WO2024082951A1

WO2024082951A1 - Waveguide and communication system

Info

Publication number: WO2024082951A1
Application number: PCT/CN2023/122330
Authority: WO
Inventors: 任田昊; 孙科
Original assignee: 华为技术有限公司
Priority date: 2022-10-18
Filing date: 2023-09-27
Publication date: 2024-04-25
Also published as: CN117954818A

Abstract

Provided in the present application are a waveguide and a communication system. The waveguide may comprise a base body, wherein a first waveguide cavity, a second waveguide cavity and a connection structure are provided inside the base body. The base body has a first surface and a second surface, wherein the first surface is provided with a first port, and the second surface is provided with a second port and a third port, the first port and the second port respectively being in communication with the first waveguide cavity, the third port being in communication with the second waveguide cavity, and the second waveguide cavity being in communication with the first waveguide cavity by means of the connection structure. The area of a first cross-section of the first waveguide cavity is greater than the area of a second cross-section of the first waveguide cavity, the second cross-section being located between the connection structure and the second port, and the first cross-section being farther away from the second port than the second cross-section. By means of the present application, an original signal which enters a waveguide can be branched into a first branch signal and a second branch signal, and the power difference and phase difference between the first branch signal and the second branch signal can be adjusted, such that the power difference meets a power difference requirement, and the phase difference meets a phase difference requirement.

Description

A waveguide and communication system

This application claims the priority of the Chinese patent application filed with the China Patent Office on October 18, 2022, with application number 202211272215.X and application name “A waveguide and communication system”, the entire contents of which are incorporated by reference in this application.

Technical Field

The present application relates to the field of communication technology, and in particular to a waveguide and a communication system.

Background technique

The communication system usually includes an antenna, a signal processor, and a waveguide connected between the antenna and the signal processor. The antenna may include multiple feed sources, each of which transmits the received signal to the signal processor through the waveguide. After the signal processor processes the signal, it sends the processed signal to the waveguide, and the waveguide divides the received signal into multiple branch signals, which are sent to multiple feed sources respectively and radiated by each feed source.

In the related art, the multi-branch signals output by the waveguide include a first branch signal and multiple second branch signals. The waveguide can adjust the power of the second branch signal to obtain a specific power difference between the first branch signal and the second branch signal. Since there is a certain relationship between the phase difference and the power difference between the first branch signal and the second branch signal, a specific phase difference will be obtained while adjusting the power, but the phase difference often does not meet the phase difference requirement. Therefore, in actual use, it is often necessary to additionally install a connecting waveguide between the waveguide and the antenna to meet the required phase difference. However, the additional connecting waveguide affects the power difference, which in turn causes the power difference to not meet the power difference requirement.

Summary of the invention

The present application provides a waveguide and a communication system, which can branch an original signal entering the waveguide into a first branch signal and a second branch signal, and can adjust the power difference between the first branch signal and the second branch signal so that the power difference meets the power difference requirement, and adjust the phase difference between the first branch signal and the second branch signal so that the phase difference meets the phase difference requirement.

In the first aspect, the present application provides a waveguide, which can be applied to a communication system. Specifically, it can be applied to a communication system for transmitting signals from a base station to a relay station. In addition to the waveguide, the communication system may also include an antenna and a signal processor, wherein the waveguide is connected between the antenna and the signal processor. The antenna may include a main reflector, a sub-reflector, and a first feed and a second feed located between the main reflector and the sub-reflector. The sub-reflector receives the signal transmitted back from the base station, and transmits it to the main reflector after passing through the first feed and the second feed, and then transmits it to the signal processor through the waveguide. After the signal processor processes all received signals, it transmits them to the antenna through the waveguide and radiates the signal through the antenna.

The waveguide may include: a substrate, wherein a first waveguide cavity, a second waveguide cavity and a connecting structure are provided inside the substrate. The substrate has a first surface and a second surface, a first port is provided on the first surface, and a second port and a third port are provided on the second surface, wherein the first port and the second port are respectively connected to the first waveguide cavity, the third port is connected to the second waveguide cavity, and the second waveguide cavity is connected to the first waveguide cavity through the connecting structure. The area of the first cross section of the first waveguide cavity is greater than the area of the second cross section of the first waveguide cavity, the second cross section is located between the connecting structure and the second port, and the first cross section is farther away from the second port than the second cross section. It can be understood that, assuming that the first waveguide cavity extends along a third direction, the first cross section and the second cross section are both perpendicular to the third direction. The first cross section and the second cross section can both be rectangular. The cross sections of the connecting structure and the second waveguide cavity can also be rectangular.

When the waveguide is used in a communication system, the first port is used to connect to the signal processor, the second port and the third port are both used to connect to the antenna, and the second port is connected to the first feed source, and the third port is connected to the second feed source. The initial signal emitted from the signal processor enters the first waveguide cavity from the first port, and then in the process of transmitting forward in the first waveguide cavity, at least two branch signals are branched out when passing through the connecting structure, namely the first branch signal and the second branch signal. Among them, the first branch signal continues to transmit forward in the first waveguide cavity, and is transmitted to the first feed source in the antenna through the second port; the second branch signal is transmitted to the second waveguide cavity after passing through the connecting structure, and is transmitted forward to the third port in the second waveguide cavity, and is transmitted to the second feed source in the antenna through the third port. After the second branch signal enters the second waveguide cavity through the connecting structure, its power will change; while the original signal and the branched first branch signal are always transmitted in the first waveguide cavity, so their power has hardly changed. Therefore, the second branch signal output from the third port is different from the second branch signal output from the second port. There is a power difference between the power of the branch signals, and the power difference can be adjusted by adjusting the cross-sectional area of the connection structure.

In addition, since 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, that is, a part of the area of the first waveguide cavity is in a closed shape from the first port to the second port, so that the closed structure can provide a certain 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 the impedance provided by the second waveguide cavity for the second branch signal, so that the phase of the first branch signal output from the second port and the phase of the second branch signal output from the third port have a difference, that is, the present application can make the phase difference between the first branch signal and the second branch signal. Moreover, the numerical value of the phase difference can be adjusted by adjusting the difference between the area of the first cross section and the area of the second cross section. In the present application, the power difference and phase difference of the first branch signal and the second branch signal can be adjusted respectively, so that the power difference meets the power difference requirement, and the phase difference meets the phase difference requirement.

