Adjacent band tri-band dual-polarized antenna

Abstract

The application discloses a kind of adjacent frequency band three-frequency dual polarization antennas, comprising: ultra-wideband orthogonal mode coupler, including sequentially connected first circular waveguide, mode separation cavity and second circular waveguide, mode separation cavity is connected first horizontal polarization branch, second horizontal polarization branch, first vertical polarization branch and second vertical polarization branch respectively by multiple side surface coupling holes;High-frequency orthogonal mode coupler, including sequentially connected third circular waveguide, waveguide transition structure and high-frequency vertical polarization port, waveguide transition structure is connected high-frequency horizontal polarization port by side surface coupling hole, the input end of third circular waveguide is connected second circular waveguide;First duplexer, second duplexer are used for combining horizontal polarization branch, vertical polarization branch respectively;By the above compact structure, the present application can be realized in low frequency, middle frequency and high frequency three frequency bands on dual polarization transmission, while saving space, it can also effectively expand the use of frequency spectrum resources, improve communication capacity.

Description

Technical Field

[0001] This invention relates to the field of communication antenna technology, and in particular to a tri-band dual-polarized antenna in adjacent frequency bands. Background Technology

[0002] With the rapid development of communication technology, especially the gradual popularization of 5G and 5G+ networks, higher requirements have been placed on the transmission rate and reliability of microwave antennas. Traditional microwave antennas typically operate in the 6GHz to 42GHz frequency band. Although they can provide high transmission reliability, spectrum resources are becoming increasingly scarce, and the transmission bandwidth is relatively low, making it difficult to meet the ever-increasing demand for communication capacity. To address this challenge, the industry has proposed a variety of solutions, such as dual-band antennas that combine E-band (71-86GHz) with conventional frequency bands (15 / 18 / 23 / 26 / 28 / 32 / 38GHz), as well as low-frequency dual-band solutions (such as 4+11GHz, 4+7wGHz, 6+10wGHz, 7+10wGHz, etc.).

[0003] However, these solutions still have certain limitations in terms of transmission distance, weather influence, and antenna aperture. For example, although the E-band can provide a transmission capacity of up to 20Gbps, the transmission distance is relatively short and is greatly affected by weather. While the low-frequency dual-band solution can effectively resist multipath fading and other interference, it usually requires a large antenna aperture and is not suitable for all scenarios. Therefore, developing an antenna technology that can achieve higher transmission capacity and longer transmission distance with limited spectrum resources has become an urgent problem to be solved in the current communication field. Summary of the Invention

[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art. This invention proposes a tri-band dual-polarized antenna in adjacent frequency bands. By adopting key components such as an ultra-wideband orthogonal mode coupler, a high-frequency orthogonal mode coupler, and a duplexer, dual-polarized transmission in three frequency bands (low frequency, medium frequency, and high frequency) can be achieved. This can save space, effectively expand the utilization of spectrum resources, and improve communication capacity.

[0005] This invention provides a tri-band dual-polarization antenna in adjacent frequency bands, comprising: an ultra-wideband orthogonal mode coupler, including a first circular waveguide, a mode separation cavity, and a second circular waveguide connected in sequence; the mode separation cavity is connected to a first horizontal polarization branch, a second horizontal polarization branch, a first vertical polarization branch, and a second vertical polarization branch respectively through multiple side coupling holes; the input end of the first circular waveguide is a common signal port, and the output end of the second circular waveguide is a main signal port; a high-frequency orthogonal mode coupler, including a third circular waveguide, a waveguide transition structure, and a high-frequency vertical polarization port connected in sequence; the waveguide transition structure is connected to the high-frequency horizontal polarization port through side coupling holes; the input end of the third circular waveguide is connected to the main signal port; and a first duplexer, including a first combining structure and a first low-frequency branch. The first low-frequency branch and the second intermediate-frequency branch are connected to the first combiner structure, and the first combiner structure is connected to the first low-frequency branch and the first intermediate-frequency branch. The output of the first low-frequency branch is a low-frequency horizontal polarization port, and the output of the first intermediate-frequency branch is an intermediate-frequency horizontal polarization port. The second duplexer includes a second combiner structure, a second low-frequency branch and a second intermediate-frequency branch. The output of the first vertical polarization branch and the second vertical polarization branch are connected to the second combiner structure, and the second combiner structure is connected to the second low-frequency branch and the second intermediate-frequency branch. The output of the second low-frequency branch is a low-frequency vertical polarization port, and the output of the second intermediate-frequency branch is an intermediate-frequency vertical polarization port.

[0006] In some embodiments, the mode separation cavity is connected to the first horizontal polarization branch through a first side coupling hole, to the first vertical polarization branch through a second side coupling hole, to the second horizontal polarization branch through a third side coupling hole, and to the second vertical polarization branch through a fourth side coupling hole; wherein the first side coupling hole and the third side coupling hole are disposed opposite to each other on the left and right sides of the mode separation cavity, and the second side coupling hole and the fourth side coupling hole are disposed opposite to each other on the upper and lower sides of the mode separation cavity, and the included angle between adjacent polarization branches is 90 degrees.

[0007] In some embodiments, the diameter of the second circular waveguide is smaller than the diameter of the first circular waveguide, and the mode separation cavity includes a multi-segment annular stepped structure whose diameter gradually decreases along the direction from the first circular waveguide to the second circular waveguide.

[0008] In some embodiments, each polarization branch includes a multi-gradient ridge waveguide, one end of which is connected to a corresponding side coupling aperture, and the other end is provided with multiple gradient ridges to form a low-pass filter.

