CN116014440A

CN116014440A - Dual-frequency feed antenna with high cross-frequency ratio

Info

Publication number: CN116014440A
Application number: CN202310058394.5A
Authority: CN
Inventors: 程潇鹤; 姚远; 刘焱; 刘子豪
Original assignee: Beijing University of Posts and Telecommunications
Current assignee: Beijing University of Posts and Telecommunications
Priority date: 2023-01-16
Filing date: 2023-01-16
Publication date: 2023-04-25

Abstract

The invention provides a dual-frequency feed antenna with a high cross-frequency ratio, which comprises two side channels and a central channel, wherein the central channel is arranged between the two side channels; the double-frequency feed source antenna with the high cross frequency ratio is divided into three equal division power segments, a waveguide conversion segment and an output segment; the central channel is provided with a first input port in three paths of equal-power segments, and two side channels and the central channel are provided with communication channels; the two side channels and the central channel which are positioned in the waveguide conversion section are respectively used for accessing signals output by the two side channels and the central channel in three paths of equal-division power segments and transmitting the signals to the output section; the central channel at the output section is also provided with an electromagnetic band gap structure, the second input channel of the double-frequency feed source antenna with the high cross frequency ratio is connected with the central channel, the second input channel inputs the accessed signal into the electromagnetic band gap structure, and the two side channels and the central channel are both provided with horn mouths for outputting the signal at the output section.

Description

Dual-frequency feed antenna with high cross-frequency ratio

Technical Field

The invention relates to the technical field of communication, in particular to a double-frequency feed source antenna with a high cross-frequency ratio.

Background

The fifth generation mobile communication technology is used as a new generation broadband mobile communication technology, and has the characteristics of high speed, low time delay, large connection and the like. And 5G network large-scale construction brings massive new site requirements. Both remote mountain areas, rivers, lakes and seas and urban special areas or special scenes have places where optical fibers cannot reach, so that the mobile backhaul of massive 5G base stations faces a bottleneck. The microwave is used as an important solution for mobile backhaul, not only can replace or supplement optical fibers, but also has the characteristics of low cost, easiness in deployment and the like, and can assist in rapid deployment of a 5G network. However, the traditional frequency band microwave (6-42 GHz) frequency spectrum resource is increasingly strained, the bandwidth capacity is very limited, and the backhaul requirement of the ultra-large bandwidth (10G level) in the 5G era is difficult to meet. The communication system integrating microwaves and millimeter waves can work in microwave and millimeter wave frequency bands at the same time, and is a key technology for balancing high-reliability and high-speed communication. As a core resource for the development of mobile communication technology, spectrum resources are precious and scarce. Compared with the traditional microwave communication, the microwave and millimeter wave fusion communication system benefits from rich millimeter wave spectrum resources, and can effectively solve the problem of limited rate caused by shortage of microwave spectrum resources. Compared with a millimeter wave communication system, the microwave and millimeter wave converged communication system can exert the characteristic of microwave channel stability, and avoid the restriction of adverse propagation conditions such as atmospheric gas, rainfall, and vapor condensate attenuation existing in millimeter wave communication. Especially in high power long distance application scenarios, such as satellite-to-ground communication, base station wireless backhaul, etc., its adverse factors will greatly affect link stability. At present, in the aspect of satellite-to-ground communication, the low-orbit satellite constellation is utilized to realize the seamless link of the global Internet so as to integrate multimedia and multi-channel communication broadcasting services, and the method is one of the fields of rapid rising and development in the global scope in recent years.

The microwave and millimeter wave fusion communication has the characteristic of high cross frequency ratio, namely, the working frequency ratio of millimeter wave and microwave is large. Aiming at the characteristic of large cross-frequency scale of a microwave and millimeter wave fusion communication system, the prior art carries out fusion design on a microwave transmission line and a millimeter wave transmission line structurally, and transmits electromagnetic waves at different frequency bands through different ports of a dual-mode transmission line, so that the characteristic that a single transmission line can work in microwave and millimeter wave frequency bands simultaneously and efficiently is realized. Most of the existing dual-mode transmission lines adopt a complementary structure. Recently, a novel dual-mode transmission line with an electromagnetic band gap structure introduced by a gap waveguide is proposed, and the dielectric loss is effectively avoided by a pure metal structure, so that the dual-mode transmission line has the advantage of lower transmission loss. Also in terms of integrated design, short boards are not shown compared to SIW (substrate integrated waveguide).