In some embodiments, the area of the second cross section is smaller than the area of the end face of the first waveguide cavity at the second port. Since the second cross section is located between the second port and the connection structure, when the area of the second cross section is smaller than the area of the end face of the first waveguide cavity at the second port, the first waveguide cavity is open from the second cross section to the second port. For the first waveguide cavity, it is closed from the first cross section to the second cross section, and closed from the second cross section to the second port. Therefore, the area of the cross section of the first waveguide cavity decreases first and then increases. Since the first port needs to be connected to the waveguide connector of the signal processor, the second port also needs to be connected to the waveguide connector of the first feed source of the antenna, and the waveguide connector is usually a standardized fixed size. When the area of the cross section of the first waveguide cavity decreases first and then increases, the area of the first port and the area of the second port at both ends of the first waveguide cavity can be made to adopt the same size. More specifically, the first port and the second port can be set to the same shape and size, so that the waveguide is better applied to the waveguide connector with standardized size.

In some embodiments, the size of the first section along the first direction is greater than the size of the second section along the first direction, and the size of the first section along the second direction is the same as the size of the second section along the second direction. It can be understood that the first direction is perpendicular to the third direction. The first direction may refer to the width direction of the first waveguide cavity section, and the second direction may refer to the length direction of the first waveguide cavity section. In this way, the area of the first section may be greater than the area of the second section by setting the size of the first section along the first direction to be greater than the size of the second section along the first direction. When the size of the first section along the second direction is the same as the size of the second section along the second direction, the cavity surface of the first waveguide cavity perpendicular to the second direction may be a plane as a whole, and the size between the plane and the center line of the first waveguide cavity is the same everywhere, thereby reducing the difficulty of processing the cavity surface of the first waveguide cavity.

In some other embodiments, the size of the first cross section along the second direction is greater than the size of the second cross section along the second direction, and the size of the first cross section along the first direction is the same as the size of the second cross section along 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 refer to the length direction of the first waveguide cavity cross section.

In other embodiments, a size of the first cross section along the first direction is greater than a size of the second cross section along the first direction, and a size of the first cross section along the second direction is greater than a size of the second cross section along the second direction.

In some embodiments, the size of the second cross section along the first direction is smaller than the size of the end face along the first direction, the size of the second cross section along the second direction is the same as the size of the end face along the second direction, and the second direction is perpendicular to the first direction. In this way, the size of the second cross section along the first direction can be set to be smaller than the size of the end face along the first direction, so that the area of the second cross section is smaller than the area of the end face. When the size of the second cross section along the second direction is the same as the size of the end face along the second direction, the cavity surface of the first waveguide cavity perpendicular to the second direction can be a plane as a whole, and the size between the plane and the center line of the first waveguide cavity is the same everywhere, thereby reducing the difficulty of processing the cavity surface of the first waveguide cavity.

In other embodiments, the size of the second cross section along the second direction is smaller than the size of the end surface along the second direction, and the size of the second cross section along the first direction is the same as the size of the end surface along the first direction.

In other embodiments, a size of the second cross section along the first direction is smaller than a size of the end surface along the first direction, and a size of the second cross section along the second direction is smaller than a size of the end surface along the second direction.

In some embodiments, the first waveguide cavity includes a first cavity section and a second cavity section near the second port, the first cavity section is connected to an end of the second cavity section away from the second port; the cross-sectional area of the first cavity section gradually decreases from the end away from the second port to the end near the second port. In this way, the first cavity section gradually closes from the end away from the second port to the end near the second port, and the cross-sectional area is in a gradual state rather than a sudden change state, thereby avoiding the problem of signal energy loss caused by a sudden change in the cross-sectional area.

In some embodiments, the cross-sectional area of the second cavity segment gradually increases from the end away from the second port to the end close to the second port. In this way, the second cavity segment is open from the end away from the second port to the end close to the second port, and the cross-sectional area is in a gradual state rather than a sudden change state, thereby avoiding the problem of signal energy loss caused by a sudden change in the cross-sectional area.

In some embodiments, at least one cavity surface in the first cavity segment is inclined toward the center line of the first cavity segment; and/or at least one cavity surface in the second cavity segment is inclined toward the center line of the second cavity segment. The first cavity segment may include four cavity surfaces connected end to end and enclosed in a closed shape, one of the four cavity surfaces is inclined toward the center line of the first cavity segment, or two of the cavity surfaces are inclined toward the center line of the first cavity segment. The cavity surface is inclined, or three of the 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 can 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.

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.

In some embodiments, the interior of the substrate further comprises a cut-off surface, the second waveguide cavity extends to the cut-off surface in a direction away from the third port, and the projection of the cut-off surface on the cavity surface of the first waveguide cavity is located between the first port and the connection structure; the waveguide further comprises an impedance matching structure convexly arranged on the 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 portion arranged on the cavity surface of the second waveguide cavity and a second convex portion arranged on the first convex portion, the dimension of the second convex portion along the third direction is smaller than the dimension of the first convex portion along the third direction, and the third direction is the extension direction of the first waveguide cavity. Since the projection of the cut-off surface on 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 and the third port in the second waveguide cavity, that is, a part of the second waveguide cavity is located on one side of the connection structure, and the second part of the second waveguide cavity is located on the other side of the connection structure. When 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 another 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 cutoff surface provides impedance for part of the second branch signal that enters the first part of the second waveguide cavity and is transmitted to the cutoff surface, so that the second branch signal is in a high impedance state. In this way, there is no need to connect an additional matching load to the second branch signal, thereby simplifying the structure of the waveguide and reducing the cost of the communication system.

