Array antenna with series-fed coupling network

Abstract

The invention relates to the technical field of communication, and discloses an array antenna with a series-fed coupling network, which comprises an antenna radiation layer, an upper-layer antenna plate, a series-fed coupling network layer and a lower-layer antenna plate. Wherein the antenna radiation layer is located on the top surface of the upper-layer antenna plate, the series-feed coupling network layer is located on the top surface of the lower-layer antenna plate, and the upper-layer antenna plate and the lower-layer antenna plate are in press fit; the antenna radiation layer comprises a plurality of radiation patches and a plurality of feed signal holes; the series-fed coupling network layer further comprises a power divider, a public radio frequency port, a plurality of series-fed networks and a plurality of groups of coupling structures; the input port of the power divider is connected with the public radio frequency port, and the output port is connected with the series feed network; an interface of the series feed network is connected with the coupler which corresponds to the feed signal hole. The array antenna has the advantages of small size, low system complexity, low signal transmission loss, high production efficiency, high yield and the like.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an array antenna with a series-fed coupling network. Background Art

[0002] The existing array antenna with series-fed coupling network is usually composed of an independent passive antenna board and an independent series-fed coupling module, or the coupling network and the antenna patch are placed together on the same layer. There are the following defects: First, the high-integration integrated design is not adopted, which leads to an exponential increase in the number of RF connectors between the passive antenna board and the series-fed coupling module, resulting in an increase in the size of the array antenna; second, in addition to RF interconnection, mechanical interconnection needs to be considered, resulting in an increase in the complexity of system integration; third, the combination of the passive antenna board and the independent series-fed coupling module will lead to an increase in the signal transmission path, increase transmission loss, and affect the performance and efficiency of the system; fourth, during production, the series-fed coupling network module needs to be produced separately and tested, and the tested series-fed coupling network module is assembled with the passive antenna board into an array antenna. When the array antenna is tested, the production process is cumbersome, the production efficiency is reduced, and influencing factors are easily introduced in the entire production process, resulting in a decrease in the yield rate. Fifth, placing the coupling network and antenna patch on the same layer will reduce the isolation between the antenna patches by more than 10dB, sacrificing the array pattern scanning performance. At the same time, since the coupling network is also on the radiation layer of the antenna patch, the antenna's anti-interference performance will also be reduced.

[0003] In view of this, this application is hereby filed. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the existing array antenna with a series-fed coupling network has large size, high system complexity, large signal transmission loss, low isolation, low production efficiency and low yield.

[0005] In order to solve the above technical problems, the present invention is implemented by the following technical solutions: The invention discloses an array antenna with a series-fed coupling network, which can be used for Ka band. The array antenna comprises an antenna radiation layer, an upper antenna board, a series-fed coupling network layer and a lower antenna board; the antenna radiation layer is located on the top surface of the upper antenna board, the series-fed coupling network layer is located on the top surface of the lower antenna board, and the upper antenna board is pressed together with the lower antenna board; the antenna radiation layer comprises a plurality of radiation patches arranged in an array; a feeding signal hole is provided at the feeding point of each radiation patch; the series-fed coupling network layer comprises a plurality of feeding signal holes, and the plurality of feeding signal holes of the series-fed coupling network layer correspond one-to-one to the plurality of feeding signal holes of the antenna radiation layer; the series-fed coupling network layer also comprises a power divider, a common radio frequency port, a plurality of series-fed networks and a plurality of coupling structures; the power divider comprises an input port and a plurality of output ports, the input port is connected to the common radio frequency port, and one of the output ports is connected to one end of one of the series-fed networks; the series-fed network comprises a plurality of interfaces, the coupling structure comprises a plurality of couplers, one of the interfaces is connected to one of the couplers, and one of the couplers corresponds to one of the feeding signal holes of the series-fed coupling network layer.

[0006] Furthermore, a plurality of grounding holes are arranged in a ring around each of the radiation patches.

