Millimeter-wave radar antenna and its wave focusing method

Abstract

The present invention relates to the technical field of transmission devices, and particularly to a millimeter-wave radar antenna and a wave focusing method thereof, which includes a waveguide component and two dielectric substrates. The waveguide component is disposed between the two dielectric substrates, and the two dielectric substrates are respectively connected to both ends of the waveguide component. The waveguide component includes a plurality of cylindrical conductors, and the arrangement of the plurality of cylindrical conductors forms an arrangement trajectory, which is in a horn shape. One end of the arrangement trajectory is a closed end, and the other end of the arrangement trajectory is an open end. The millimeter-wave radar antenna of the present invention can achieve the concentration of energy as much as possible under the condition of a small size, so as to achieve a farther detection distance.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission devices, and particularly relates to a millimeter-wave radar antenna and a wave focusing method thereof. Background Art

[0002] With the continuous research on communication technologies, current communication systems are developing towards the direction of intelligence, miniaturization, and integration. Especially with the wave of intelligentization in modern automobiles, more and more advanced sensors are deployed on the vehicle body, and at the same time, there are relatively high requirements for the size and performance of the sensors. Various object detection and sensing technologies can provide functions such as adaptive cruise control and automatic emergency braking.

[0003] A millimeter-wave radar is a radar that operates in the millimeter-wave band. Generally, millimeter waves refer to electromagnetic waves with a frequency range of 30 - 300 GHz (corresponding to a wavelength of 1 - 10 mm). The wavelength of millimeter waves is between centimeter waves and light waves, so millimeter waves have the advantages of both microwave guidance and optoelectronic guidance.

[0004] The millimeter-wave radar used in automobiles refers to a radar that uses millimeter-level wavelengths (currently mainly using frequency bands of 24 GHz, 77 GHz, or 79 GHz). It can quickly and accurately obtain information about targets around the vehicle and the drone, such as relative distance, relative speed, angle, whether there is an object, the direction of movement, etc., and track, identify, and classify the targets based on the detected information, and make corresponding warnings or decisions. The millimeter-wave radar has the characteristics of small volume, light weight, and high spatial resolution, and is all-weather (except in heavy rain) and all-day.

[0005] The millimeter-wave radar mainly includes a millimeter-wave antenna, a millimeter-wave transceiver front end, a baseband processing module, and an alarm module. For existing millimeter-wave radar antennas, their wave focusing effect is not good, the energy concentration effect from the opening is not good, and the propagation and detection distance of the millimeter-wave radar are affected. Summary of the Invention

[0006] The present invention aims to solve one of the above technical problems.

[0007] To solve one of the above technical problems, the present invention provides a millimeter-wave radar antenna, including a waveguide assembly and two dielectric substrates. The waveguide assembly is disposed between the two dielectric substrates, and the two dielectric substrates are respectively connected to both ends of the waveguide assembly. The waveguide assembly includes a plurality of cylindrical conductors, and the arrangement of the plurality of cylindrical conductors forms an arrangement trajectory, the arrangement trajectory is in a horn shape, one end of the arrangement trajectory is a closed end, and the other end of the arrangement trajectory is an open end;

[0008] The arrangement trajectories of the multiple cylindrical conductors include Trajectory 1 and Trajectory 2. Trajectory 1 is located on one side of Trajectory 2. Trajectory 1 includes a first straight segment and a first arc segment. Trajectory 2 includes a second straight segment and a second arc segment. The position of the first straight segment corresponds to that of the second straight segment, and the position of the second arc segment corresponds to that of the first arc segment. The first straight segment and the second straight segment are arranged in parallel. The second arc segment and the first arc segment form the horn shape. A waveguide channel is formed between Trajectory 1 and Trajectory 2. The waveguide channel includes Channel 1 and Channel 2. Channel 1 is the channel formed between the first straight segment and the second straight segment, and Channel 2 is the channel formed between the first arc segment and the second arc segment. Channel 2 is in the shape of a flared opening. Trajectory 1 and Trajectory 2 are symmetrically arranged with respect to the vertical symmetry plane of the dielectric substrate.

