Low-sidelobe X-waveband waveguide slot array antenna

Abstract

The invention belongs to the technical field of antennas, and particularly relates to a low-sidelobe X-waveband waveguide slot array antenna. The antenna comprises an antenna array plane, the antenna array plane comprises a plurality of sub-array antennas which are arranged in parallel at equal intervals, each sub-array antenna is a waveguide slot array antenna, each waveguide slot array antenna is externally connected with a TR assembly, and the center-to-center distance d1 between every two adjacent waveguide slot antennas is 16mm; according to the technical requirements, horizontal polarization is achieved in the mode that an inclined slot is formed in the narrow side of a rectangular waveguide, finally, the design of the low-sidelobe horizontal polarization waveguide slot traveling wave array antenna is achieved, and the sidelobe level in the antenna working frequency range averagely meets the design target that the sidelobe level of a transmitting pitching face is lower than-12dB, the sidelobe level of a receiving pitching face is lower than-25dB, and the sidelobe level of the receiving pitching face is lower than-25dB. According to the invention, the side lobe level of the azimuth plane is lower than-25dB, the normal transmitting gain is greater than 35dBi (full-band), the receiving gain is greater than 33.5 dBi, and the antenna has the advantages of low side lobe, high gain and narrow beam, and is suitable for being applied to an X-band radar communication system.

Description

Technical Field

[0001] The invention belongs to the technical field of antennas, and in particular relates to a low sidelobe X-band waveguide slot array antenna. Background Art

[0002] Modern electronic countermeasures require that useful information be received in complex electromagnetic environments and specific electromagnetic interference without being disturbed or affected by clutter. This requires that the receiving and transmitting antennas have the advantages of low side lobes, high gain, and concentrated beam pointing, so as to improve the radar's anti-interference ability. Waveguide slot antennas have just such advantages. The low side lobe feature of the antenna means that the energy radiated in the specified direction is more concentrated, and it is not easily interfered by ground clutter, which can effectively ensure the integrity of the information transmitted by the transceiver antenna. Due to the characteristics of compact structure, high radiation efficiency, and easy control of aperture amplitude distribution, waveguide slot antennas are widely used in ship-borne, missile-borne radars, navigation and other radar systems and microwave communications.

[0003] The antenna design of some X-band radar communication systems in the prior art needs to meet the following requirements: the sidelobe level of the transmitting elevation plane is lower than -12dB, the sidelobe level of the receiving elevation plane is lower than -25dB, the sidelobe level of the azimuth plane is lower than -25dB, the normal transmission gain is greater than 35dBi (full frequency band), and the receiving gain is greater than 33.5dBi; however, the antenna design that meets the above technical requirements often finds it difficult to meet the requirements of low sidelobe, high gain and narrow beam.

[0004] Based on this, the applicant considered designing a low-sidelobe X-band waveguide slot array antenna with low sidelobe, high gain and narrow beam. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a low-sidelobe, high-gain and narrow-beam low-sidelobe X-band waveguide slot array antenna.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A low sidelobe X-band waveguide slot array antenna, comprising an antenna array surface, wherein the antenna array surface comprises a plurality of sub-array antennas arranged in parallel at equal intervals, each sub-array antenna is a waveguide slot array antenna, and each waveguide slot array antenna is externally connected to a TR component;

[0008] Each waveguide slot antenna is in a hollow tubular shape, and a plurality of radial slots communicating with the inner hollow are opened axially and tilted upward on the top side of each waveguide slot antenna, and the radial slots on two adjacent waveguide slot antennas are symmetrical structures.

[0009] The working principle and advantages of a low sidelobe X-band waveguide slot array antenna in this technical solution are:

[0010] According to the technical requirements, horizontal polarization is achieved by opening slanted slots on the narrow side of the rectangular waveguide, and finally the design of a low sidelobe horizontally polarized waveguide slot traveling wave array antenna is realized. The sidelobe levels within the operating frequency range of the antenna meet the design goals: the sidelobe level of the transmitting elevation plane is lower than -12dB, the sidelobe level of the receiving elevation plane is lower than -25dB, and the sidelobe level of the azimuth plane is lower than -25dB. The normal transmission gain is greater than 35dBi (full frequency band), and the receiving gain is greater than 33.5dBi. The antenna meets the requirements of various indicators and has the advantages of low sidelobe, high gain and narrow beam. It is suitable for application in X-band radar communication systems.