[0007] Furthermore, the array antenna with a series-fed coupling network also includes a first reference ground plane, an intermediate layer antenna board and a second reference ground plane; the first reference ground plane is located on the bottom surface of the upper layer antenna board, the second reference ground plane is located on the bottom surface of the lower layer antenna board, and the intermediate layer antenna board is pressed between the upper layer antenna board and the lower layer antenna board; the first reference ground plane and the second reference ground plane each include a plurality of feed signal holes, and the series-fed coupling network layer, the first reference ground plane and the second reference ground plane each include a plurality of grounding holes; the pattern composed of the plurality of feed signal holes and the plurality of grounding holes of the first reference ground plane corresponds to the pattern composed of the plurality of feed signal holes and the plurality of grounding holes of the antenna radiation layer; the pattern composed of the plurality of feed signal holes and the plurality of grounding holes of the series-fed coupling network layer is exactly the same as the pattern composed of the plurality of feed signal holes and the plurality of grounding holes of the antenna radiation layer; the pattern composed of the plurality of feed signal holes and the plurality of grounding holes of the second reference ground plane corresponds to the pattern composed of the plurality of feed signal holes and the plurality of grounding holes of the series-fed coupling network layer.

[0008] Furthermore, the array antenna with a series-fed coupling network also includes a step blind groove; the step blind groove sequentially passes through the antenna radiation layer, the upper antenna board, the first reference ground plane and the middle antenna board; the common RF port is located below the step blind groove.

[0009] Furthermore, the series-fed coupling network layer is a stripline, and the step blind slot is a microstrip line.

[0010] Furthermore, the series-fed coupling network layer also includes a plurality of load resistors and a plurality of groups of isolated ground holes; one of the load resistors is connected to the other end of one of the series-fed networks; and a group of isolated ground holes is arranged near each of the load resistors.

[0011] Furthermore, the second reference ground plane also includes a common RF port and multiple groups of isolated ground holes; the common RF port of the second reference ground plane corresponds to the common RF port of the series-fed coupling network layer; the multiple groups of isolated ground holes of the second reference ground plane correspond to the multiple groups of isolated ground holes of the series-fed coupling network layer.

[0012] Furthermore, the series-fed coupling network layer also includes a plurality of isolation resistors; one of the isolation resistors is provided at a branch node of the power divider.

[0013] Furthermore, the upper antenna board and the lower antenna board are both Ro3003 high-frequency laminate boards, and the middle antenna board is made of PP material; the upper antenna board, the middle antenna board and the lower antenna board are all provided with a plurality of positioning pin holes.

[0014] Furthermore, the plurality of radiation patches are arranged in a triangular array, and the isolation between antennas is increased by increasing the distance between antenna units and staggering their placement.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. A laminated structure including a multi-layer antenna board is adopted, the antenna radiation layer and the series-fed coupling network layer are arranged in layers, and the series-fed coupling network layer is embedded in the laminated structure of the multi-layer antenna board by pressing, so as to realize the high integration of the antenna radiation layer and the series-fed coupling network layer; at the same time, the multiple series-fed networks are combined into one channel through a power divider in the series-fed coupling network layer and then output from a common RF port, so as to realize the amplitude and phase calibration and state detection of each channel. The beneficial effects of the array antenna with a multi-layer antenna board laminated structure are: first, the integration and compactness of the array antenna are improved, thereby reducing the number of RF connectors between the passive antenna and the series-fed coupling network, and reducing the size and weight of the array antenna; second, the profile height of the array antenna is reduced, thereby shortening the signal transmission path between the passive antenna and the series-fed coupling module and reducing the RF loss; third, the precise matching and interconnection between the multi-layer antenna boards reduces the RF interconnection and mechanical interconnection between the passive antenna and the series-fed coupling network, thereby reducing the complexity of system integration and use; fourth, there is no need to conduct partial production and testing of the passive antenna and the series-fed coupling network, which can greatly reduce the production process and improve production efficiency. Fifth, the series-fed coupling network and the antenna patch are placed on different layers, which enhances the isolation between the series-fed network and the antenna patch, reduces the impact of the series-fed coupling network on the antenna pattern scanning performance, and is also conducive to enhancing the isolation between the control antenna patches. Sixth, strong anti-interference ability. Due to the embedded calibration coupling network, the interference signal from the external environment cannot directly enter the calibration coupling network during the calibration working mode (in the inner layer, it is shielded by the ground layer, and has strong anti-interference ability). Seventh, high isolation, higher isolation between antenna patches (compared to the design where the calibration coupling network and the antenna are located on the same layer, there is no coupling network between the antenna patches, which are completely separated by the ground space and the ground layer, so the isolation between the antenna patches can also be increased), and higher isolation between the antenna patch and the calibration coupling network (because the antenna patch and the calibration coupling network are located on the first and third layers respectively, and the second layer is a design architecture for shielding the ground layer, which improves the isolation between the two and has little mutual influence).

