Multi-branch antenna unit and phased array antenna

Abstract

The invention relates to the technical field of satellite communication, in particular to a multi-branch antenna unit and a phased-array antenna. The multi-branch antenna unit comprises a multi-branch radiation structure and a feed structure. The multi-branch radiation structure comprises a first flat plate, a second flat plate and a third flat plate which are symmetrically arranged, the feed structure comprises a rectangular metal cavity, a dielectric substrate, a first port, a second port, two feed probes and a microstrip line. The first port and the second port are symmetrically arranged at the bottom of the feed structure, and the first port and the second port are respectively connected to two ends of the microstrip line through feed probes; the dielectric substrate is arranged in the rectangular metal cavity. The external feed power supply is excited through the first port or the second port to form two radiation beams with symmetrical pointing directions, beam scanning of the whole space can be realized only by providing amplitude-phase control of one sub-scanning area, meanwhile, the gain drop is small, and flat scanning gain can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite communications, and in particular to a multi-branch antenna unit and a phased array antenna. Background Art

[0002] Antennas are one of the most important components of satellite communication links, and their performance directly determines the quality of satellite communications. In current medium and low-orbit high-throughput satellite communication systems, parabolic antennas are mostly used as communication terminals, but they have the defects of large profile, inflexible beam control, low integration and high maintenance cost, making it difficult to adapt to the needs of high-speed satellite-to-ground interconnection communications in the context of low-orbit satellite Internet. Phased array antennas can achieve beam control, but phased array antennas generally have the problem of large gain drop when scanning at large angles, which greatly affects the communication performance of the phased array in the process of tracking satellites, resulting in a reduction in the effective communication range. The antenna gain of the current phased array when it reaches the maximum scanning angle has a larger gain drop than the maximum normal gain, and flat scanning gain cannot be achieved.

[0003] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The main purpose of the present invention is to provide a multi-branch antenna unit and a phased array antenna, aiming to solve the technical problem in the prior art that the antenna gain of the phased array antenna drops significantly compared to the normal direction when scanning to the maximum angle.

[0005] To achieve the above object, the present invention proposes a multi-branch antenna unit, which includes: a multi-branch radiation structure and a feeding structure; The multi-branch radiation structure comprises: first to third flat plates arranged symmetrically, wherein two adjacent flat plates respectively form the first to second branches; The feeding structure comprises: a rectangular metal cavity, a dielectric substrate, a first port, a second port, two feeding probes and a microstrip line; The first port and the second port are symmetrically arranged at the bottom of the feeding structure, and the first port and the second port are respectively connected to two ends of the microstrip line through the feeding probe; The dielectric substrate is arranged in the rectangular metal cavity, and the multi-branch radiation structure is arranged above the rectangular metal cavity; An external power supply excites the microstrip line through the first port or the second port to form an electromagnetic field which is then fed into the multi-branch radiation structure to form a radiation beam.

[0006] Optionally, the dielectric substrate comprises, from bottom to top: a first dielectric layer and a second dielectric layer; The first dielectric layer and the second dielectric layer have the same thickness; The first port and the second port are arranged at the bottom of the first dielectric layer, the two feeding probes are arranged inside the first dielectric layer, and the microstrip line is arranged at the interface between the first dielectric layer and the second dielectric layer.

[0007] Optionally, in the multi-branch radiation structure, the symmetrically arranged first flat plate and the third flat plate are set to the same first preset height, the second flat plate is set to the second preset height, and the first to third flat plates are set to the same first preset thickness; The first plate and the second plate form a first branch, and the second plate and the third plate form a second branch; The first branches and the second branches have the same first preset distance.

[0008] Optionally, the direction and width of the radiation beam are adjusted according to the first preset height, the second preset height, the first preset thickness and the first preset spacing.

[0009] Optionally, the height of the rectangular metal cavity is twice the thickness of the first dielectric layer.

[0010] In addition, to achieve the above objective, the present invention further provides a phased array antenna, which includes a plurality of multi-branch antenna units as described above and T / R components corresponding to the number of the multi-branch antenna units.

[0011] Optionally, the phased array antenna comprises: N one-dimensionally arranged multi-branch antenna units, where N is an integer greater than 1; Adjacent multi-branch antenna units are connected in series through the T / R component.