The high-span frequency ratio feed antenna is one of core devices in a remote communication system such as base station backhaul, satellite-to-ground communication and the like. In the system, a feed source is required to realize beam stability and approximately equal lobe width under the condition of high cross frequency ratio. The existing dual-frequency feed source radiates through using different feeds in coaxial forms in different frequency bands, such as nesting combination of various types of antenna units. Although there is a breakthrough in functionality and optimizing performance, the problem of unstable radiation patterns in the coaxial architecture is difficult to solve.

Disclosure of Invention

In view of the above, embodiments of the present invention provide a dual frequency feed antenna with a high frequency-to-cross ratio that obviates or mitigates one or more of the disadvantages of the prior art.

One aspect of the present invention provides a dual frequency feed antenna with a high cross-frequency ratio, comprising two side channels and a central channel, the central channel being disposed between the two side channels;

the dual-frequency feed source antenna with the high span frequency ratio is divided into three equal power dividing sections, a waveguide conversion section and an output section, wherein the waveguide conversion section is arranged between the three equal power dividing sections and the output section; the central channel is provided with a first input port in three equal-power segments, and two side channels and the central channel in the three equal-power segments are provided with communication channels for transmitting signals accessed by the central channel to the two side channels;

the two side channels and the central channel which are positioned in the waveguide conversion section are respectively used for accessing signals output by the two side channels and the central channel in three equal-division power segments and transmitting the signals to the output section;

the central channel at the output section is also provided with an electromagnetic band gap structure, the second input channel of the dual-frequency feed antenna with the high cross frequency ratio is connected with the central channel, the second input channel inputs the accessed signal into the electromagnetic band gap structure, and the two side channels and the central channel are both provided with a horn mouth for outputting the signal at the output section.

By adopting the scheme, the novel dual-frequency feed antenna is provided by introducing the electromagnetic band gap thought, firstly, the novel dual-frequency feed antenna adopts a three-layer horn array and electromagnetic band gap structure, has no coaxial structure, can enable the radiation pattern to be more stable, solves the problem of uncertain radiation pattern existing under the coaxial structure, and has the advantages that both high frequency and low frequency only contain TE10 modes, and the mode is simple.

In some embodiments of the invention, the central channel at the output section comprises a propagation section for accommodating an electromagnetic bandgap structure, the propagation section being in communication with the flare.

In some embodiments of the invention, the electromagnetic bandgap structure comprises a plurality of electromagnetic bands, each of the electromagnetic bands having a plurality of metal units arranged in an array, the output location of the second input channel being arranged between the plurality of electromagnetic bands.

In some embodiments of the invention, the electromagnetic band comprises two inner electromagnetic bands and two outer electromagnetic bands, the two inner electromagnetic bands being disposed between the two outer electromagnetic bands.

In some embodiments of the invention, the output port of the second input channel is connected to the bottom of a central channel, which is connected to the signal connected to the second input channel from the bottom.

In some embodiments of the invention, the output port of the second input channel is disposed between two inner electromagnetic bands.

In some embodiments of the invention, the communication channel is comprised of a plurality of channels, one end of which communicates with the central channel and the other end communicates with the side channels.

In some embodiments of the invention, the central channel at the waveguide transition section comprises a converging section and a bending section, the converging section having a gradually decreasing cross-section along the output direction of the signal, the output end of the converging section being connected to the bending section.

In some embodiments of the invention, the bending section is provided with a bent channel structure, which transmits signals into the output section.

In some embodiments of the invention, the side channels above the waveguide transition are provided with steps through which the side channels below the central channel are bent upwards and through which the side channels below the central channel are bent downwards.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and drawings.

It will be appreciated by those skilled in the art that the objects and advantages that can be achieved with the present invention are not limited to the above-described specific ones, and that the above and other objects that can be achieved with the present invention will be more clearly understood from the following detailed description.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate and together with the description serve to explain the invention.