In some embodiments, 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 of the second waveguide cavity taken along a plane and the center of the cross section of the first waveguide cavity taken along a plane, and the plane is located between the connecting structure and the second port. The center of the first feed and the center of the second feed in the antenna usually have a large spacing, and when the first waveguide cavity and the second waveguide cavity in the waveguide both adopt standardized waveguide cavity sizes, the size of the second port is the same as the size of the third port. Then, the distance between the center of the first feed and the center of the second feed is greater than the sum of the distance from the center of the second port to its edge and the distance from the center of the third port to its edge. 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 of the second waveguide cavity taken along a plane and the center of the cross section of the first waveguide cavity taken along the same plane, then the distance between the center of the third port and the center of the second port is greater than the sum of the distance from the center of the second port to its edge and the distance from the center of the third port to its edge, thereby making the distance between the center of the third port and the center of the second port match the distance between the center of the first feed and the center of the second feed, without the need to install connecting waveguides on the second port and the third port to match the above two distances. Therefore, the structure of the communication system can be further simplified and the cost can be reduced.

In some embodiments, an end of at least a portion of the second waveguide cavity near the third port is tilted toward a direction away from the first waveguide cavity. In this way, the distance between the end of at least a portion of the second waveguide cavity near the third port and the center line of the first waveguide cavity is greater than the distance between the end of at least a portion of the second waveguide cavity far from the third port and the center line of the first waveguide cavity, thereby facilitating the distance between the center of the second port and the center of the third port to match the distance between the center of the first feed source and the center of the second feed source.

In some embodiments, the second waveguide cavity includes a third cavity section near the third port and a fourth cavity section connected to one end of the third cavity section away from the third port, the end of the fourth cavity section near the third cavity section is inclined in a direction away from the first waveguide cavity, and the extension direction of the third cavity section is the same as the extension direction of the first waveguide cavity. In this way, while ensuring 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 source and the center of the second feed source, the connection mutation point between the third cavity section and the fourth cavity section can be located inside the waveguide. In this way, when setting the phase difference and power difference, the influence of the connection mutation point between the third cavity section and the fourth cavity section can be fully considered, so that the power difference and phase difference between the first branch signal and the second branch signal output from the waveguide are consistent with the power difference and phase difference between the first branch signal and the second branch signal entering the antenna.

In some other embodiments, the center line of the second waveguide cavity is a straight line, and there is an angle between the center line of the second waveguide cavity and an extension line of the center line of the first waveguide cavity.

In some embodiments, the first surface is opposite to the second surface. Since the first port is located on the first surface and the second port is located on the second surface, when the first surface and the second surface are opposite, the first port and the second port can be arranged relative to each other, that is, the center of the first port and the center of the second port are located on the same straight line. In this way, the center line of the first waveguide cavity is a straight line, thereby reducing the problem of energy loss of the first branch signal caused by the bending of the first waveguide cavity.

In some embodiments, the number of the second waveguide cavities is at least two, the number of the connecting structures is at least two, and the at least two second waveguide cavities are connected to the first waveguide cavity through at least two connecting structures. In this way, the number of the second waveguide cavities can be the same as the number of feed sources in the antenna. When the feed source includes a first feed source and two second feed sources, the number of the second waveguide cavities can be two, wherein the first waveguide cavity The first waveguide cavity is connected to the first feed source through the second port, and the two second waveguide cavities are connected to the two second feed sources through their respective second ports.

In some embodiments, at least two second waveguide cavities are arranged around the first waveguide cavity in an array with the first waveguide cavity as the center. Since the multiple second feed sources in the antenna are arranged around the first feed source in an array with the first feed source as the center, the second waveguide cavity can be directly connected to the second feed source through the third port without installing other connecting waveguides.

In a second aspect, the present application provides a communication system, comprising an antenna, a signal processor and any of the above waveguides, wherein the waveguide is connected between the antenna and the signal processor. The communication system can achieve all the effects of the above waveguides.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

FIG1 is a diagram of an application scenario proposed in an embodiment of the present application;

FIG2 is a schematic diagram of the structure of a communication system provided in an embodiment of the present application;

FIG3 is a schematic diagram of the structure of a waveguide in the related art;

FIG4 is a schematic diagram of the structure of a waveguide in a first embodiment of the present application at a first viewing angle;

FIG5 is a schematic diagram of the structure of the waveguide shown in FIG4 at a second viewing angle;

FIG6 is a schematic structural diagram of the waveguide shown in FIG4 at a third viewing angle;

FIG7 is a half-sectional view of the waveguide shown in FIG4;

FIG8 is a partial enlarged schematic diagram of point A in FIG7;

FIG9 is a cross-sectional schematic diagram of a waveguide in a second embodiment of the present application;

FIG10 is a cross-sectional schematic diagram of a waveguide in a third embodiment of the present application;

FIG11 is a cross-sectional schematic diagram of a waveguide in a fourth embodiment of the present application;

FIG12 is a cross-sectional schematic diagram of a waveguide in a fifth embodiment of the present application;

FIG13 is a cross-sectional schematic diagram of a waveguide in a sixth embodiment of the present application.

Figure 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 device; 20-waveguide; 21-substrate; 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 mounting hole; 213-second boss; 2130-second mounting hole; 214-first surface; 2141-first port; 215-second surface surface; 2152-second port; 2153-third port; 2154-fourth port; 22-first waveguide cavity; 221-fifth cavity section; 222-first cavity section; 223-second cavity section; 224-first cavity surface; 225-second cavity surface; 23-second waveguide cavity; 231-sixth cavity section; 232-fourth cavity section; 233-third cavity section; 24-third waveguide cavity; 241-seventh cavity section; 242-ninth cavity section; 243-eighth cavity section; 25-connecting structure; 251-first connecting structure; 252-second connecting structure; 26-cutoff surface; 261-first cutoff surface; 262-second cutoff surface; 27-first impedance matching structure; 271-first convex portion; 272-second convex portion; 28-second impedance matching structure.

Detailed ways

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

The term "and/or" in this article is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

The terms "first" and "second" in the description and claims of the embodiments of the present application are used to distinguish different objects rather than to describe a specific order of objects. For example, a first target object and a second target object are used to distinguish different target objects rather than to describe a specific order of target objects.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more than two. For example, multiple processing units refer to two or more processing units; multiple systems refer to two or more systems.