[0016] 2. A large number of grounding holes are arranged around each radiation patch, which can effectively increase the isolation between array elements and reduce the interference between array elements.

[0017] 3. Since the series-fed coupling network layer is integrated in the middle position of the array antenna, a step blind groove is added to facilitate the welding and assembly of the coupling network and the RF connector, thereby improving the reliability and connectivity of the array antenna.

[0018] 4. The series-fed coupling network layer is a stripline, and the step blind slot is a microstrip line, which can enhance the shielding performance of the series-fed coupling network.

[0019] 5. The buried resistor process is adopted. On the one hand, the load resistor is buried in the series feed network to ensure that the series feed network does not need to add additional load and can be well matched; on the other hand, the isolation resistor is buried in the power divider to ensure that the power divider has good isolation performance. The buried resistor process can also reduce the number of external components connected to the array antenna, further improving the overall integration and reliability of the array antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A side view of an array antenna with a series-fed coupling network provided by an embodiment of the present invention; Figure 2 A top view of the antenna radiation layer provided by an embodiment of the present invention; Figure 3 A top view of a first reference ground plane provided in an embodiment of the present invention; Figure 4 A top view of a series-fed coupling network layer provided in an embodiment of the present invention; Figure 5 A top view of a second reference ground plane provided in an embodiment of the present invention.

[0022] Marks and corresponding parts names in the attached drawings: 1-antenna radiation layer, 2-upper antenna board, 3-series feed coupling network layer, 4-lower antenna board, 5-first reference ground plane, 6-middle antenna board, 7-second reference ground plane, 8-step blind groove, 9-positioning pin hole, 11-radiation patch, 12-feed signal hole, 13-grounding hole, 31-power divider, 32-public RF port, 33-series feed network, 34-coupler, 35-load resistor, 36-isolation ground hole, 37-isolation resistor. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0024] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other embodiments, in order to avoid obscuring the present invention, well-known structures, circuits, materials, or methods are not specifically described.

[0025] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] In the description of the present invention, the directions or positional relationships indicated by terms such as “front”, “rear”, “left”, “right”, “up”, “down”, “vertical”, “horizontal”, “high”, “low”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0027] Embodiment: Provide an array antenna with a series-fed coupling network, adopt a multi-layer antenna board stacking process, arrange the passive antenna board and the series-fed coupling network module in layers, and integrate the series-fed coupling network module into the array antenna, thereby improving the integration of the entire array antenna. Figure 1 As shown, the array antenna with a series-fed coupling network consists of an antenna radiation layer 1, an upper antenna board 2 (Ro3003 high-frequency laminate), a first reference ground plane 5, an intermediate antenna board 6 (made of PP), a series-fed coupling network layer 3, a lower antenna board 4 (Ro3003 high-frequency laminate) and a second reference ground plane 7, and a step blind groove 8 and an isolation ground hole 36 are added. Among them, the antenna radiation layer 1 is located on the top surface of the upper antenna board 2, the series-fed coupling network layer 3 is located on the top surface of the lower antenna board 4, the first reference ground plane 5 is located on the bottom surface of the upper antenna board 2, and the second reference ground plane 7 is located on the bottom surface of the lower antenna board 4; reference Figures 2 to 5The upper antenna board 2, the middle antenna board 6 and the lower antenna board 4 are all provided with positioning pin holes 9, and the upper antenna board 2, the middle antenna board 6 and the lower antenna board 4 are pressed together in sequence by the positioning pins to form a laminated structure including three layers of antenna boards.