[0009] In some embodiments, the high-frequency orthogonal mode coupler includes a vertical rectangular waveguide and a horizontal rectangular waveguide. The vertical rectangular waveguide is connected to the waveguide transition structure. The output end of the vertical rectangular waveguide is the high-frequency vertical polarization port. The waveguide transition structure is connected to the horizontal rectangular waveguide through a side coupling hole. The output end of the horizontal rectangular waveguide is the high-frequency horizontal polarization port. The waveguide transition structure includes a multi-segment stepped structure that gradually narrows along the direction from the third circular waveguide to the vertical rectangular waveguide.

[0010] In some embodiments, the side coupling hole is a strip-shaped through hole arranged along the signal direction of the mode separation cavity, and the length of the strip-shaped through hole is one-quarter wavelength of the 7GHz low-frequency signal.

[0011] In some embodiments, the first combining structure and the second combining structure each include an H-plane 90-degree bend waveguide structure, a three-section twisted waveguide structure and a combiner connected in sequence. The combiner is a common port of the duplexer input terminal, used to combine the two signals and transmit them to the corresponding low-frequency branch and medium-frequency branch.

[0012] In some embodiments, an arched structure is formed between the low-frequency branch and the medium-frequency branch in the first duplexer and the second duplexer. The arched structure is connected to the combiner. Both the low-frequency branch and the medium-frequency branch are provided with multiple resonators, and the resonators are cylindrical or square in shape.

[0013] In some embodiments, the low-frequency branch has a CT cross-coupling structure formed by connecting three adjacent resonators through a metal rod, and an adjustment screw is provided at the center of the resonator.

[0014] In some embodiments, the system further includes a feed source connected to the signal common port. The feed source includes a radiator, a sub-reflector, and a circular waveguide. The bottom end of the radiator has a tapered groove, and the sub-reflector is nested in the tapered groove. The top end of the radiator is inserted into one end of the circular waveguide, and the other end of the circular waveguide is connected to the common port of the mode separation cavity through two interconnected cylindrical cavities.

[0015] According to embodiments of the present invention, an anti-interference ultra-wideband antenna is provided, which has at least the following beneficial effects: The adjacent-band tri-frequency dual-polarized antenna of the present invention, by adding a high-frequency channel at the orthogonal mode coupler, forms a five-channel structure, enabling dual-polarized transmission in three frequency bands: low frequency, mid frequency, and high frequency. This improves the antenna's communication capacity and transmission efficiency, enhances the isolation between high frequency and mid-low frequency, and effectively reduces the antenna structure volume. The ultra-wideband orthogonal mode coupler includes a first circular waveguide, a mode separation cavity, and a second circular waveguide connected sequentially. The mode separation cavity is connected to a first horizontal polarization branch, a second horizontal polarization branch, a first vertical polarization branch, and a second vertical polarization branch through multiple side coupling holes. The input end of the first circular waveguide is a common signal port for receiving mixed signals from the antenna. The ultra-wideband orthogonal mode coupler separates the mid-low frequency polarizations and extracts the high-frequency signal. The output end of the second circular waveguide serves as the main signal port for transmitting the separated signal to the subsequent high-frequency orthogonal mode coupler. The device comprises: a high-frequency orthogonal mode coupler, including a third circular waveguide, a waveguide transition structure, and a high-frequency vertical polarization port connected in sequence; the waveguide transition structure is connected to the high-frequency horizontal polarization port through a side coupling hole, used to separate high-frequency signals to obtain high-frequency vertical polarization signals and high-frequency horizontal polarization signals; a first duplexer, including a first combiner structure, a first low-frequency branch, and a first intermediate-frequency branch, used to perform frequency band separation of the low-frequency and intermediate-frequency signals in the first and second horizontal polarization branches to obtain corresponding low-frequency horizontal polarization signals and intermediate-frequency horizontal polarization signals; and a second duplexer, including a second combiner structure, a second low-frequency branch, and a second intermediate-frequency branch, used to perform frequency band separation of the low-frequency and intermediate-frequency signals in the first and second vertical polarization branches to obtain corresponding low-frequency vertical polarization signals and intermediate-frequency vertical polarization signals. In summary, this application, through the above compact structural design, realizes dual-polarization transmission in three frequency bands: low-frequency, intermediate-frequency, and high-frequency, which can save space while effectively expanding the utilization of spectrum resources and improving communication capacity.

[0016] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0017] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0019] Figure 1This is a schematic diagram of the ultra-wideband orthogonal mode coupler in this invention;

[0020] Figure 2 This is a front view of the ultra-wideband orthogonal mode coupler of the present invention;

[0021] Figure 3 This is a schematic diagram of the high-frequency orthogonal mode coupler in this invention;

[0022] Figure 4 This is a schematic diagram of the structure of the first duplexer in this invention;

[0023] Figure 5 This is a schematic diagram of the structure of the tri-band dual-polarized antenna in adjacent frequency bands in this invention;

[0024] Figure 6 This is another structural schematic diagram of the tri-band dual-polarized antenna in adjacent frequency bands in this invention;

[0025] Figure 7 This is a schematic diagram of the feed source structure in this invention.

