Radar antenna device with its radar elements

Abstract

This invention discloses a radar antenna device and its radar elements. The radar antenna device is for mounting on one side surface of a vehicle and includes: a base; a first antenna circuit board disposed on one surface of the base; and a second antenna circuit board disposed on the same surface of the base. A first angle is formed between the first antenna circuit board and the side surface of the vehicle, and a second angle is formed between the second antenna circuit board and the side surface of the vehicle. Both the first angle and the second angle are greater than or equal to 15 degrees and less than or equal to 25 degrees.

Description

Technical Field

[0001] This invention relates to a radar antenna device and its radar elements. Background Technology

[0002] To enhance driving safety, modern vehicles are equipped with systems such as blind spot detection, lane change assist, automatic cruise control, parking assist, automatic braking, collision warning, and lane departure detection. These systems typically include a vehicle-mounted radar system, which can accurately and reliably detect and locate surrounding objects in any environment.

[0003] Because side-detection radars for commercial vehicles (buses, vans, trucks, etc.) have an extremely wide detection range, ideally covering at least a 180-degree detection area with the side of the vehicle as the plane, and due to the physical characteristics and limitations of existing tandem patch antennas, their radiation energy at large angles is currently weak. This necessitates the use of two systems for side-detection radars, one located on the left and one on the right side of the vehicle's side plane perpendicular to the normal.

[0004] In response to the need for a flatter vehicle exterior, the thinner design of side detection radar is a future trend. Summary of the Invention

[0005] This invention relates to an antenna architecture applicable to automotive radar, specifically for side-detection radar in commercial vehicles (buses, vans, trucks, etc.), to achieve a thinner design for side-detection radar.

[0006] According to a first aspect of the present invention, a radar antenna device is provided for mounting on one side surface of a vehicle, comprising: a base; a first antenna circuit board disposed on one surface of the base; and a second antenna circuit board disposed on the surface of the base, wherein a first angle is formed between the first antenna circuit board and the side surface of the vehicle, and a second angle is formed between the second antenna circuit board and the side surface of the vehicle, wherein both the first angle and the second angle are greater than or equal to 15 degrees and less than or equal to 25 degrees.

[0007] According to a second aspect of the present invention, a radar element is provided, comprising: a feed line; a plurality of radiating elements connected to the feed line and disposed on both sides of the feed line, each of the plurality of radiating elements having a first length; and a plurality of parasitic elements disposed on both sides of the feed line and arranged alternately with the plurality of radiating elements, each of the plurality of parasitic elements having a second length, wherein the second length is different from the first length, and each of the plurality of parasitic elements has a minimum spacing equal to or less than 0.2 mm between itself and the feed line.

[0008] To provide a better understanding of the above and other aspects of the present invention, specific embodiments are described below in conjunction with the accompanying drawings: Attached Figure Description

[0009] Figure 1A This is a schematic diagram of an example antenna circuit board according to an embodiment of the present invention;

[0010] Figure 1B This is a schematic diagram of the signal area of ​​an example antenna circuit board with radar elements according to an embodiment of the present invention;

[0011] Figure 2A and Figure 2B These are, respectively, a perspective view of a radar antenna device along the X-axis and a schematic diagram of an antenna circuit board according to an embodiment of the present invention;

[0012] Figure 2C This is an external view of a radar antenna device according to an embodiment of the present invention along the X-axis direction;

[0013] Figure 2D This is a bottom view of a radar antenna device according to an embodiment of the present invention along the Z-axis direction;

[0014] Figure 2E This is a perspective view of a radar antenna device according to an embodiment of the present invention;

[0015] Figure 2F and Figure 2G These are perspective views of a radar antenna device along the X-axis and schematic diagrams of an antenna circuit board, respectively, according to another embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of a radar element according to an embodiment of the present invention;

[0017] Figure 4 This is a comparison diagram of the radiation field patterns of the antenna in an embodiment of the present invention and a conventional antenna in the XZ plane;