[0028] like Figure 2 As shown, the antenna radiation layer 1 includes 128 triangular array radiation patches 11, which are arranged in an array of 8×16. A corresponding feeding signal hole 12 is provided at the feeding point of each radiation patch 11, and a circle of 32 grounding holes 13 are arranged around each radiation patch 11 to increase the isolation between array elements and reduce interference between array elements.

[0029] like Figure 3 As shown, 128 feed signal holes 12 are also distributed on the first reference ground plane 5, and a circle of 32 ground holes 13 is distributed around each feed signal hole 12. Except that no radiation patch 11 is arranged on the first reference ground plane 5, the pattern consisting of 128 feed signal holes 12 and 128×32 ground holes 13 distributed thereon corresponds to the pattern consisting of 128 feed signal holes 12 and 128×32 ground holes 13 of the antenna radiation layer 1.

[0030] like Figure 4 As shown, there are 128 feed signal holes 12 distributed on the series-fed coupling network layer 3, and a circle of 32 ground holes 13 is distributed around each feed signal hole 12. Except that the radiation patch 11 is not arranged on the series-fed coupling network layer 3, the pattern composed of 128 feed signal holes 12 and 128×32 ground holes 13 distributed thereon is exactly the same as the pattern composed of 128 feed signal holes 12 and 128×32 ground holes 13 of the antenna radiation layer 1. Figure 4 , the series-fed coupling network layer 3 also includes a 1N4 Wilkins power divider 31, a public radio frequency port 32, 4 series-fed networks 33 and 4 groups of coupling structures. Among them, the output port of the 1N4 Wilkins power divider 31 is connected to the public radio frequency port 32, and each output port of the 1N4 Wilkins power divider 31 is respectively connected to one end of a series-fed network 33; each series-fed network 33 has 2×16 interfaces, and each group of coupling structures includes 16 couplers 34, one interface is connected to one coupler 34, and one coupler 34 corresponds to one feeding signal hole 12 on the series-fed coupling network layer 3. According to the above connection relationship, on the series-fed coupling network layer 3, each series-fed network 33 connects 2×16, a total of 32 couplers 34 corresponding to the feeding signal hole 12, and then synthesizes the 4 series-fed networks 33 of the whole array into one through the 1N4 Wilkinson power divider 31, and outputs through the public radio frequency port 32.

[0031] It should be noted that the array antenna with a series-fed coupling network provided in this embodiment adopts a buried resistor process. Specifically, Figure 4 In the example, each branch node of the 1N4 Wilkins power divider 31 is connected to an isolation resistor 37, which ensures that the power divider 31 has good isolation performance; in addition, the other end of each series feed network 33 is also connected to a load resistor 35, which ensures that the series feed network 33 does not need to add additional load and can be well matched; and a group of isolation ground holes 36 are also provided near each load resistor 35 to improve isolation. The buried resistor process can also reduce the number of external components connected to the array antenna, further improving the overall integration and reliability of the array antenna.