[0012] Optionally, the phased array antenna comprises: the multi-branch antenna units arranged in an M*M rectangular shape, where M is an integer greater than 1; The phased array antenna further comprises: a one-to-M power splitter; The multi-branch antenna units in one direction of the rectangular array are combined through the one-to-M power divider to form 2M input ports of the one-to-M power divider; The input ports of the 2M adjacent one-to-M power dividers except the first and the last one are connected in series through the T / R assembly.

[0013] Optionally, the phased array antenna comprises: N one-dimensionally arranged multi-branch antenna units, wherein N is an integer greater than 1, and adjacent multi-branch antenna units are arranged in parallel feeding; The phased array antenna also includes: a one-to-N power divider and N single-pole double-throw switches; The input end of each T / R component is connected to the output port of the one-to-N power divider, the output end of each T / R component is connected to the input end of a single-pole double-throw switch, and the two output ends of each single-pole double-throw switch are respectively connected to the first port and the second port of the corresponding multi-branch antenna unit.

[0014] Optionally, the phased array antenna comprises: the multi-branch antenna units arranged in an M*M rectangular shape; The phased array antenna also includes: a one-to-M power divider and a single-pole double-throw switch; The multi-branch antenna units in one direction of the rectangular array are combined through the one-to-M power divider to form 2M input ports of the one-to-M power divider; The input ports of the adjacent one-to-M power dividers are connected through the two output ports of the single-pole double-throw switch, and the input end of the single-pole double-throw switch is connected to the output end of the corresponding T / R component.

[0015] The present invention provides a multi-branch antenna unit and a phased array antenna, the multi-branch antenna unit comprises: a multi-branch radiation structure and a feeding structure; the multi-branch radiation structure comprises: symmetrically arranged first to third flat plates, two adjacent flat plates respectively forming first to second branches; the feeding structure comprises: a rectangular metal cavity, a dielectric substrate, a first port, a second port, two feeding probes and a microstrip line; the first port and the second port are symmetrically arranged at the bottom of the feeding structure, the first port and the second port are respectively connected to the two ends of the microstrip line through the feeding probe; the dielectric substrate is arranged in the rectangular metal cavity; an external feeding source excites the microstrip line through the first port or the second port, and then an electromagnetic field is formed and fed into the multi-branch radiation structure to form a radiation beam. The external feeding source excites through the first port or the second port respectively to form two symmetrically directed radiation beams, and only needs to provide an amplitude and phase control of a sub-scanning area to realize beam scanning of the entire space, and at the same time, the gain drop is small, and a flat scanning gain can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1It is a structural schematic diagram of a first embodiment of a multi-branch antenna unit of the present invention; Figure 2 It is a schematic structural diagram of a multi-branch radiation structure in a first embodiment of a multi-branch antenna unit of the present invention; Figure 3 It is a structural front view of a multi-branch radiation structure in a first embodiment of a multi-branch antenna unit of the present invention; Figure 4 It is a structural side view of a multi-branch radiation structure in a first embodiment of a multi-branch antenna unit of the present invention; Figure 5 It is a structural schematic diagram of the feeding structure and the dielectric layer distribution in the first embodiment of the multi-branch antenna unit of the present invention; Figure 6 It is a schematic structural diagram of a feeding structure in a first embodiment of a multi-branch antenna unit of the present invention; Figure 7 A top view of the structure of the feeding structure in the first embodiment of the multi-branch antenna unit of the present invention; Figure 8 The radiation patterns generated by different ports of the excitation antenna unit in the first embodiment of the multi-branch antenna unit of the present invention; Fig. 9 A schematic diagram of the electric field of the TEM mode formed by the feeding structure in the first embodiment of the multi-branch antenna unit of the present invention; Fig.10 A schematic diagram of a magnetic field of a TEM mode formed by a feeding structure in a first embodiment of a multi-branch antenna unit of the present invention; Fig.11 It is a schematic structural diagram of a first embodiment of a phased array antenna of the present invention; Fig.12 It is a schematic structural diagram of a second embodiment of the phased array antenna of the present invention; Fig.13 A schematic diagram of the distribution of feed ports of a second embodiment of a phased array antenna according to the present invention; Fig.14 It is a schematic structural diagram of a third embodiment of the phased array antenna of the present invention; Fig.15 It is a schematic structural diagram of a fourth embodiment of the phased array antenna of the present invention; Fig.16 A schematic diagram of the distribution of feed ports of a fourth embodiment of a phased array antenna according to the present invention; Fig.17 The beam scanning patterns of the first and third embodiments of the phased array antenna of the present invention; Fig.18 The beam scanning patterns of the second and fourth embodiments of the phased array antenna of the present invention.