Fig. 1 is a schematic structural diagram of an embodiment of a dual-frequency feed antenna with high cross-frequency ratio of the present invention;

FIG. 2 is a schematic diagram of a three-way equally divided work segment;

FIG. 3 is a schematic diagram of a waveguide transition segment;

FIG. 4 is a schematic structural diagram of an output section;

FIG. 5 is a schematic perspective view of the output section at another angle;

FIG. 6 is a graph of the input return loss effect of the present invention in one frequency band;

FIG. 7 is a graph of the input return loss effect of the present invention in another frequency band;

FIG. 8 is a graph showing the effect of the lobe width-gain in a frequency band of the present invention;

FIG. 9 is a graph showing the effect of lobe width-gain in another band of the present invention;

fig. 10 is a schematic diagram of the pass band and stop band of the present invention.

Description of the reference numerals

The technical scheme of the invention can be more clearly understood and described by the description of the reference numerals in combination with the embodiment of the invention.

1. A side channel; 2. a central passage; 3. dividing the three paths equally into power segments; 31. a first input port; 32. a communication passage; 4. a waveguide transition section; 41. a convergence section; 42. bending sections; 43. a step section; 5. an output section; 51. an electromagnetic bandgap structure; 511. an inner tape; 512. an external magnetic tape; 52. a propagation section; 53. a horn mouth; 6. and a second input channel.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments and the accompanying drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent. The exemplary embodiments of the present invention and the descriptions thereof are used herein to explain the present invention, but are not intended to limit the invention.

It should be noted here that, in order to avoid obscuring the present invention due to unnecessary details, only structures and/or processing steps closely related to the solution according to the present invention are shown in the drawings, while other details not greatly related to the present invention are omitted.

It should be emphasized that the term "comprises/comprising" when used herein is taken to specify the presence of stated features, elements, steps or components, but does not preclude the presence or addition of one or more other features, elements, steps or components.

It is also noted herein that the term "coupled" may refer to not only a direct connection, but also an indirect connection in which an intermediate is present, unless otherwise specified.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

To solve the above problems, as shown in fig. 1 to 4, the present invention proposes a dual-frequency feed antenna with a high cross-frequency ratio, comprising two side channels 1 and a central channel 2, the central channel 2 being disposed between the two side channels 1;

the dual-frequency feed source antenna with the high span frequency ratio is divided into three paths of equal-division power segments 3, a waveguide conversion segment 4 and an output segment 5, wherein the waveguide conversion segment 4 is arranged between the three paths of equal-division power segments 3 and the output segment 5; the central channel 2 is provided with a first input port 31 in a three-way equal-division segment 3, two side channels 1 and the central channel 2 on the three-way equal-division segment 3 are provided with a communication channel 32, and the communication channel 32 is used for transmitting signals accessed by the central channel 2 to the two side channels 1;

in an implementation, the first input port 31 inputs a standard rectangular waveguide in TE10 mode.

With the above scheme, considering the layout of the standard waveguide flange interface, the input signal is input into the first input port 31 in TE10 mode by the standard rectangular waveguide, and then needs to be fed into the first input port 31 of the three-way power divider after waveguide conversion and matching section and impedance matching.

The two side channels 1 and the central channel 2 which are positioned in the waveguide conversion section 4 are respectively used for accessing signals output by the two side channels 1 and the central channel 2 in the three paths of equal-division power segments 3 and transmitting the signals to the output section 5;

the central channel 2 at the output section 5 is further provided with an electromagnetic bandgap structure 51, the second input channel 6 of the dual-frequency feed antenna with high cross-frequency ratio is connected with the central channel 2, the second input channel 6 inputs the accessed signal into the electromagnetic bandgap structure 51, and the two side channels 1 and the central channel 2 are both provided with a horn mouth 53 for outputting the signal at the output section 5.

The scheme solves the bottleneck problems of unstable pattern, complex structure and the like of the traditional double-frequency feed source in the application scene such as 5G base station backhaul, satellite-to-ground communication and the like. The method meets the back transmission requirement of 5G ultra-large bandwidth, can perfectly adapt to the back transmission requirement of various complex environments to the base station, and can ensure the effectiveness of system communication and the reliability of communication. The novel double-frequency feed source not only can replace or be used as the supplement of optical fibers, but also has the characteristics of low cost, easiness in deployment and the like, and can assist in rapid deployment of a 5G network.