Microwaves are a type of electromagnetic waves, and the frequency range of microwaves is 300MHz-300GHz. E-band microwaves are a type of microwave, and their frequency range includes 71GHz-76GHz and 81GHz-86GHz. E-band microwaves are microwaves that are used more frequently in the process of transmitting the signal of the base station back to the repeater or central station. The base station can use a point-to-point communication method to transmit the signal back to the repeater 13 or the central station. When the station is actually deployed, that is, as shown in FIG1, when the communication system 12 is arranged between the base station 11 and the repeater 13, the number of communication systems 12 between the base station 11 and the relay station 13 can be determined based on the distance between the base station 11 and the relay station 13, and the transmission distance of the communication system 12 to the signal. For example, as shown in FIG1, two communication systems 12 are arranged between the base station 11 and the relay station 13, and the base station 11 transmits the signal to be transmitted back to the relay station 13 through the two communication systems 12 in turn.

As shown in FIG2 , the communication system 12 generally includes an antenna 14 and a signal processor 15. The antenna 14 mainly uses a high-gain parabolic antenna. In actual use, there is often an interference problem with the communication system 12, so the directional pattern of the parabolic antenna is required to have the characteristics of low side lobes. The signal processor 15 can be an E-band device.

As shown in FIG2 , the antenna 14 may include a main reflector 141, a sub-reflector 142, and a plurality of feed sources 143 located between the main reflector 141 and the sub-reflector 142. For ease of description, the plurality of feed sources 143 include a first feed source 1431, a second feed source 1432, and a third feed source 1433. The main reflector 141 receives the signal returned by the base station 11, and reflects it to the sub-reflector 142, which reflects it to the first feed source 1431, the second feed source 1432, and the third feed source 1433, and then transmits it to the signal processor 15. The signal processor 15 processes all received signals, and then transmits the processed signals to the antenna 14, and the antenna 14 radiates the signals.

In order to make the antenna 14 have the characteristics of low side lobe, the structure of the optimized feed source 143, the main reflector 141 and the sub-reflector 142 is usually adopted to achieve this, but the low side lobe performance of the antenna 14 is still poor after optimization. Therefore, as shown in FIG2, a signal processing device 16 can also be added between the antenna 14 and the signal processor 15, and the power and phase of the signal can be adjusted to make the electromagnetic field superimposed in the spatial position, so as to increase or decrease the energy in the required direction, thereby achieving better low side lobe performance. The signal processing device 16 can be an active signal processing device 16 or a passive signal processing device 16. When an active signal processing device 16 is adopted, the active signal processing device 16 can include active devices such as a frequency modulator and a phase shifter, so as to branch the original signal received from the signal processor 15 into multiple branch signals, and process each branch signal through the frequency modulator so that there is a power difference between one branch signal and other branch signals; and process each branch signal through the phase shifter so that there is a phase difference between one branch signal and other branch signals. The advantage of the active signal processing device 16 is that it can flexibly realize the required amplitude and phase weights, but its disadvantage is that the cost is relatively high.

The passive signal processing device 16 can be, for example, a waveguide 20 as shown in FIG3 , which has no power supply and is mainly used to branch the signal sent by the signal processor 15 into multiple branch signals, and adjust the power and phase of some branch signals in the multiple branch signals so that there is a power difference and phase difference between one branch signal and other branch signals. Due to its low cost, it is widely used.

In the related art, as shown in FIG3 , the waveguide 20 includes a substrate 21, on the surface of which are arranged a first input port 2111, a second input port 2112 and a third input port 2113 located on both sides of the first input port 2111, a first output port 2121 communicating with the first input port 2111, a second output port 2122 communicating with the second input port 2112, and a third output port 2123 communicating with the third input port 2113. The first input port 2111 is used 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 used to connect to the first feed source 1431, the second feed source 1432, and the third feed source 1433 in the antenna 14, respectively. The second input port 2112 and the third input port 2113 are respectively connected to the external matching waveguide 20, and the standard matching load of the corresponding frequency band can be transmitted to the second input port 2112 and the third input port 2113 through the matching waveguide 20.

As shown in FIG3 , the interior of the substrate 21 has a first waveguide cavity 22, a second waveguide cavity 23 and a third waveguide cavity 24. The two ends of the first waveguide cavity 22 are respectively connected to the first input port 2111 and the first output port 2121, the two ends of the second waveguide cavity 23 are respectively connected to the second input port 2112 and the second output port 2122, and the two ends of the third waveguide cavity 24 are respectively connected to the third input port and the third output port 2123. The second waveguide cavity 23 and the third waveguide cavity 24 are respectively connected to the first waveguide cavity 22. It can be understood that in FIG3 , the dotted lines represent the contour lines located inside the substrate 21 but blocked by the entity and cannot be seen from the outside.

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

In the related art, the waveguide 20 can adjust the power of the second branch signal by adjusting the size of the connection between the first waveguide cavity 22 and the second waveguide cavity 23 to obtain a specific power difference between the first branch signal and the second branch signal; and adjust the power of the third branch signal by adjusting the size of the connection between the first waveguide cavity 22 and the third waveguide cavity 24 to obtain a specific power difference between the first branch signal and the third branch signal. Since there is a certain relationship between the phase difference and the power difference of the two signals, a specific phase difference will be obtained while adjusting the power, but the phase difference often does not meet the phase difference requirement. Therefore, in actual use, it is often necessary to additionally install a connecting waveguide between the waveguide 20 and the antenna 14 to meet the required phase difference, but the additional connecting waveguide affects the power difference, which in turn causes the power difference to not meet the power difference requirement.

Based on this, as shown in FIG4 , an embodiment of the present application provides a waveguide 20, and the waveguide 20 may include: a substrate 21. The substrate 21 includes a body 211 and a first boss 212 fixed to both ends of the body 211 and a second boss 213 shown in FIG5 . A plurality of first mounting holes 2120 are provided on the first boss 212, and the plurality of first mounting holes 2120 are used to be fixedly connected to the signal processor 15 shown in FIG2 . As shown in FIG5 , a plurality of second mounting holes 2130 are also provided on one end of the body 211 that fixes the second boss 213, and the plurality of second mounting holes 2130 are used to be fixedly connected to the antenna 14 shown in FIG2 .

For ease of description, as shown in FIG4 , three directions may be defined, namely, the X direction (first direction), the Y direction (second direction), and the Z direction (third direction), wherein the Z direction represents the length direction of the waveguide 20 , the X direction represents the width direction of the waveguide 20 , and the Y direction represents the height direction of the waveguide 20 .

