example, the first cross section may be a cross section of one end that is of the first cavity segment 222 and that is away from the second cavity segment 223, and the second cross section may be a cross section of one end that is of the first cavity segment 222 and that is close to the second cavity segment 223. In an embodiment, a cross-sectional area of the first cavity segment 222 gradually decreases from one end away from the second port 2152 to one end close to the second port 2152. In other words, as shown in FIG. 8, the cross-sectional area of the first cavity segment 222 gradually decreases in the Z direction. In this way, the first cavity segment 222 is gradually tapered from the end away from the second port 2152 to the end close to the second port 2152, and the cross-sectional area changes gradually instead of changing suddenly, so that a problem of an energy loss of a signal caused by a sudden change of the cross-sectional area can be avoided.

[0058] As shown in FIG. 7, when the cross-sectional area of the first cavity segment 222 gradually decreases from the end away from the second port 2152 to the end close to the second port 2152, the first cavity segment 222 is in a tapered shape from one end connected to the fifth cavity segment 221 to one end connected to the second cavity segment 223. In this way, a structure in the tapered shape can provide specific impedance for the first branch signal transmitted in the first cavity segment 222, so that the impedance provided by the first cavity segment 222 for the first branch signal is different from impedance provided by the second waveguide cavity 23 for the second branch signal. In this way, a difference exists between a phase of the first branch signal output from the second port 2152 and a phase of the second branch signal output from the third port 2153. In other words, in this embodiment of this application, a phase difference can exist between the first branch signal and the second branch signal, and a difference between the area of the first cross section and the area of the second cross section can be adjusted, to adjust a value of the phase difference. In this embodiment of this application, the power difference and the phase difference between the first branch signal and the second branch signal can be separately adjusted, so that the power difference meets a power difference requirement, and the phase difference meets a phase difference requirement. In addition, a fluctuation of the power difference generated in this embodiment of this application is less than or equal to 0.5 dB, a fluctuation of the phase difference is less than or equal to 10°, and a loss is less than or equal to 0.5 dB.

[0059] In a possible implementation, a size of the first cavity segment 222 in the first direction gradually decreases from the end connected to the fifth cavity segment 221 to the end connected to the second cavity segment 223, and sizes of the first cavity segment 222 in the second direction are the same. In this way, the size of the first cavity segment 222 in the first direction may be set to gradually decrease, so that the area of the cross section of the first cavity segment 222 gradually decreases. When sizes of the first cavity segment 222 in the second direction are the same, a cavity surface that is on the first waveguide cavity 22 and that is perpendicular to the second direction may be a plane as a whole, and distances between the plane and the center line a1 of the first waveguide cavity 22 are the same. In this way, processing difficulty of the cavity surface of the first waveguide cavity 22 can be reduced.

[0060] As shown in FIG. 8, the first cavity segment 222 includes a first cavity surface 224, a second cavity surface 225, a third cavity surface (not shown in FIG. 8), and a fourth cavity surface (not shown in FIG. 8) that are sequentially connected end to end to enclose a tetragonal shape. The first cavity surface 224 is opposite to the second cavity surface 225, and the third cavity surface is opposite to the fourth cavity surface. Both the third cavity surface and the fourth cavity surface are parallel to the Z direction. Both the first cavity surface 224 and the second cavity surface 225 are inclined toward the center line a1 of the first cavity segment 222. Alternatively, the first cavity surface 224 is inclined toward the center line a1 of the first cavity segment 222, and the second cavity surface 225 is parallel to the Z direction; or the second cavity surface 225 is inclined toward the center line a1 of the first cavity segment 222, and the first cavity surface 224 is parallel to the Z direction.

[0061] In another possible implementation, a size of the first cavity segment 222 in the second direction gradually decreases from the end connected to the fifth cavity segment 221 to the end connected to the second cavity segment 223, and sizes of the first cavity segment 222 in the first direction are the same. Both the first cavity surface 224 and the second cavity surface 225 are parallel to the Z direction. Both the third cavity surface and the fourth cavity surface are inclined toward the center line a1 of the first cavity segment 222. Alternatively, the third cavity surface is inclined toward the center line a1 of the first cavity segment 222, and the fourth cavity surface is parallel to the Z direction; or the third cavity surface is parallel to the Z direction, and the fourth cavity surface is inclined toward the center line a1 of the first cavity segment 222.