[0011] Furthermore, a center distance d1 between two adjacent waveguide slot antennas is 16 mm.

[0012] Furthermore, the distance d2 between two adjacent radial slots is 19.3 mm, the cutting depth c of each radial slot is -19.42° to 19.43°, and the inclination angle r is 3.35 mm to 3.7 mm.

[0013] Furthermore, the hollow tubular waveguide slot antenna has a length of 1810 mm, a height of 25.4 mm, a width of 12.7 mm, and a wall thickness of 1.27 mm.

[0014] Furthermore, the multiple radial slots on each waveguide slot antenna satisfy Taylor distribution by setting different cutting depths c and tilt angles r.

[0015] Furthermore, the antenna array surface includes 16 waveguide slot array antennas.

[0016] Furthermore, each waveguide slot array antenna is provided with 33 radial slots.

[0017] Furthermore, the waveguide slot array antenna is made of aluminum.

[0018] Furthermore, a plurality of metal mounting blocks are protrudingly provided on the bottom side of each waveguide slot antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of a low sidelobe X-band waveguide slot array antenna according to an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the top view of the structure of the low sidelobe X-band waveguide slot array antenna according to an embodiment of the present invention;

[0021] Figure 3 for Figure 2 The enlarged schematic diagram of point A in the middle;

[0022] Figure 4 1 is a schematic diagram of the structure of a low sidelobe X-band waveguide slot array antenna from the left side according to an embodiment of the present invention;

[0023] Figure 5 Schematic diagram of the three-dimensional structure of the waveguide slot array antenna according to an embodiment of the present invention;

[0024] Figure 6 for Figure 5 The enlarged schematic diagram of point B in the middle;

[0025] Figure 7 It is a source standing wave when the low sidelobe X-band waveguide slot array antenna of an embodiment of the present invention is made of aluminum;

[0026] Figure 8 The E-plane radiation pattern of the antenna array with equal amplitude excitation when the low sidelobe X-band waveguide slot array antenna according to an embodiment of the present invention is made of aluminum;

[0027] Fig. 9 The H-plane radiation pattern of the antenna array with equal amplitude excitation when the low sidelobe X-band waveguide slot array antenna according to an embodiment of the present invention is made of aluminum;

[0028] Fig.10 The E-plane, H-plane, sum and difference beams and deflection beam patterns of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.2 GHz according to an embodiment of the present invention;

[0029] Fig.11 The E-plane, H-plane, sum and difference beams and deflection beam patterns of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.25 GHz according to an embodiment of the present invention;

[0030] Fig.12 The E-plane, H-plane, sum and difference beams and deflection beam directivity diagrams of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.3 GHz according to an embodiment of the present invention;

[0031] Fig.13 The E-plane, H-plane, sum and difference beams and deflection beam patterns of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.35 GHz according to an embodiment of the present invention;

[0032] Fig.14 The E-plane, H-plane, sum and difference beams and deflection beam patterns of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.4 GHz according to an embodiment of the present invention;

[0033] Fig.15 The E-plane, H-plane, sum and difference beams and deflection beam patterns of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.45 GHz according to an embodiment of the present invention;

[0034] Fig.16The E-plane, H-plane, sum and difference beams and deflection beam patterns of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.5 GHz according to an embodiment of the present invention;

[0035] Fig.17 The E-plane, H-plane, sum and difference beams and deflection beam directivity diagrams of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.55 GHz according to an embodiment of the present invention;

[0036] Fig.18 The E-plane, H-plane, sum and difference beams and deflection beam directivity diagrams of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.6 GHz according to an embodiment of the present invention;

[0037] Fig.19 The E-plane, H-plane, sum and difference beams and deflection beam directivity diagrams of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.65 GHz according to an embodiment of the present invention;

[0038] Fig. 20 The E-plane, H-plane, sum and difference beams and deflection beam directivity diagrams of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.7 GHz according to an embodiment of the present invention;

[0039] Fig.21 The E-plane, H-plane, sum and difference beams and deflection beam directivity diagrams of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.75 GHz according to an embodiment of the present invention;