[0018] Figure 5 This is a comparison diagram of the radiation field patterns of the antenna in an embodiment of the present invention and a conventional antenna in the XZ plane;

[0019] Figure 6 This is a comparison diagram of the radiation field patterns of the antenna in an embodiment of the present invention and a conventional antenna in the XZ plane;

[0020] Figure 7 This is a comparison diagram of the radiation field patterns of the antenna in an embodiment of the present invention and a conventional antenna in the XZ plane;

[0021] Figure 8 This is a comparison diagram of the radiation field patterns of the antenna in an embodiment of the present invention and a conventional antenna in the XZ plane;

[0022] Figure 9 This is a comparison diagram of the radiation field pattern of the antenna in the XZ plane according to an embodiment of the present invention.

[0023] Symbol Explanation

[0024] 100A, 100”: Radar antenna device

[0025] 110, 110a, 110b, 110a”, 110b”, 110': Antenna circuit board

[0026] 111, 111a, 111b: Radar transmitting elements

[0027] 112: Radar receiving element

[0028] 113: Arithmetic Unit

[0029] 113a: First Signal Zone

[0030] 113b: Second Signal Zone

[0031] 113θ1, 113θ2, 114a, 114b: included angle

[0032] 115a: Upper boundary

[0033] 115b: Lower boundary

[0034] 115c: Normal

[0035] 115d: First distance

[0036] 115e: Second distance

[0037] 115f, 115g: Vertical distance

[0038] 116: First Surface

[0039] 117: Detection blind spot

[0040] 117a, 130t: Vertex

[0041] 120A, 120”: Base

[0042] 126Ba, 126b”: Second surface of the base

[0043] 117: Detection blind spot

[0044] 130a: First outer casing

[0045] 130b: Second outer casing

[0046] 130c: Connecting part

[0047] 140a, 140b: Connectors

[0048] 150: Bracket

[0049] 150a: Upper bracket

[0050] 150a1,150a2: Bevel

[0051] 150b: Lower bracket

[0052] 130a1,130b1: Bottom surface

[0053] S: Side length

[0054] S': Short side

[0055] L: Length of side S

[0056] W: Width of the shorter side S'

[0057] 200: Outer shell

[0058] 200t: Top surface

[0059] 200a, 200b: Shell surface

[0060] 140: Waterproof cable exit feature

[0061] 290: Vehicle side surface

[0062] 310: Radar components

[0063] 311: Feed line

[0064] 312: Radiation element

[0065] 313: Parasitic element

[0066] 311A, 311B: The two ends of feed line 311

[0067] 311M: Middle of feed line 311

[0068] L1, L2: Length Detailed Implementation

[0069] The technical terms used in this specification are based on common terminology in the field. Where this specification provides explanations or definitions for certain terms, the interpretations of those terms shall be based on the explanations or definitions provided in this specification. Each embodiment of the present invention has one or more technical features. Where feasible, those skilled in the art may selectively implement some or all of the technical features in any embodiment, or selectively combine some or all of the technical features in these embodiments.

[0070] Figure 1A A schematic diagram of an example antenna circuit board 110 according to an embodiment of the present invention is shown. Figure 1AAs shown, the antenna printed circuit board 110 has a radar transmitting element 111 and a radar receiving element 112, which are disposed on a first surface 116 of the antenna printed circuit board 110. The radar transmitting element 111 of the antenna printed circuit board 110 can transmit radar signals, and the radar receiving element 112 can receive radar signals reflected from objects for object detection. Figure 1A In the example, one radar transmitting element 111 and one radar receiving element 112 are each disposed on the antenna circuit board 110, but the present invention is not limited thereto. In some embodiments, multiple radar transmitting elements and multiple radar receiving elements may be disposed on the antenna circuit board 110, for example, two radar transmitting elements and four radar receiving elements, or designed according to other requirements. The antenna circuit board 110 may also have a processing unit 113, which may be disposed on the first surface 116 of the antenna circuit board 110 or on the other side as needed. The processing unit 113 may be electrically connected to the radar receiving element 112 and the radar transmitting element 111 to process the radar signals transmitted and received by them. Depending on the radar antenna radiation pattern, there will be different transmitted signal strengths in different directions in the hemispherical region relative to the first surface 116 of the antenna circuit board 110, which will then be referred to Figure 1B The details are as follows. Below, both the radar transmitting element 111 and the radar receiving element 112 can be referred to as radar elements.