[0009] The millimeter-wave radar antenna of the present invention can concentrate energy as much as possible when the size is small to achieve a farther detection distance. By arranging multiple cylindrical conductors in a horn shape, the arrangement trajectory of the cylindrical conductors has a first arc segment and a second arc segment. Compared with a conventional horn antenna, when the opening length is the same, the peak value of the internal electric field of the millimeter-wave radar antenna of the present invention is increased. Therefore, better energy concentration can be achieved to reach a farther detection distance. To increase the peak value of the internal electric field of a conventional horn antenna, the opening length needs to be increased, which requires increasing the size and occupied space of the waveguide component. The millimeter-wave radar antenna of the present invention can also concentrate energy as much as possible and reach a farther detection distance when the size is small.

[0010] Further, there is a third straight segment between the first straight segment and the second straight segment. The third straight segment is located at the closed end. One end of the first straight segment and one end of the second straight segment are connected by the third straight segment. The third straight segment is formed by arranging multiple cylindrical conductors.

[0011] Further, a cable is connected to one of the dielectric substrates. The cable is located inside the arrangement trajectory and on the symmetry line of Trajectory 1 and Trajectory 2.

[0012] Further, the cable is perpendicular to the dielectric substrate. The distance between the cable and the closed end is D, and D = 1 / 4λ, where where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal.

[0013] Further, the first arc segment and the second arc segment are in a power function, and the power function presented by the first arc segment and the second arc segment is where the value range of P' is 0.7 ≤ P' ≤ 1.2.

[0014] Further, the diameter of the cylindrical conductors in the first straight segment and the second straight segment is D1, where D1 = 0.15λ, and the distance between two adjacent cylindrical conductors in the first straight segment and the second straight segment is P1, where P1 = 0.3λ, where where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal.

[0015] Further, the diameter of the cylindrical conductors in the first arc segment and the second arc segment is D2, where D2 = 0.15λ, and the distance between two adjacent cylindrical conductors in the first arc segment and the second arc segment is P2, where P2 = 0.42λ, where where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal.

[0016] Further, the lengths of the first straight segment and the second straight segment are both L1, and the value range of L1 is λ ≤ L1 ≤ 3λ, where where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal.

[0017] Further, the lengths of the first arc segment and the second arc segment are both L2, and 0.9 ≤ L2 / L1 ≤ 1.

[0018] Further, the first trajectory and the second trajectory are symmetrically arranged with respect to the straight line k. The intersection point of the first straight segment and the first arc segment is point a, the end point of the first arc segment is point b, the straight line where points a and b are located is the straight line m, and the included angle between the straight line m and the straight line k is A, and the value range of A is 24° ≤ A ≤ 28°

[0019] Further, the connection line between point a and point b forms a line segment ab, and the length of the line segment ab is L ab , the straight line where the first straight segment is located is the straight line F, and the included angle between the straight line F and the straight line m is B. According to the corresponding angles theorem, the angle of A is the same as the angle of B, that is then L2 = L bc cos A.

[0020] The present invention also provides a method for focusing the wave of a millimeter-wave radar antenna, including the following steps:

[0021] S1, a plurality of cylindrical conductors are arranged along the first trajectory and the second trajectory to form a waveguide channel for propagating the millimeter-wave radar between the first trajectory and the second trajectory, and the millimeter-wave radar signal propagates from the closed end to the open end;

[0022] S2, the millimeter wave radar signal first propagates in channel one toward channel two. When the millimeter wave radar propagates in channel one, the width of channel one is equal everywhere, and the millimeter wave radar propagates in a straight line in channel one;

[0023] S3, the millimeter-wave radar enters channel 2 from channel 1. Channel 2 is horn-shaped. The millimeter-wave radar signal first expands to both sides and propagates forward in channel 2.

[0024] S4, the trajectory of the second arc segments on both sides of channel 2 is a power function, and the millimeter-wave radar signal is gathered in large quantities in channel 2, achieving a wave focusing effect;

[0025] S5, the slopes of the second arc segments on both sides of channel 2 gradually decrease, and the millimeter-wave radar signal propagates toward the opening in channel 2 and gradually gathers toward the opening;

[0026] S6, millimeter-wave radar signal propagates outward from the opening.

[0027] The beneficial effect of the present invention is that the millimeter-wave radar antenna and the wave focusing method thereof of the present invention can achieve the goal of concentrating energy as much as possible in a case of a small size to achieve a longer detection distance. By arranging a plurality of cylindrical conductors into a horn shape, the arrangement trajectory of the cylindrical conductors has a first arc segment and a second arc segment. Compared with a conventional horn antenna, under the condition of the same opening length, the internal electric field peak value of the millimeter-wave radar antenna of the present invention is improved, so that better energy concentration can be achieved to achieve a longer detection distance. To increase the internal electric field peak value of a conventional horn antenna, the opening length needs to be increased, which requires increasing the size and occupied space of the waveguide component. The millimeter-wave radar antenna of the present invention can also achieve the goal of concentrating energy as much as possible in a case of a small size to achieve a longer detection distance.