[0026] Figure label:

[0027] 100. Ultra-wideband orthogonal mode coupler; 101. First circular waveguide; 102. Mode separation cavity; 103. Second circular waveguide; 110. Signal common port; 120. Signal main port; 130. First horizontal polarization branch; 140. Second horizontal polarization branch; 150. First vertical polarization branch; 160. Second vertical polarization branch; 170. High-frequency orthogonal mode coupler; 180. First duplexer; 190. Second duplexer; 201. Multi-gradient ridge waveguide; 301. Third circular waveguide; 302. Waveguide transition structure; 303. Vertical rectangular waveguide; 304. Horizontal rectangular waveguide. 310. High-frequency vertical polarization port; 320. High-frequency horizontal polarization port; 401. First low-frequency branch; 402. First intermediate-frequency branch; 403. CT cross-coupling structure; 410. Connecting end; 420. Low-frequency horizontal polarization port; 430. Intermediate-frequency horizontal polarization port; 501. H-plane 90-degree bend waveguide structure; 502. Three-section twisted waveguide structure; 503. Combiner; 610. Low-frequency vertical polarization port; 620. Intermediate-frequency vertical polarization port; 700. Feed source; 701. Radiator; 702. Sub-reflector; 703. Circular waveguide; 704. Conical slot. Detailed Implementation

[0028] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0029] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the number itself, while "above," "below," "within," etc. are understood to include the number itself. "Any one" refers to one or more, and "at least one of the following" and similar expressions refer to any combination of these items, including any combination of single or multiple items. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0030] It should be noted that the terms "setting," "installing," and "connecting" in the embodiments of this invention should be interpreted broadly. Those skilled in the art can reasonably determine the specific meaning of the above terms in the embodiments of this invention in conjunction with the specific content of the technical solution. For example, the term "connection" can be a mechanical connection, an electrical connection, or a connection that allows for mutual communication; it can be a direct connection or an indirect connection through an intermediate medium.

[0031] It should be noted that the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Currently, with the rapid development of communication technology, especially the gradual popularization of 5G and 5G+ networks, higher requirements are being placed on the transmission rate and reliability of microwave antennas. Traditional microwave antennas typically operate in the 6GHz to 42GHz frequency band. Although they can provide high transmission reliability, spectrum resources are becoming increasingly scarce, and the transmission bandwidth is relatively low, making it difficult to meet the ever-increasing demand for communication capacity. To address this challenge, the industry has proposed a variety of solutions, such as dual-band antennas that combine E-band (71-86GHz) with conventional frequency bands (15 / 18 / 23 / 26 / 28 / 32 / 38GHz), as well as low-frequency dual-band solutions (such as 4+11GHz, 4+7wGHz, 6+10wGHz, 7+10wGHz, etc.). However, these solutions still have certain limitations in terms of transmission distance, weather influence, and antenna aperture. For example, although the E-band can provide a transmission capacity of up to 20Gbps, the transmission distance is relatively short and is greatly affected by weather. While the low-frequency dual-band solution can effectively resist multipath fading and other interference, it usually requires a large antenna aperture and is not suitable for all scenarios. Therefore, developing an antenna technology that can achieve higher transmission capacity and longer transmission distance with limited spectrum resources has become an urgent problem to be solved in the current communication field.

[0033] Based on this, the purpose of this invention is to at least solve one of the technical problems existing in the prior art. This invention proposes a tri-band dual-polarized antenna in adjacent frequency bands. By adopting key components such as an ultra-wideband orthogonal mode coupler, a high-frequency orthogonal mode coupler, and a duplexer, dual-polarized transmission in three frequency bands (low frequency, medium frequency, and high frequency) can be achieved. This can save space, effectively expand the utilization of spectrum resources, and improve communication capacity.

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0035] refer to Figures 1 to 7 , Figure 1 This is a schematic diagram of the ultra-wideband orthogonal mode coupler in this invention; Figure 2 This is a front view of the ultra-wideband orthogonal mode coupler of the present invention; Figure 3 This is a schematic diagram of the high-frequency orthogonal mode coupler in this invention; Figure 4 This is a schematic diagram of the structure of the first duplexer in this invention; Figure 5 This is a schematic diagram of the structure of the tri-band dual-polarized antenna in adjacent frequency bands in this invention; Figure 6 This is another structural schematic diagram of the tri-band dual-polarized antenna in adjacent frequency bands in this invention; Figure 7 This is a schematic diagram of the feed source structure in this invention.

[0036] like Figure 5 and Figure 6As shown, this embodiment of the invention provides a tri-band dual-polarized antenna in adjacent frequency bands, including: an ultra-wideband orthogonal mode coupler 102, comprising a first circular waveguide 101, a mode separation cavity 102, and a second circular waveguide 103 connected in sequence. The mode separation cavity 102 is connected to a first horizontal polarization branch 130, a second horizontal polarization branch 140, a first vertical polarization branch 150, and a second vertical polarization branch 160 respectively through multiple side coupling holes. The input end of the first circular waveguide 101 is a signal common port 110, and the output end of the second circular waveguide 103 is a signal main port 120; a high-frequency orthogonal mode coupler 170, comprising a third circular waveguide 301, a waveguide transition structure 302, and a high-frequency vertical polarization port 310 connected in sequence. The waveguide transition structure 302 is connected to a high-frequency horizontal polarization port 320 through side coupling holes, and the input end of the third circular waveguide 301 is connected to the signal main port 120; A duplexer 180 includes a first combining structure, a first low-frequency branch 401, and a first intermediate-frequency branch 402. The output terminals of the first horizontally polarized branch 130 and the second horizontally polarized branch 140 are connected to the first combining structure. The first combining structure is connected to the first low-frequency branch 401 and the first intermediate-frequency branch 402. The output terminal of the first low-frequency branch 401 is a low-frequency horizontally polarized port 420, and the output terminal of the first intermediate-frequency branch 402 is an intermediate-frequency horizontally polarized port 430. A second duplexer 190 includes a second combining structure, a second low-frequency branch, and a second intermediate-frequency branch. The output terminals of the first vertically polarized branch 150 and the second vertically polarized branch 160 are connected to the second combining structure. The second combining structure is connected to the second low-frequency branch and the second intermediate-frequency branch. The output terminal of the second low-frequency branch is a low-frequency vertically polarized port 610, and the output terminal of the second intermediate-frequency branch is an intermediate-frequency vertically polarized port 620.