[0018] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0019] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] The main solution of the embodiment of the present invention is: the multi-branch antenna unit includes: a multi-branch radiation structure and a feeding structure; the multi-branch radiation structure includes: symmetrically arranged first to third plates, and two adjacent plates respectively constitute the first to second branches; the feeding structure includes: a rectangular metal cavity, a dielectric substrate, a first port, a second port, two feeding probes and a microstrip line; the first port and the second port are symmetrically arranged at the bottom of the feeding structure, and the first port and the second port are respectively connected to the two ends of the microstrip line through the feeding probes; the dielectric substrate is arranged in the rectangular metal cavity; an external feeding source excites the microstrip line through the first port or the second port, and then feeds the electromagnetic field into the multi-branch radiation structure to form a radiation beam.

[0024] In the current medium and low-orbit high-throughput satellite communication systems, parabolic antennas are mostly used as communication terminals, but they have large profiles, inflexible beam control, low integration, and high maintenance costs, making it difficult to adapt to the needs of high-speed satellite-to-ground interconnection communications in the context of low-orbit satellite Internet. Phased array antennas have the advantages of high integration, fast beam scanning, and flexible beam control (beamforming, multi-beam). They have been widely used in satellite communications and other fields, but phased array antennas generally have the problem of gain drop when scanning at large angles, which greatly affects the communication performance of the phased array in the process of tracking satellites, resulting in a reduction in the effective communication range.

[0025] Continuous Transverse Stub (CTS) array antennas have been widely used in terminals of mobile communication systems. The tangential branches of CTS cut off the longitudinal conduction current, generating displacement current, which can radiate outward. Currently, the types of CTS antennas with beam scanning capabilities are electronically scanned CTS antennas, variable inclination continuous tangential stub arrays (VICTS) antennas, and frequency-scanned CTS antennas. Among them, frequency-scanned CTS antennas cannot generate beam pointing at different angles at a fixed frequency.

[0026] The antenna gain when the front phased array reaches the maximum scanning angle has a larger gain drop compared to the normal maximum gain, and it is impossible to achieve flat scanning gain. The planar structure of the pseudo-conformal (Pseudo Curved Surface Conformal, PCSC) phased array antenna uses antenna units with different beam tilts, resulting in a high sidelobe level after the array. The VICTS antenna uses a series-fed CTS branch to achieve beam scanning by changing the wavefront phase of the TEM wave generated by the feed source through the relative rotation of the feeding layer and the radiating layer. The feeding structure of VICTS is complex. In addition, the current VICTS antenna has a gain drop of more than 3dB within the scanning range, and it is impossible to achieve flat scanning gain.

[0027] Reference Figure 1 , Figure 1 FIG. 1 is a schematic diagram of the structure of a first embodiment of a multi-branch antenna unit according to the present invention. Figure 1As shown, in this embodiment, the multi-branch antenna unit includes: a multi-branch radiation structure 10 and a feeding structure 20. The multi-branch radiation structure 10 includes: first to third flat plates that are symmetrically arranged, and two adjacent flat plates respectively constitute the first branch and the second branch. The feeding structure 20 includes: a first port 201, a second port 202, two feeding probes 203, a microstrip line 204, a rectangular metal cavity 205 and a dielectric substrate; the first port 201 and the second port 202 are symmetrically arranged at the bottom of the feeding structure 20, and the first port 201 and the second port 202 are respectively connected to the two ends of the microstrip line 204 through the feeding probe 203; the dielectric substrate is arranged in the rectangular metal cavity 205, and the multi-branch radiation structure 10 is arranged above the rectangular metal cavity 205.

[0028] It should be noted that the multi-branch antenna unit proposed in this embodiment can be a CTS antenna unit. The external feed source excites the microstrip line through the first port or the second port, and after forming an electromagnetic field, it is fed into the multi-branch radiation structure to form a radiation beam. The external feed source excites through the first port or the second port to form two symmetrical radiation beams pointing to ±35°. The phased array antenna formed by this embodiment as the antenna unit only needs to provide amplitude and phase control of a sub-scanning area to achieve beam scanning of the entire scanning space (-65° to 65°). The gain drop in the entire scanning space (-65° to 65°) is small, less than 2dBi, and a flat scanning gain can be achieved.

