A multi-beam antenna and a beam scanning feeding structure

Abstract

The application relates to the technical field of two-dimensional multi-beam antennas, in particular to a multi-beam antenna and a beam scanning feed structure; the structure comprises a cylindrical Luneberg lens and a feed unit; a pair of two feed units located at the same direction angle are sequentially combined into an input port through a non-contact power divider; the non-contact power divider comprises an input end waveguide section and a gap waveguide section; by mechanically moving the non-contact feed network on the elevation plane of the structure, the path length from the input port to the feed unit can be changed, the phase of the feed unit is adjusted, rapid mechanical scanning of the elevation plane is realized, the problem that slow scanning speed is caused by the use of multiple phase shifters in electrically-controlled scanning and the problem that it is difficult to realize beam scanning by fixing the feed network are solved; in combination with multi-beam in the azimuth plane and beam scanning in the elevation plane, two-dimensional multi-beam coverage can be realized, and the number of placed feed antennas and the number of radiated beams are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of two-dimensional multi-beam antenna, and particularly relates to a multi-beam antenna and a beam scanning feed structure. BACKGROUND

[0002] With the frequency rising to the terahertz band, the size of the antenna is further reduced, the arrangement of multiple feed antennas of the spatial feed antenna system including the lens antenna or the reflector antenna is more difficult, and it is difficult to realize two-dimensional multi-beam large-angle radiation. The existing multi-beam lens antenna mainly realizes mechanical movement scanning or multi-feed excitation radiation through a single feed antenna, but the number of beams is limited and the scanning range is small. The dragon lens has the advantage of large-angle multi-beam radiation, but there are few reports of multi-beam dragon lens antennas at the terahertz band at present, and the multi-beam radiation in the azimuth plane is limited to one dimension, and the beam scanning implementation in the elevation plane is a problem to be solved. SUMMARY

[0003] In view of the deficiencies in the prior art, the present application aims to provide a multi-beam antenna and a beam scanning feed structure, which can realize multi-beam radiation in two-dimensional space.

[0004] To solve the above technical problems, the technical scheme provided by the present application is as follows: a multi-beam antenna and a beam scanning feed structure, which comprises a cylindrical dragon lens and a plurality of feed units arranged around the outer periphery of the cylindrical dragon lens in the same coaxial direction as the cylindrical dragon lens;

[0005] A pair of two feed units located in the same direction angle are sequentially combined into an input port through a non-contact power divider and a non-contact feed network is constructed, the non-contact power divider comprises an input end waveguide section and a gap waveguide section, and the two output ends of the gap waveguide section are connected with the input ends of the feed units through the vertically arranged switching structure waveguide section;

[0006] There is a height difference between the switching structure waveguide section and the gap waveguide section, forming a stepped structure;

[0007] By mechanically moving the non-contact feed network on the elevation plane of the structure, the path length from the input port to the feed unit can be changed, and the phase of the feed unit can be adjusted, thereby realizing multi-beam scanning in the vertical direction of the elevation plane;

[0008] The non-contact power divider is designed based on the gap waveguide, the gap waveguide section comprises a bottom metal layer, a top metal layer and a plurality of unit metal columns arranged in the bottom metal layer, and the non-contact power divider realizes non-contact mechanical movement through the air gap between the top metal layer and the unit metal columns.

[0009] Further, the two said feed source units at the same direction angle are combined into M-level input ports by M-level non-contact power dividers in turn, and from the first said M-level input port, the M-level input ports of the adjacent two layers are combined into M-1-level input ports by M-1-level non-contact power dividers, and so on until the input port of the first level is combined.

[0010] Further, the two said feed source units at the same direction angle are combined into M-level input ports by M-level non-contact power dividers in turn, and from the first said M-level input port, the M-level input ports of the adjacent two layers are combined into M-1-level input ports by M-1-level non-contact power dividers, and so on until the input port of the first level is combined.

[0011] Further, the input waveguide is connected with the gap waveguide section through a matching diaphragm, and the shape and size of the matching diaphragm are adjusted according to the working bandwidth requirement of the feed source unit.

[0012] Further, the cylindrical Luneberg lens has N layers, N-2 inner layers adopt a dielectric ring unit structure, the outermost two layers adopt a discrete dielectric column unit structure, the discrete dielectric ring unit structures of the outermost two layers are connected into one through a dielectric ring, and ten layers of structures are connected to form an integral lens structure through radial dielectric rods.

