Elevation angle antenna for microwave landing system

Abstract

The invention relates to an elevation angle antenna for a microwave landing system, and belongs to the technical field of microwave antennas. Comprising elevation antenna units, isolation baffles, coupling waveguides, corner reflectors, supporting frames and an antenna bottom plate, the elevation antenna units are arranged and installed on the antenna bottom plate at equal intervals, the supporting frames are located on the two sides of the elevation antenna units, and the coupling waveguides are arranged on the supporting frames on the two sides respectively; the two sides of each elevation antenna unit are each provided with an isolation baffle, and the isolation baffles on the two sides of the elevation antenna unit, the supporting frame, the coupling waveguide and the corner reflector installed on the upper side of the coupling waveguide jointly form a radiation cavity of the elevation antenna unit to achieve beam forming. According to the invention, the problem that a complex calibration network and a beam forming structure need to be added in the antenna in the prior art is solved, the integrated processing mode is adopted, the processing structure is simple, the manufacturing cost is reduced, the structure stability is good, and a good beam forming effect and a coupling characteristic are shown in a frequency band.

Description

Technical Field

[0001] The present invention belongs to the field of navigation technology, and further relates to an elevation antenna in the field of antenna technology. The present invention can be used in a microwave landing system. Background Art

[0002] The development of microwave landing systems has always been closely linked to the development of the entire aviation industry. As a relatively new and extremely important landing equipment, it can affect whether the aircraft can land safely in the designated area and ensure the safety of people's lives and property. In recent years, with the rapid rise of the aviation industry, the continuous expansion of the civil aviation user group, and the strong market demand that has spawned a large number of operating companies, it is urgent to develop a high-precision, high-performance microwave landing equipment. The elevation antenna used in the microwave landing system needs to achieve channel calibration, and at the same time requires antenna beamforming to achieve beam coverage of the detection target. In order to achieve channel calibration and beamforming, a calibration network and beamforming structure need to be added to the antenna, which makes the antenna structure complicated, which is not conducive to the miniaturization of the antenna design and cost reduction.

[0003] The Beijing Radio Measurement Institute disclosed a slotted waveguide, a radiating unit, a waveguide calibration network and a phased array antenna in its patent application document "A slotted waveguide, a radiating unit, a waveguide calibration network and a phased array antenna" (application number 202211611341.3, application publication number CN 116231281 A). The slotted waveguide includes a waveguide tube, in which a first feeding cavity and a second feeding cavity are provided, the first feeding cavity is located on the right side of the second feeding cavity, and two unit coupling transverse slits that penetrate the first feeding cavity are provided on the right side of the front upper end of the waveguide tube. The radiating slot is located on the rear side of the coupling slot, and channel calibration is achieved by coupling energy through the coupling waveguide, and horizontal / vertical polarized waves are radiated through the radiating slot. However, the disadvantage that still exists is that the coupler couples the microwave energy in the antenna transmission waveguide through the coupling slot, instead of coupling the microwave energy radiated by the antenna near field. Moreover, the calibration network and the radiating antenna of the antenna are independent of each other, the antenna size is large, and because the radiating antenna is compact, it is impossible to add a shaping structure around the radiating antenna, and it cannot meet the requirements of elevation antenna calibration and beam forming of the microwave landing system.

[0004] The 29th Institute of China Electronics Technology Group Corporation disclosed a broadband shaped antenna based on a multi-turn beamforming radiator in its patent application "A broadband shaped antenna based on a multi-turn beamforming radiator" (application number 202210948460.1, application publication number CN 115360503 A), including a coaxial waveguide conversion unit, a rectangular waveguide conversion unit, a choke ring reflector, and a beamforming radiator connected in sequence, and the beamforming radiator includes a plurality of circular ring-shaped beamforming radiators. The invention solves the problems of poor radiation performance, small power capacity, and large volume in the prior art. However, the disadvantage is that the antenna realizes beam forming through a beam former. For an elevation antenna for a microwave landing system composed of multiple antenna units, using a shaped radiator including several circular beam forming radiating elements as an antenna shaping structure will greatly increase the difficulty of antenna design and antenna cost, and adding an additional calibration network will further increase the complexity of the antenna structure, which cannot meet the requirements of elevation antenna calibration and beam forming of the microwave landing system.

