High-gain low-sidelobe antenna

Abstract

The invention relates to a high-gain low-sidelobe antenna. The power divider comprises a first power division torsion network which comprises a channel arranged along a first direction and two sub-channels divided towards two sides of a second direction along the channel; the plurality of coupling grooves are distributed on the two sub-channels along a second direction; the number of the second power division torsion networks corresponds to the number of the coupling grooves, each second power division torsion network is arranged on one side of the corresponding coupling groove along a third direction, and each second power division torsion network extends along the first direction; the coupling slot is used for receiving a signal transmitted by the corresponding coupling slot and transmitting the signal to two sides of the first direction; and the number of the slot radiation units corresponds to that of the second power division torsion networks, and each slot radiation unit comprises a plurality of slot radiation slots distributed along the first direction. The antenna is compact in structure, and the sidelobe level is effectively reduced while high gain is met.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle-mounted radars, and in particular to a high-gain and low-sidelobe antenna. Background Art

[0002] Vehicle-mounted forward radars are usually installed in front of a vehicle for detecting and warning of front targets. It is required that the radar antenna has high-gain and low-sidelobe characteristics, so as to increase the target detection distance and reduce environmental interference. However, traditional two-layer waveguide antennas usually distribute signals in the horizontal and vertical directions with the help of a power divider, and the structural volume is often large, which is not conducive to meeting the miniaturization requirements of vehicle-mounted radars; at the same time, it is difficult to balance the processing accuracy to meet the requirements of high gain and low sidelobes. Summary of the Invention

[0003] Therefore, the present invention provides a high-gain and low-sidelobe antenna, which has a compact structure and effectively reduces the sidelobe level while meeting high gain.

[0004] To solve the above technical problems, the present invention provides a high-gain and low-sidelobe antenna, including: A first power division and torsion network, including a channel arranged along a first direction and two sub-channels branched out from both sides of the channel along a second direction; A plurality of coupling slots, distributed along the second direction on the two sub-channels; A plurality of second power division and torsion networks, the number of which is correspondingly set with the coupling slots. Each of the second power division and torsion networks is arranged on one side of the corresponding coupling slot along a third direction, and each of the second power division and torsion networks extends along the first direction for receiving the signal transmitted by the corresponding coupling slot and transmitting the signal to both sides along the first direction; A plurality of slot radiation units, the number of which is correspondingly set with the second power division and torsion networks. Each of the slot radiation units includes a plurality of slot radiation slots distributed along the first direction. The slot radiation unit is configured to radiate the signal output through the corresponding second power division and torsion network into free space after receiving the signal; Wherein, the first direction, the second direction and the third direction are perpendicular to each other in pairs.

[0005] In an embodiment of the present invention, surface current suppression slots are arranged on both sides of each of the slot radiation units along the second direction for suppressing the surface current near the radiation port and reducing the antenna sidelobe level.

[0006] In an embodiment of the present invention, the surface current suppression slots extend along the first direction.

[0007] In an embodiment of the present invention, it includes a three-layer structure distributed along the third direction, which are respectively: The first-layer structure includes the lower half of the first power-dividing and twisting network; The second-layer structure includes the upper half of the first power-dividing and twisting network and several of the coupling slots; The third-layer structure includes several of the second power-dividing and twisting networks, several of the slot radiation elements, and the surface current suppression slot.

[0008] In an embodiment of the present invention, the number of the coupling slots, the second power-dividing and twisting networks, the slot radiation elements, and the slot radiation slots is four each.

[0009] In an embodiment of the present invention, the gain of the antenna in the 0° direction is 20 dBi, and the sidelobe levels in the azimuth plane and the elevation plane are not less than 20 dB.

[0010] In an embodiment of the present invention, within the range of 75.1 - 79 GHz, the return loss of the antenna is ≤ -15 dB.

[0011] The above technical solution of the present invention has the following advantages compared with the prior art: For the high-gain and low-sidelobe antenna of the present invention, the antenna has the advantages of high gain and low sidelobe level. The structure is relatively compact, and the power-dividing network is used for signal transmission in the horizontal and vertical directions, so that the distance between two of the four radiation elements is small, thereby reducing the antenna sidelobe.

[0012] In the present invention, through the reasonable layout of the first power-dividing and twisting network and the second power-dividing and twisting network, the energy is fully coupled and concentratedly radiated in multiple directions, increasing the gain of the antenna in the 0° direction by 20 dBi. At the same time, surface current suppression slots are added on both sides of the slot radiation slot, effectively weakening the surface current coupling of the antenna and significantly reducing the antenna sidelobe level, so that the sidelobe levels in the azimuth plane and the elevation plane are ≥ 20 dB.