[0037] It is understood that the adjacent frequency band tri-band dual-polarized antenna of the present invention, by adding a high-frequency channel at the orthogonal mode coupler to form a five-channel structure, can realize dual-polarized transmission in three frequency bands: low frequency, medium frequency, and high frequency. This improves the antenna's communication capacity and transmission efficiency, enhances the isolation between high frequency and mid-low frequency, and effectively reduces the antenna structure volume. Specifically, the ultra-wideband orthogonal mode coupler 102 is used to separate the two polarizations of the mid-low frequency band and separate the high-frequency signal. The output end of the second circular waveguide 103 serves as the main signal port 120, used to transmit the separated signal to the subsequent high-frequency orthogonal mode coupler 170. The high-frequency orthogonal mode coupler 170 is used to separate the high-frequency signal to obtain the high-frequency vertical... The system comprises a direct polarization signal and a high-frequency horizontal polarization signal; a first duplexer 180 is used to perform frequency band separation on the low- and mid-frequency signals in the first horizontal polarization branch 130 and the second horizontal polarization branch 140 to obtain the corresponding low-frequency horizontal polarization signal and mid-frequency horizontal polarization signal; a second duplexer 190 is used to perform frequency band separation on the low- and mid-frequency signals in the first vertical polarization branch 150 and the second vertical polarization branch 160 to obtain the corresponding low-frequency vertical polarization signal and mid-frequency vertical polarization signal; in summary, this application achieves dual-polarization transmission in three frequency bands (low-frequency, mid-frequency, and high-frequency) through the above compact structural design, which can effectively expand the utilization of spectrum resources and improve communication capacity while saving space.

[0038] It is worth noting that this invention upgrades existing dual-band dual-polarized antennas by adding a third band, expanding the range from two bands (6GHz and 7GHz) to three bands (6GHz, 7GHz, and 10GHz). This upgrade enables the antenna to perform dual-polarized transmission over a wider spectrum, significantly improving communication capacity. Furthermore, since the 6GHz and 7GHz signals are spaced only 0.1GHz apart, with a relative bandwidth of approximately 1.5%, this places extremely high demands on traditional duplexer technology, posing significant challenges in theory, design, manufacturing processes, and tolerance. However, this invention achieves stable dual-polarized transmission across three bands. In addition, based on the above structure, the antenna aperture ranges from 0.3m to 1.8m, meeting the needs of transmission over different distances and exhibiting strong applicability and flexibility. By achieving three-band transmission on a single antenna, this invention not only improves communication capacity but also effectively reduces tower rental and manufacturing costs, reaching a cost equivalent to that of a single-band antenna, thereby improving efficiency and cost-effectiveness and providing users with significant economic advantages.

[0039] like Figure 1 and Figure 2As shown, in some embodiments, corresponding to the ultra-wideband orthogonal mode coupler 102, the first circular waveguide 101 serves as the signal inlet, receiving the mixed polarization signal from the antenna. Its input end is defined as the signal common port 110, responsible for guiding the unseparated signal into the coupler. The mode separation cavity 102, through its internal structural design, can effectively separate signals of different polarizations. The cavity is provided with multiple side coupling holes, which are respectively connected to the first horizontal polarization branch 130, the second horizontal polarization branch 140, the first vertical polarization branch 150, and the second vertical polarization branch 160 to achieve signal separation. The second circular waveguide 103 serves as the output part of the mode separation cavity 102. Its output end is defined as the signal main port 120, responsible for transmitting the separated signal to the subsequent high-frequency orthogonal mode coupler 170. The design of the second circular waveguide 103 ensures the stability and low loss of the signal during transmission.

[0040] In some embodiments, corresponding to the high-frequency orthogonal mode coupler 170, the third circular waveguide 301 receives the signal from the main signal port 120 of the ultra-wideband orthogonal mode coupler 102 and serves as a transmission channel for high-frequency signals. The waveguide transition structure 302 connects the third circular waveguide 301 and the high-frequency vertical polarization port 310. Through its internal side coupling holes, the high-frequency horizontal polarization signal is separated and transmitted to the high-frequency horizontal polarization port 320. The high-frequency vertical polarization port 310 is specifically used to output high-frequency vertical polarization signals, ensuring efficient transmission and separation of high-frequency signals.

[0041] In some embodiments, corresponding to the first duplexer 180, the first combiner receives signals from the first horizontal polarization branch 130 and the second horizontal polarization branch 140, and performs combiner processing on these signals for subsequent separation and transmission; the first low-frequency branch 401 receives signals from the first combiner and further separates the low-frequency horizontal polarization signal, and outputs it through its output port; the first intermediate frequency branch 402 also receives signals from the first combiner and is used to separate the intermediate frequency horizontal polarization signal, and outputs it through its output port; corresponding to the second duplexer 190, the second combiner is similar to the first duplexer 180, but processes vertical polarization signals. It receives signals from the first vertical polarization branch 150 and the second vertical polarization branch 160 and performs combiner processing; the second low-frequency branch receives signals from the second combiner and separates the low-frequency vertical polarization signal, and outputs it through its output port; the second intermediate frequency branch is responsible for separating the intermediate frequency vertical polarization signal, and outputs it through its output port.

[0042] In this design, the main signal port 120 of the ultra-wideband orthogonal mode coupler 102 is connected to the third circular waveguide 301 of the high-frequency orthogonal mode coupler 170 via the second circular waveguide 103, ensuring continuous transmission of high-frequency signals. The first duplexer 180 and the second duplexer 190 are respectively connected to the horizontal polarization branch and the vertical polarization branch of the ultra-wideband orthogonal mode coupler 102 through their combining structures, achieving effective signal separation and transmission. Inside the first duplexer 180 and the second duplexer 190, the combining structures are respectively connected to the low-frequency branch and the intermediate-frequency branch, ensuring that signals of different frequency bands can be effectively separated and transmitted to the corresponding ports. Through the above detailed design and connection relationships, the ultra-wideband orthogonal mode coupler 102 and its related components of this application can achieve efficient separation and transmission of dual-polarized signals in the low-frequency, intermediate-frequency and high-frequency bands, meeting the requirements of modern communication systems for high-capacity, long-distance and high-reliability transmission.