[0028] Other advantages include small size and small antenna opening size. Under the same opening size, the electric field strength is improved, that is, more energy is emitted, the directionality is good, almost all the energy is concentrated and emitted through the antenna, and the antenna transmission system is composed of only two upper and lower dielectric substrates and a cylindrical conductor, with low cost, simple structure and easy processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0030] Figure 1 It is a schematic diagram of the structure of the millimeter wave radar antenna of the optimal embodiment of the present invention.

[0031] Figure 2 It is a schematic diagram of the cylindrical conductor arrangement trajectory of the optimal embodiment of the present invention.

[0032] Figure 3It is a schematic diagram of the power function presented by the first arc segment and the second arc segment in the embodiment of the present invention.

[0033] Figure 4 It is a schematic diagram of the power function presented by the first arc segment and the second arc segment in the embodiment of the present invention.

[0034] In the figure: 1. Dielectric substrate; 2. Cylindrical conductor; 3. First straight segment; 4. First arc segment; 5. Second straight segment; 6. Second arc segment; 7. Third straight segment; 8. Open end; 9. Closed end. Detailed implementation manners

[0035] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] As Figures 1 to 4As shown, it is the optimal embodiment of the present invention, a millimeter-wave radar antenna, which includes a waveguide component and two dielectric substrates 1. The waveguide component is arranged between the two dielectric substrates 1, and the two dielectric substrates 1 are respectively connected to the two ends of the waveguide component. The waveguide component includes a plurality of cylindrical conductors 2, and the arrangement of the plurality of cylindrical conductors 2 forms an arrangement trajectory, which is in a horn shape. One end of the arrangement trajectory is a closed end, and the other end is an open end.

[0038] The arrangement trajectory of the plurality of cylindrical conductors 2 includes a trajectory one and a trajectory two. Trajectory one is located on one side of trajectory two. Trajectory one includes a first straight segment 3 and a first arc segment 4. Trajectory two includes a second straight segment 5 and a second arc segment 6. The position of the first straight segment 3 corresponds to the position of the second straight segment 5, and the position of the second arc segment 6 corresponds to the position of the first arc segment 4. The first straight segment 3 and the second straight segment 5 are arranged in parallel. The horn shape is formed by the second arc segment 6 and the first arc segment 4. A waveguide channel is formed between trajectory one and trajectory two. Trajectory one and trajectory two are symmetrically arranged with respect to the vertical symmetry plane of the dielectric substrate 1. The waveguide channel includes a channel one and a channel two. Channel one is the channel formed between the first straight segment 3 and the second straight segment 5, and channel two is the channel formed between the first arc segment 4 and the second arc segment 6. Channel two is in the shape of a horn mouth.

[0039] There is a third straight segment 7 between the first straight segment 3 and the second straight segment 5. The third straight segment 7 is located at the closed end. The length of the third straight segment is a. The first straight segment and the second straight segment are both perpendicular to the third straight segment. One end of the first straight segment 3 and one end of the second straight segment 5 are connected by the third straight segment 7. The third straight segment 7 is formed by arranging a plurality of cylindrical conductors 2.

[0040] A cable is connected to one of the dielectric substrates. The cable is located inside the arrangement trajectory. The cable is located on the symmetry line of trajectory one and trajectory two. The cable is perpendicular to the dielectric substrate. The distance between the cable and the closed end is D, and D = 1 / 4λ, where where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal. Specifically, the two dielectric substrates are an upper dielectric substrate and a lower dielectric substrate, and the cable is located on the lower dielectric substrate.