[0040] Fig. 22 The E-plane, H-plane, sum and difference beams and deflection beam directivity diagrams of the antenna array of the low sidelobe X-band waveguide slot array antenna at 9.8 GHz according to an embodiment of the present invention;

[0041] In the above drawings: 100, antenna array surface; 110, sub-array antenna; 111, radial slot; 112, metal mounting block. DETAILED DESCRIPTION

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0043] Refer to Figure 1 to Figure 6This embodiment provides a low sidelobe X-band waveguide slot array antenna, which includes an antenna array surface 100, the antenna array surface 100 includes a plurality of sub-array antennas 110 arranged in parallel at equal intervals, each sub-array antenna 110 is a waveguide slot array antenna, and each waveguide slot array antenna is externally connected to a TR component;

[0044] Each waveguide slot antenna is in a hollow tubular shape, and a plurality of sub-array antennas 111 connected to the hollow interior of each waveguide slot antenna are arranged axially upwardly inclined on the top side of the waveguide slot antenna, and the sub-array antennas 111 on two adjacent waveguide slot antennas are symmetrical structures.

[0045] In this embodiment, according to technical requirements, horizontal polarization is achieved by opening an oblique slot on the narrow side of a rectangular waveguide, and finally the design of a low sidelobe horizontally polarized waveguide slot traveling wave array antenna is realized. The sidelobe levels within the operating frequency range of the antenna meet the design goals: the sidelobe level of the transmitting elevation plane is lower than -12dB, the sidelobe level of the receiving elevation plane is lower than -25dB, the sidelobe level of the azimuth plane is lower than -25dB, the normal transmission gain is greater than 35dBi (full frequency band), and the receiving gain is greater than 33.5dBi. The antenna meets the requirements of various indicators and has the advantages of low sidelobe, high gain and narrow beam, and is suitable for application in X-band radar communication systems.

[0046] Preferably, the center distance d1 between two adjacent waveguide slot antennas is 16 mm.

[0047] Preferably, the distance d2 between two adjacent sub-array antennas 111 is 19.3 mm, the cutting depth c of each sub-array antenna 111 is -19.42° to 19.43°, and the tilt angle r is 3.35 mm to 3.7 mm.

[0048] Preferably, the hollow tubular waveguide slot antenna has a length of 1810 mm, a height of 25.4 mm, a width of 12.7 mm, and a wall thickness of 1.27 mm.

[0049] Preferably, the multiple sub-array antennas 111 on each waveguide slot antenna satisfy Taylor distribution by setting different cutting depths c and tilt angles r.

[0050] Preferably, the antenna array surface 100 includes 16 waveguide slot array antennas.

[0051] Preferably, each waveguide slot array antenna is provided with 33 sub-array antennas 111 .

[0052] Preferably, the waveguide slot array antenna is made of aluminum.

[0053] Preferably, a plurality of metal mounting blocks 112 are protruding from the bottom side of each waveguide slot antenna to facilitate the fixed installation of the waveguide slot antenna.

[0054] The aluminum waveguide slot array antenna model is simulated and compared through simulation calculation:

[0055] like Figure 7 As shown, the aluminum waveguide slot array antenna simulates and calculates active standing waves;

[0056] like Figure 8 As shown in Table 1, the simulation calculation of the aluminum waveguide slot array antenna with equal amplitude excitation E-plane radiation pattern can be obtained:

[0057]

[0058]

[0059] Table 1 Radiation characteristics of the E-plane pattern of the antenna array with equal amplitude excitation

[0060] like Fig. 9 As shown in Table 2, the simulation calculation of the aluminum waveguide slot array antenna array with equal amplitude excitation H-plane radiation pattern can be obtained:

[0061]

[0062] Table 2 Radiation characteristics of H-plane pattern of antenna array with equal amplitude excitation

[0063] From the above simulation results, it can be concluded that the antenna array gain of equal amplitude excitation is 36.19~36.632dBi, and the beam width is between 1.16° and 1.31°. The requirement that the transmit antenna array gain is greater than or equal to 35dBi is met. In addition, the aluminum waveguide has little effect on the gain, beam width, side lobe and other indicators of the array antenna.