[0005] Therefore, one of the urgent problems to be solved in the current antenna technology field is to design an elevation antenna with a simple structure that can achieve beamforming and calibration. Such a design is expected to reduce the complexity of the antenna structure and meet the requirements of the microwave landing system for a simple structure and easy installation. Summary of the invention

[0006] The technical problems to be solved by the present invention are:

[0007] In order to avoid the shortcomings of the prior art, the present invention provides an elevation antenna for a microwave landing system, which is used to solve the problem that the traditional antenna needs to add a complex shaping structure, and the coupling calibration network cannot accurately calibrate the antenna, and cannot be applied to a low-cost and high-performance microwave landing system.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] An elevation antenna for a microwave landing system, characterized in that it comprises: N elevation antenna units, 2N isolation baffles, 2 coupling waveguides, 2 corner reflectors, 2 support frames and an antenna bottom plate, N≥2;

[0010] The N elevation antenna units are arranged at equal intervals and vertically installed on the antenna bottom plate; the two support frames are parallel to the elevation antenna units and are located on the front and rear sides of the elevation antenna units, and a coupling waveguide is symmetrically arranged on each of the two support frames; each coupling waveguide is provided with N coupling slots aligned with the center of the elevation antenna unit on the side facing the elevation antenna unit, and microwave energy is coupled to each elevation antenna unit for calibration; an isolation baffle is arranged on the left and right sides of each elevation antenna unit, and the isolation baffle, the support frame, the coupling waveguide and the corner reflector installed on the upper side of the coupling waveguide together constitute the radiation cavity of the elevation antenna unit to realize beam forming.

[0011] A further technical solution of the present invention: the elevation antenna unit is a metal Vivaldi antenna.

[0012] A further technical solution of the present invention is as follows: the wide side of the coupling waveguide is parallel to the antenna bottom plate, and the narrow side of the coupling waveguide is perpendicular to the antenna bottom plate.

[0013] A further technical solution of the present invention is that the coupling slots of the coupling waveguide are inclined slots, and adjacent coupling slots have opposite inclined directions.

[0014] A further technical solution of the present invention is that one end of the coupling waveguide is connected to the waveguide coaxial conversion as a coupling calibration upper port, and the other end is connected to the waveguide coaxial conversion as a coupling calibration lower port.

[0015] A further technical solution of the present invention is that the elevation antenna is processed by metal integration to ensure that the bottom surface of the isolation baffle is tightly connected to the antenna bottom plate, and both sides of the isolation baffle are tightly connected to the support frame and the outer wall of the coupling waveguide.

[0016] A further technical solution of the present invention is as follows: the length of the coupling waveguide is greater than the total length of the N elevation antenna units.

[0017] A further technical solution of the present invention is as follows: the corner reflector adopts a rectangular strip structure, and the length of the corner reflector is consistent with the length of the coupled waveguide.

[0018] The beneficial effects of the present invention are:

[0019] The elevation antenna for a microwave landing system provided by the present invention has the following advantages compared with the prior art:

[0020] First, the radiation cavity composed of an isolation baffle, a support frame, a coupling waveguide and a corner reflector realizes beamforming, and at the same time realizes antenna calibration by coupling the energy of each radiation unit through the coupling waveguide. The antenna adopts an integrated design of shaping and calibration, and uses the same structure to achieve different functions, which overcomes the problem of the prior art that a complex calibration network and beamforming structure need to be added inside the antenna, making the present invention suitable for application scenarios of low-cost and high-performance antenna systems. The elevation antenna of the present invention is processed by metal integration. This unique design not only simplifies the manufacturing process, but also reduces the number of components, further reduces the manufacturing cost, improves the manufacturing efficiency, and can ensure good contact between the components, thereby improving the structural stability of the antenna.