[0071] Figure 1B A schematic diagram illustrating the signal region of an example antenna circuit board 110 having a radar transmitting element 111 according to an embodiment of the present invention is shown. In this embodiment, the radar antenna radiation pattern of the radar transmitting element 111 is designed to be directional, that is, the signal transmission intensity (gain) of the radar transmitting element 111 is stronger at a specific angle. In this example, the signal transmission intensity of the radar transmitting element 111 radiates from the center of the radar transmitting element 111 towards the normal 115c perpendicular to the first surface 116 of the antenna circuit board 110, wherein the normal 115c passes through the center of the radar transmitting element 111, and the gain of the signal transmission intensity of the radar transmitting element 111 is maximum in the direction of the normal 115c. Furthermore, in Figure 1BIn the example, the x and y directions are interchangeable. According to Table 1 below, the region within a 140° field of view (FoV) where the angle between the antenna circuit board 110 and the normal 115c of the first surface 116 is between -70° and 0° and between 0° and 70° is considered to have better signal transmission strength (average gain of 4.62 to 10.79 dB), and is defined as the first signal region 113a. The region within a 70° to 90° and -70° to -90° angle with the normal 115c of the first surface 116 is considered to have poorer signal transmission strength (lower gain) (average gain of -4.75 to -6.31 dB), and is defined as the second signal region 113b.

[0072] Table 1: Relationship between antenna transmitted signal strength (gain) and angle

[0073]

[0074] Figures 2A to 2E A radar antenna device 100A according to an embodiment of the present invention is illustrated. Wherein, Figure 2A and Figure 2B A perspective view of the radar antenna device 100A along the X-axis and a schematic diagram of the antenna circuit board 110 are shown respectively. Figure 2C Draw an external view of the radar antenna assembly 100A along the X-axis. Figure 2D A bottom view of the radar antenna assembly 100A along the Z-axis is shown. Figure 2E A three-dimensional view of radar antenna device 100A is shown.

[0075] like Figure 2A , Figure 2B and Figure 2C As shown, antenna circuit boards 110a” and 110b” are respectively covered by a first housing 130a and a second housing 130b. The first housing 130a and the second housing 130b are transparent. The first housing 130a and the second housing 130b each have multiple connecting portions 130c that connect to the base 120A (e.g., ...). Figure 2C As shown, it is fixed to the side surface 290 of the vehicle. Figure 2D As shown, the base 120A includes two sets of brackets 150 located on both sides of the first housing 130a and the second housing 130b, respectively. Each set of brackets 150 includes an upper mounting bracket 150a and a lower mounting bracket 150b. The upper mounting bracket 150a is detachably connected to the connecting part 130c, and the lower mounting bracket 150b is detachably connected to the vehicle side surface 290. Figure 2E As shown, the upper mounting bracket 150a and the lower mounting bracket 150b are in an "L" shape.