[0064] like Figure 10 to Figure 22 As shown, Figure 10 to Figure 22 The E-plane, H-plane, sum and difference beams, and deflected beam patterns of the antenna array at different frequencies are displayed. By analyzing the influence of the waveguide material on the radiation performance of the waveguide slot antenna, the following conclusions can be drawn:

[0065] 1) The low sidelobe X-band waveguide slot array antenna has no effect on the overall active standing wave;

[0066] 2) The overall gain, beamwidth, sidelobe and other indicators of the low sidelobe X-band waveguide slot array antenna are not much different;

[0067] 3) Low sidelobe X-band waveguide slot array antenna can cooperate with the system to meet the index requirements according to the system function requirements and the difference beam.

[0068] The antenna of this scheme is designed in an integrated manner. It transmits electromagnetic waves through a rectangular waveguide and uses the amplitude distribution specified by opening gaps of different inclination angles and depths on the narrow side of the waveguide to achieve low sidelobe energy radiation. The input end of the antenna is connected to the waveguide coaxial conversion to achieve coaxial line transmission of microwave signals, which is compatible with the back-end transceiver channel; the output end is connected to the waveguide load to absorb the remaining energy radiated by the antenna, reduce reflections, and ensure the performance indicators of the antenna radiation pattern and voltage standing wave ratio.

[0069] Two adjacent rows of subarray antennas 110 are arranged symmetrically in angle to improve the cross-polarization isolation of the antenna array surface. At the same time, adjacent subarray antennas 110 are spaced apart to form choke slots to reduce the coupling between adjacent subarray antennas 110 and enhance the accuracy of the waveguide slot array antenna when performing multi-beam synthesis and angle measurement.

[0070] Waveguide slot array antennas can be processed in an integrated manner using CNC machine tools. Through secondary clamping and high-precision positioning, the degradation of antenna performance caused by processing errors is reduced, and the two problems of antenna processing accuracy and installation accuracy are successfully solved. It also greatly reduces the design complexity of antenna mounting fixtures, improves assembly efficiency, and saves production costs.

[0071] Specifically, the waveguide slot array antenna may also be made of copper.

[0072] The above are only preferred implementations of the present invention. It should be pointed out that a number of modifications and improved technical solutions made by those skilled in the art without departing from the technical solution should also be deemed to fall within the scope of protection required by the claims.

Claims

1. A low sidelobe X-band waveguide slot array antenna, characterized in that: The antenna array comprises a plurality of sub-array antennas arranged in parallel at equal intervals, each sub-array antenna is a waveguide slot array antenna, and each waveguide slot array antenna is externally connected to a TR component; Each waveguide slot antenna is in a hollow tubular shape, and a plurality of radial slots communicating with the inner hollow are opened axially and tilted upward on the top side of each waveguide slot antenna, and the radial slots on two adjacent waveguide slot antennas are symmetrical structures.

2. The low sidelobe X-band waveguide slot array antenna according to claim 1, characterized in that: The center distance d1 between two adjacent waveguide slot antennas is 16 mm.

3. The low sidelobe X-band waveguide slot array antenna according to claim 1, characterized in that: The distance d2 between two adjacent radial slots is 19.3 mm, the cutting depth c of each radial slot is -19.42°~19.43°, and the inclination angle r is 3.35 mm~3.7 mm.

4. The low sidelobe X-band waveguide slot array antenna according to claim 1, characterized in that: The hollow tubular waveguide slot antenna has a length of 1810 mm, a height of 25.4 mm, a width of 12.7 mm, and a wall thickness of 1.27 mm.

5. The low sidelobe X-band waveguide slot array antenna according to claim 1, characterized in that: The multiple radial slots on each waveguide slot antenna satisfy Taylor distribution by setting different cutting depths c and tilt angles r.

6. The low sidelobe X-band waveguide slot array antenna according to claim 1, characterized in that: The antenna array surface includes 16 waveguide slot array antennas.

7. The low sidelobe X-band waveguide slot array antenna according to claim 1, characterized in that: Each waveguide slot array antenna has 89 radial slots.

8. The low sidelobe X-band waveguide slot array antenna according to claim 1, characterized in that: The waveguide slot array antenna is made of aluminum.

9. The low sidelobe X-band waveguide slot array antenna according to claim 1, characterized in that: A plurality of metal mounting blocks are protruding from the bottom side of each waveguide slot antenna.

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