[0021] Second, the elevation antenna for the microwave landing system of the present invention improves the isolation between the radiation units by adding an isolation baffle between the radiation units. At the same time, the radiation cavity of each radiation unit is independent of each other, and the radiation unit corresponds to the coupling gap one by one. The energy of each unit is coupled for antenna calibration, avoiding the adverse effects of coupling of other radiation units. In addition, the present invention adopts a near-field coupling method to directly couple the microwave energy of the antenna unit, so that the present invention can calibrate the inconsistency of the antenna radiation unit, improve the antenna calibration accuracy, and enhance the radiation capacity of the antenna system, thereby meeting the use requirements of the microwave landing system for accurate antenna calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0023] Figure 1 It is a schematic diagram of the elevation antenna structure for a microwave landing system of the present invention;

[0024] Figure 2 is a side view of the elevation antenna structure for a microwave landing system of the present invention;

[0025] Figure 3 It is a three-dimensional diagram of the elevation antenna structure for the microwave landing system of the present invention;

[0026] Figure 4 It is a standing wave curve diagram of the elevation antenna radiation unit for the microwave landing system of the present invention;

[0027] Figure 5 is the elevation antenna radiation pattern for the microwave landing system of the present invention;

[0028] Figure 6 is a curve diagram of the elevation antenna port isolation for the microwave landing system of the present invention;

[0029] Figure 7 It is a curve diagram of the elevation antenna coupling amplitude for the microwave landing system of the present invention. Description of the drawings:

[0031] 1- elevation antenna unit, 2- isolation baffle, 3- coupling waveguide, 4- corner reflector, 5- support frame, 6- antenna base plate, 7- coupling slot, 8- coupling calibration upper port, 9- coupling calibration lower port. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] The present invention proposes an elevation antenna for a microwave landing system, in which N elevation antenna units are arranged at equal intervals and installed on an antenna bottom plate, a support frame is located at the front and rear sides of the elevation antenna unit, coupling waveguides are respectively arranged on the support frames on both sides, each coupling waveguide is provided with N coupling slots aligned with the center of the elevation antenna unit to couple the microwave energy of each elevation antenna unit for antenna calibration; an isolation baffle is arranged on each side of each elevation antenna unit, and the isolation baffles on both sides of the elevation antenna unit, the support frame, the coupling waveguide and the corner reflector installed on the upper side of the coupling waveguide together constitute the radiation cavity of the elevation antenna unit to realize beam forming.

[0034] The present invention avoids the problem that the prior art needs to add complex beamforming structures around the antenna unit, which is difficult to process and assemble. The radiation cavity composed of the isolation baffle, the support frame, the coupling waveguide and the corner reflector can realize the elevation antenna beamforming. At the same time, the coupling waveguide that constitutes the radiation cavity can couple the energy of the antenna unit through the coupling slot to realize antenna calibration, avoiding the problem that the prior art needs to add a complex calibration network inside the antenna. The coupling waveguide of the present invention can calibrate the inconsistency of the antenna unit itself. At the same time, the isolation baffle improves the isolation between the radiation units, further improving the antenna calibration effect and the antenna radiation capability.

[0035] Embodiment 1:

[0036] The application scenario of the example of the present invention is an elevation antenna for a microwave landing system, that is, an antenna array with a shaped beam and a calibration network.

[0037] Reference Figure 1The overall structure of the elevation antenna for the microwave landing system of the present invention is further described. The present invention comprises N elevation antenna units 1, 2N isolation baffles 2, 2 coupling waveguides 3, 2 corner reflectors 4, 2 support frames 5 and an antenna bottom plate 6, wherein N≥2.

