Feeder line structure for reducing antenna pattern fluctuation

Abstract

The invention provides a feeder line structure for reducing the fluctuation of an antenna pattern. The feeder line structure comprises an antenna microstrip feeder line, a shielding cover and an isolation wall, the shielding cover is a hollow metal cavity, is arranged outside the antenna microstrip feeder, has a gap with the antenna microstrip feeder, and is used for isolating mutual interference between the antenna and the chip; the isolation walls are arranged between the GND of the antenna microstrip feeder and the shielding cover at intervals, one end of each isolation wall is connected with the GND of the antenna microstrip feeder, the other end of each isolation wall is connected with the shielding cover, and the isolation walls are used for blocking electromagnetic energy coupling leakage between the antenna microstrip feeders. According to the invention, the isolation wall and the wave-absorbing material can be combined, and the fluctuation of an antenna pattern is effectively reduced. By adjusting the parameters of the isolation wall and the wave-absorbing material, different antenna design and application requirements can be met, and the structure is suitable for various antenna types and scenes, such as a microstrip antenna and an array antenna.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter-wave radar, and particularly to a feeder structure for reducing the fluctuation of the antenna pattern. Background Art

[0002] Millimeter-wave radar antennas play an important role in various application scenarios, and their usage backgrounds are extensive and diverse. Millimeter-wave radars transmit millimeter waves and send these electromagnetic waves through antennas. When the electromagnetic waves encounter a target object, part of the electromagnetic waves will be reflected back and captured by the receiving antenna of the radar. By comparing the transmitted signal and the received echo signal, the millimeter-wave radar can analyze information such as the distance, angle, and speed of the object, thereby determining its specific position.

[0003] Microstrip lines are one of the commonly used feeders for millimeter-wave radar antennas, and they are semi-open transmission lines. Due to the limited routing space, there is inevitably a certain amount of coupling between lines. This coupling will cause fluctuations in the antenna radiation pattern, and in severe cases, it will affect the normal use of the radar. Summary of the Invention

[0004] Based on this, it is necessary to provide a feeder structure for reducing the fluctuation of the antenna pattern in view of the above technical problems.

[0005] A feeder structure for reducing the fluctuation of the antenna pattern includes: an antenna microstrip feeder, a shielding cover, and a partition wall;

[0006] The shielding cover is a hollow metal cavity, and there is a gap between the outside of the antenna microstrip feeder and the antenna microstrip feeder, which is used to isolate the mutual interference between the antenna and the chip; the partition wall is arranged at intervals between the GND of the antenna microstrip feeder and the shielding cover, one end is connected to the GND of the antenna microstrip feeder, and the other end is connected to the shielding cover, which is used to block the coupling and leakage of electromagnetic energy between the antenna microstrip feeders.

[0007] In one embodiment, it further includes: an absorbing material;

[0008] The absorbing material is arranged at the top end inside the shielding cover and is used to absorb the coupled and leaked electromagnetic waves between the antenna microstrip feeders.

[0009] In one embodiment, it further includes: the partition wall is made of metal.

[0010] In one embodiment, it further includes: the partition wall is made of an absorbing material.

[0011] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: By combining the isolation wall and the wave-absorbing material, the fluctuation of the antenna pattern can be effectively reduced. The isolation wall can effectively shield the interference of external electromagnetic waves. Most of the energy will be reflected, and only a small part of the energy can enter the interior, and this part of the energy will decay exponentially with the depth of entering the isolation wall. The isolation wall has high mechanical strength and stability, and can withstand certain external forces and environmental changes, thereby protecting the feeder structure from damage. The wave-absorbing material can absorb the radiated electromagnetic energy existing between the antenna elements, thereby effectively reducing the coupling between the antenna elements, further reducing the fluctuation of the antenna pattern, and improving the performance of the antenna. The metal wall shields the interference of external electromagnetic waves, while the wave-absorbing material absorbs the radiated electromagnetic energy between the antenna elements. The combined action of the two makes the antenna pattern more stable.