[0029] Reference Figure 2 , Figure 3 and Figure 4 , Figure 2 It is a structural schematic diagram of a multi-branch radiation structure in the first embodiment of a multi-branch antenna unit of the present invention, Figure 3 It is a structural front view of the multi-branch radiation structure in the first embodiment of the multi-branch antenna unit of the present invention, Figure 4It is a structural side view of a multi-branch radiation structure in the first embodiment of a multi-branch antenna unit of the present invention. In the multi-branch radiation structure 10, the symmetrically arranged first plate 101 and the third plate 103 have the same first preset height (h2), the second plate 102 is set to a second preset height (h1), and the first to third plates have the same first preset thickness (w2). The first plate 101 and the second plate 102 constitute a first branch 104, the second plate 102 and the third plate 103 constitute a second branch 105, and the first branch 104 and the second branch 105 have the same first preset spacing (w1). Among them, the second preset height (h1) needs to be greater than the first preset height (h2), that is, the height of the second plate is greater than the first plate and the third plate so that the beam pointing of the antenna unit is deflected. The beam pointing of the antenna unit can be deflected differently by adjusting the specific values ​​of the first preset height (h2), the second preset height (h1) and the first preset spacing (w1).

[0030] In a possible implementation, the first preset height (h2) can be set to 11.5 mm, the second preset height (h1) can be set to 16 mm, and the first preset spacing (w1) can be set to 4.82 mm, and by feeding the first port and the second port respectively, the antenna unit generates a ±35° beam pointing.

[0031] Reference Figure 5 , Figure 6 and Figure 7 , Figure 5 It is a schematic diagram of the structure of the feeding structure and the dielectric layer distribution in the first embodiment of the multi-branch antenna unit of the present invention. Figure 6 It is a schematic diagram of the structure of the feeding structure in the first embodiment of the multi-branch antenna unit of the present invention, Figure 7 1 is a top view of the structure of the feeding structure in the first embodiment of the multi-branch antenna unit of the present invention. The feeding structure of the multi-branch antenna unit of the present invention is composed of a rectangular metal cavity and a dielectric substrate, and the dielectric substrate includes from bottom to top: a first dielectric layer 206 and a second dielectric layer 207. The thickness of the rectangular metal cavity is w3, and the length, width, and height of the rectangular metal cavity are D1, L1, and h3 respectively. Figure 6 The first dielectric layer 206 is shown as covering a microstrip line with a width of D2 and a length of L2. Two symmetrically positioned feeding probes are connected to the microstrip line. The height of the two feeding probes is consistent with the height of the first dielectric layer 206. The GND is located on the bottom surface of the first dielectric layer 206 and a hole is opened on the GND as the feeding ports of the two feeding probes, namely the first port and the second port. The characteristic impedance of the feeding port can be set to 50Ω. The second dielectric layer 207 covers the top of the first dielectric layer 206. The dielectric layer can be composed of F4B dielectric (a high-frequency board made of polytetrafluoroethylene material).

[0032] It should be noted that the radiation beam direction and width are adjusted according to the first preset height (h2), the second preset height (h1), the first preset thickness (w2), and the first preset spacing (w1). It can make the main beam directions of the radiation pattern of the multi-branch CTS antenna unit point to ±35° and have a 2dB beam width greater than 65°. That is, when the first port is fed, the main radiation beam direction of the multi-branch antenna unit is +35°, and when the second port is fed, the main radiation beam direction of the antenna unit is -35°, and the two patterns are symmetrical. Refer to Figure 8 , Figure 8 The radiation patterns generated by different ports of the excitation antenna unit in the first embodiment of the multi-branch antenna unit of the present invention are shown in FIG. 2 , wherein the 2dB beam width is greater than 65°.

[0033] It should be understood that the microstrip line is excited by the feeding probe, and the excited microstrip line is in the feeding structure composed of the rectangular metal cavity and the dielectric layer (such as Figure 5 As shown in the figure, a transverse (TEM) electromagnetic field is formed, and the TEM electromagnetic field is fed into the CTS branch of the antenna unit to form radiation. Fig. 9 and Fig.10 , Fig. 9 FIG. 1 is a schematic diagram of an electric field of a TEM mode formed by a feeding structure in a first embodiment of a multi-branch antenna unit of the present invention. Fig.10 It is a schematic diagram of the magnetic field of the TEM mode formed by the feeding structure in the first embodiment of the multi-branch antenna unit of the present invention.