[0038] Among them, the elevation antenna unit 1 is a metal Vivaldi elevation antenna unit, and the N elevation antenna units 1 are arranged at equal intervals and installed on the antenna base plate 6. The two support frames 5 are parallel to the elevation antenna unit 1 and are located on the front and rear sides of the elevation antenna unit 1. A coupling waveguide 3 is respectively arranged on each support frame 5, and the two coupling waveguides 3 are symmetrically distributed with the elevation antenna unit 1 as the symmetry axis. One end of the coupling waveguide 3 is connected to the waveguide coaxial conversion as the coupling calibration upper port 8, and the other end is connected to the waveguide coaxial conversion as the coupling calibration lower port 9. Each coupling waveguide 3 is provided with N coupling slots 7 aligned with the center of the elevation antenna unit 1 to couple the microwave energy of each elevation antenna unit 1 for antenna calibration. The coupling slots 7 are slanted slots, and the inclination directions of adjacent coupling slots are opposite. An isolation baffle 2 is arranged on the left and right sides of each elevation antenna unit 1. The isolation baffles 2 on the left and right sides of the elevation antenna unit 1, the support frames 5 on the front and rear sides, the coupling waveguide 3 and the corner reflector 4 installed on the upper side of the coupling waveguide 3 together constitute the radiation cavity of the elevation antenna unit 1 to realize beamforming.

[0039] Reference Figure 2 , the elevation antenna structure for the microwave landing system of the present invention is further described. Figure 2 The coupling waveguides 3 are respectively arranged on the support frames 5 on both sides, the wide side of the coupling waveguide 3 is parallel to the antenna bottom plate 6, the narrow side of the coupling waveguide 3 is perpendicular to the antenna bottom plate 6, the length of the coupling waveguide 3 is greater than the total length of the N elevation antenna units 1, and the corner reflector 4 adopts a rectangular strip structure, and the length is consistent with the length of the coupling waveguide 3. The elevation antenna unit 1, the isolation baffle 2, the coupling waveguide 3, the corner reflector 4, the support frame 5 and the antenna bottom plate 6 that constitute the elevation antenna are all metal integrated structures, and are processed by an integrated processing method to ensure that the bottom surface of the isolation baffle 2 is tightly connected to the antenna bottom plate 6, and the two sides of the isolation baffle 2 are tightly connected to the support frame 5 and the outer wall of the coupling waveguide 3, and the electrical connection between the various components is good, with good structural stability.

[0040] The effect of the present invention can be further illustrated by the following simulation experiment.

[0041] 1. Simulation conditions

[0042] Use High Frequency Structure Simulator to simulate Figure 1 Elevation antenna for a microwave landing system is shown.

[0043] 2. Simulation Content

[0044] Simulation 1: Figure 1 The elevation antenna for the microwave landing system shown in the figure is brought into the simulation software for simulation, and the following is obtained: Figure 3 The standing wave curve of the radiation unit port changes with frequency.

[0045] from Figure 4 It can be seen that the frequency range of the standing wave at the port of the elevation antenna radiation unit for the microwave landing system of the present invention below 1.5 is 5.03-5.09 GHz. It can be seen that the elevation antenna radiation unit of the present invention has good impedance matching characteristics.

[0046] Simulation 2: Figure 1 The elevation antenna for the microwave landing system shown in the figure is brought into the simulation software for simulation, and the following is obtained: Figure 5 The antenna radiation pattern is shown.

[0047] from Figure 5 It can be seen that the embodiment of the present invention realizes a convex beamforming effect on the antenna H surface through a radiation cavity composed of an isolation baffle, a support frame, a coupling waveguide and a corner reflector, and realizes low side lobes on the antenna E surface by controlling the distribution of the antenna port feeding amplitude. It can be seen that the elevation antenna of the present invention has good radiation characteristics.