[0012] The feeder structure of the present invention is applicable to a variety of antenna types and scenarios, such as microstrip antennas, array antennas, etc. By adjusting the parameters of the isolation wall and the wave-absorbing material, different antenna designs and application requirements can be adapted. Brief Description of the Drawings

[0013] Figure 1A Schematic diagram of the microstrip feeder structure of the antenna in one embodiment;

[0014] Figure 1B Schematic diagram of the cross-section AA' of the microstrip feeder of the antenna in one embodiment;

[0015] Figure 1C Schematic diagram of the cross-section BB' of the microstrip feeder of the antenna in one embodiment;

[0016] Figure 2 Schematic diagram of the ideal direction of antenna ② in one embodiment;

[0017] Figure 3 Schematic diagram of the actual direction of antenna ② in one embodiment;

[0018] Figure 4 Schematic diagram of the electromagnetic wave coupling leakage of the microstrip feeder of the antenna in one embodiment;

[0019] Figure 5 Schematic diagram of a feeder structure for reducing the fluctuation of the antenna pattern in one embodiment;

[0020] Figure 6A Schematic diagram of a partial area of the microstrip feeder of the antenna in one embodiment;

[0021] Figure 6B Schematic diagram of the cross-section BB' of a feeder structure for reducing the fluctuation of the antenna pattern in one embodiment;

[0022] Figure 6C Schematic diagram of the microstrip feeder structure of the antenna in one embodiment;

[0023] Figure 7 Schematic diagram of electromagnetic wave coupling leakage of a feeder structure for reducing antenna pattern fluctuation in an embodiment

[0024] Figure 8 Schematic diagram of the actual direction of antenna ② of a feeder structure for reducing antenna pattern fluctuation in an embodiment

[0025] Figure 9A Schematic diagram of a feeder structure for reducing antenna pattern fluctuation with wave-absorbing materials arranged in an embodiment

[0026] Figure 9B Schematic diagram of the CC' cross-section of a feeder structure for reducing antenna pattern fluctuation with wave-absorbing materials arranged in an embodiment

[0027] Figure 10 Schematic diagram of coupling leakage between antenna microstrip feeders after arranging wave-absorbing materials in an embodiment

[0028] Figure 11 Schematic diagram of the actual direction of antenna ② after arranging wave-absorbing materials in an embodiment

[0029] Figure 12A Schematic diagram of an isolation degree simulation model in an embodiment

[0030] Figure 12B Schematic diagram of the isolation degree simulation result in an embodiment

[0031] Figure 13 Schematic diagram of the isolation degree between feeders after arranging isolation walls in an embodiment

[0032] Figure 14 Schematic diagram of the isolation degree between feeders after arranging wave-absorbing materials in an embodiment Specific implementation manners

[0033] Before describing the specific implementation manners of the present invention, the overall concept of the present invention is described as follows:

[0034] When designing a millimeter-wave radar, a shielding cover is used to cover the chip and the microstrip line to isolate the mutual interference between the antenna and the chip. Usually, the shielding cover is a hollow metal cavity, and there is no isolation wall between the antenna microstrip feeders. At this time, the radiation leakage of the antenna microstrip feeders, under the reflection of the metal shielding cover, will bounce and oscillate to the adjacent microstrip line, resulting in poor isolation between the antenna microstrip feeders and causing fluctuations or even distortions in the antenna radiation pattern. Especially such as Figure 1A 、 Figure 1B and Figure 1CThe shown antenna array, when the middle antenna ② radiates, ideally, its azimuth pattern is a relatively smooth curve, as Figure 2 shown. However, the actual radiation pattern is as Figure 3 shown, with a large distortion in the middle of the pattern, seriously affecting the radar performance.