[0034] In this embodiment, the multi-branch antenna unit includes: a multi-branch radiation structure and a feeding structure; the multi-branch radiation structure includes: symmetrically arranged first to third flat plates, and two adjacent flat plates respectively form the first to second branches; the feeding structure includes: a rectangular metal cavity, a dielectric substrate, a first port, a second port, two feeding probes and a microstrip line; the first port and the second port are symmetrically arranged at the bottom of the feeding structure, and the first port and the second port are respectively connected to the two ends of the microstrip line through the feeding probe; the dielectric substrate is arranged in the rectangular metal cavity; the external feeding source excites the microstrip line through the first port or the second port, and then feeds into the multi-branch radiation structure to form a radiation beam after forming an electromagnetic field. The external feeding source excites through the first port or the second port to form two symmetrical radiation beams pointing to ±35°, and the phased array antenna formed by using this embodiment as the antenna unit only needs to provide an amplitude and phase control of a sub-scanning area to realize beam scanning of the entire scanning space (-65° to 65°), and the gain drop in the entire scanning space (-65° to 65°) is small, less than 2dBi, and a flat scanning gain can be achieved. The main radiation directions of the multi-branch CTS antenna unit under excitation of different ports are respectively toward ±35°, and a 2dB beam width greater than 65° is formed in the main radiation beam direction, and the two generated directional patterns are symmetrical.

[0035] In addition, in order to achieve the above-mentioned purpose, an embodiment of the present invention further proposes a phased array antenna, wherein the phased array antenna includes a plurality of the above-mentioned multi-branch antenna units and the corresponding T / R components. Since the phased array antenna includes the above-mentioned multi-branch antenna units, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0036] Reference Fig.11 , Fig.11 FIG. 1 is a schematic diagram of the structure of the first embodiment of the phased array antenna of the present invention. Fig.11As shown, in this embodiment, the phased array antenna is a one-dimensional series-fed phased array antenna, including: N one-dimensionally arranged multi-branch antenna units, where N is an integer greater than 1; adjacent multi-branch antenna units are connected in series through the T / R component. Beam scanning (-65° to 65°) can be performed on the yoz plane. This embodiment is described by taking a one-dimensional 8-unit series-fed phased array antenna as an example. Among them, the one-dimensional 8-unit series-fed phased array antenna includes: a feeding port (①) of the antenna unit, a T / R component (②), and the T / R component can be a transmit / receive component, which is composed of a power amplifier and a phase shifter, and is used to amplify the antenna transmit / receive signal and control the direction of the antenna radiation beam. In the arrangement direction y of the array, except for the first port (Port1) and the last port (Port2), the two adjacent ports of the antenna unit are connected to the input end (In) and the output end (Out) of the T / R component (②) in sequence.

[0037] It should be noted that, by utilizing the symmetry of the designed multi-branch antenna unit structure, the T / R component only needs to provide amplitude and phase control of a sub-scanning area to achieve beam scanning of the entire scanning space (-65° to 65°). The scanning range of the phased array (-65° to 65°) is divided into two sub-scanning areas (-65° to 0°) and (0° to 65°) with 0° as the dividing line. Fig.11 When the feeding port (port1) of the one-dimensional 8-element serially fed phased array antenna shown is fed, the antenna will scan in the range of 0-65°; when the feeding port (port2) of the phased array antenna is fed using the amplitude and phase control of the sub-scanning area (0° to 65°), the antenna will scan in the range of (-65° to 0°).

[0038] It should be understood that multiple other types of structures can also be used, such as an antenna unit with two feeding ports formed by combining different types of coupling structures. When the feeding port (Port1) is excited, the main beam of the antenna unit radiation pattern points to a specific direction and the 2dB beam width of the pattern covers a certain angle range. When the feeding port (Port2) is excited, the main beam of the antenna unit radiation beam points to the opposite direction of the main beam obtained by exciting the feeding port (Port1). The shapes of the patterns obtained by respectively exciting the feeding port (Port1) and the feeding port (Port2) of the antenna unit are symmetrical. After the antenna units are formed into a phased array antenna, the symmetry of the designed antenna unit structure is used to divide the scanning range of the phased array into two left and right sub-scanning areas with 0° as the dividing line. The T / R component only needs to provide the amplitude and phase control of one sub-scanning area to achieve beam scanning within a certain range. Within a certain beam scanning range, the gain drop of the phased array antenna is small, the gain change of the scanning beam is flat, and flat scanning gain can be achieved.