As shown in fig. 4, in some embodiments of the invention, the central channel 2 at the output section 5 comprises a propagation section 52 for housing an electromagnetic bandgap structure 51, said propagation section being in communication with the flare 53.

In some embodiments of the present invention, the electromagnetic bandgap structure 51 includes a plurality of electromagnetic bands, each of the electromagnetic bands having a plurality of metal units arranged in an array, and the output position of the second input channel 6 is disposed between the plurality of electromagnetic bands.

In the implementation process, the metal unit can be a cuboid metal column or a metal sheet.

As shown in fig. 5, in some embodiments of the present invention, the electromagnetic bands include two inner electromagnetic bands 511 and two outer electromagnetic bands 512, the two inner electromagnetic bands 511 being disposed between the two outer electromagnetic bands 512.

In some embodiments of the invention, as shown in fig. 5, the output port of the second input channel 6 is connected to the bottom of the central channel 2, and the central channel 2 is connected to the signal connected to the second input channel 6 from the bottom.

In some embodiments of the invention, as shown in fig. 5, the output port of the second input channel 6 is disposed between two inner electromagnetic bands 511.

By adopting the scheme, the four groups of electromagnetic tapes are contained, the middle two groups of electromagnetic tapes are arranged in a horn shape, as shown in fig. 10, high-frequency electromagnetic waves are restrained to propagate between the middle two groups of electromagnetic tapes by utilizing the stop band characteristic of the electromagnetic band gap structure 51, and the outer two groups of electromagnetic tapes are symmetrically distributed on two sides to ensure that signals can be more uniformly distributed in the whole waveguide space instead of being distributed on the middle two groups of electromagnetic tapes in a concentrated manner during low-frequency transmission, so that a more ideal radiation pattern is obtained. Because the diameter surface of the output horn mouth 53 is too narrow, the horn mouth is unfavorable for matching with free space, and a section of pyramid structure is terminated at the rear end of the horn mouth to improve matching. The signals output by the output ports of the three paths of equal-power segments 3 are radiated out through the pyramid structure which is connected with the output ports.

In some embodiments of the invention, as shown in fig. 2, the communication channel 32 is composed of a plurality of channels, one end of which communicates with the central channel 2 and the other end of which communicates with the side channel 1.

By adopting the scheme, the three-way power segment is provided with a rectangular waveguide input port and three rectangular waveguide output ports, and the first input port 31 of the TE10 mode outputs three-way equal-power signals through two groups of identical coupling grooves and feeds into two pyramid horns and an H-plane EBG (electromagnetic band gap) horn respectively.

In the specific implementation process, the E plane is also called an electric plane and refers to a direction plane parallel to the direction of the electric field; the H plane, also called the magnetic plane, refers to the direction plane parallel to the direction of the magnetic field.

In the specific implementation process, the three-way power segment also comprises an impedance matching segment and three-way power dividers which are sequentially connected, an input signal is input into the impedance matching segment and is input into the three-way power dividers through the impedance matching segment,

as shown in fig. 3, in some embodiments of the present invention, the central channel 2 at the waveguide transition section 4 includes a convergence section 41 and a bending section 42, the convergence section 41 gradually decreases in cross section along the output direction of the signal, and the output end of the convergence section 41 is connected to the bending section 42.

In some embodiments of the invention, the bending section 42 is provided with a bent channel structure, which transmits signals into the output section 5.

By adopting the scheme, as the three-way power segmentation output port is a rectangular waveguide, the output signal is required to be fed into the H-face EBG horn after waveguide conversion and matching sections in consideration of the fact that the metal EBG is loaded in the adopted H-face EBG horn antenna. The middle part of the conversion section is bent, so that a propagation path is increased, and three paths of output phases are finally output to be equal on the diameter surface of the bell mouth 53.

As shown in fig. 3, in some embodiments of the present invention, the side channels 1 located at the waveguide transition section 4 are provided with step sections 43, and the side channels 1 located above the central channel 2 are bent upward by the step sections 43, and the side channels 1 located below the central channel 2 are bent downward by the step sections 43.

The beneficial effect of this scheme includes:

1. as shown in figures 6-9, with the increase of frequency, the 10dB lobe widths of the E face and the H face of the radiation pattern of the feed source antenna are approximately equal, so that the problem of unstable pattern of the existing double-frequency feed source is solved.