[0041] The first arc segment and the second arc segment are in a power function. The power function presented by the first arc segment and the second arc segment is Where the value range of P' is 0.7 ≤ P' ≤ 1.2, the lengths of the first straight line segment and the second straight line segment are both L1, and the value range of L1 is λ ≤ L1 ≤ 3λ. The lengths of the first arc segment and the second arc segment are both L2, and 0.9 ≤ L2 / L1 ≤ 1. Locus 1 and locus 2 are symmetrically arranged with respect to the straight line k. The intersection point of the first straight line segment and the first arc segment is point b, and the end point of the first arc segment is point c. The straight line where points b and c are located is the straight line m, and the included angle between the straight line m and the straight line k is A. The value range of A is 24° ≤ A ≤ 28°. The angle of A will determine the length and size of the opening at the open end. If the opening is too large, the wave signal cannot be well concentrated when transmitted at the opening, which will reduce the propagation distance of the wave signal and result in poor propagation. If the opening is too small, the energy of the wave signal transmitted from the opening is small, affecting the propagation of the wave signal. The length of the line segment bc is L bc , the straight line where the first straight line segment is located is the straight line F, and the included angle between the straight line F and the straight line m is B. According to the corresponding angles theorem, the angle of A is the same as the angle of B, that is Then L2 = L bc cos A. After the power function of the first arc segment and the second arc segment locus is determined, by determining the angle value of A, the value of L2 can be determined. Therefore, the length value of L2 is also related to the size of the opening. The value of L2 and the size of the opening affect each other, and there is also a certain relationship between the length value of L2 and the length value of L1, that is, 0.9 ≤ L2 / L1 ≤ 1. Therefore, there is also a certain relationship between the size of the length value of L1 and A. By setting A to an appropriate angle, the opening size and L2 and L1 can be further adapted to the energy concentration of the wave signal and the propagation direction of the signal. 0.9 ≤ L2 / L1 ≤ 1 is beneficial to the straight-line propagation of the wave signal in channel 1 and is beneficial to the concentration of the wave signal in channel 2. The value range of A is 24° ≤ A ≤ 28°, which limits the size range of the opening and the conduction direction of the wave at the opening, making the wave signal more concentrated at the opening and the propagation direction will also be more accurately along the opening orientation for propagation.

[0042] The first arc segment 4 in trajectory one and the second arc segment 6 in trajectory two are both distributed in a power function trajectory. When the millimeter-wave radar signal is conducted in the waveguide channel, the millimeter-wave radar signal first conducts forward through channel one, and then when it conducts in channel two, due to the power function trajectories of the first arc segment 4 and the second arc segment 6, the trajectories of the first arc segment 4 and the second arc segment 6 are convex outward, and the energy of the millimeter-wave radar signal will be more concentrated in channel two. And because the first arc segment 4 and the second arc segment 6 are in a power function trajectory, channel two will have a tendency to gradually contract inward at the opening. Therefore, the energy of the wave signal can be further concentrated at the horn mouth, and the propagation performance is further improved. Compared with a waveguide channel of the same opening size, the electric field intensity in channel two will be relatively higher, more energy is emitted, the signal can be better concentrated at the opening for emission, the signal propagation distance is farther, and the signal intensity is stronger.

[0043] In this embodiment, P' = 0.8, the opening length of the open end is L3, L3 = 2.27λ, and the length of the closed end is a, a = 0.9λ.

[0044] The diameter of the cylindrical conductor 2 in the first straight segment 3 and the second straight segment 5 is D1, D1 = 0.15λ, the distance between two adjacent cylindrical conductors 2 in the first straight segment 3 and the second straight segment 5 is P1, P1 = 0.3λ, the diameter of the cylindrical conductor 2 in the first arc segment 4 and the second arc segment 6 is D2, D2 = 0.15λ, and the distance between two adjacent cylindrical conductors 2 in the first arc segment 4 and the second arc segment 6 is P2, P2 = 0.42λ.

[0045] The present invention also provides a wave focusing method for a millimeter-wave radar antenna, including the following steps:

[0046] S1, a plurality of cylindrical conductors are arranged along trajectory one and trajectory two to form a waveguide channel for propagating the millimeter-wave radar between trajectory one and trajectory two, and the millimeter-wave radar signal propagates from the closed end to the open end;

[0047] S2, the millimeter-wave radar signal now propagates in the direction of channel two in channel one. When the millimeter-wave radar propagates in channel one, the width of channel one is equal everywhere, and the millimeter-wave radar propagates in a straight line in channel one;

[0048] S3, the millimeter-wave radar enters channel two from channel one. Channel two is in a horn shape, and the millimeter-wave radar signal first expands to both sides and propagates forward in channel two;

[0049] S4. The trajectories of the second arc segments on both sides of Channel 2 are in the form of a power function. Millimeter-wave radar signals gather in large quantities in Channel 2, achieving the effect of wave concentration. Since the second arc segments are in the form of a power function, for the same opening size, the space of Channel 2 is larger than that of waveguide channels of other shapes, and the wave concentration effect is better, preventing millimeter-waves from spreading out during propagation and having a better energy concentration effect.