[0039] In one possible implementation, an antenna unit is formed by a coupling structure composed of multiple magnetic current elements, or an antenna unit is formed by a coupling structure composed of multiple current sources, and an antenna unit is formed by a coupling structure composed of a mixture of multiple magnetic current sources and current sources; for example, an antenna unit is formed by a coupling structure composed of multiple electric dipole antennas and slot antennas, an antenna unit is formed by a coupling structure composed of multiple electric dipole antennas and microstrip antennas, an antenna unit is formed by a coupling structure composed of multiple microstrip antennas, an antenna unit is formed by a coupling structure composed of multiple slot antennas, an antenna unit is formed by a coupling structure composed of multiple electric dipole antennas, etc.; and a perturbation unit is added next to the antenna or an asymmetric structure is used to change the main beam direction of the antenna radiation pattern to point to a specific direction.

[0040] Reference Fig.12 , Fig.12 FIG. 1 is a schematic diagram of the structure of the second embodiment of the phased array antenna of the present invention. Fig.12 As shown, in this embodiment, the phased array antenna is a two-dimensional series-fed phased array antenna, and the antenna includes: the multi-branch antenna units arranged in an M*M rectangular shape, where M is an integer greater than 1. The phased array antenna also includes: a one-to-M power divider and a T / R component. Fig.13 The diagram is a schematic diagram of the distribution of feed ports of the second embodiment of the phased array antenna of the present invention. This embodiment is described by taking a two-dimensional 8*8 unit series-fed phased array antenna as an example. The one-to-eight power splitter (③) is used to combine the feed ports of the antenna units in the array.

[0041] like Fig.13 As shown, the 8*8 array antenna has 16 columns of feed ports arranged along the x direction, and each column has 8 feed ports. There are 8 rows of feed ports arranged along the y direction. Fig.12 As shown, each column of feed ports arranged along the x direction of the two-dimensional series-fed phased array antenna is combined by a one-to-eight power divider (③) to form 16 input ports of the power divider (③). The input ports of the 16 power dividers (③) are numbered A1 to A16, respectively. In addition to the ports A1 and A16 at both ends of the array, the two adjacent ports from A2 to A15 are connected to the input and output ends of the T / R component (②) in sequence (A2 is connected to the input port of the T / R component, and A3 is connected to the output port of the T / R component, and so on), forming a two-dimensional series-fed phased array antenna, which can perform beam scanning (-65° to 65°) on the yoz plane.

[0042] Similar to the first embodiment of the phased array antenna, by utilizing the symmetry of the designed antenna unit structure, the T / R component only needs to provide amplitude and phase control of a sub-scanning area to achieve beam scanning of the entire scanning space (-65° to 65°). Fig.12When the feeding port (port1) of the 8*8 element phased array antenna shown is fed, the antenna will scan in the range of 0°-65°; when the feeding port (port2) of the 8*8 element phased array antenna is fed, the antenna will scan in the range of -65° to 0°, and finally perform beam scanning in the range of ±65°.

[0043] Reference Fig.14 , Fig.14 FIG. 1 is a schematic diagram of the structure of the third embodiment of the phased array antenna of the present invention. Fig.14 As shown, in this embodiment, the phased array antenna is a one-dimensional parallel-fed phased array antenna, including: N one-dimensionally arranged multi-branch antenna units, adjacent multi-branch antenna units are arranged for parallel feeding; the phased array antenna includes: N one-dimensionally arranged multi-branch antenna units, wherein N is an integer greater than 1, and adjacent multi-branch antenna units are arranged for parallel feeding. The phased array antenna also includes: a one-to-N power divider and N single-pole double-throw switches; the input end of each T / R component is connected to the output port of the one-to-N power divider, the output end of each T / R component is connected to the input end of a single-pole double-throw switch, and the two output ends of each single-pole double-throw switch are respectively connected to the corresponding feed port of the multi-branch antenna unit. The T / R component only needs to provide amplitude and phase control of a sub-scanning area and switch different feed ports of the antenna unit through the single-pole double-throw switch to achieve (-65° to 65°) beam scanning on the yoz plane.