As shown in FIG6 , the substrate 21 has a first surface 214 and a second surface 215 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 FIG4 , a first port 2141 is provided on the first surface 214. As shown in FIG5 , 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 are all of the same shape and size. When the waveguide 20 is applied to the communication system 12, it can be fixed to the signal processor 15 through the plurality of first mounting holes 2120 on the first boss 212, and the first port 2141 can be connected to the signal processor 15 through a waveguide connector. It can be fixedly connected to the antenna 14 through multiple second mounting holes 2130, and the second port 2152, the third port 2153 and the fourth port 2154 can be respectively connected to the first feed source 1431, the second feed source 1432 and the third feed source 1433 of the antenna 14 through three waveguide connectors.

As shown in FIG. 6 , the first port 2141 and the second port 2152 are opposite to each other, that is, the center of the first port 2141 and the center of the second port 2152 are located on the same straight line.

As shown in FIG. 2 , since the second feed 1432 and the third feed 1433 are distributed on both sides of the first feed 1431, that is, the second feed 1432, the first feed 1431 and the third feed 1433 are arranged along the X direction, in order to simplify the structure of the waveguide 20 connector and the structure of the connecting device between the waveguide 20 and the antenna 14, as shown in FIG. 5 , the third port 2153 and the fourth port 2154 can be distributed on both sides of the second port 2152.

As shown in Fig. 7, the interior of the base 21 is provided with a first waveguide cavity 22, a second waveguide cavity 23, a third waveguide cavity 24 and two connecting structures 25. In this embodiment, the cross-sectional shapes of the first waveguide cavity 22, the second waveguide cavity 23, the third waveguide cavity 24 and the two connecting structures 25 can all be rectangular. The cross section of the first waveguide cavity 22 can refer to the cross section of the first waveguide cavity 22 taken along a surface perpendicular to the Z direction.

As shown in Fig. 7, the second waveguide cavity 23 and the third waveguide cavity 24 are connected to the first waveguide cavity 22 through two connecting structures 25, respectively, and the second waveguide cavity 23 and the third waveguide cavity 24 are respectively located on both sides of the first waveguide cavity 22. For ease of description, the two connecting structures 25 are named as the first connecting structure 251 and the second connecting structure 252, respectively, wherein the first connecting structure 251 is connected between the first waveguide cavity 22 and the second waveguide cavity 23, and the second connecting structure 252 is connected between the first waveguide cavity 22 and the third waveguide cavity 24.

As shown in Fig. 7, the first port 2141 and the second port 2152 are respectively connected to the two ends of the first waveguide cavity 22, the third port 2153 is connected to the second waveguide cavity 23, and the fourth port 2154 is connected to the third waveguide cavity 24. The initial signal sent from the signal processor 15 enters the first waveguide cavity 22 from the first port 2141, and then in the process of forward transmission in the first waveguide cavity 22, three branch signals are branched out when passing through the first connection structure 251 and the second connection structure 252, which are the first branch signal, the second branch signal and the third branch signal. Among them, the first branch signal continues to be transmitted forward in the first waveguide cavity 22, and is transmitted to the first feed source 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 connecting structure 251, and is transmitted forward to the third port 2153 in the second waveguide cavity 23, and is transmitted to the second feed source 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 connecting structure 252, and is transmitted forward to the fourth port 2154 in the third waveguide cavity 24, and is transmitted to the third feed source 1433 in the antenna 14 through the fourth port 2154.

After the second branch signal passes through the first connection structure 251 and enters the second waveguide cavity 23, its power will change. After passing through the second connection structure 252 and then the third waveguide cavity 24, its power will also change, while the first branch signal branched out is always transmitted in the first waveguide cavity 22, and its power has almost no change, therefore, there is a power difference between the second branch signal output from the third port 2153 and the first branch signal output from the second port 2152; there is a power difference between the third branch signal output from the fourth port 2154 and the first branch signal output from the second port 2152. Moreover, the numerical value of the power difference between the second branch signal and the first branch signal can be adjusted by adjusting the cross-sectional area of the first connection structure 251, and the numerical value of the power difference between the third branch signal and the first branch signal can be adjusted by adjusting the cross-sectional area of the second connection structure 252.

The dotted line in the middle of FIG7 represents the center line a1 of the first waveguide cavity. As shown in FIG7 , the center line a1 of the first waveguide cavity 22 can be a straight line, and the first waveguide cavity 22 extends along the Z direction. In this way, the problem of energy loss of the first branch signal caused by the bending of the first waveguide cavity 22 can be reduced.

As shown in FIG7 , the first waveguide cavity 22 includes a fifth cavity section 221 near the first port 2141, a second cavity section 223 near the second port 2152, and a first cavity section 222 located between the fifth cavity section 221 and the second cavity section 223. The first connection structure 251 and the second connection structure 252 are both connected to the fifth cavity section 221. After the initial signal emitted from the signal processor 15 enters the first waveguide cavity 22 from the first port 2141, it first enters the fifth cavity section 221, and branches into a first branch signal, a second branch signal, and a third branch signal when passing through the first connection structure 251 and the second connection structure 252, wherein the first branch signal continues to be transmitted forward in the fifth cavity section 221, and enters the first cavity section 222 and the second cavity section 223 in sequence, and then is output from the second port 2152.

The cross-sectional area of the fifth cavity segment 221 is the same everywhere. As shown in FIG. 7 , the area of the first cross-section of the first cavity segment 222 is greater than the area of the second cross-section of the first cavity segment 222 , the second cross-section is located between the connecting 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 the end of the first cavity segment 222 away from the second cavity segment 223 , and the second cross-section may be a cross-section of the end of the first cavity segment 222 close to the second cavity segment 223 . In one embodiment, 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 , that is, as shown in FIG. 8 , the cross-sectional area of the first cavity segment 222 gradually decreases in the direction of the Z direction. In this way, the first cavity segment 222 gradually closes from the end away from the second port 2152 to the end close to the second port 2152 , and the cross-sectional area is in a gradual state rather than a sudden change state, thereby avoiding the problem of energy loss of the signal due to a sudden change in the cross-sectional area.