[0050] S5. The slopes of the second arc segments on both sides of Channel 2 gradually decrease. Millimeter-wave radar signals propagate in Channel 2 towards the opening direction and gradually gather towards the opening. Since the slopes of the second arc segments gradually decrease, millimeter-wave radar first spreads in Channel 2, then gathers, and then converges, and the energy is more concentrated at the opening.

[0051] S6. Millimeter-wave radar signals propagate outwards from the opening. Since the energy is more concentrated at the opening, the propagation and detection distance of millimeter-wave radar signals is farther.

[0052] In this embodiment, a 77 GHz millimeter-wave radar signal is taken as an example, and the wavelength where c = 3×10 8 m / s. Then, it can be obtained that the diameter of the cylindrical conductors in the first straight segment and the second straight segment is D1 = 0.59 mm, the interval P1 between two adjacent cylindrical conductors in the first straight segment and the second straight segment is P1 = 0.3λ, so P1 is 1.17 mm, the length L1 of the first straight segment and the second straight segment is 9.28 mm, and the length L2 of the first arc segment and the second arc segment is 9.36 mm; the opening length L3 of the open end is 8.85 mm, and the distance D between the cable and the closed end is 0.98 mm.

[0053] Compared with a conventional horn antenna, for the millimeter-wave radar antenna in this embodiment, when the opening length is the same at 8.85 mm, the peak value of the electric field in the cavity of the conventional horn antenna is 4.65 V / m, and the peak value of the electric field in the cavity of the millimeter-wave radar antenna in this embodiment is 5.38 V / m. That is, the strongest electric field point in the cavity is increased to 1.16 times, the energy in the antenna is more concentrated, and the millimeter-wave radar signal can reach a farther detection distance.

[0054] The beneficial effects of the present invention are that the millimeter-wave radar antenna and its wave focusing method of the present invention can concentrate energy as much as possible under the condition of a small size to achieve a longer detection distance. By arranging a plurality of cylindrical conductors 2 in a horn shape, the arrangement trajectory of the cylindrical conductors 2 has a first arc segment 4 and a second arc segment 6. Compared with a conventional horn antenna, under the condition of the same opening length, the peak value of the internal electric field of the millimeter-wave radar antenna of the present invention is increased. Therefore, better energy concentration can be achieved to reach a longer detection distance. For a conventional horn antenna to increase the peak value of the internal electric field, it is necessary to increase the opening length, which requires increasing the size and occupied space of the waveguide component. The millimeter-wave radar antenna of the present invention can also concentrate energy as much as possible under a small size to reach a longer detection distance;

[0055] It also has the advantages of a small volume, a small antenna opening size, an increased electric field strength under the same opening size, that is, more energy is emitted, good directivity, almost all the energy is concentrated and emitted via the antenna, and the antenna emission system is only composed of two upper and lower dielectric substrates 1 and cylindrical conductors 2, with low cost, simple structure and easy processing.

[0056] Taking the above ideal embodiments of the present invention as an inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A millimeter-wave radar antenna, comprising a waveguide component and two dielectric substrates (1), the waveguide component is disposed between the two dielectric substrates (1), and the two dielectric substrates (1) are respectively connected to both ends of the waveguide component. Characterized in that: The waveguide component includes a plurality of cylindrical conductors (2), and the arrangement of the plurality of cylindrical conductors (2) forms an arrangement trajectory, the arrangement trajectory is in a horn shape, one end of the arrangement trajectory is a closed end (9), and the other end of the arrangement trajectory is an open end (8); The arrangement trajectories of the plurality of cylindrical conductors (2) include a trajectory one and a trajectory two, the trajectory one is located on one side of the trajectory two, the trajectory one includes a first straight segment (3) and a first arc segment (4), the trajectory two includes a second straight segment (5) and a second arc segment (6), the position of the first straight segment (3) corresponds to the position of the second straight segment (5), the position of the second arc segment (6) corresponds to the position of the first arc segment (4), the first straight segment (3) and the second straight segment (5) are arranged in parallel, the second arc segment (6) and the first arc segment (4) form the horn shape, a waveguide channel is formed between the trajectory one and the trajectory two, the waveguide channel includes a channel one and a channel two, the channel one is a channel formed between the first straight segment (3) and the second straight segment (5), the channel two is a channel formed between the first arc segment (4) and the second arc segment (6), the channel two is in a horn mouth shape, and the trajectory one and the trajectory two are symmetrically arranged with respect to the vertical symmetry plane of the dielectric substrate (1); The first arc segment and the second arc segment are in a power function, and the power function presented by the first arc segment and the second arc segment is , where The value range of is 0.7 ≤ ≤ 1.2, and the trajectories of the first arc segment (4) and the second arc segment (6) are convex outward.