[0013] In the present invention, the twisting network and the radiation structure are arranged in the first direction, the second direction, and the third direction respectively. Through the demarcation of the three-layer structure, each functional module can be stacked and distributed within a limited size. This design not only meets the volume and processing requirements of vehicle-mounted radars, but also is conducive to processing and assembly through the demarcation layers A and B. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to make the content of the present invention easier to be clearly understood, the present invention will be further described in detail below according to the specific embodiments of the present invention in conjunction with the drawings.

[0015] Figure 1 It is a front view schematic diagram of the high-gain and low-sidelobe antenna of the present invention.

[0016] Figure 2It is a top view schematic diagram of the high-gain low-sidelobe antenna of the present invention.

[0017] Figure 3 It is a schematic diagram of the overall structure of the high-gain low-sidelobe antenna of the present invention.

[0018] Figure 4 It is a schematic diagram of signal transmission of the high-gain low-sidelobe antenna of the present invention.

[0019] Figure 5 It is the simulation result of the high-gain low-sidelobe antenna of the present invention Figure 1 。

[0020] Figure 6 It is the simulation result of the high-gain low-sidelobe antenna of the present invention Figure 2 。

[0021] Description of the reference numerals in the drawings of the specification: 1. First power divider torsion network; 11. Channel; 12. Sub-channel; 2. Coupling slot; 3. Second power divider torsion network; 4. Slot radiation element; 41. Slot radiation groove; 5. Surface current suppression slot; 1-1. First layer structure; 1-2. Second layer structure; 1-3. Third layer structure. Detailed implementation manners

[0022] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the specific embodiments cited are not intended to limit the present invention.

[0023] In the present invention, if there is a description of directions (up, down, left, right, front and back), it is only for the convenience of describing the technical solution of the present invention, rather than indicating or implying that the technical features referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0024] In the present invention, the meaning of "several" is one or more, the meaning of "multiple" is two or more, and "greater than", "less than", "exceeding", etc. are understood not to include the present number; "above", "below", "within", etc. are understood to include the present number. In the description of the present invention, if there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0025] In the present invention, unless otherwise clearly defined, terms such as "arranged", "installed", and "connected" should be understood in a broad sense. For example, they can be directly connected, or indirectly connected through an intermediate medium; they can be fixedly connected, or detachably connected, or integrally formed; they can be mechanically connected, or electrically connected or capable of communicating with each other; they can be the communication inside two components or the interaction relationship between two components. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0026] Referring to Figure 1 、 Figure 2 As shown, a high-gain low-sidelobe antenna of the present invention includes: The first power divider and twist network 1 includes a channel 11 arranged along a first direction and two sub-channels 12 branched out from both sides of the channel 11 along a second direction; A plurality of coupling slots 2 are distributed on the two sub-channels 12 along the second direction; A plurality of second power divider and twist networks 3, the number of which is correspondingly set with the coupling slots 2. Each of the second power divider and twist networks 3 is arranged on one side of the corresponding coupling slot 2 along a third direction, and each of the second power divider and twist networks 3 extends along the first direction, and is used for receiving the signal transmitted by the corresponding coupling slot 2 and transmitting the signal to both sides along the first direction; A plurality of slot radiation units 4, the number of which is correspondingly set with the second power divider and twist networks 3. Each of the slot radiation units 4 includes a plurality of slot radiation slots 41 distributed along the first direction. The slot radiation unit 4 is used for radiating to free space after receiving the signal output by the corresponding second power divider and twist network 3; Wherein, the first direction, the second direction, and the third direction are perpendicular to each other in pairs, and are respectively Figure 1 、 Figure 2 the X, Y, and Z directions in

[0027] Specifically, referring to Figure 1 、 Figure 3 As shown, surface current suppression slots 5 are arranged on both sides of each of the slot radiation units 4 along the second direction, and are used for suppressing the surface current near the radiation port and reducing the antenna sidelobe level. In order to improve the gain and reduce the antenna sidelobe, the depth, opening width, and spacing of the surface current suppression slots 5 arranged on both sides of the radiation slot can be adjusted to meet the antenna waveform requirements.

[0028] In one embodiment, the surface current suppression slot 5 extends along the first direction.

[0029] In one embodiment, in order to facilitate processing, a demarcation layer A and B are provided, so that the antenna forms a three-layer structure distributed along the third direction, which are respectively: The first - layer structure 1 - 1 includes the lower half of the first power - dividing and twisting network 1; The second - layer structure 1 - 2 includes the upper half of the first power - dividing and twisting network 1 and several coupling slots 2; The third - layer structure 1 - 3 includes several second power - dividing and twisting networks 3, several slot radiation units 4, and the surface - current suppression slot 5.

[0030] It can be understood that the signal first enters the first - layer structure 1 - 1 in the third direction. After passing through the lower half and the upper half of the first power - dividing and twisting network 1, the signal is distributed in the first direction and the second direction.