[0062] In another possible implementation, a size of the first cavity segment 222 in the first direction gradually decreases from the end connected to the fifth cavity segment 221 to the end connected to the second cavity segment 223, and a size of the first cavity segment 222 in the second direction gradually decreases from the end connected to the fifth cavity segment 221 to the end connected to the second cavity segment 223. The first cavity surface 224, the second cavity surface 225, the third cavity surface, and the fourth cavity surface are all inclined toward the center line a1 of the first cavity segment 222.

[0063] As shown in FIG. 7, an area of a cross section of one end that is of the second cavity segment 223 and that is away from the second port 2152 is less than an area of an end face of the second cavity segment 223 at the second port 2152. In an embodiment, a cross-sectional area of the second cavity segment 223 gradually increases from the end away from the second port 2152 to the end close to the second port 2152. In other words, as shown in FIG. 8, the cross-sectional area of the second cavity segment 223 gradually increases in the Z direction. In this way, the second cavity segment 223 is in a flared shape from the end away from the second port 2152 to the end close to the second port 2152, and the cross-sectional area changes gradually instead of changing suddenly, so that a problem of an energy loss of a signal caused by a sudden change of the cross-sectional area can be avoided.

[0064] When the area of the cross section of the end that is of the second cavity segment 223 and that is away from the second port 2152 is less than the area of the end face of the second cavity segment 223 at the second port 2152, the second cavity segment 223 is in the flared shape from one end connected to the first cavity segment 222 to one end connected to the second port 2152. For the first waveguide cavity 22, the cross section of the first waveguide cavity 22 first remains unchanged, then gradually decreases, and then gradually increases. Because the first port 2141 needs to be connected to the waveguide connector of the signal processor 15, and the second port 2152 also needs to be connected to the waveguide connector of the first feed 1431 of the antenna 14, the waveguide connector is usually in a standard fixed size. When the area of the cross section of the first waveguide cavity 22 first remains unchanged, then decreases, and then increases, the areas of the first port 2141 and the second port 2152 that are located at two ends of the first waveguide cavity 22 can be the same. More specifically, the first port 2141 and the second port 2152 can be set to be in a same shape and size, to facilitate better use of the waveguide 20 in a standard size connector of the waveguide 20.

[0065] In a possible implementation of this application, a size of the second cavity segment 223 in the first direction gradually increases from the end connected to the first cavity segment 222 to the end connected to the second port 2152, and sizes of the second cavity segment 223 in the second direction are the same. In this way, a size of the second cavity segment 223 in the first direction may be set to be less than a size of the end face in the first direction, so that the area of the second cavity segment 223 is less than the area of the end face. When the size of the second cavity segment 223 in the second direction is the same as a size of the end face in the second direction, the cavity surface that is on the first waveguide cavity 22 and that is perpendicular to the second direction may be a plane as a whole, and distances between the plane and the center line a1 of the first waveguide cavity 22 are the same. In this way, processing difficulty of the cavity surface of the first waveguide cavity 22 can be reduced.

[0066] In another possible implementation of this application, the size of the second cavity segment 223 in the second direction gradually increases from the end connected to the first cavity segment 222 to the end connected to the second port 2152, and sizes of the second cavity segment 223 in the first direction are the same.

[0067] In another possible implementation of this application, the size of the second cavity segment 223 in the first direction gradually increases from the end connected to the first cavity segment 222 to the end connected to the second port 2152, and the size of the second cavity segment 223 in the second direction gradually increases from the end connected to the first cavity segment 222 to the end connected to the second port 2152.

[0068] The second cavity segment 223 may include four cavity surfaces that are sequentially connected end to end to enclose a tetragonal shape, and at least one of the four cavity surfaces is inclined toward the center line a1 of the second cavity segment 223. One of the four cavity surfaces is inclined toward the center line a1 of the first cavity segment 222, or two of the four cavity surfaces are inclined toward the center line a1 of the first cavity segment 222, or three of the four cavity surfaces are inclined toward the center line a1 of the first cavity segment 222, or all of the four cavity surfaces are inclined toward the center line a1 of the first cavity segment 222, and the cavity surface inclined toward the center line a1 of the first cavity segment 222 may be a plane. In this way, the cavity surface inclined toward the center line a1 of the first cavity segment 222 can better provide impedance for the first branch signal.