2. The millimeter-wave radar antenna according to claim 1, Characterized in that: There is a third straight segment (7) between the first straight segment (3) and the second straight segment (5), the third straight segment (7) is located at the closed end (9), one end of the first straight segment (3) and one end of the second straight segment (5) are connected by the third straight segment (7), and the third straight segment (7) is formed by arranging a plurality of cylindrical conductors (2).

3. The millimeter-wave radar antenna according to claim 1, Characterized in that: A cable is connected to one of the dielectric substrates, the cable is located inside the arrangement trajectory, and the cable is located on the symmetry line of the trajectory one and the trajectory two.

4. The millimeter-wave radar antenna according to claim 3, Characterized in that: The cable is arranged perpendicular to the dielectric substrate, and the distance between the cable and the closed end is D. The , where , where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal.

5. The millimeter-wave radar antenna according to claim 1, Characterized in that: The diameter of the cylindrical conductors in the first straight segment and the second straight segment is D1, where D1 = 0.15λ. The distance between two adjacent cylindrical conductors in the first straight segment and the second straight segment is P1, where P1 = 0.3λ, where , where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal.

6. The millimeter-wave radar antenna according to claim 1, Characterized in that: The diameter of the cylindrical conductors in the first arc segment and the second arc segment is D2, where D2 = 0.15λ, and the distance between two adjacent cylindrical conductors in the first arc segment and the second arc segment is P2, where P2 = 0.42λ, where , where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal.

7. The millimeter-wave radar antenna according to claim 1, Characterized in that: The lengths of the first straight line segment and the second straight line segment are both L1, and the value range of L1 is λ ≤ L1 ≤ 3λ, where , where c is the propagation speed of the wave signal in the medium, and f is the frequency of the wave signal.

8. The millimeter-wave radar antenna according to claim 7, Characterized in that: The lengths of the first arc segment and the second arc segment are both L2, and 0.9 ≤ L2 / L1 ≤ 1.

9. The millimeter-wave radar antenna according to claim 1, Characterized in that: The first trajectory and the second trajectory are symmetrically arranged with respect to the straight line k. The intersection point of the first straight line segment and the first arc segment is point b, and the end point of the first arc segment is point c. The straight line where points b and c are located is the straight line m, and the included angle between the straight line m and the straight line k is A, and the value range of A is 24° ≤ A ≤ 28°.

10. The millimeter-wave radar antenna according to claim 9, characterized in that: The line connecting the point b and the point c forms a line segment bc, and the length of the line segment bc is L bc , the straight line where the first straight line segment is located is the straight line F, and the included angle between the straight line F and the straight line m is B. According to the corresponding angle theorem, the angle of A is the same as the angle of B, that is , then .

11. A method for focusing waves of the millimeter-wave radar antenna according to any one of claims 1-10, characterized in that: comprises the following steps: S1, a plurality of cylindrical conductors are arranged along the first trajectory and the second trajectory, and a waveguide channel for propagating millimeter-wave radar is formed between the first trajectory and the second trajectory, and the millimeter-wave radar signal propagates from the closed end to the open end; S2, the millimeter-wave radar signal first propagates in the first channel in the direction of the second channel. When the millimeter-wave radar propagates in the first channel, the width of the first channel is equal everywhere, and the millimeter-wave radar propagates along a straight line in the first channel; S3, the millimeter-wave radar enters the second channel from the first channel. The second channel is in a horn shape, and the millimeter-wave radar signal first expands to both sides and propagates forward in the second channel; S4, the trajectories of the second arc segments on both sides of the second channel are in a power function, and the millimeter-wave radar signals are largely concentrated in the second channel to achieve a wave focusing effect; S5, the slopes of the second arc segments on both sides of the second channel gradually decrease, and the millimeter-wave radar signals propagate in the second channel in the direction of the opening and gradually concentrate towards the opening; S6, the millimeter-wave radar signal propagates outwards from the opening.

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