As shown in FIG7 , when the cross-sectional area of the first cavity section 222 gradually decreases from the end away from the second port 2152 to the end close to the second port 2152, the first cavity section 222 is closed from the end connected to the fifth cavity section 221 to the end connected to the second cavity section 223. In this way, the closed structure can provide a certain impedance for the first branch signal transmitted in the first cavity section 222, so that the impedance provided by the first cavity section 222 for the first branch signal is different from the impedance provided by the second waveguide cavity 23 for the second branch signal, thereby making the phase of the first branch signal output from the second port 2152 and the phase of the second branch signal output from the third port 2153 have a difference, that is, the embodiment of the present application can make the phase difference between the first branch signal and the second branch signal, and the numerical value of the phase difference can be adjusted by adjusting the difference between the area of the first cross section and the area of the second cross section. In the embodiment of the present application, the power difference and phase difference of the first branch signal and the second branch signal can be adjusted respectively, so that the power difference meets the power difference requirement, and the phase difference meets the phase difference requirement. In addition, the fluctuation of the power difference generated by the embodiment of the present application is less than or equal to 0.5dB, the fluctuation of the phase difference is less than or equal to 10°, and the loss is less than or equal to 0.5dB.

In a possible implementation, the size of the first cavity segment 222 along 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 the size of the first cavity segment 222 along the second direction is the same everywhere. In this way, the size of the first cavity segment 222 along the first direction can be set to gradually decrease, so that the cross-sectional area of the first cavity segment 222 gradually decreases. When the size of the first cavity segment 222 along the second direction is the same everywhere, the cavity surface perpendicular to the second direction on the first waveguide cavity 22 can be a plane as a whole, and the size between the plane and the center line a1 of the first waveguide cavity 22 is the same everywhere, thereby reducing the difficulty of processing the cavity surface of the first waveguide cavity 22.

As shown in FIG8 , the first cavity segment 222 includes a first cavity surface 224, a second cavity surface 225, a third cavity surface (not shown in FIG8 ), and a fourth cavity surface (not shown in FIG8 ) which are connected end to end to form a quadrilateral shape. Among them, the first cavity surface 224 and the second cavity surface 225 are opposite, and the third cavity surface and the fourth cavity surface are opposite. The third cavity surface and the fourth cavity surface are both parallel to the Z direction. The first cavity surface 224 and the second cavity surface 225 are both 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.

In another possible implementation, the size of the first cavity segment 222 along 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 the size of the first cavity segment 222 along the first direction is the same everywhere. The first cavity surface 224 and the second cavity surface 225 are both parallel to the Z direction. The third cavity surface and the fourth cavity surface are both inclined toward the center line a1 of the first cavity segment 222, or 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 Inclined toward the center line a1 of the first cavity segment 222 .

In another possible implementation, the size of the first cavity segment 222 along 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 the size of the first cavity segment 222 along 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.

As shown in FIG7 , the cross-sectional area of the end of the second cavity segment 223 away from the second port 2152 is smaller than the end surface area of the second cavity segment 223 at the second port 2152. In one embodiment, the 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, that is, as shown in FIG8 , 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 open from the end away from the second port 2152 to the end close to the second port 2152, and the cross-sectional area is in a gradual state rather than a sudden change, thereby avoiding the problem of signal energy loss caused by a sudden change in the cross-sectional area.

When the cross-sectional area of the end of the second cavity section 223 away from the second port 2152 is smaller than the end surface area of the second cavity section 223 at the second port 2152, the second cavity section 223 is open from the end connected to the first cavity section 222 to the end connected to the second port 2152. For the first waveguide cavity 22, the cross-sectional area of the first waveguide cavity 22 remains unchanged at first, then gradually decreases, and then gradually increases. Since the first port 2141 needs to be connected to the waveguide connector of the signal processor 15, the second port 2152 also needs to be connected to the waveguide connector of the first feed source 1431 of the antenna 14, and the waveguide connector is usually a standardized fixed size. When the cross-sectional area of the first waveguide cavity 22 remains unchanged at first, then decreases, and then increases, it is convenient to make the area of the first port 2141 and the area of the second port 2152 at both ends of the first waveguide cavity 22 adopt the same size, more specifically, it is convenient to set the first port 2141 and the second port 2152 to the same shape and size, so that the waveguide 20 is better applied to the waveguide 20 connector with standardized size.

In a possible implementation of the present application, the size of the second cavity segment 223 along 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 along the second direction is the same everywhere. In this way, the size of the second cavity segment 223 along the first direction can be set to be smaller than the size of the end face along the first direction, so that the area of the second cavity segment 223 is smaller than the area of the end face. When the size of the second cavity segment 223 along the second direction is the same as the size of the end face along the second direction, the cavity surface of the first waveguide cavity 22 perpendicular to the second direction can be a plane as a whole, and the size between the plane and the center line a1 of the first waveguide cavity 22 is the same everywhere, thereby reducing the difficulty of processing the cavity surface of the first waveguide cavity 22.

In another possible implementation of the present application, the size of the second cavity segment 223 along 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 the size of the second cavity segment 223 along the first direction is the same everywhere.

In another possible implementation of the present application, the size of the second cavity segment 223 along 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 along the second direction gradually increases from the end connected to the first cavity segment 222 to the end connected to the second port 2152.

The second cavity segment 223 may include four cavity surfaces connected end to end in sequence to form a quadrilateral 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 cavity surfaces are inclined toward the center line a1 of the first cavity segment 222, or three of the cavity surfaces are inclined toward the center line a1 of the first cavity segment 222, or all 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.

As shown in FIG7 , the interior of the base body 21 also has two cut-off surfaces 26, which are respectively located on both sides of the first waveguide cavity 22. The projections of the two cut-off surfaces 26 on 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 as the first cut-off surface 261 and the second cut-off surface 262. Among them, 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 and the third port 2153 in the second waveguide cavity 23, that is, the first part of the second waveguide cavity 23 is located on one side of the first connection structure 251, and the 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 cutoff surface 262 and the fourth port 2154 in the third waveguide cavity 24 , that is, the first part of the third waveguide cavity 24 is located on one side of the second connection structure 252 , and the second part of the third waveguide cavity 24 is located on the other side of the second connection structure 252 .