[0043] like Figure 1 and Figure 2 As shown, in some embodiments, the mode separation cavity 102 is connected to the first horizontal polarization branch 130 through the first side coupling hole, to the first vertical polarization branch 150 through the second side coupling hole, to the second horizontal polarization branch 140 through the third side coupling hole, and to the second vertical polarization branch 160 through the fourth side coupling hole, so that the mode separation cavity 102 can separate and transmit signals of different polarizations.

[0044] Specifically, the first side coupling hole and the third side coupling hole are arranged opposite to each other on the left and right sides of the mode separation cavity 102, and the second side coupling hole and the fourth side coupling hole are arranged opposite to each other on the upper and lower sides of the mode separation cavity 102 to ensure stable signal transmission and efficient separation. The included angle between adjacent polarization branches is 90 degrees, so that signals of different polarizations do not interfere with each other during transmission, thereby improving signal isolation and transmission efficiency.

[0045] In some embodiments, the ultra-wideband orthogonal mode coupler 102 of the present invention operates in the frequency band of 5.925GHz-11.7GHz. The ultra-wideband orthogonal mode coupler 102 differs from the conventional structure. First, it has four coupling ports for extension and then combining. The four-port method can effectively reduce losses. In addition, the ultra-wideband orthogonal mode coupler 102 also includes a duplexer function, which can transmit high-frequency 10GHz signals through the lower second circular waveguide 103, effectively improving circuit efficiency. The four coupling ports on the side are used to transmit low-frequency and intermediate-frequency information of 6GHz (5.925GHz-7.075GHz) and 7GHz (7.175GHz-8.5GHz). Thus, the three frequency bands can be combined together. The ultra-wideband feed network composed of the orthogonal mode coupler and the duplexer separates the three frequency bands and polarizations, realizing three-band dual-polarization transmission.

[0046] In some embodiments, the relative arrangement of the first side coupling hole and the third side coupling hole allows the first horizontal polarization branch 130 to be connected to the mode separation cavity 102 through the first side coupling hole, while the second horizontal polarization branch 140 is connected to the mode separation cavity 102 through the third side coupling hole. The relative arrangement of the second side coupling hole and the fourth side coupling hole allows the first vertical polarization branch 150 to be connected to the mode separation cavity 102 through the second side coupling hole, while the second vertical polarization branch 160 is connected to the mode separation cavity 102 through the fourth side coupling hole. The included angle between adjacent polarization branches is 90 degrees. It can be understood that the transmission paths of the horizontally polarized signal and the vertically polarized signal within the mode separation cavity 102 are perpendicular to each other. This layout ensures that signals of different polarizations do not interfere with each other during transmission, thereby improving signal isolation and transmission efficiency.

[0047] It is worth noting that, through the reasonable layout of the first, second, third, and fourth side coupling holes, and the 90-degree angle design between adjacent polarization branches, the mode separation cavity 102 can efficiently separate and transmit signals of different polarizations, thereby optimizing the signal transmission path, reducing signal loss and interference during transmission, and improving signal isolation and transmission efficiency. This enables the antenna to work stably in a multi-band, dual-polarization environment, meeting the high capacity and high reliability requirements of modern communication systems.

[0048] In some embodiments, the diameter of the second circular waveguide 103 is smaller than the diameter of the first circular waveguide 101. This design allows the signal to gradually adapt to the change in waveguide diameter as it is transmitted from the first circular waveguide 101 to the second circular waveguide 103, reducing signal transmission loss and reflection. It is understood that a smaller waveguide diameter can better match the wavelength of high-frequency signals, thereby reducing signal attenuation during transmission. In addition, this gradual change in diameter can also reduce signal discontinuity at the waveguide interface, further improving the signal transmission quality.

[0049] In some embodiments, the mode separation cavity 102 includes a multi-segment annular stepped structure with a gradually decreasing diameter along the direction from the first circular waveguide 101 to the second circular waveguide 103. As the waveguide diameter gradually decreases, the signal propagation path in the cavity also gradually changes. This change helps to separate signals of different polarizations, and the multi-segment annular stepped structure can also reduce signal reflection and interference in the cavity, improving signal transmission efficiency and stability. It is understood that the presence of coupling holes will cause discontinuous high-frequency signal transmission and generate high-order mode interference signal transmission. To address this, this application can connect two circular waveguides with several stepped segments and reduce the diameter of the circular waveguide for high-frequency transmission to achieve the technical effect of reducing high-order modes. In addition, the main port 120 for transmitting high-frequency signals extends through a circular waveguide with a reduced size after exiting the mode separation cavity 102.

[0050] In some embodiments, each polarization branch includes a multi-gradient ridge waveguide 201. One end of the multi-gradient ridge waveguide 201 is connected to a corresponding side coupling hole, and the other end is provided with multiple gradient ridges to form a low-pass filter. This design enables the polarization branch to not only effectively transmit signals but also filter them. Specifically, the ridge design of the multi-gradient ridge waveguide 201 can form a low-pass filter, which can effectively isolate high-frequency signals and ensure the transmission quality of low-frequency signals. In this way, the polarization branch can effectively filter signals while transmitting them, improving signal purity and transmission efficiency.