[0048] Simulation 3: Figure 1 The elevation antenna for the microwave landing system shown in the figure is brought into the simulation software for simulation, and the following is obtained: Figure 5 The curve showing the change of the radiating unit port isolation with frequency.

[0049] from Figure 6 It can be seen that the embodiment of the present invention achieves a port isolation of more than 20 dB in the frequency range of 5.03 to 5.09 GHz by adding an isolation baffle between the radiation units. It can be seen that the elevation antenna of the present invention has good port isolation characteristics in the frequency band.

[0050] Simulation 4: Figure 1 The elevation antenna for the microwave landing system shown in the figure is brought into the simulation software for simulation, and the following is obtained: Figure 5 The coupling calibration upper and lower ports coupling amplitude curve shown varies with frequency.

[0051] from Figure 7 It can be seen that the standard deviation of the coupling amplitude in the frequency range of 5.03-5.09 GHz of the embodiment of the present invention is within 1.5 dB. It can be seen that the elevation antenna of the present invention has good coupling characteristics within the frequency band, and can realize accurate calibration of the antenna.

[0052] The above simulation results show that the elevation antenna for the microwave landing system of the present invention has good impedance matching and port isolation characteristics, and has good beamforming effect and coupling characteristics.

[0053] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. An elevation antenna for a microwave landing system, characterized in that: include: N elevation antenna units (1), 2N isolation baffles (2), 2 coupling waveguides (3), 2 corner reflectors (4), 2 support frames (5) and an antenna base plate (6), N≥2; The N elevation antenna units (1) are arranged at equal intervals and vertically mounted on an antenna bottom plate (6); the two support frames (5) are parallel to the elevation antenna units (1) and are located on the front and rear sides of the elevation antenna units (1); and one coupling waveguide (3) is symmetrically arranged on each of the two support frames (5); each coupling waveguide (3) has N coupling slots (7) aligned with the center of the elevation antenna unit (1) on the side facing the elevation antenna unit (1), and couples microwave energy to each elevation antenna unit (1) for calibration; and each elevation antenna unit (1) has an isolation baffle (2) on the left and right sides, and the isolation baffle (2), the support frame (5), the coupling waveguide (3) and a corner reflector (4) mounted on the upper side of the coupling waveguide (3) together form a radiation cavity of the elevation antenna unit (1) to achieve beamforming.

2. The elevation antenna for a microwave landing system according to claim 1, characterized in that: The elevation antenna unit (1) is a metal Vivaldi antenna.

3. The elevation antenna for a microwave landing system according to claim 1, characterized in that: The wide side of the coupling waveguide (3) is parallel to the antenna bottom plate (6), and the narrow side of the coupling waveguide (3) is perpendicular to the antenna bottom plate (6).

4. The elevation antenna for a microwave landing system according to claim 1, characterized in that: The coupling slots (7) of the coupling waveguide (3) are inclined slots, and adjacent coupling slots (7) have opposite inclination directions.

5. The elevation antenna for a microwave landing system according to claim 1, characterized in that: One end of the coupling waveguide (3) is connected to a waveguide coaxial conversion as a coupling calibration upper port (8), and the other end is connected to a waveguide coaxial conversion as a coupling calibration lower port (9).

6. The elevation antenna for a microwave landing system according to claim 1, characterized in that: The elevation antenna is processed by metal integration processing to ensure that the bottom surface of the isolation baffle (2) is tightly connected to the antenna bottom plate (6), and the two sides of the isolation baffle (2) are tightly connected to the support frame (5) and the outer wall of the coupling waveguide (3).

7. The elevation antenna for a microwave landing system according to claim 1, characterized in that: The length of the coupling waveguide (3) is greater than the total length of the N elevation antenna units (1).

8. The elevation antenna for a microwave landing system according to claim 1, characterized in that: The corner reflector (4) adopts a rectangular strip structure, and its length is consistent with the length of the coupling waveguide (3).

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