As shown in FIG. 7 , the waveguide 20 further includes a first impedance matching structure 27 convexly disposed on 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 portion 271 disposed on the cavity surface of the second waveguide cavity 23 and a second convex portion 272 disposed on the first convex portion 271 toward the second waveguide cavity 23. The size of the second convex portion 272 along the X direction is the same as that of the first convex portion 271. The dimensions of the protrusions 271 along the X direction are the same and are the same as the dimensions of the second waveguide cavity 23 along the X direction. The dimension of the second protrusion 272 along the Z direction is smaller than the dimension of the first protrusion 271 along the Z direction.

As shown in FIG7 , the second waveguide cavity 23 includes a sixth cavity section 231 near the first cutoff surface 261, a third cavity section 233 near the third port 2153, and a fourth cavity section 232 located between the sixth cavity section 231 and the third cavity section 233. The first connection structure 251 is connected to the sixth cavity section 231. After the initial signal sent by the signal processor 15 enters the first waveguide cavity 22 from the first port 2141, it branches out into a first branch signal, a second branch signal, and a 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. When 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 section 231 from one side of the first connection structure 251 and is transmitted to the first cutoff surface 261; another part of the second branch signal enters the third cavity section 233 from the other side of the first connection structure 251 and is output from the third port 2153 through the fourth cavity section 232. The first cutoff surface 261 can provide impedance for part of the second branch signal that enters the sixth cavity segment 231 and is transmitted to the first cutoff surface 261, so that the second branch signal is in a high impedance state. In this way, there is no need to connect an additional matching load to the second branch signal, thereby simplifying the structure of the waveguide 20 and reducing the cost of the communication system 12.

As shown in FIG6 , the distance L1 between the center of the third port 2153 and the center of the second port 2152 is greater than the distance L2 between the center of the cross section of the second waveguide cavity 23 taken along a plane and the center of the cross section of the first waveguide cavity 22 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 distance between the center of the first feed 1431 and the center of the second feed 1432 in the antenna 14. When the first waveguide cavity 22 and the second waveguide cavity 23 in the waveguide 20 both adopt standardized waveguide cavity sizes, the size of the second port 2152 is the same as the size of the third port 2153. Then, the distance between the center of the first feed 1431 and the center of the second feed 1432 is greater than the sum of the distance from the center of the second port 2152 to its edge and the distance from the center of the third port 2153 to its edge. 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 of the second waveguide cavity 23 taken along a plane and the center of the cross section of the first waveguide cavity 22 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 the sum of the distance from the center of the second port 2152 to its edge and the distance from the center of the third port 2153 to its edge, thereby making the distance L1 between the center of the third port 2153 and the center of the second port 2152 match the distance between the center of the first feed source 1431 and the center of the second feed source 1432, without the need to install a connecting waveguide 20 on the second port 2152 and the third port 2153 to match the above two distances. Therefore, the structure of the communication system 12 can be further simplified and the cost can be reduced.

As shown in FIG7 , one end of the fourth cavity segment 232 close to the third cavity segment 233 is inclined in a direction away from the first waveguide cavity 22, and the extension direction of the third cavity segment 233 is the same as the extension direction of the first waveguide cavity 22. In this way, while ensuring 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 source 1431 and the center of the second feed source 1432, the connection mutation point between the third cavity segment 233 and the fourth cavity segment 232 can be located inside the waveguide 20. In this way, when setting the phase difference and power difference, the influence of the connection mutation point between the third cavity segment 233 and the fourth cavity segment 232 can be fully considered, so that the power difference and phase difference between the first branch signal and the second branch signal output from the waveguide 20 are consistent with the power difference and phase difference between the first branch signal and the second branch signal of the feed source 143 entering the antenna 14.

As shown in FIG6 , the third waveguide cavity 24 and the second waveguide cavity 23 are symmetrical structures about 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. One end of the ninth cavity segment 242 close to the eighth cavity segment 243 is inclined in a direction away from the first waveguide cavity 22. The extension direction of the eighth cavity segment 243 is the same as the extension direction of the first waveguide cavity 22.

As shown in Fig. 7, the waveguide 20 further includes a second impedance matching structure 28 protruding from the 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, and will not be described again.

After the initial signal sent from the signal processor 15 enters the first waveguide cavity 22 from the first port 2141, it branches out into a first branch signal, a second branch signal and a 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. When 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 another part of the third branch signal enters the ninth cavity segment 242 from the other side of the second connection structure 252 and then passes through the eighth cavity segment 243 and is output from the fourth port 2154. The second cut-off surface 262 can 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, there is no need to connect an additional matching load to the third branch signal, thereby simplifying the structure of the waveguide 20 and reducing the cost of the communication system 12.

In the embodiment shown in FIG. 9 , the difference from the embodiment shown in FIG. 8 is the structure of the cavity surface 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.

In the embodiment shown in FIG. 10, the difference between the embodiment shown in FIG. 7 is that the third waveguide cavity 24, the second cutoff 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. That is, as shown in FIG. 10, in the embodiment, the second surface 215 of the substrate 21 is provided with the second port 2152 and the third port 2153. The interior of the substrate 21 is provided with the first waveguide cavity 22, the second waveguide cavity 23, the first connection structure 251, the first cutoff surface 261 and the first impedance matching structure 27. The initial signal emitted from the signal processor 15 enters the first waveguide cavity 22 from the first port 2141, and then in the process of forward transmission in the first waveguide cavity 22, two branch signals are branched out when passing through the first connection structure 251, namely the first branch signal and the second branch signal. Among them, the first branch signal continues to be transmitted forward in the first waveguide cavity 22, and is transmitted to the first feed source 1431 in the antenna 14 shown in Figure 2 through the second port 2152; the second branch signal is transmitted to the second waveguide cavity 23 after passing through the first connecting structure 251, and is transmitted forward to the third port 2153 in the second waveguide cavity 23, and is transmitted to the second feed source 1432 in the antenna 14 shown in Figure 2 through the third port 2153.

In other embodiments, the number of second waveguide cavities 23 and third waveguide cavities can be increased based on 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 the center.