[0013] Further, the input ends of the plurality of said feed source units formed by rotating in the azimuth plane are converted to input ends located in the same plane through a curved waveguide.

[0014] Compared with the prior art, the present scheme has the following advantages:

[0015] The present scheme realizes rapid mechanical scanning in the elevation plane, solves the problem that the use of multiple phase shifters causes slow scanning speed and fixed feed network is difficult to realize beam scanning. The non-contact power divider in the form of gap waveguide to waveguide reduces the channel switching loss and complexity. The feed source units at different azimuth angles are converted to input ports located in the same plane through a feed channel, which improves the switching speed of different feed excitations and reduces the volume of the feed array. Combined with the azimuth plane multi-beam and the beam scanning in the elevation plane, two-dimensional multi-beam coverage can be realized, effectively improving the number of feed antennas and the number of radiation beams. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the present application together with the embodiments thereof, and explain the present application, and do not constitute a limitation of the present application. In the drawings:

[0017] Figure 1 It is a schematic diagram of the overall structure of the multi-beam antenna in the present application;

[0018] Figure 2is a top view of the multi-beam antenna in the present application;

[0019] Figure 3 is a side view of the feeding structure in the present application;

[0020] Figure 4 is a structural schematic diagram of the cylindrical Luneburg lens;

[0021] Figure 5 is a structural schematic diagram of the subarray;

[0022] Figure 6 is a structural schematic diagram of the non-contact power divider;

[0023] Figure 7 is a structural schematic diagram of the waveguide power divider;

[0024] Figure 8 is a structural schematic diagram of the gap waveguide-to-waveguide vertical transition structure;

[0025] Figure 9 is a structural schematic diagram of the gap waveguide structure and the gap waveguide unit;

[0026] Figure 10 is a schematic diagram of the elevation plane beam scanning direction in the present embodiment;

[0027] Figure 11 is a schematic diagram of the azimuth plane multi-beam radiation direction in the present embodiment;

[0028] Figure 12 is a schematic diagram of the impedance matching in the present embodiment;

[0029] In the figure: 1-cylindrical Luneburg lens, 2-feeding unit, 3-feeding network, 4-first level input port, 5-bent waveguide, 6-waveguide input end plane, 7-waveguide power divider, 8-first level non-contact power divider, 9-second level non-contact power divider, 10-gap waveguide-to-waveguide transition structure, 11-medium ring unit structure, 12-medium column unit structure, 13-medium ring, 14-medium rod, 15-first subarray, 16-second subarray, 17-third subarray, 18-fourth subarray, 19-first second level input port, 20-second second level input port, 21-matching diaphragm, 22 / 30-output end waveguide section / gap waveguide section, 23-input end waveguide section, 24-top layer metal, 25-bottom layer metal, 26-unit metal column, 27-waveguide power divider input end waveguide, 28-waveguide power divider output end waveguide, 29-transition structure waveguide section, 31-gap waveguide unit. DETAILED DESCRIPTION

[0030] The preferred examples of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred examples described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0031] As Figures 1-9 shown, the multi-beam antenna and beam scanning feeding structure of the present application includes a cylindrical Luneberg lens 1 and a plurality of feed units 2 arranged around the outer periphery of the cylindrical Luneberg lens 1 in the same coaxial direction as the cylindrical Luneberg lens 1. In this embodiment, the feed units 2 are feed horns.

[0032] In this embodiment, the cylindrical Luneberg lens 1 has a total of ten layers distributed radially. In view of the problem of removing printing supports, a dielectric ring unit structure 11 is used for the inner eight layers. In view of the problems of processing precision and molding size, a discrete dielectric column unit structure 12 is used for the outermost two layers. The outermost two layers of the discrete dielectric ring unit structure 11 are connected as a whole through a dielectric ring 13, and the ten layers of structures are connected to form an integrated lens structure through a radial dielectric rod 14. The structure composed of the dielectric ring 13 and the dielectric rod 14 is a connecting structure, which is helpful to realize the integrated processing of the lens.