[0044] This embodiment is described by taking a one-dimensional 8-element parallel-fed phased array antenna as an example, and a one-to-eight power divider (④) is used to combine the input ports of the T / R component (②). Fig.14 As shown, the two feeding ports of each antenna unit are connected to the output of the single-pole double-throw switch, the output of the T / R component (②) is connected to the input of the single-pole double-throw switch, and the input port of the T / R component is connected to the output port of the one-to-eight power divider (④). When the one-dimensional 8-unit parallel-fed phased array antenna is working, the input end of the one-to-eight power divider (④) is fed, and the T / R component only needs to provide amplitude and phase control of a sub-scanning area and switch different feeding ports of the antenna unit through a single-pole double-throw switch to achieve (-65° to 65°) beam scanning on the yoz plane. Specifically, when the input end of the one-to-eight power divider (④) is fed, and all the single-pole double-throw switches are turned to the left to connect the B group ports (the B group ports are composed of ports B1 to B8, 8 ports), the eight one-dimensionally arranged phased array antennas achieve (0-65°) spatial beam scanning; when all the single-pole double-throw switches are turned to the right to connect the C group ports (the C group ports are composed of ports C1 to C8, 8 ports), the eight one-dimensionally arranged phased arrays achieve (-65°-0°) spatial beam scanning.

[0045] Reference Fig.15 , Fig.15 FIG. 4 is a schematic diagram of the structure of a fourth embodiment of a phased array antenna according to the present invention. Fig.15 As shown, in this embodiment, the phased array antenna is a two-dimensional parallel-fed phased array antenna, and the antenna includes: the multi-branch antenna units arranged in an M*M rectangular shape; the phased array antenna also includes: a one-to-M power divider, a single-pole double-throw switch, and a T / R component; Fig.16 This is a schematic diagram of the distribution of feeding ports of the fourth embodiment of the phased array antenna of the present invention. This embodiment is described by taking a two-dimensional 8*8 unit parallel-fed phased array antenna as an example, and a one-to-eight power divider is used as the power divider.

[0046] like Fig.16 As shown, the 8*8 array antenna has 16 columns of feed ports arranged along the x direction, and each column has 8 feed ports. There are 8 rows of feed ports arranged along the y direction. Fig.15 As shown, each column of feed ports of the two-dimensional parallel-fed phased array antenna arranged along the x direction is combined with a one-to-eight power divider (③) to form 16 input ports of the power divider (③). The input ports of the 16 power dividers (③) are numbered A1 to A16. Among the input ports (A1 to A16) of the 16 power dividers (③), each two adjacent input ports are connected with the output ports of a single-pole double-throw switch. A total of 8 single-pole double-throw switches are required. The input end of the single-pole double-throw switch consists of a D group port (D group port consists of ports D1 to D8, 8 ports) and an E group port (E group port consists of ports E1 to E8, 8 ports). The single-pole double-throw switch connects the E group port or the D group port by switching. The input ends of these 8 single-pole double-throw switches are connected to the output ends of the 8 T / R components. The input ends of the 8 T / R components are connected to the output end of the one-to-eight power divider (④). When the input end of the one-to-eight power divider (④) is fed, the T / R component only needs to provide amplitude and phase control of a sub-scanning area and switch different feeding ports of the antenna unit through the single-pole double-throw switch to achieve beam scanning (-65° to 65°) on the yoz plane. Specifically, when the input end of the one-to-eight power divider (④) is fed and all the single-pole double-throw switches are turned to the left to connect the D group ports (the D group ports are composed of 8 ports from ports D1 to D8), the 8*8 two-dimensionally arranged phased array antenna achieves (0°-65°) spatial beam scanning; when all the single-pole double-throw switches are turned to the right to connect the E group ports (the E group ports are composed of 8 ports from ports E1 to E8), the 8*8 two-dimensionally arranged phased array antenna achieves (-65°-0°) spatial beam scanning.

[0047] Fig.17 The beam scanning patterns of the first and third embodiments of the phased array antenna of the present invention are shown in FIG. Fig.18 : is the beam scanning pattern of the second and fourth embodiments of the phased array antenna of the present invention. Fig.17 As shown, the first and third embodiments of the phased array antenna of the present invention have a maximum gain of 13.1dBi and a minimum gain of 12.7dBi within a scanning range of ±65°, and a gain drop of less than 2dBi, which can achieve a flat scanning gain. Fig.18 As shown, the second and fourth embodiments of the phased array antenna of the present invention have a maximum gain of 21.1dBi and a minimum gain of 19.1dBi (when scanning to ±65°) within a scanning range of ±65°, and a gain drop of less than 2dBi, which can achieve a flat scanning gain. At the same time, the one-dimensional scanning phased array antenna of the present invention can also be combined with a turntable to form an electromechanical hybrid two-dimensional phased array antenna system with two-dimensional scanning functions in elevation and azimuth.