[0069] As shown in FIG. 7, two cut-off surfaces 26 further exist inside the base 21, the two cut-off surfaces 26 are respectively located on two sides of the first waveguide cavity 22, and projections of the two cut-off surfaces 26 onto the cavity surface of the first waveguide cavity 22 are both located between the first port 2141 and the connection structure 25. For ease of description, the two cut-off surfaces 26 are respectively named a first cut-off surface 261 and a second cut-off surface 262. The second waveguide cavity 23 extends to the first cut-off surface 261 in a direction away from the third port 2153. In this way, the first connection structure 251 is located between the first cut-off surface 261 in the second waveguide cavity 23 and the third port 2153. In other words, a first part of the second waveguide cavity 23 is located on one side of the first connection structure 251, and a second part of the second waveguide cavity 23 is located on the other side of the first connection structure 251. The third waveguide cavity 24 extends to the second cut-off surface 262 in a direction away from the fourth port 2154. In this way, the second connection structure 252 is located between the second cut-off surface 262 in the third waveguide cavity 24 and the fourth port 2154. In other words, a first part of the third waveguide cavity 24 is located on one side of the second connection structure 252, and a second part of the third waveguide cavity 24 is located on the other side of the second connection structure 252.

[0070] As shown in FIG. 7, the waveguide 20 further includes a first impedance matching structure 27 that protrudes from the cavity surface of the second waveguide cavity 23, and the first impedance matching structure 27 is opposite to the first connection structure 251. The first impedance matching structure 27 includes a first convex part 271 disposed on the cavity surface of the second waveguide cavity 23 and a second convex part 272 that is disposed on the first convex part 271 and that faces the second waveguide cavity 23. A size of the second convex part 272 in the X direction is the same as a size of the first convex part 271 in the X direction, and both are the same as the size of the second waveguide cavity 23 in the X direction. A size of the second convex part 272 in the Z direction is less than a size of the first convex part 271 in the Z direction.

[0071] As shown in FIG. 7, the second waveguide cavity 23 includes a sixth cavity segment 231 close to the first cut-off surface 261, a third cavity segment 233 close to the third port 2153, and a fourth cavity segment 232 located between the sixth cavity segment 231 and the third cavity segment 233. The first connection structure 251 is connected to the sixth cavity segment 231. After entering the first waveguide cavity 22 from the first port 2141, the initial signal sent by the signal processor 15 is branched into the first branch signal, the second branch signal, and the third branch signal when passing through the first connection structure 251, and the second branch signal is transmitted to the second waveguide cavity 23 through the first connection structure 251. After the second branch signal enters the second waveguide cavity 23 from the first connection structure 251, a part of the second branch signal enters the sixth cavity segment 231 from one side of the first connection structure 251, and is transmitted to the first cut-off surface 261, and the other part of the second branch signal enters the third cavity segment 233 from the other side of the first connection structure 251, then passes through the fourth cavity segment 232, and is output from the third port 2153. The first cut-off surface 261 may provide impedance for the part of the second branch signal that enters the sixth cavity segment 231 and is transmitted to the first cut-off surface 261, so that the second branch signal is in a high impedance state. In this way, no additional matching load needs to be connected for the second branch signal, so that a structure of the waveguide 20 can be simplified, and costs of the communication system 12 can be reduced.

[0072] As shown in FIG. 6, a distance L1 between a center of the third port 2153 and a center of the second port 2152 is greater than a distance L2 between a center of a cross section that is of the second waveguide cavity 23 and that is taken along a plane and a center of a cross section that is of the first waveguide cavity 22 and that is taken along a plane B-B, and the plane B-B is located between the connection structure 25 and the second port 2152. There is usually a large gap between a center of the first feed 1431 and a center of the second feed 1432 in the antenna 14. When both the first waveguide cavity 22 and the second waveguide cavity 23 in the waveguide 20 are in a standard waveguide cavity size, a size of the second port 2152 is the same as a size of the third port 2153. In this case, the distance between the center of the first feed 1431 and the center of the second feed 1432 is greater than a sum of a distance from the center of the second port 2152 to an edge of the second port 2152 and a distance from the center of the third port 2153 to an edge of the third port 2153. When the distance L2 between the center of the third port 2153 and the center of the second port 2152 is greater than the distance L1 between the center of the cross section that is of the second waveguide cavity 23 and that is taken along the plane and the center of the cross section that is of the first waveguide cavity 22 and that is taken along the same plane, the distance L2 between the center of the third port 2153 and the center of the second port 2152 is greater than a sum of the distance between the center of the second port 2152 and the edge of the second port 2152 and the distance between the center of the third port 2153 and the edge of the third port 2153. In this way, the distance L1 between the center of the third port 2153 and the center of the second port 2152 can match the distance between the center of the first feed 1431 and the center of the second feed 1432, and there is no need to additionally install a connection waveguide 20 on the second port 2152 and the third port 2153 to match the two distances. This can further simplify the structure of the communication system 12 and reduce the costs.