[0033] In this embodiment, the input ends of the plurality of feed horns formed by rotating in the azimuth plane are converted to input ends located in the same plane, i.e., the waveguide input end plane 6, through the curved waveguide 5. Starting from the first layer of feed horns, the adjacent two layers of feed horns located in the same azimuth angle are successively combined into a subarray through a waveguide power divider 7. The waveguide power divider 7 includes a waveguide power divider input end waveguide 27 and a waveguide power divider output end waveguide 28 located at both ends. In this embodiment, it successively includes a first subarray 15, a second subarray 16, a third subarray 17, and a fourth subarray 18. Starting from the first subarray, the adjacent two layers of subarrays are successively combined into M-level input ports through M-level non-contact power dividers. As can be seen, in this embodiment, the first subarray 15 and the second subarray 16 are combined into a first two-level input port 19 through a first-level non-contact power divider 8, and the third subarray 17 and the fourth subarray 18 are combined into a second two-level input port 20. Starting from the first M-level input port, the adjacent two sides of the M-level input ports are combined into M-1-level input ports through M-1-level non-contact power dividers. In this way, it is combined into a one-level input port 4. In this embodiment, the first two-level input port 19 and the second two-level input port 20 are combined into a one-level input port 4 through a two-level non-contact power divider 9. The two-level non-contact power dividers in this embodiment and the one-level input port 4 together constitute a non-contact feeding network.

[0034] The non-contact power dividers 8 from M to one level each include an input end waveguide section 23 and an output end waveguide section, i.e., a gap waveguide section 22 / 30. The two output ends of the gap waveguide section 22 / 30 are connected to the input ends of the feed units 2 through a vertically arranged switching structure waveguide section 29, and there is a height difference between the switching structure waveguide section 29 and the gap waveguide section 22 / 30, forming a stepped structure, as Figure 3As shown, a stepped gap waveguide-to-waveguide transition structure 10 is formed.

[0035] Thus, by mechanically moving the non-contact feed network on the elevation plane, the path length from the input port to the feed element 2 can be changed, and thus the phase of the feed element 2 is adjusted, and multi-beam scanning on the elevation plane in the vertical direction is achieved.

[0036] Further, the non-contact power divider 8 / 9 is designed based on a gap waveguide, the gap waveguide section 30 includes a bottom metal layer 25, a top metal layer 24, and a plurality of unit metal columns 26 arranged in the bottom metal layer 25, and each unit metal column 26 constitutes a gap waveguide unit 31. The non-contact power divider 8 / 9 is mechanically moved by the air gap between the top metal layer 24 and the unit metal column 26.

[0037] The input end waveguide section 23 is connected to the gap waveguide section 22 / 30 through a matching diaphragm 21. In this embodiment, the matching diaphragm 21 is triangular and integrated with the top metal layer 24, and can be moved simultaneously. The shape and size of the matching diaphragm 21 can be adjusted to adjust the impedance distribution of the non-contact power divider 8 / 9. The shape of the matching diaphragm 21 is not necessarily triangular, but can also be other shapes such as rectangular, trapezoidal, stepped, etc.

[0038] Thus, in this scheme, the same azimuth angle feed array includes the feed element 2 and the feed network 3, and the feed network 3 includes the input end of the feed element 2 to the input end of the entire feed array.

[0039] Mechanically moving the first secondary input port 19 and the second secondary input port 20 along the vertical direction, and the primary input port 4, can change the path length of the primary input port 4 to each subarray, and thus adjust the phases of the first subarray 15 to the fourth subarray 18, and thus realize beam scanning on the elevation plane in the vertical direction. Figure 10 The figure shows the elevation plane beam scanning direction diagram in this embodiment. For the eight-layer feed structure in different azimuth angles in this embodiment, moving the primary and secondary input ports on the elevation plane respectively, multi-beam radiation of the antenna in the two-dimensional space can be achieved. Figure 11 The figure shows the azimuth plane multi-beam radiation direction diagram in this embodiment. Figure 12 The figure shows the impedance matching diagram in this embodiment.