[0048] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

[0049] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0051] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A multi-branch antenna unit, characterized in that: The multi-branch antenna unit comprises: a multi-branch radiation structure and a feeding structure; The multi-branch radiation structure comprises: first to third flat plates arranged symmetrically, wherein two adjacent flat plates respectively form the first to second branches; The feeding structure comprises: a rectangular metal cavity, a dielectric substrate, a first port, a second port, two feeding probes and a microstrip line; The first port and the second port are symmetrically arranged at the bottom of the feeding structure, and the first port and the second port are respectively connected to two ends of the microstrip line through the feeding probe; The dielectric substrate is arranged in the rectangular metal cavity, and the multi-branch radiation structure is arranged above the rectangular metal cavity; An external power supply excites the microstrip line through the first port or the second port to form an electromagnetic field which is then fed into the multi-branch radiation structure to form a radiation beam.

2. The multi-branch antenna unit according to claim 1, characterized in that: The dielectric substrate comprises, from bottom to top: a first dielectric layer and a second dielectric layer; The first dielectric layer and the second dielectric layer have the same thickness; The first port and the second port are arranged at the bottom of the first dielectric layer, the two feeding probes are arranged inside the first dielectric layer, and the microstrip line is arranged at the interface between the first dielectric layer and the second dielectric layer.

3. The multi-branch antenna unit according to claim 2, characterized in that: In the multi-branch radiation structure, the symmetrically arranged first plate and the third plate are set to the same first preset height, the second plate is set to the second preset height, and the first to third plates are set to the same first preset thickness; The first plate and the second plate form a first branch, and the second plate and the third plate form a second branch; The first branches and the second branches have the same first preset distance.

4. The multi-branch antenna unit according to claim 3, characterized in that: The direction and width of the radiation beam are adjusted according to the first preset height, the second preset height, the first preset thickness and the first preset spacing.

5. The multi-branch antenna unit according to claim 4, characterized in that: The height of the rectangular metal cavity is twice the thickness of the first dielectric layer.

6. A phased array antenna, characterized in that: The phased array antenna comprises a plurality of multi-branch antenna units as claimed in any one of claims 1 to 5 and T / R components corresponding to the number of the multi-branch antenna units.

7. The phased array antenna according to claim 6, characterized in that: The phased array antenna comprises: N one-dimensionally arranged multi-branch antenna units, wherein N is an integer greater than 1; Adjacent multi-branch antenna units are connected in series through the T / R component.

8. The phased array antenna according to claim 6, characterized in that: The phased array antenna comprises: the multi-branch antenna units arranged in an M*M rectangular shape, wherein M is an integer greater than 1; The phased array antenna further comprises: a one-to-M power splitter; The multi-branch antenna units in one direction of the rectangular array are combined through the one-to-M power divider to form 2M input ports of the one-to-M power divider; The input ports of the 2M adjacent one-to-M power dividers except the first and the last one are connected in series through the T / R assembly.

9. The phased array antenna according to claim 6, characterized in that: The phased array antenna comprises: N one-dimensionally arranged multi-branch antenna units, wherein N is an integer greater than 1, and adjacent multi-branch antenna units are arranged in parallel feeding; The phased array antenna also includes: a one-to-N power divider and N single-pole double-throw switches; The input end of each T / R component is connected to the output port of the one-to-N power divider, the output end of each T / R component is connected to the input end of a single-pole double-throw switch, and the two output ends of each single-pole double-throw switch are respectively connected to the first port and the second port of the corresponding multi-branch antenna unit.

10. The phased array antenna according to claim 6, characterized in that: The phased array antenna comprises: the multi-branch antenna units arranged in an M*M rectangular shape; The phased array antenna also includes: a one-to-M power divider and a single-pole double-throw switch; The multi-branch antenna units in one direction of the rectangular array are combined through the one-to-M power divider to form 2M input ports of the one-to-M power divider; The input ports of the adjacent one-to-M power dividers are connected through the two output ports of the single-pole double-throw switch, and the input end of the single-pole double-throw switch is connected to the output end of the corresponding T / R component.

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