[0076] like Figure 2A As shown, antenna circuit board 110a” and antenna circuit board 110b” are separated by first housing 130a and second housing 130b respectively. The shortest first distance 115d between antenna circuit board 110a” and antenna circuit board 110b” is between 10mm and 30mm, for example, 18.4mm. This makes the second distance 115e between the vertex 117a of the detection blind zone 117 and the second surface 126bA of the base 120A between 50mm and 70mm, for example, 61.7mm. The vertical distance 115f between the highest point of 0a and the highest point of the antenna circuit board 110b and the second surface 126bA of the base of the base 120A is between 30mm and 40mm, for example, 33.8mm. The first housing 130a and the second housing 130b each have a vertex 130t, and the maximum vertical distance 115g between them and the second surface 126bA of the base of the base 120A is between 30.1mm and 50mm, for example, between 40mm and 50mm (related to the assembly height of the radar antenna device 100A). That is, in this design, the second distance 115e can be shortened to 61.7mm (reducing the detection blind zone), and the vertical distance 115f can be shortened to 33.8mm, and the vertical distance 115g can be reduced to 40mm (reducing the assembly height of the radar antenna device 100A). In this example, the radar antenna device 100A also has connectors 140a and 140b (in Figure 2D As shown in the figure, the antenna circuit boards 110a” and 110b” are respectively coupled to the antenna circuit boards 110a” and 110b”, and can be used to electrically connect external devices (such as control units or computing units) to transmit signals, such as the detection signals of radar antenna device 100A.

[0077] like Figure 2CAs shown, the upper mounting bracket 150a has two inclined surfaces 150a1 and 150a2, which are parallel to the bottom surface 130a1 of the first housing 130a and the bottom surface 130b1 of the second housing 130b, respectively. In one embodiment, the angle between the inclined surfaces 150a1 and 150a2 and the second base surface 126bA of the base 120A is used to determine the first angle 114a and the second angle 114b formed between the antenna circuit boards 110a” and 110b” and the second base surface 126bA of the base 120A, which are both greater than or equal to 15 degrees and less than or equal to 25 degrees. That is, the first angle 114a and the second angle 114b formed between the antenna circuit boards 110a” and 110b” and the side surface of the vehicle are both greater than or equal to 15 degrees and less than or equal to 25 degrees. In another embodiment, the vehicle surface on which the radar antenna device 100A is to be installed may be uneven or not perfectly perpendicular to the ground. Therefore, the upper mounting bracket 150a and the lower mounting bracket 150b can be adjusted by connecting elements (not shown), such as screws, so that when the radar antenna device 100A is installed on the vehicle surface, the second surface 126bA of its base 120A can be as perpendicular to the ground as possible and parallel to the vehicle's direction of travel (such as the front or rear of the vehicle).

[0078] Furthermore, the triangular area formed by the intersection point (vertex 117a) of the upper boundaries 115a of the two first signal zones 113a, the center of radar transmitting element 111a, and the center of radar transmitting element 111b is the detection blind zone 117. The detection blind zone 117 is not located in the first signal zone 113a and completely overlaps with the second signal zone 113b with weaker signal strength. The detection blind zone 117 even includes areas without signals.

[0079] The angles 113θ1 and 113θ2 between the lower boundary 115b of the two first signal areas 113a and the side surface 290 of the vehicle body are between 15 degrees and 25 degrees, for example, 20 degrees.

[0080] Figure 2F and Figure 2G A perspective view of a radar antenna device 100” along the X-axis and a schematic diagram of an antenna circuit board 110' are shown respectively, according to an embodiment of the present invention. The difference between radar antenna device 100” and radar antenna device 100A is that the antenna circuit board 110” (which can simultaneously represent antenna circuit board 110a” and antenna circuit board 110b) is as follows: Figure 2GThe dimensions of the antenna circuit board 110 of the radar antenna device 100' are different from those of the antenna circuit board 110". The antenna circuit board 110" is rectangular and has a side length S and a short side S', the length of which is less than the side length S of the antenna circuit board 110. In one embodiment, the length L of the side length S of the antenna circuit board 110" is between 44mm and 66mm (e.g., but not limited to 66mm), and the width W of the short side S' of the antenna circuit board 110" is between 30mm and 50mm (e.g., but not limited to 39.2mm). Since the antenna circuit boards 110a" and 110b" are parallel to the second base surface 126b" of the base 120" with side length S, a first included angle 114a and a second included angle 114b are formed between the short side S' and the second base surface 126b" of the base 120" (e.g., but not limited to). The angle is 20 degrees, which shortens the second distance 115e between the apex 117a of the detection blind zone 117 and the second surface 126b” of the base 120” to between 30mm and 50mm, for example, but not limited to 26.9mm. The vertical distance 115f between the highest point of the antenna circuit boards 110a” and 110b” and the second surface 126b” of the base 120” is reduced to less than 30mm, for example, but not limited to 12mm, so that the shortest vertical distance 115g between the top surface 200t of the housing 200 (which has housing surface 200a, housing surface 200b and top surface 200t located between housing surface 200a and housing surface 200b) and the vehicle side surface 310 can be reduced to between 27.7mm and 47.6mm (for example, but not limited to 18.7mm) (regarding the assembly height of the radar antenna device 100”). In this example, the radar antenna device 100” also has a waterproof outgoing wire feature 140, which can be used to electrically connect to an external device (e.g., a control unit or a computing unit) to transmit signals, such as the detection signals of the radar antenna device.