[0073] As shown in FIG. 7, one end that is of the fourth cavity segment 232 and that is close to the third cavity segment 233 is inclined toward a direction away from the first waveguide cavity 22, and an extension direction of the third cavity segment 233 is the same as an extension direction of the first waveguide cavity 22. In this way, it can be ensured that the distance between the center of the second port 2152 and the center of the third port 2153 matches the distance between the center of the first feed 1431 and the center of the second feed 1432, and a sudden change position of a connection between the third cavity segment 233 and the fourth cavity segment 232 can be located inside the waveguide 20. In this way, when a phase difference and a power difference are set, impact of the sudden change position of the connection between the third cavity segment 233 and the fourth cavity segment 232 can be fully taken into account, so that a power difference and a phase difference between the first branch signal and the second branch signal that are output from the waveguide 20 are consistent with a power difference and a phase difference between the first branch signal and the second branch signal that enter the feed 143 of the antenna 14.

[0074] As shown in FIG. 6, the third waveguide cavity 24 and the second waveguide cavity 23 are of a symmetric structure with respect to the center line a1 of the first waveguide cavity 22, and the third waveguide cavity 24 includes a seventh cavity segment 241 close to the second cut-off surface 262, an eighth cavity segment 243 close to the fourth port 2154, and a ninth cavity segment 242 located between the seventh cavity segment 241 and the eighth cavity segment 243. An end that is of the ninth cavity segment 242 and that is close to the eighth cavity segment 243 is inclined toward the direction away from the first waveguide cavity 22. An extension direction of the eighth cavity segment 243 is the same as the extension direction of the first waveguide cavity 22.

[0075] As shown in FIG. 7, the waveguide 20 further includes a second impedance matching structure 28 that protrudes from a cavity surface of the third waveguide cavity 24, and the second impedance matching structure 28 is opposite to the second connection structure 252. The second impedance matching structure 28 is the same as the first impedance matching structure 27. Details are not described herein again.

[0076] After entering the first waveguide cavity 22 from the first port 2141, the initial signal sent by the signal processor 15 is branched into the first branch signal, the second branch signal, and the third branch signal when passing through the second connection structure 252, and the third branch signal is transmitted to the third waveguide cavity 24 through the second connection structure 252. After the third branch signal enters the third waveguide cavity 24 from the connection structure 25, a part of the third branch signal enters the seventh cavity segment 241 from one side of the connection structure 25, and is transmitted to the second cut-off surface 262, and the other part of the third branch signal enters the ninth cavity segment 242 from the other side of the second connection structure 252, then passes through the eighth cavity segment 243, and is output from the fourth port 2154. The second cut-off surface 262 may provide impedance for the part of the third branch signal that enters the seventh cavity segment 241 and is transmitted to the second cut-off surface 262, so that the third branch signal is in a high impedance state. In this way, no additional matching load needs to be connected for the third branch signal, so that a structure of the waveguide 20 can be simplified, and costs of the communication system 12 can be reduced.

[0077] The embodiment shown in FIG. 9 is different from the embodiment shown in FIG. 8 in cavity surface structures of the first cavity segment 222 and the second cavity segment 223. In the embodiment shown in FIG. 8, the cavity surfaces of the first cavity segment 222 and the second cavity segment 223 are both planes. In this embodiment, as shown in FIG. 9, the cavity surface of the first cavity segment 222 is a stepped surface, and the cavity surface of the second cavity segment 223 is also a stepped surface. In this way, the stepped surface of the first cavity segment 222 can provide impedance for the first branch signal transmitted in the first cavity segment 222.