[0035] After analysis, the inventor found that the main reason for these problems is that when antenna ② works, the chip transmits the electromagnetic wave signal through the feeding microstrip line to antenna ② for radiation. Due to the aforementioned reasons, during the transmission process of the electromagnetic wave signal, it will be coupled and leaked to the feeding microstrip lines of antenna ① and antenna ③. This part of the coupled and leaked electromagnetic wave will be radiated out through antenna ① and antenna ③, and coherently superimpose with the electromagnetic wave radiated out by antenna ②, thus causing distortion of the pattern of antenna ②. The energy of the coupled and leaked electromagnetic wave is as Figure 4 shown. It can be seen that there is a strong electromagnetic energy coupling and leakage from the microstrip feeding line of antenna ② to the microstrip feeding lines of antenna ① and antenna ③. Therefore, the present invention proposes a feeding line structure for reducing the fluctuation of the antenna pattern. An isolation wall is provided between the antenna microstrip feeding lines on the shielding cover to block the electromagnetic energy coupling and leakage between the microstrip feeding lines, thereby improving the above-mentioned problem of antenna pattern distortion.

[0036] After introducing the overall concept of the present invention, in order to make the purpose, technical solution and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below through specific embodiments in conjunction with the drawings.

[0037] It should be noted that unless otherwise defined, the technical terms or scientific terms used in one or more embodiments of this specification should have the ordinary meaning understood by those with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in one or more embodiments of this specification do not represent any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. "Connection" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0038] In one embodiment, as Figure 5 , 6A, as shown in FIGS. 6B and 6C, a feeder structure for reducing the fluctuation of the antenna pattern is provided, including: an antenna microstrip feeder 10, a shielding cover 11 and a partition wall 12. Specifically, the antenna microstrip feeder 10 includes: TOP (top layer), Substrate (dielectric substrate), GND (ground layer) and VIA (via).

[0039] The shielding cover 11 is a hollow metal cavity, which is arranged outside the antenna microstrip feeder 10 with a gap between it and the antenna microstrip feeder 10, and is used to isolate the mutual interference between the antenna and the chip; the partition wall 12 is arranged at intervals between the GND of the antenna microstrip feeder 10 and the shielding cover 11, one end is connected to the GND of the antenna microstrip feeder 10, and the other end is connected to the shielding cover 11, and is used to block the electromagnetic energy coupling leakage between the antenna microstrip feeders 10.

[0040] Specifically, the partition wall 12 can be made of metal, or can be made of an absorbing material or a high-loss material. Any material that can reduce the coupling between channels can be used.

[0041] In one embodiment, the partition wall 12 is made of metal. After the metal partition wall 12 is set, the electromagnetic wave energy coupling leakage between the antenna microstrip feeders 10 is greatly reduced, as Figure 7 shown. It can be seen that the coupling leakage at this time is significantly reduced. At this time, the pattern of antenna ② is as Figure 8 shown. It can be seen that the distortion phenomenon of the pattern is significantly improved.

[0042] On this basis, an absorbing material 13 can also be arranged at the top end inside the shielding cover 11 to absorb the coupling leakage electromagnetic waves between the antenna microstrip feeders 10. Thereby, the distortion phenomenon of the aforementioned antenna pattern can also be improved. The arrangement of the absorbing material 13 is as Figure 9A and Figure 9B shown. At this time, the electromagnetic coupling leakage situation between the antenna microstrip feeders 10 is as Figure 10 shown. The radiation pattern of antenna ② is as Figure 11 shown. It can be seen that after the absorbing material 13 is arranged, the coupling leakage between the antenna microstrip feeders 10 is also improved to a certain extent, and the distortion phenomenon of the pattern of antenna ② is also improved.

[0043] A feeder structure for reducing the fluctuation of the antenna pattern provided by the present invention is by setting a partition wall between the antenna microstrip feeders, or by adding an absorbing material on the top of the shielding cover. It can effectively improve the isolation between the antenna microstrip feeders and improve the problem of antenna pattern distortion.