[0081] Figure 3 An embodiment of a radar element according to an embodiment of the present invention is shown. For example... Figure 3 As shown, a radar element 310 according to an embodiment of the present invention is implemented as, for example but not limited to, a tandem antenna element. The radar element 310 can be used to implement a radar transmitting element 111 and a radar receiving element 112. The radar element 310 includes: a feed line 311, a plurality of radiating elements 312, and a plurality of parasitic elements 313. The radar element 310 is formed on an antenna circuit board 110 (such as a first antenna circuit board 110a” or a second antenna circuit board 110b”). In one possible embodiment of the present invention, the antenna circuit board 110 is a Teflon-containing composite material suitable for millimeter-wave high-frequency applications. However, the material of the antenna circuit board 110 is not limited to this; any material suitable for use as an antenna circuit board 110 is suitable for application in the present invention.

[0082] The feed line 311 receives the current transmitted from the millimeter-wave IC via the high-frequency coplanar waveguide and microstrip line, and distributes the current to multiple radiating elements 312 so that the multiple radiating elements 312 can emit electromagnetic waves synchronously.

[0083] Multiple radiating elements 312 are connected to the feed line 311 and disposed on both sides of the feed line 311. Each of the multiple radiating elements 312 has a first length L1. The multiple radiating elements 312 are spaced apart along the Y-axis direction on the positive X-axis side and the negative X-axis side of the feed line 311, that is, some of the multiple radiating elements 312 are located on the positive X-axis side, and the remaining multiple radiating elements 312 are on the negative X-axis side. For example, but not limited to, multiple radiating elements 312 are disposed on the positive X-axis side and the negative X-axis side of the feed line 311, for example, 2 to 10, wherein the number of radiating elements 312 on the positive X-axis side and the negative X-axis side of the feed line 311 is the same. The multiple radiating elements 312 are, for example, but not limited to, rectangular (i.e., patch-shaped). Furthermore, as shown in Figure 3, in one embodiment of the present invention, the width of the plurality of radiating elements 312 decreases sequentially from the middle 311M of the feed line 311 towards both ends 311A ​​and 311B of the feed line 311. That is, in another possible embodiment of the present invention, the width of the plurality of radiating elements 312 decreases sequentially from the middle of the feed line 311 towards both ends of the feed line 311.

[0084] Multiple parasitic elements 313 are disposed on both sides of the feed line 311 and staggered around multiple radiating elements 312, and each of the multiple parasitic elements 313 has a second length L2. The second length L2 of the parasitic element 313 differs from the first length L1 of the radiating element 312. More specifically, the second length L2 is less than 2.2 mm and greater than the first length L1. In one embodiment, the multiple parasitic elements 313 are spaced apart on both sides of the feed line 311, with one parasitic element 313 disposed between two adjacent radiating elements 312. In a possible embodiment of the invention, the second length of the multiple parasitic elements 313 is less than 2.2 mm, while the width of the multiple parasitic elements 313 is not particularly limited; the distance between the multiple parasitic elements 313 and the feed line 311 is equal to or less than 0.2 mm. In one embodiment, each of the plurality of parasitic elements 313 has a minimum spacing equal to or less than 0.2 mm between itself and the feed line 311, that is, the plurality of parasitic elements 313 are not connected to the feed line 311, and the plurality of parasitic elements 313 are electrically insulated from or open-circuited with the feed line 311.