[0078] The embodiment shown in FIG. 10 is different from the embodiment shown in FIG. 7 in that, in this embodiment, the third waveguide cavity 24, the second cut-off surface 262, the second connection structure 252, the second impedance matching structure 28, and the fourth port 2154 are removed from the embodiment shown in FIG. 7. In other words, as shown in FIG. 10, in this embodiment, the second port 2152 and the third port 2153 are provided on the second surface 215 of the base 21. The first waveguide cavity 22, the second waveguide cavity 23, the first connection structure 251, the first cut-off surface 261, and the first impedance matching structure 27 are provided inside the base 21. After entering the first waveguide cavity 22 from the first port 2141, the initial signal sent by the signal processor 15 is branched into two branch signals, namely the first branch signal and the second branch signal, when passing through the first connection structure 251 in a process of being transmitted forward in the first waveguide cavity 22. The first branch signal continues to be transmitted forward in the first waveguide cavity 22, and is transmitted to the first feed 1431 in the antenna 14 shown in FIG. 2 through the second port 2152. The second branch signal is transmitted to the second waveguide cavity 23 after passing through the first connection structure 251, is transmitted forward in the second waveguide cavity 23 to the third port 2153, and is transmitted to the second feed 1432 in the antenna 14 shown in FIG. 2 through the third port 2153.

[0079] In another embodiment, a quantity of second waveguide cavities 23 and a quantity of third waveguide cavities may be increased on a basis of the embodiment shown in FIG. 7. The plurality of second waveguide cavities 23 and the plurality of third waveguide cavities 24 are arranged around the first waveguide cavity 22 in an array with the first waveguide cavity 22 as a center.

[0080] The embodiment shown in FIG. 11 is different from the embodiment shown in FIG. 7 in a position relationship between the first surface 214 and the second surface 215, and extension directions of the first waveguide cavity 22, the second waveguide cavity 23, and the third waveguide cavity 24. In the embodiment shown in FIG. 7, the first surface 214 is opposite to the second surface 215. In this embodiment, as shown in FIG. 11, the first surface 214 and the second surface 215 are adjacent surfaces. In this way, the center line a1 of the first waveguide cavity 22 is a non-linear line. The first waveguide cavity 22 first extends along the Z direction, and then extends along the X direction. The extension direction of the third cavity segment 233 of the second waveguide cavity 23 and the extension direction of the eighth cavity segment 243 of the third waveguide cavity 24 are always the same as the extension direction of the first waveguide cavity 22, that is, first extending along the Z direction and then extending along the X direction.

[0081] The embodiment shown in FIG. 12 is different from the embodiment shown in FIG. 7 in structures of the second waveguide cavity 23 and the third waveguide cavity 24. In the embodiment shown in FIG. 7, the second waveguide cavity 23 includes the sixth cavity segment 231, the fourth cavity segment 232, and the third cavity segment 233, the end that is of the fourth cavity segment 232 and that is close to the third cavity segment 233 is inclined toward the direction away from the first waveguide cavity 22, and the extension direction of the third cavity segment 233 is the same as that of the first cavity segment 222. In this embodiment, as shown in FIG. 12, the second waveguide cavity 23 includes the sixth cavity segment 231 close to the first cut-off surface 261 and the fourth cavity segment 232 close to the third port 2153, and the fourth cavity segment 232 is inclined toward the first waveguide cavity 22 as a whole.

[0082] In the embodiment shown in FIG. 7, the third waveguide cavity 24 includes the seventh cavity segment 241, the ninth cavity segment 242, and the eighth cavity segment 243, the end that is of the ninth cavity segment 242 and that is close to the eighth cavity segment 243 is inclined toward the direction away from the first waveguide cavity 22, and the extension direction of the eighth cavity segment 243 is the same as that of the first waveguide cavity 22. In this embodiment, as shown in FIG. 12, the third waveguide cavity 24 includes the seventh cavity segment 241 close to the second cut-off surface 262 and the eighth cavity segment 243 close to the fourth port 2154, and the eighth cavity segment 243 is inclined toward the first waveguide cavity 22 as a whole.

[0083] The embodiment shown in FIG. 13 is different from the embodiment shown in FIG. 7 in extension directions of the third cavity segment 233 and the eighth cavity segment 243 in the second waveguide cavity 23. In the embodiment shown in FIG. 7, the extension directions of the third cavity segment 233 and the eighth cavity segment 243 are separately the same as the extension direction of the first cavity segment 222. In this embodiment, as shown in FIG. 13, one end that is of the third cavity segment 233 and that is close to the third port 2153 is inclined toward the first waveguide cavity 22, but an inclination angle of the third cavity segment 233 is less than an inclination angle of the fourth cavity segment 232. One end that is of the eighth cavity segment 243 and that is close to the fourth port 2154 is inclined toward the first waveguide cavity 22, but an inclination angle of the eighth cavity segment 243 is less than an inclination angle of the ninth cavity segment 242.