[0051] like Figure 3 As shown, in some embodiments, the high-frequency orthogonal mode coupler 170 includes a vertical rectangular waveguide 303 and a horizontal rectangular waveguide 304. The vertical rectangular waveguide 303 is connected to a waveguide transition structure 302. The output end of the vertical rectangular waveguide 303 is a high-frequency vertical polarization port 310. The waveguide transition structure 302 is connected to the horizontal rectangular waveguide 304 through a side coupling hole. The output end of the horizontal rectangular waveguide 304 is a high-frequency horizontal polarization port 320. It can be understood that the high-frequency orthogonal mode coupler 170 can efficiently handle the transmission and separation of high-frequency signals. The structural design of the vertical rectangular waveguide 303 and the horizontal rectangular waveguide 304 enables the high-frequency signal to be effectively separated and transmitted within the coupler. The design of the waveguide transition structure 302 further ensures the smooth transition of the signal between different waveguides, reducing signal reflection and loss.

[0052] In some embodiments, the waveguide transition structure 302 includes a multi-segment stepped structure that gradually narrows along the direction from the third circular waveguide 301 to the vertical rectangular waveguide 303, enabling the waveguide transition structure 302 to more effectively transition and transmit signals. It is understood that as the waveguide width gradually narrows, the propagation path of the signal within the transition structure also gradually changes. This change helps to reduce signal reflection and loss, improve signal transmission efficiency, and the multi-segment stepped structure can also reduce signal discontinuity at the waveguide interface, further improving signal transmission quality.

[0053] In some embodiments, the side coupling hole is a strip-shaped through hole arranged along the signal direction of the mode separation cavity 102. The length of the strip-shaped through hole is one-quarter wavelength of the 7GHz low-frequency signal. This design enables the coupling hole to effectively couple the 7GHz low-frequency signal, ensuring that the low-frequency signal generates a standing wave at the coupling hole, thereby enhancing the signal coupling efficiency.

[0054] like Figure 5 and Figure 6 As shown, in some embodiments, both the first and second combining structures include a 90-degree H-plane bend waveguide structure 501, a three-section twisted waveguide structure 502, and a combiner 503 connected in sequence. The 90-degree H-plane bend waveguide structure 501 is used to change the signal propagation direction, enabling effective transmission and separation of signals between different polarization branches. The three-section twisted waveguide structure 502 is used to further adjust the phase and amplitude of the signal, ensuring that the signals can be effectively combined at the combiner 503. The combiner 503 serves as the common port of the duplexer input, used to combine the two signals and transmit them to the corresponding low-frequency and medium-frequency branches. This design not only improves signal transmission efficiency but also reduces signal loss and interference during transmission.

[0055] like Figure 4 As shown, in some embodiments, an arched structure is formed between the low-frequency branch and the intermediate-frequency branch in the first duplexer 180 and the second duplexer 190. The middle part of the arched structure is connected to the combiner 503 through the connecting end 410. Both the low-frequency branch and the intermediate-frequency branch are equipped with multiple resonators, which are cylindrical or square-prism shaped. The arched structure design allows the low-frequency branch and the intermediate-frequency branch to be effectively separated in space, thereby reducing mutual interference between signals. The resonators further improve the filtering performance of the branches, ensuring the purity and stability of the signal during transmission. It can be understood that the resonators can effectively suppress unwanted frequency components, thereby improving the isolation and transmission efficiency of the signal.

[0056] In some embodiments, the waveguide transition structure 302 includes a multi-segment stepped structure that gradually narrows along the direction from the third circular waveguide 301 to the vertical rectangular waveguide 303. This design enables the waveguide transition structure 302 to more effectively transition and transmit signals. As the waveguide width gradually narrows, the propagation path of the signal within the transition structure also gradually changes. This change helps to reduce signal reflection and loss, and improve signal transmission efficiency. The multi-segment stepped structure can also reduce signal discontinuity at the waveguide interface, further improving the signal transmission quality.

[0057] In some embodiments, the low-frequency branch contains a CT cross-coupling structure 403 formed by connecting three adjacent resonators through a metal rod. An adjustment screw is provided at the center of each resonator. This CT cross-coupling structure 403 design enables the low-frequency branch to achieve better filtering performance and signal transmission characteristics. Specifically, the three resonators are connected by a metal rod to form a loop, which can generate the required transmission zero point, thereby improving standing wave performance and reducing losses. The setting of the adjustment screw allows for fine-tuning of the resonant frequency of the resonator to optimize the signal transmission performance.

[0058] In some embodiments, the low-frequency branch and the intermediate-frequency branch of the first duplexer 180 and the second duplexer 190 can each use 8 resonators, which are connected by metal rods. The low-frequency branch has 3 resonant pillars connected together to form a loop, which is a CT triangular cross-coupled structure. The coupling between the resonators is mainly improved by adjusting the screw depth. Reasonably matching the depth of each screw can optimize and improve the duplexer performance until it meets the usage requirements. The duplexer of the present invention can achieve an isolation width of 100MHz while ensuring an isolation of -30dB between the two frequency bands. The transmission frequency of the low-frequency port is 5.925-7.075GHz, and the transmission frequency of the intermediate-frequency port is 7.175-8.5GHz.

[0059] In some embodiments, the multi-gradient ridge waveguide 201 is an asymmetric gradient ridge structure, specifically including: the ridge of the waveguide increases in gradient along the signal transmission direction, with the ridge height gradually increasing from 0.5 mm to 2.0 mm, forming a gradual impedance change; a chamfered opening structure is provided at the end of the ridge waveguide, with an opening angle of 30°-45°, to suppress high-frequency reflection; adjacent ridge waveguides are connected by a metal diaphragm with a thickness of 0.1 times the lowest frequency wavelength λ, to achieve broadband signal matching, thereby effectively improving the suppression effect.