[0031] In the second - layer structure 1 - 2, several coupling slots 2 are distributed along the second direction on two sub - channels 12, and are used to introduce the distributed signal to the corresponding positions. Each coupling slot 2 couples the received energy to the second power - dividing and twisting network 3 in the third - layer structure 1 - 3. In the third - layer structure 1 - 3, the second power - dividing and twisting network 3 further transmits the signal received from the coupling slot 2 to both sides in the first direction and outputs it to the slot radiation unit 4. Each slot radiation unit 4 includes several slot radiation slots 41 distributed along the first direction, and finally realizes the radiation of energy into free space. The surface - current suppression slot 5 is used to weaken the coupling between the waveguide surface current and the radiation wave, reduce the energy leakage outside the main radiation lobe, and thus effectively reduce the sidelobe level.

[0032] In one embodiment, referring to Figure 1 as shown, the numbers of the coupling slot 2, the second power - dividing and twisting network 3, the slot radiation unit 4, and the slot radiation slot 41 are all four.

[0033] Referring to Figure 4 as shown, when the antenna works, the signal enters the first power - dividing and twisting network 1 in the a direction, is transmitted to both sides in the b direction, then passes through 4 coupling slots 2 and is transmitted in the c direction, then passes through the second power - dividing and twisting network 3 and is transmitted to both sides in the d direction, and finally the energy is radiated through the radiation slot.

[0034] Referring to Figure 5 as shown, the operating frequency band of this waveguide antenna is 75.1 - 79 GHz @ - 15 dB (within 75.1 - 79 GHz, the return loss ≤ - 15 dB), and it has a bandwidth of 4 GHz. It ensures that the vehicle - mounted millimeter - wave radar can meet the requirements of different frequency signals in applications, and enhances the system's detection ability and anti - interference ability for targets.

[0035] As Figure 6As shown, the radiation pattern of the waveguide antenna shows that the antenna gain is 20 dBi @ 0° (the gain in the 0° direction is 20 dBi), and the sidelobe levels in the azimuth plane and elevation plane are ≥ 20 dB. This antenna features high gain and low sidelobes, which can greatly improve the detection performance of vehicle-mounted millimeter-wave radars.

[0036] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A high-gain and low-side-lobe antenna, characterized in that, Comprising: A first power divider and twist network (1), including a channel (11) arranged along a first direction and two sub-channels (12) branched out from both sides of the channel (11) along a second direction; A plurality of coupling slots (2), distributed along the second direction on the two sub-channels (12); A plurality of second power divider and twist networks (3), the number of which is correspondingly set with the coupling slots (2), each of the second power divider and twist networks (3) is arranged on one side of the corresponding coupling slot (2) along a third direction, and each of the second power divider and twist networks (3) extends along the first direction, for receiving the signal transmitted by the corresponding coupling slot (2) and transmitting the signal to both sides of the first direction; A plurality of slot radiation units (4), the number of which is correspondingly set with the second power divider and twist networks (3), each of the slot radiation units (4) includes a plurality of slot radiation slots (41) distributed along the first direction, and the slot radiation unit (4) is used for radiating to free space after receiving the signal output by the corresponding second power divider and twist network (3); Wherein, the first direction, the second direction and the third direction are perpendicular to each other in pairs.

2. The high-gain and low-sidelobe antenna according to claim 1, characterized in that Surface current suppression slots (5) are arranged on both sides of each of the slot radiation units (4) along the second direction, for suppressing the surface current near the radiation port and reducing the antenna sidelobe level.

3. A high-gain low-sidelobe antenna according to claim 2, characterized in that The surface current suppression slot (5) extends along the first direction.

4. A high-gain low-sidelobe antenna according to claim 2, characterized in that, It includes a three-layer structure distributed along the third direction, respectively: The first layer structure (1-1), including the lower half of the first power divider and twist network (1); The second layer structure (1-2), including the upper half of the first power divider and twist network (1) and a plurality of the coupling slots (2); The third layer structure (1-3), including a plurality of the second power divider and twist networks (3), a plurality of the slot radiation units (4) and the surface current suppression slots (5).

5. A high-gain low-sidelobe antenna according to claim 1, characterized in that The number of the coupling slots (2), the second power divider and twist networks (3), the slot radiation units (4) and the slot radiation slots (41) is four.

6. The high-gain low-sidelobe antenna according to claim 1, characterized in that The gain of the antenna in the 0° direction is 20 dBi, and the sidelobe levels in the azimuth plane and the elevation plane are not less than 20 dB.

7. A high-gain low-sidelobe antenna according to claim 1, characterized in that, Within the range of 75.1 - 79 GHz, the return loss of the antenna is ≤ -15 dB.

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