[0044] When there is no partition wall between the antenna microstrip feeders, the isolation between the antenna microstrip feeders is as Figure 12A and Figure 12BAs shown in the figure. Among them, Port11 is the port 1 of feeder 1, and Port12 is the port 2 of feeder 1. Port21, Port22, Port31, Port32 and so on. It can be seen from the simulation results that the isolation degree curve oscillates severely at this time. The reason is as described above, due to the radiation leakage of the microstrip line, under the reflection of the metal shielding cover, it reflects back and forth and oscillates.

[0045] After adding the isolation wall, the isolation degree between the microstrip feeders of the obtained antenna is as Figure 13 shown in the figure. At this time, not only the value of the isolation degree increases significantly, but also the above-mentioned oscillation phenomenon disappears. The resulting benefit is to improve the pattern distortion phenomenon.

[0046] After adding the absorbing material, the isolation degree between the microstrip feeders of the obtained antenna is as Figure 14 shown in the figure. At this time, the above-mentioned oscillation phenomenon also disappears. It can also improve the pattern distortion phenomenon.

[0047] A feeder structure for reducing the fluctuation of the antenna pattern provided by the present invention, a feeder structure combining an isolation wall and an absorbing material, can effectively reduce the fluctuation of the antenna pattern. The isolation wall can effectively shield the interference of external electromagnetic waves. Most of the energy will be reflected, and only a small part of the energy can enter the interior, and this part of the energy will decay exponentially with the depth of entering the isolation wall. The isolation wall has high mechanical strength and stability, and can withstand certain external forces and environmental changes, so as to protect the feeder structure from damage. The absorbing material can absorb the radiated electromagnetic energy existing between the antenna elements, thereby effectively reducing the coupling between the antenna elements. This absorption effect can further reduce the fluctuation of the antenna pattern and improve the performance of the antenna. The metal wall shields the interference of external electromagnetic waves, while the absorbing material absorbs the radiated electromagnetic energy between the antenna elements. The two work together to make the antenna pattern more stable.

[0048] The structure provided by the present invention is applicable to various antenna types and scenarios, such as microstrip antennas, array antennas, etc. By adjusting the parameters of the isolation wall and the absorbing material, it can adapt to different antenna design and application requirements.

[0049] Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is only exemplary, and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples; under the concept of the present invention, the technical features between the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the embodiments of the present invention as described above, and they are not provided in detail for the sake of brevity.

[0050] In the case where specific details are set forth to describe exemplary embodiments of the present invention, it will be apparent to those skilled in the art that the present invention embodiments can be practiced without these specific details or with variations of these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive. Although the present invention has been described in connection with specific embodiments of the present invention, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description.

[0051] Embodiments of the present invention are intended to cover all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the embodiments of the present invention shall be included within the protection scope of the present invention.

Claims

1. A feeder structure for reducing the fluctuation of the antenna pattern, characterized in that, Including: An antenna microstrip feeder, a shielding cover, and a partition wall; The shielding cover is a hollow metal cavity. There is a gap between the outside of the antenna microstrip feeder and the antenna microstrip feeder, which is used to isolate the mutual interference between the antenna and the chip. The partition wall is arranged at intervals between the GND of the antenna microstrip feeder and the shielding cover, with one end connected to the GND of the antenna microstrip feeder and the other end connected to the shielding cover, which is used to block the electromagnetic energy coupling leakage between the antenna microstrip feeders.

2. The feeder structure for reducing the fluctuation of the antenna pattern according to claim 1, wherein Further including: Absorbing material; The absorbing material is arranged at the top inside the shielding cover, which is used to absorb the coupled and leaked electromagnetic waves between the antenna microstrip feeders.

3. A feeder structure for reducing the fluctuation of an antenna pattern according to claim 1, characterized in that, Further including: The partition wall is made of metal.

4. The feeder structure for reducing the fluctuation of the antenna pattern according to claim 1, characterized in that Further including: The partition wall is made of absorbing material.

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