[0032] like Figure 5 As shown, 128 feed signal holes 12 are uniformly distributed on the second reference ground plane 7, and a circle of 32 ground holes 13 is distributed around each feed signal hole 12. Except that no radiation patch 11 is arranged on the second reference ground plane 7, the pattern consisting of 128 feed signal holes 12 and 128×32 ground holes 13 distributed thereon corresponds to the pattern consisting of 128 feed signal holes 12 and 128×32 ground holes 13 of the series-fed coupling network layer 3. In addition, the four groups of isolated ground holes 36 of the second reference ground plane 7 also correspond to the four groups of isolated ground holes 36 of the series-fed coupling network layer 3.

[0033] Furthermore, in order to facilitate the welding and assembly of the coupling network and the RF connector and improve the reliability and connectivity of the array antenna, the array antenna with a series-fed coupling network provided in this embodiment is also added. Figures 1 to 3 The step blind groove 8 shown in the figure, the public radio frequency port 32 is located below the step blind groove 8. Figure 1 It can be seen that the step blind slot 8 passes through the antenna radiation layer 1, the upper antenna board 2, the first reference ground plane 5 and the middle antenna board 6 from top to bottom. It should be noted that the array antenna of this embodiment adopts stripline transmission as the main method and microstrip line transmission as the auxiliary method, that is, the series-fed coupling network layer 3 is a stripline and the step blind slot 8 is a microstrip line, the purpose of which is to increase the shielding performance of the series-fed coupling network and avoid crosstalk.

[0034] To summarize, the array antenna with a series-fed coupling network provided in this embodiment adopts a stacked structure including a multi-layer antenna board, arranges the antenna radiation layer and the series-fed coupling network layer in layers, and embeds the series-fed coupling network layer in the stacked structure of the multi-layer antenna board by pressing, so as to achieve a high degree of integration between the antenna radiation layer and the series-fed coupling network layer; at the same time, in the series-fed coupling network layer, multiple series-fed networks are synthesized into one channel through a power divider and output from a common RF port, so as to achieve amplitude and phase calibration and status detection for each channel. The beneficial effects of the array antenna with a multi-layer antenna board stacking structure are: first, the integration and compactness of the array antenna are improved, thereby reducing the number of RF connectors between the passive antenna and the series-fed coupling network, and reducing the size and weight of the array antenna; second, the cross-sectional height of the array antenna is reduced, thereby shortening the signal transmission path between the passive antenna and the series-fed coupling module and reducing RF losses; third, the precise matching and interconnection between the multi-layer antenna boards reduces the RF interconnection and mechanical interconnection between the passive antenna and the series-fed coupling network, thereby reducing the complexity of system integration and use; fourth, there is no need to carry out partial production and testing of the passive antenna and the series-fed coupling network, which can greatly reduce the production process and improve production efficiency.

[0035] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An array antenna with a series-fed coupling network, characterized in that: It comprises an antenna radiation layer (1), an upper antenna board (2), a series-fed coupling network layer (3) and a lower antenna board (4); The antenna radiation layer (1) is located on the top surface of the upper antenna board (2), the series-fed coupling network layer (3) is located on the top surface of the lower antenna board (4), and the upper antenna board (2) and the lower antenna board (4) are pressed together; The antenna radiation layer (1) comprises a plurality of radiation patches (11) arranged in an array; a feeding signal hole (12) is provided at a feeding point of each of the radiation patches (11); The series-fed coupling network layer (3) comprises a plurality of feeding signal holes (12), and the plurality of feeding signal holes (12) of the series-fed coupling network layer (3) correspond one-to-one to the plurality of feeding signal holes (12) of the antenna radiation layer (1); The series-fed coupling network layer (3) further includes a power divider (31), a common radio frequency port (32), a plurality of series-fed networks (33) and a plurality of coupling structures; The power divider (31) comprises an input port and a plurality of output ports, the input port being connected to the common radio frequency port (32), and one of the output ports being connected to one end of one of the series feed networks (33); The series-fed network (33) includes a plurality of interfaces, the coupling structure includes a plurality of couplers (34), one of the interfaces is connected to one of the couplers (34), and one of the couplers (34) corresponds to one feeding signal hole (12) of the series-fed coupling network layer (3).