[0040] In addition, the diameter of the cylindrical Luneburg lens 1 can be increased, so that more feed array 2 can be arranged in the azimuth plane to achieve higher gain and larger scale multi-beam radiation. The height of the cylindrical Luneburg lens 1 can also be increased, thereby increasing the number of sub-arrays in the subsequent structure, and more feed networks 3 are needed to connect, thereby achieving larger scale multi-beam radiation. For example, the height of the cylindrical Luneburg lens 1 in the embodiment is doubled, so that the number of sub-arrays is also doubled. The upper eight layers and the lower eight layers need to be combined into four sub-arrays, and then combined into a one-level input port 4 through a non-contact power divider 8. Then the one-level input ports 4 of the upper and lower parts need to be combined into the same input by another non-contact power divider 8.

[0041] In the embodiment, the diameter of the cylindrical Luneburg lens 1 is 15mm, the total height is 16mm, the aperture of the feed horn is 2.54mm*1.5mm, the length is 1.6mm, the waveguide port is 2.54*1.27mm, the impedance bandwidth is greater than 30%, the elevation plane beam scanning angle range is greater than ±10°, and the azimuth plane multi-beam coverage range is ±70°.

[0042] The scheme realizes fast mechanical scanning in the elevation plane, solves the problem of slow scanning speed caused by the use of multiple phase shifters in electrically controlled scanning, and solves the problem of fixed feed network that is difficult to realize beam scanning. The non-contact power divider in the form of gap waveguide to waveguide reduces the channel switching loss and complexity. The feed source units at different azimuth angles are converted to input ports in the same plane through the feed channel, which improves the switching speed of different feed excitations and reduces the volume of the feed array. Combined with the azimuth plane multi-beam and the beam scanning in the elevation plane, two-dimensional multi-beam coverage can be realized, and the number of feed antennas and the number of radiation beams are effectively improved.

[0043] Finally, it should be noted that: the above only for the preferred examples of the present application, and not for limiting the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-beam antenna and a beam scanning feed structure, characterized in that, The structure includes a cylindrical Luneburg lens and several feed units arranged around the outer periphery of the cylindrical Luneburg lens in a direction coaxial with the cylindrical Luneburg lens. Two pairs of feed units located at the same directional angle are sequentially combined into an input port through a non-contact power divider to construct a non-contact power supply network. The non-contact power divider includes an input waveguide section and a gap waveguide section. The two output ends of the gap waveguide section are respectively connected to the input end of the feed unit through a vertically arranged transition structure waveguide section. There is a height difference between the transition structure waveguide section and the gap waveguide section, forming a stepped structure; By mechanically moving the non-contact feed network on the pitch plane of the structure, the path length from the input port to the feed unit can be changed, thereby adjusting the phase of the feed unit and realizing multi-beam scanning on the vertical pitch plane. The non-contact power divider is designed based on a gap waveguide. The gap waveguide segment includes a bottom metal and a top metal, as well as several unit metal pillars spaced apart on the bottom metal. The non-contact power divider achieves non-contact mechanical movement through the air gap between the top metal and the unit metal pillars.

2. The multi-beam antenna and beam scanning feed structure according to claim 1, characterized in that, Two feed units located at the same directional angle are sequentially combined into an M-level input port by an M-level non-contact power divider. Starting from the first M-level input port, the M-level input ports of adjacent layers are then combined into an M-1 level input port by an M-1 level non-contact power divider, and so on until they are combined into a single-level input port.

3. The multi-beam antenna and beam scanning feed structure according to any one of claims 1 or 2, characterized in that, Two feed units located at the same directional angle are sequentially combined into a subarray by a waveguide power divider, and starting from the first subarray, the subarrays of adjacent layers are combined into an input port by the non-contact power divider.

4. The multi-beam antenna and beam scanning feed structure according to claim 1, characterized in that, The input waveguide is connected to the gap waveguide section via a matching diaphragm, the shape and size of which are adjusted according to the operating bandwidth requirements of the feed unit.

5. The multi-beam antenna and beam scanning feed structure according to claim 1, characterized in that, The cylindrical Luneburg lens has N layers. The inner N-2 layers adopt a dielectric ring unit structure, and the outermost two layers adopt a discrete dielectric cylinder unit structure. The outermost two discrete dielectric ring unit structures are connected into one unit by a dielectric ring, and then the ten layers are connected by a radial dielectric rod to form an integral lens structure.

6. The multi-beam antenna and beam scanning feed structure according to claim 1, characterized in that, The input ends of the multiple feed units formed by rotation on the azimuth plane are converted to input ends located on the same plane via a bent waveguide.

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