[0060] In some embodiments, among the three resonators of the CT cross-coupling structure 403, the middle resonator can be cylindrical, and the two side resonators can be square prisms. The three are connected in series by a U-shaped metal rod. The square prism resonator is nested inside a small cylindrical resonator, and the distance between the two is 0.05λ, forming a double coupling. The resonator adjusting screw adopts a tapered thread design, and the end of the screw is embedded with a polytetrafluoroethylene gasket to avoid parasitic capacitance caused by metal contact, thereby optimizing the duplexer VSWR and inter-segment isolation.

[0061] like Figure 7 As shown, in some embodiments, a feed 700 is also included, connected to a signal common port 110. The feed 700 includes a radiator 701, a sub-reflector 702, and a circular waveguide 703. A tapered groove 704 is formed at the bottom of the radiator, within which the sub-reflector is nested. The top of the radiator is inserted into one end of the circular waveguide, and the other end of the circular waveguide is connected to the common port of the mode separation cavity 102 via two interconnected cylindrical cavities. This feed design allows signals to be efficiently transmitted from the feed to the mode separation cavity 102, thereby achieving the separation and transmission of signals with different polarizations. The tapered groove design of the radiator helps improve signal radiation efficiency, while the sub-reflector further optimizes the signal transmission path, reducing signal loss and interference. The use of the circular waveguide ensures the stability and efficiency of the signal during transmission, thereby improving the performance of the entire antenna system.

[0062] In some embodiments, the ultra-wideband antenna feed of the present invention employs circular waveguide feeding. The dimensions of the circular waveguide match the dual-band dual-polarization feed network of the present invention. The use of the circular waveguide not only improves signal transmission efficiency but also makes the feed structure more compact and stable. The radiator uses PPO material as the substrate. PPO material has a very stable dielectric constant (ε=2.55) and a very low loss tangent, making it very suitable for use in ultra-wideband feeds. The radiator has a slotted conical shape, which helps improve signal radiation efficiency and directivity. In addition, a sub-reflector made of metallic material is nested on the top surface of the radiator. The main function of the sub-reflector is to reflect electromagnetic energy from the circular waveguide back to the main surface of the antenna, thereby improving signal transmission efficiency.

[0063] In some embodiments, the sub-reflector of the feed spreads out from bottom to top at a certain angle to match the top surface structure of the radiator, so that the sub-reflector can effectively reflect electromagnetic energy to the main surface of the antenna, reducing signal loss and interference; the sub-reflector and the edge of the radiator are provided with grooves, and the grooves are filled with glue to tightly connect the sub-reflector and the radiator. This connection method not only improves the stability of the structure, but also reduces signal reflection and loss at the connection point.

[0064] In some embodiments, the top surface curve of the feed head is composed of several line segments. This tapered extension structure can effectively reduce edge illumination of the feed and prevent energy leakage from the feed reflected onto the main surface. At the same time, this structure allows the feed to transmit energy at a certain focal distance, which can effectively reduce the secondary reflection of energy reflected onto the main surface onto the feed and avoid coupling reactions that affect the feed performance.

[0065] In some embodiments, the circular waveguide is a metal structure and can be manufactured using an extrusion molding process. It can transmit vertically polarized and horizontally polarized signals and is a commonly used waveguide device in microwave reflector antennas. The modes transmitted within the circular waveguide are TE11, TM01, and TE21. The frequency responses of each mode are different, and the transmission bandwidth can be expanded by reasonably configuring the phase of each mode. This invention optimizes and configures the slotted structure and stepped dimensions of the radiator, especially the stepped structure within the waveguide, thereby matching the phase of each mode and increasing the operating bandwidth.

[0066] In some embodiments, the present invention can fully utilize the characteristic that the TM mode only contributes to the E-plane pattern and does not contribute to the H-plane pattern, so that the beamwidths of the E-plane and H-plane patterns are basically the same, thereby achieving the purpose of two polarization equalization beams in the primary pattern of the feed source; in addition, the circular waveguide uses an inner diameter of 2a=31mm, and the cutoff frequencies of each mode are shown in Table (1) below:

[0067] Table (1)

[0068]

[0069] Based on the cutoff frequency mentioned above, the operating frequency fwork must meet the condition: fTE11≤fwork≤fTM11. Therefore, the maximum operating frequency of the feed of this invention is 5.6GHz-11.7GHz. With the dual-band three-polarization feed network, the overall system operating frequency of this invention is 5.925GHz-11.7GHz, enabling the antenna to operate stably on multiple frequency bands and meeting the requirements of modern communication systems for high capacity and high reliability.

[0070] In some embodiments, the adjacent frequency band tri-band dual-polarized antenna of the present invention can be used in conjunction with a parabolic reflector, and can be matched with reflectors of different apertures according to the usage requirements.

[0071] In summary, this invention proposes a low VSWR and high isolation tri-band dual-polarized antenna. By employing an ultra-wideband orthogonal mode coupler (5.925GHz-11.7GHz), the mid-low frequency polarizations are separated, and the high-frequency signal is isolated. The high-frequency signal is then separated by a high-frequency orthogonal mode coupler. Each polarization port in the mid-low frequency range is further separated into two frequency bands by loading a duplexer, thereby achieving tri-band dual polarization. Combined with an ultra-wideband microwave antenna, TE11, TM01, and TE21 modes can be excited within the waveguide and applied to the entire operating frequency band, maximizing the operating frequency. The material and shape of the ultra-wideband radiator effectively distribute electromagnetic energy rationally, reducing edge illumination levels, resulting in antenna radiation performance with high gain, low sidelobes, high XPD, and low VSWR.