2. The feed source structure is complex, the radiation part of the feed source main body is a three-layer horn array, the feed network main body is a three-way equal power divider, and the whole structure is simple and clear and is easy to realize.

3. The problem of the complex mode of the double-frequency feed source is solved, the double-frequency feed source is fed by a double-frequency transmission line based on an electromagnetic band gap structure 51, and both high frequency and low frequency only contain TE10 modes, and the mode is single.

In this disclosure, features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, and various modifications and variations can be made to the embodiments of the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The dual-frequency feed antenna with the high cross-frequency ratio is characterized by comprising two side channels (1) and a central channel (2), wherein the central channel (2) is arranged between the two side channels (1);

the dual-frequency feed source antenna with the high span frequency ratio is divided into three paths of equal-division power segments (3), a waveguide conversion segment (4) and an output segment (5), wherein the waveguide conversion segment (4) is arranged between the three paths of equal-division power segments (3) and the output segment (5); the central channel (2) is provided with a first input port (31) on three paths of equal-division power segments (3), two side channels (1) and the central channel (2) on the three paths of equal-division power segments (3) are provided with communication channels (32), and the communication channels (32) are used for transmitting signals accessed by the central channel (2) to the two side channels (1);

the two side channels (1) and the central channel (2) which are positioned in the waveguide conversion section (4) are respectively used for accessing signals output by the two side channels (1) and the central channel (2) in the three paths of equal-division work segments (3) and transmitting the signals to the output section (5);

the central channel (2) in the output section (5) is further provided with an electromagnetic band gap structure (51), a second input channel (6) of the dual-frequency feed antenna with high cross-frequency ratio is connected with the central channel (2), the second input channel (6) inputs an accessed signal into the electromagnetic band gap structure (51), and both the side channels (1) and the central channel (2) are provided with a bell mouth (53) for outputting the signal in the output section (5).

2. Dual frequency feed antenna with high frequency cross-over according to claim 1, characterized in that the central channel (2) at the output section (5) comprises a propagation section (52) for housing an electromagnetic bandgap structure (51), which is in communication with the horn mouth (53).

3. The dual frequency feed antenna with high frequency cross-over ratio of claim 1, wherein the electromagnetic bandgap structure (51) comprises a plurality of electromagnetic bands, each of the electromagnetic bands having a plurality of metallic elements arranged in an array, the output location of the second input channel (6) being arranged between the plurality of electromagnetic bands.

4. A dual frequency feed antenna with high frequency cross-over ratio according to claim 3, characterized in that the electromagnetic band comprises two inner electromagnetic bands (511) and two outer electromagnetic bands (512), the two inner electromagnetic bands (511) being arranged between the two outer electromagnetic bands (512).

5. The dual frequency feed antenna with high frequency cross ratio according to claim 4, characterized in that the output port of the second input channel (6) is connected to the bottom of the central channel (2), the central channel (2) being bottom-accessed to the signal accessed by the second input channel (6).

6. The dual frequency feed antenna with high frequency cross ratio of claim 5, wherein the output port of the second input channel (6) is arranged between two inner electromagnetic bands (511).

7. The dual frequency feed antenna with high frequency cross ratio according to claim 1, characterized in that the communication channel (32) is composed of a plurality of channels, one end of which is in communication with the central channel (2) and the other end is in communication with the side channel (1).

8. The dual frequency feed antenna with high frequency-cross ratio according to claim 1, characterized in that the central channel (2) at the waveguide transition section (4) comprises a converging section (41) and a bending section (42), the converging section (41) gradually decreases in cross section along the output direction of the signal, and the output end of the converging section (41) is connected with the bending section (42).

9. Dual frequency feed antenna with high frequency cross-over according to claim 8, characterized in that the meander section (42) is provided with a meander channel structure, which meander channel structure passes signals into the output section (5).

10. Dual frequency feed antenna with high frequency cross ratio according to claim 1, characterized in that the side channel (1) at the waveguide transition section (4) is provided with a step (43), the side channel (1) above the central channel (2) is folded upwards by the step (43) and the side channel (1) below the central channel (2) is folded downwards by the step (43).