[0085] Furthermore, the arrangement of the plurality of parasitic elements 313 and the plurality of radiating elements 312 is, for example, but not limited to, aligning the radiating elements 312 on either side (upper or lower) of the feed line 311 with the parasitic elements 313 on the opposite side of the feed line 311. Here, "alignment" is not limited to precise alignment. In one possible embodiment of the invention, the center of the radiating elements 312 on either side (upper or lower) of the feed line 311 is aligned with the center of the parasitic elements 313 on the opposite side of the feed line 311. That is, each of the plurality of radiating elements 312 on either side of the feed line 311 is aligned with one of the plurality of parasitic elements 313 on the opposite side of the feed line 311.

[0086] As can be seen from the above, in one embodiment of the present invention, a combination of comb-shaped radiating elements and feed lines is used to change the polarization direction of radiation, so that the single-layer feed mode can be continued and parasitic elements can be placed between each radiating unit.

[0087] The following description, in conjunction with the accompanying drawings, illustrates a comparison of the radiation pattern of an antenna (radar element) according to an embodiment of the present invention with that of a conventional antenna.

[0088] Figure 4 This diagram shows a comparison of the radiation patterns of an antenna according to an embodiment of the present invention and a conventional antenna in the XZ plane. The X-axis represents the azimuth angle in degrees; the Y-axis represents the gain in dBi. Maximum gain occurs at a horizontal azimuth angle of 0 degrees. The waveform passing through the azimuth angle of 0 degrees is the main lobe, and the two waveforms adjacent to the main lobe are side lobes, one of which is located at a negative azimuth angle and the other at a positive azimuth angle. Figure 4 It can be seen that although the gain decreases by 5dB at the direct forward direction (i.e., 0 degrees), the gain increases by 5.5dB at larger angles (70 degrees). Therefore, it can be seen that the antenna of one embodiment of the present invention is of great help in detecting objects at large angles, and the total length of the antenna of one embodiment of the present invention is almost constant.

[0089] Depend on Figure 4 As can be seen, in one embodiment of the present invention, the minimum angle between the surface of the antenna circuit board and the vehicle body is 15 degrees, and the corresponding maximum antenna radiation angle is 75 degrees; and the maximum angle between the surface of the antenna circuit board and the vehicle body is 25 degrees, and the corresponding antenna radiation angle is 65 degrees. Figure 4 As shown, the antenna of an embodiment of the present invention has a gain that is on average about 6 dB greater than that of a conventional antenna in the same angle range (between 65 and 75 degrees). According to the radar ranging formula, under the condition that all other factors remain unchanged, the detection range of the antenna of the present invention is 1.4 times greater than that of existing antennas. Therefore, it can be seen that the antenna of the present invention significantly improves the detection of objects at large angles.

[0090] Even worse, in Figure 4 In this example, if each side (top and bottom) of the radar element's feed line includes nine radiating elements and nine parasitic elements, it can be shown that an embodiment of the present invention can meet the energy detection requirements. Furthermore, to ensure that the radar element and the radar receiving element maintain the same polarization direction, the parasitic elements are standard rectangles. This is because if the parasitic elements are non-standard rectangles, it may cause interference between the spacing of the radar receiving elements, or the polarization directions of the radar receiving elements and the radar element may be inconsistent. In addition, in Figure 4 Although the gain drops by 5dB at the forward normal direction (0°), it still has a gain of 11dBi. Similarly, at a large angle of 70°, the gain increases by 5.5dB to 9.28dBi. The energy difference between these two locations (0° and 70°) is only about 2dB, which suggests that the radar element of this embodiment is very helpful for large-angle detection. Furthermore, the total antenna length of the radar element of this embodiment is almost the same as that of a conventional antenna.