[0084] 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. A waveguide, comprising a base, wherein a first waveguide cavity, a second waveguide cavity, and a connection structure are provided inside the base, the base has a first surface and a second surface, a first port is provided on the first surface, a second port and a third port are provided on the second surface, the first port and the second port separately communicate with the first waveguide cavity, the third port communicates with the second waveguide cavity, and the second waveguide cavity communicates with the first waveguide cavity through the connection structure; and
an area of a first cross section of the first waveguide cavity is greater than an area of a second cross section of the first waveguide cavity, the second cross section is located between the connection structure and the second port, and the first cross section is farther away from the second port than the second cross section.

2. The waveguide according to claim 1, wherein the area of the second cross section is less than an area of an end face that is of the first waveguide cavity and that is at the second port.

3. The waveguide according to claim 1 or 2, wherein a size of the first cross section in a first direction is greater than a size of the second cross section in the first direction; and/or
a size of the first cross section in a second direction is greater than a size of the second cross section in the second direction, and the second direction is perpendicular to the first direction.

4. The waveguide according to claim 2, wherein a size of the second cross section in a first direction is less than a size of the end face in the first direction; and/or
a size of the second cross section in a second direction is less than a size of the end face in the second direction, and the second direction is perpendicular to the first direction.

5. The waveguide according to claim 2, wherein the first waveguide cavity comprises a first cavity segment and a second cavity segment that is close to the second port, and the first cavity segment is connected to one end that is of the second cavity segment and that is away from the second port; and
a cross-sectional area of the first cavity segment gradually decreases from one end away from the second port to one end close to the second port.

6. The waveguide according to claim 5, wherein a cross-sectional area of the second cavity segment gradually increases from one end away from the second port to one end close to the second port.

7. The waveguide according to claim 5 or 6, wherein at least one cavity surface of the first cavity segment is inclined toward a center line of the first cavity segment; and/or
at least one cavity surface of the second cavity segment is inclined toward a center line of the second cavity segment.

8. The waveguide according to claim 5 or 6, wherein at least one cavity surface of the first cavity segment is a stepped surface; and/or
at least one cavity surface of the second cavity segment is a stepped surface.

9. The waveguide according to any one of claims 1 to 8, wherein a cut-off surface further exists inside the base, the second waveguide cavity extends to the cut-off surface in a direction away from the third port, and a projection of the cut-off surface onto a cavity surface of the first waveguide cavity is located between the first port and the connection structure; and
the waveguide further comprises an impedance matching structure that protrudes from a cavity surface of the second waveguide cavity, the impedance matching structure is opposite to the connection structure, the impedance matching structure comprises a first convex part disposed on the cavity surface of the second waveguide cavity and a second convex part disposed on the first convex part, a size of the second convex part in a third direction is less than a size of the first convex part in the third direction, and the third direction is an extension direction of the first waveguide cavity.

10. The waveguide according to any one of claims 1 to 9, wherein a distance between a center of the third port and a center of the second port is greater than a distance between a center of a cross section that is of the second waveguide cavity and that is taken along a plane and a center of a cross section that is of the first waveguide cavity and that is taken along the plane, and the plane is located between the connection structure and the second port.

11. The waveguide according to claim 10, wherein one end that is of at least a part of a cavity segment of the second waveguide cavity and that is close to the third port is inclined toward a direction away from the first waveguide cavity.

12. The waveguide according to claim 10 or 11, wherein the second waveguide cavity comprises a third cavity segment close to the third port and a fourth cavity segment connected to one end that is of the third cavity segment and that faces away from the third port, one end that is of the fourth cavity segment and that is close to the third cavity segment is inclined toward the direction away from the first waveguide cavity, and an extension direction of the third cavity segment is the same as the extension direction of the first waveguide cavity.

13. The waveguide according to any one of claims 1 to 12, wherein the first surface is opposite to the second surface.

14. The waveguide according to any one of claims 1 to 13, wherein there are at least two second waveguide cavities, there are at least two connection structures, and the at least two second waveguide cavities are separately connected to the first waveguide cavity through the at least two connection structures.

15. The waveguide according to claim 14, wherein the at least two second waveguide cavities are arranged around the first waveguide cavity in an array with the first waveguide cavity as a center.

16. A communication system, comprising an antenna, a signal processor, and the waveguide according to any one of claims 1 to 15, wherein the waveguide is connected between the antenna and the signal processor.

Drawing