Claims

1. A tri-band dual-polarized antenna in adjacent frequency bands, characterized in that, include: An ultra-wideband orthogonal mode coupler includes a first circular waveguide, a mode separation cavity, and a second circular waveguide connected in sequence. The mode separation cavity is connected to a first horizontal polarization branch, a second horizontal polarization branch, a first vertical polarization branch, and a second vertical polarization branch through multiple side coupling holes. The input end of the first circular waveguide is a common signal port, and the output end of the second circular waveguide is a main signal port. A high-frequency orthogonal mode coupler includes a third circular waveguide, a waveguide transition structure, and a high-frequency vertical polarization port connected in sequence. The waveguide transition structure is connected to the high-frequency horizontal polarization port through a side coupling hole, and the input end of the third circular waveguide is connected to the main signal port. The first duplexer includes a first combining structure, a first low-frequency branch, and a first intermediate-frequency branch. The output terminals of the first horizontally polarized branch and the second horizontally polarized branch are connected to the first combining structure. The first combining structure is connected to the first low-frequency branch and the first intermediate-frequency branch. The output terminal of the first low-frequency branch is a low-frequency horizontally polarized port, and the output terminal of the first intermediate-frequency branch is an intermediate-frequency horizontally polarized port. The second duplexer includes a second combining structure, a second low-frequency branch, and a second intermediate-frequency branch. The output terminals of the first vertical polarization branch and the second vertical polarization branch are connected to the second combining structure. The second combining structure is connected to the second low-frequency branch and the second intermediate-frequency branch. The output terminal of the second low-frequency branch is a low-frequency vertical polarization port, and the output terminal of the second intermediate-frequency branch is an intermediate-frequency vertical polarization port. in: The mode separation cavity is connected to the first horizontal polarization branch through a first side coupling hole, to the first vertical polarization branch through a second side coupling hole, to the second horizontal polarization branch through a third side coupling hole, and to the second vertical polarization branch through a fourth side coupling hole. The first side coupling hole and the third side coupling hole are disposed opposite to each other on the left and right sides of the mode separation cavity, and the second side coupling hole and the fourth side coupling hole are disposed opposite to each other on the upper and lower sides of the mode separation cavity. The included angle between adjacent polarization branches is 90 degrees. Each polarization branch includes a multi-gradient ridge waveguide; the multi-gradient ridge waveguide is an asymmetric gradient ridge structure, and the spine of the multi-gradient ridge waveguide increases in gradient along the signal transmission direction, with the ridge height gradually increasing from 0.5 mm to 2.0 mm, forming a gradual impedance change; the ends of the multi-gradient ridge waveguide are provided with a chamfered opening structure with an opening angle of 30°-45° to suppress high-frequency reflections; adjacent multi-gradient ridge waveguides are connected by a metal diaphragm, and the thickness of the metal diaphragm is 0.1 times the lowest frequency wavelength λ.

2. The adjacent frequency band tri-band dual-polarized antenna according to claim 1, characterized in that, The diameter of the second circular waveguide is smaller than that of the first circular waveguide, and the mode separation cavity includes a multi-segment annular stepped structure whose diameter gradually decreases along the direction from the first circular waveguide to the second circular waveguide.

3. The adjacent frequency band tri-band dual-polarized antenna according to claim 1, characterized in that, One end of the multi-gradient ridge waveguide is connected to the corresponding side coupling hole, and the other end is provided with multiple gradient ridges to form a low-pass filter.

4. The adjacent frequency band tri-band dual-polarized antenna according to claim 1, characterized in that, The high-frequency orthogonal mode coupler includes a vertical rectangular waveguide and a horizontal rectangular waveguide. The vertical rectangular waveguide is connected to the waveguide transition structure. The output end of the vertical rectangular waveguide is the high-frequency vertical polarization port. The waveguide transition structure is connected to the horizontal rectangular waveguide through a side coupling hole. The output end of the horizontal rectangular waveguide is the high-frequency horizontal polarization port. The waveguide transition structure includes a multi-segment stepped structure that gradually narrows along the direction from the third circular waveguide to the vertical rectangular waveguide.

5. The adjacent frequency band tri-band dual-polarized antenna according to claim 1, characterized in that, The side coupling hole is a strip-shaped through hole arranged along the signal direction of the mode separation cavity, and the length of the strip-shaped through hole is one-quarter wavelength of the 7GHz low-frequency signal.

6. The adjacent frequency band tri-band dual-polarized antenna according to claim 1, characterized in that, Both the first and second combining structures include an H-plane 90-degree bend waveguide structure, a three-section twisted waveguide structure, and a combiner connected in sequence. The combiner is the common port of the duplexer input, used to combine the two signals and transmit them to the corresponding low-frequency branch and medium-frequency branch.

7. The adjacent frequency band tri-band dual-polarized antenna according to claim 6, characterized in that, An arched structure is formed between the low-frequency branch and the medium-frequency branch in the first duplexer and the second duplexer. The arched structure is connected to the combiner. Both the low-frequency branch and the medium-frequency branch are provided with multiple resonators, and the resonators are cylindrical or square in shape.

8. The adjacent frequency band tri-band dual-polarized antenna according to claim 7, characterized in that, The low-frequency branch contains a CT cross-coupling structure formed by connecting three adjacent resonators through a metal rod, and an adjustment screw is set at the center of each resonator.

9. The adjacent frequency band tri-band dual-polarized antenna according to claim 1, characterized in that, It also includes a feed source connected to the signal common port. The feed source includes a radiator, a sub-reflector and a circular waveguide. The bottom end of the radiator has a conical groove, and the sub-reflector is nested in the conical groove. The top end of the radiator is inserted into one end of the circular waveguide, and the other end of the circular waveguide is connected to the common port of the mode separation cavity through two interconnected cylindrical cavities.

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