[0091] Figure 5 This diagram shows a comparison of the XZ plane radiation patterns of an antenna according to an embodiment of the present invention and a conventional antenna. It can be seen from the gain at 0 angle that the antenna of the present invention experiences energy attenuation in the 0-angle direction, but the gain is significantly improved at larger angles. Therefore, it can be seen that the antenna of the present invention, through design adjustments, can increase energy at the required large angles while controlling the energy attenuation in the 0-angle direction within an acceptable range.

[0092] Figure 6 This diagram shows a comparison of the XZ plane radiation patterns of an antenna according to an embodiment of the present invention and a conventional antenna. Figure 6 It can be seen that different gains can be obtained by changing the distance G between the parasitic element 313 and the feed line 311. Figure 6 It can be seen that when the distance G = 0.2 mm, the energy at large angles can be effectively improved within a certain range, but the effect is not significant when the distance exceeds 0.2 mm. Therefore, in one embodiment of the present invention, the distance G between the parasitic element 313 and the feed line 311 is set to be less than or equal to 0.2 mm. Within this distance setting range, the energy at 0 angle is still acceptable.

[0093] Figure 7 This diagram shows a comparison of the XZ plane radiation patterns of an antenna according to an embodiment of the present invention and a conventional antenna. Figure 7It can be seen that in one embodiment of the present invention, the longer the length L2 of the parasitic element 313, the better the large-angle energy is improved. However, when the length L2 of the parasitic element 313 is equal to or exceeds 2.2 mm, two null points will be generated in the large-angle energy, indicating that resonance of higher-order modes has occurred, and this situation should be avoided as much as possible. Therefore, in one embodiment of the present invention, the length L2 of the parasitic element 313 is equal to or less than 2.2 mm. Within this length setting range, the energy at 0 angle is still acceptable.

[0094] Figure 8 This diagram shows a comparison of the XZ plane radiation patterns of an antenna according to an embodiment of the present invention and a conventional antenna. Figure 8 As can be seen, in the antenna of one embodiment of the present invention, when the width W of the parasitic element is set from 0.1 mm to 1.5 mm, the energy at 0 angle and the energy at large angle both change (approximately linearly). Therefore, in one embodiment of the present invention, there is no particular limitation on the width W of the parasitic element.

[0095] Figure 9 A comparison diagram showing the radiation pattern of the antenna in the XZ plane according to an embodiment of the present invention is displayed. Figure 9 In the example illustration, two parasitic elements and three parasitic elements are located on both sides of the feed line, respectively, but it should be understood that the present invention is not limited thereto. Furthermore, to illustrate the gain change of the radar element in the embodiment of the present invention, in... Figure 9 This compares various parasitic elements of different shapes, such as, but not limited to, standard rectangles, polygons, ellipses, or oblique rectangles (oriented differently from the antenna polarization direction) or combinations thereof. Figure 9 As can be seen, at a 70° angle, radar elements employing multiple parasitic elements of different shapes all achieve a gain of at least 3 dB. In fact, in other possible embodiments of the present invention, the shape of the parasitic elements does not need to be particularly limited, and the number of parasitic elements and radiating elements is not limited to the example of 2 or 9 pairs, that is, the number of antenna arrays is not limited to the 2×2 or 2×9 antenna arrays mentioned above; all other quantities are within the scope of the present invention.

[0096] Furthermore, in one possible embodiment of the invention, the material of the housing may be, for example but not limited to, a mixture of polybutylene terephthalate (also known as PBT plastic) and glass fiber, wherein the weight percentage of glass fiber is between 25% and 35%, and other suitable materials are also applicable, and the invention is not limited thereto.

[0097] Furthermore, in one possible embodiment of the present invention, the antenna circuit board of the radar antenna device is made of a composite material containing Teflon suitable for millimeter-wave high frequency, such as, but not limited to, the RO3003 series, because of its better radiation characteristics, but other suitable materials are also applicable, and the present invention is not limited thereto.