2. The array antenna with a series-fed coupling network according to claim 1, characterized in that: A plurality of grounding holes (13) are arranged in a ring around each of the radiation patches (11).

3. The array antenna with a series-fed coupling network according to claim 2, characterized in that: It also includes a first reference ground plane (5), an intermediate layer antenna board (6) and a second reference ground plane (7); The first reference ground plane (5) is located on the bottom surface of the upper antenna board (2), the second reference ground plane (7) is located on the bottom surface of the lower antenna board (4), and the middle antenna board (6) is pressed between the upper antenna board (2) and the lower antenna board (4); The first reference ground plane (5) and the second reference ground plane (7) both include a plurality of feed signal holes (12), and the series-fed coupling network layer (3), the first reference ground plane (5) and the second reference ground plane (7) both include a plurality of ground holes (13); a pattern formed by the plurality of feed signal holes (12) and the plurality of ground holes (13) of the first reference ground plane (5) corresponds to a pattern formed by the plurality of feed signal holes (12) and the plurality of ground holes (13) of the antenna radiation layer (1); a pattern formed by the plurality of feed signal holes (12) and the plurality of ground holes (13) of the series-fed coupling network layer (3) is completely identical to a pattern formed by the plurality of feed signal holes (12) and the plurality of ground holes (13) of the antenna radiation layer (1); and a pattern formed by the plurality of feed signal holes (12) and the plurality of ground holes (13) of the second reference ground plane (7) corresponds to a pattern formed by the plurality of feed signal holes (12) and the plurality of ground holes (13) of the series-fed coupling network layer (3).

4. An array antenna with a series-fed coupling network according to claim 3, characterized in that: It also includes a step blind groove (8); the step blind groove (8) sequentially penetrates the antenna radiation layer (1), the upper antenna board (2), the first reference ground plane (5) and the middle antenna board (6); and the public radio frequency port (32) is located below the step blind groove (8).

5. The array antenna with a series-fed coupling network according to claim 4, characterized in that: The series-fed coupling network layer (3) is a strip line, and the step blind slot (8) is a microstrip line.

6. An array antenna with a series-fed coupling network according to any one of claims 3 to 5, characterized in that: The series-fed coupling network layer (3) further comprises a plurality of load resistors (35) and a plurality of groups of isolated ground holes (36); one of the load resistors (35) is connected to the other end of one of the series-fed networks (33); and a group of isolated ground holes (36) is arranged near each of the load resistors (35).

7. The array antenna with a series-fed coupling network according to claim 6, characterized in that: The second reference ground plane (7) further comprises a common radio frequency port (32) and a plurality of groups of isolated ground holes (36); the common radio frequency port (32) of the second reference ground plane (7) corresponds to the common radio frequency port (32) of the series-fed coupling network layer (3); and the plurality of groups of isolated ground holes (36) of the second reference ground plane (7) corresponds to the plurality of groups of isolated ground holes (36) of the series-fed coupling network layer (3).

8. An array antenna with a series-fed coupling network according to any one of claims 1 to 5, characterized in that: The series-fed coupling network layer (3) further comprises a plurality of isolation resistors (37); one isolation resistor (37) is arranged at a branch node of the power divider (31).

9. An array antenna with a series-fed coupling network according to any one of claims 3 to 5, characterized in that: The upper antenna board (2) and the lower antenna board (4) are both Ro3003 high-frequency laminates, and the middle antenna board (6) is made of PP material; a plurality of positioning pin holes (9) are provided on the upper antenna board (2), the middle antenna board (6) and the lower antenna board (4).

10. An array antenna with a series-fed coupling network according to any one of claims 1 to 5, characterized in that: The plurality of radiation patches (11) are arranged in a triangular array.

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