In the embodiment shown in FIG. 11, the difference from the embodiment shown in FIG. 7 is the positional relationship between the first surface 214 and the second surface 215, and the extension direction 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 and the second surface 215 are opposite. 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-straight 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 eighth cavity segment 243 of the third waveguide cavity 24 is always the same as the extension direction of the first waveguide cavity 22, that is, first extends along the Z direction and then extends along the X direction.

The embodiment shown in FIG12 is different from the embodiment shown in FIG7 in the structures of the second waveguide cavity 23 and the third waveguide cavity 24. In the embodiment shown in FIG7, the second waveguide cavity 23 includes a sixth cavity segment 231, a fourth cavity segment 232 and a third cavity segment 233, and the end of the fourth cavity segment 232 close to the third cavity segment 233 is inclined in a direction away from the first waveguide cavity 22, and the third cavity segment 233 extends in the same direction as the first cavity segment 222. In this embodiment, as shown in FIG12, the second waveguide cavity 23 includes a sixth cavity segment 231 close to the first cutoff surface 261 and a 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.

In the embodiment shown in FIG7 , the third waveguide cavity 24 includes a seventh cavity segment 241, a ninth cavity segment 242, and an eighth cavity segment 243. The end of the ninth cavity segment 242 close to the eighth cavity segment 243 is inclined in a direction away from the first waveguide cavity 22. The eighth cavity segment 243 has the same extension direction as the first waveguide cavity 22. In this embodiment, as shown in FIG12 , the third waveguide cavity 24 includes a seventh cavity segment 241 close to the second cutoff surface 262 and an eighth cavity segment 243 close to the fourth port 2154. The eighth cavity segment 243 is inclined toward the first waveguide cavity 22 as a whole.

In the embodiment shown in FIG. 13, the difference from the embodiment shown in FIG. 7 is the extension direction 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 respectively the same as the extension direction of the first cavity segment 222. In this embodiment, as shown in FIG. 13, the end of the third cavity segment 233 close to the third port 2153 is inclined toward the first waveguide cavity 22, but the inclination angle of the third cavity segment 233 is smaller than the inclination angle of the fourth cavity segment 232. The end of the eighth cavity segment 243 close to the fourth port 2154 is inclined toward the first waveguide cavity 22, but the inclination angle of the eighth cavity segment 243 is smaller than the inclination angle of the ninth cavity segment 242.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

A waveguide, characterized in that it comprises: a substrate, wherein a first waveguide cavity, a second waveguide cavity and a connecting structure are arranged inside the substrate, the substrate has a first surface and a second surface, a first port is arranged on the first surface, and a second port and a third port are arranged on the second surface, wherein the first port and the second port are respectively communicated with the first waveguide cavity, the third port is communicated with the second waveguide cavity, and the second waveguide cavity is communicated with the first waveguide cavity through the connecting 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 connecting structure and the second port, and the first cross section is farther away from the second port than the second cross section.
The waveguide according to claim 1, characterized in that the area of the second cross section is smaller than the area of the end face of the first waveguide cavity at the second port.
The waveguide according to claim 1 or 2, characterized in that the size of the first cross section along the first direction is greater than the size of the second cross section along the first direction;

And/or, a size of the first cross section along a second direction is greater than a size of the second cross section along the second direction, and the second direction is perpendicular to the first direction.
The waveguide according to claim 2, characterized in that the size of the second cross section along the first direction is smaller than the size of the end face along the first direction;

And/or, a dimension of the second cross section along a second direction is smaller than a dimension of the end surface along the second direction, and the second direction is perpendicular to the first direction.
The waveguide according to claim 2, characterized in that the first waveguide cavity comprises a first cavity section and a second cavity section close to the second port, and the first cavity section is connected to an end of the second cavity section away from the second port;

The cross-sectional area of the first cavity segment gradually decreases from an end away from the second port to an end close to the second port.
The waveguide according to claim 5 is characterized in that a cross-sectional area of the second cavity segment gradually increases from an end far from the second port to an end close to the second port.
The waveguide according to claim 5 or 6, characterized in that at least one cavity surface in the first cavity segment is inclined toward the center line of the first cavity segment;

And/or, at least one cavity surface in the second cavity segment is inclined toward the center line of the second cavity segment.
The waveguide according to claim 5 or 6, characterized in that 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.
The waveguide according to any one of claims 1 to 8, characterized in that the interior of the substrate further comprises a cut-off surface, the second waveguide cavity extends to the cut-off surface in a direction away from the third port, and the projection of the cut-off surface on the cavity surface of the first waveguide cavity is located between the first port and the connecting structure;

The waveguide also includes an impedance matching structure protruding on the 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 portion provided on the cavity surface of the second waveguide cavity and a second convex portion provided on the first convex portion, the size of the second convex portion along the third direction is smaller than the size of the first convex portion along the third direction, and the third direction is the extension direction of the first waveguide cavity.
The waveguide according to any one of claims 1 to 9 is characterized in that 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 a cross section of the second waveguide cavity taken along a plane and the center of a cross section of the first waveguide cavity taken along the plane, and the plane is located between the connecting structure and the second port.
The waveguide according to claim 10 is characterized in that at least a portion of the second waveguide cavity is close to an end of the third port and is inclined in a direction away from the first waveguide cavity.
The waveguide according to claim 10 or 11 is characterized in that the second waveguide cavity includes a third cavity segment close to the third port, and a fourth cavity segment connected to an end of the third cavity segment away from the third port, the end of the fourth cavity segment close to the third cavity segment is inclined in a direction away from the first waveguide cavity, and the extension direction of the third cavity segment is the same as the extension direction of the first waveguide cavity.
The waveguide according to any one of claims 1 to 12, wherein the first surface is opposite to the second surface.
The waveguide according to any one of claims 1 to 13 is characterized in that the number of the second waveguide cavities is at least two, the number of the connecting structures is at least two, and at least two of the second waveguide cavities are respectively connected to the first waveguide cavity through at least two of the connecting structures.
The waveguide according to claim 14 is characterized in that at least two of the second waveguide cavities are arranged around the first waveguide cavity in an array with the first waveguide cavity as the center.
A communication system, characterized in that it comprises 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.