[0098] As can be seen from the above, in one embodiment of the present invention, in the radar antenna device, since the angle between the antenna circuit board of the radar element and the vehicle side plane is greater than or equal to 15 degrees and less than or equal to 25 degrees, the goal of making the radar antenna device thinner can be achieved, which meets the requirements.

[0099] Furthermore, in one embodiment of the present invention, since the angle between the antenna circuit board of the radar element and the side plane of the vehicle is greater than or equal to 15 degrees and less than or equal to 25 degrees, the gain of the antenna in the embodiment of the present invention is improved in the range between 65 degrees and 75 degrees, and the detection range of the antenna can be increased. Therefore, the antenna in the embodiment of the present invention has a significant improvement in the detection of objects at large angles.

[0100] While the invention may describe many specific details, these should not be construed as limiting the scope of the claimed invention, but rather as descriptions of the characteristics of particular embodiments. In this description, certain features described in the context of a single embodiment may also be implemented in combination in that single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, while features may initially be described as functioning in certain combinations, or even initially described as such combinations, in some cases one or more features may be removed from the combination, and the illustrated combination may be for a sub-combination or a variation of the sub-combination. Similarly, while operations are depicted in the figures as being performed in a specific order, this should not be construed as requiring these operations to be performed in the specific order or sequence shown, or that all depicted operations must be performed to achieve the desired result.

[0101] Although the above embodiments of the present invention only disclose some examples and implementations, changes, modifications, and enhancements can be made to the examples, implementations, and other implementations based on the disclosed content.

[0102] In summary, although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A radar antenna device for mounting on the side surface of a vehicle, comprising: Base, with a surface; A first antenna circuit board is disposed on the surface; as well as The second antenna circuit board is disposed on this surface. The first angle formed between the first antenna circuit board and the side surface of the vehicle, and the second angle formed between the second antenna circuit board and the side surface of the vehicle, are both greater than or equal to 15 degrees and less than or equal to 25 degrees.

2. The radar antenna device as claimed in claim 1, further comprising a radar element formed on the first antenna circuit board or the second antenna circuit board, the radar element comprising: Feed line; Multiple radiating elements are connected to the feed line and disposed on both sides of the feed line, and each of the multiple radiating elements has a first length; as well as Multiple parasitic elements are disposed on both sides of the feed line and arranged alternately with the multiple radiating elements, and each of the multiple parasitic elements has a second length. Wherein, the second length is different from the first length, and Each of the plurality of parasitic elements has a minimum spacing of 0.2 mm or less between it and the feed line.

3. The radar antenna device as described in claim 2, wherein, The second length is less than or equal to 2.2 mm and greater than the first length.

4. The radar antenna device as described in claim 2, wherein, Each of the plurality of radiating elements on either side of the feed line is aligned with one of the plurality of parasitic elements on the opposite side of the feed line.

5. The radar antenna device as described in claim 2, wherein, These parasitic elements are electrically insulated from the feed line.

6. A radar element, comprising: Feed line; Multiple radiating elements are connected to the feed line and disposed on both sides of the feed line, and each of the multiple radiating elements has a first length; as well as Multiple parasitic elements are disposed on both sides of the feed line and arranged alternately with the multiple radiating elements, and each of the multiple parasitic elements has a second length. Wherein, the second length is different from the first length, and Each of the plurality of parasitic elements has a minimum spacing of 0.2 mm or less between it and the feed line.

7. The radar element as claimed in claim 6, wherein, The second length is less than or equal to 2.2 mm and greater than the first length.

8. The radar element as claimed in claim 6, wherein, The width of the plurality of radiating elements decreases sequentially from the middle of the feed line toward both ends of the feed line.

9. The radar element as claimed in claim 6, wherein, Each of the plurality of radiating elements on either side of the feed line is aligned with one of the plurality of parasitic elements on the opposite side of the feed line.

10. The radar element as claimed in claim 6, wherein, The multiple parasitic elements are in the shape of a standard rectangle, polygon, ellipse, oblique rectangle, or a combination thereof.

11. The radar element as claimed in claim 6, wherein, These parasitic elements are electrically insulated from the feed line.

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