Antenna, antenna array, radar and vehicle

Abstract

The invention discloses an antenna, an antenna array, a radar and a vehicle, and relates to the technical field of antennas. The antenna comprises a feed part, an impedance conversion part, a first matching part, a radiation part and a second matching part which are connected in sequence. The antenna has a central axis, and the central axis passes through the feed part, the impedance conversion part, the first matching part, the radiation part and the second matching part. The radiation part is in central symmetry about the center of the radiation part, the radiation part comprises radiation structures, each radiation structure comprises two radiation units, and the center lines of any two adjacent radiation units deviate from the central axis in opposite directions. And by arranging the impedance conversion part, the bandwidth of the antenna can be increased. By arranging the radiation part composed of the plurality of radiation units and arranging the two adjacent radiation units to deviate from the central axis along the opposite directions, the amplitude of each radiation unit can be adjusted so as to reduce the side lobe of the antenna.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to an antenna, an antenna array, a radar and a vehicle. Background Art

[0002] In recent years, automotive millimeter-wave radar has developed rapidly, and broadband automotive radar with a 5GHz operating bandwidth and operating in the 76GHz to 81GHz millimeter-wave frequency band has become a new focus of automotive radar technology.

[0003] In the related art, vehicle-mounted millimeter-wave radar antennas are mostly in the form of comb antennas, where multiple staggered radiating units are connected in series through feeder lines to form a comb array, and each radiating unit is designed to have a different width according to a certain rule. However, in the related art, the sidelobe level of the comb antenna array is high and the working bandwidth is narrow, which cannot meet the working requirements. Summary of the invention

[0004] The present application provides an antenna, an antenna array, a radar and a vehicle, which can improve the bandwidth of the antenna and reduce the side lobes of the antenna, thereby improving the radiation efficiency of the antenna.

[0005] In a first aspect, the present application provides an antenna, which includes a feeding part, an impedance transformation part, a first matching part, a radiating part, and a second matching part connected in sequence. The antenna has a central axis, and the central axis passes through the feeding part, the impedance transformation part, the first matching part, the radiating part, and the second matching part. The radiating part is centrally symmetrical about its center, and the radiating part includes a radiating structure, each radiating structure includes two radiating units, and the center lines of any two adjacent radiating units are offset from the central axis in opposite directions.

[0006] In the present application, the impedance transformation part is provided to increase the bandwidth of the antenna. By providing a radiating part composed of multiple radiating units and arranging two adjacent radiating units to offset the central axis in opposite directions, the amplitude of each radiating unit can be adjusted to reduce the side lobe of the antenna.

[0007] In a possible design manner of the first aspect, an offset amount of a center line of the radiation unit from the central axis is negatively correlated with a distance from the radiation unit to the center of the radiation portion.

[0008] In a possible design manner of the first aspect, the length of the radiation structure is (0.8-1.2)λ, where λ is a propagation wavelength of an electromagnetic wave corresponding to an operating frequency of the antenna in a dielectric substrate.

[0009] In a possible design manner of the first aspect, two radiation units in the radiation structure have equal lengths and equal widths.

[0010] In a possible design manner of the first aspect, a width of the radiation unit is greater than 0.25λ.

[0011] In a possible design manner of the first aspect, a maximum offset of the radiation unit from the central axis is less than 0.1λ.

[0012] In a possible design manner of the first aspect, a center line of the feeding portion and a center line of the impedance transformation portion both coincide with the central axis.

[0013] In a possible design manner of the first aspect, the first matching portion and the second matching portion have the same length and the same width.

[0014] In a possible design manner of the first aspect, the first matching portion and the second matching portion are centrally symmetric about the center of the radiation portion.

[0015] In a possible design manner of the first aspect, a width of the first matching portion, a width of the second matching portion, and a width of the radiation unit are all equal.

[0016] In a possible design manner of the first aspect, a width of the impedance transformation portion is greater than a width of the feeding portion, and smaller than a width of the first matching portion.

[0017] In a possible design manner of the first aspect, the impedance transformation portion includes a first end and a second end, the first end is connected to the feeding portion, the second end is connected to the first matching portion, and the length of the impedance transformation portion is (0.2-0.3)λ.

[0018] In a possible design manner of the first aspect, the length of the impedance transformation portion is 0.25λ.

[0019] In a possible design manner of the first aspect, the impedance transformation part includes a first end and a second end, the first end is connected to the feeding part, the second end is connected to the first matching part, the width of the impedance transformation part gradually increases from the first end to the second end, and the length of the impedance transformation part is (0.4~0.6)λ.

[0020] In a possible design manner of the first aspect, the impedance transformation portion includes a plurality of impedance transformation elements connected in sequence, and the width of the impedance transformation element gradually increases from the first end to the second end.

[0021] In a possible design of the first aspect, the impedance transformation part includes a first impedance transformation part and a second impedance transformation part, the first impedance transformation part is connected to the feeding part, the second impedance transformation part is connected to the first matching part, and the width of the second impedance transformation part is greater than the width of the first impedance transformation part.

[0022] In a possible design manner of the first aspect, the impedance transformation portion is a gradual structure, and a side of the impedance transformation portion is a straight line, and the side is located between the first end and the second end.

[0023] In a possible design manner of the first aspect, the impedance transformation portion is a gradual structure, a side of the impedance transformation portion is a curve, and the side is located between the first end and the second end.

[0024] In a second aspect, the present application provides an antenna array, comprising multiple antennas according to the first aspect and any possible design thereof.

[0025] In a third aspect, the present application provides a radar, comprising a PCB board, a radio frequency chip and the antenna array provided in the second aspect, wherein the antenna array and the radio frequency chip are both arranged on the PCB board, and the antenna array is connected to the radio frequency chip.

[0026] In a fourth aspect, the present application provides a vehicle, comprising the radar provided in the third aspect.

[0027] Beneficial effects of this application:

[0028] In the embodiment of the present application, the impedance transformation part is provided to increase the bandwidth of the antenna. By providing a radiating part composed of multiple radiating units and arranging two adjacent radiating units to offset the central axis in opposite directions, the amplitude of each radiating unit can be adjusted to reduce the side lobe of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of the structure of a conventional comb antenna provided in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of the structure of an antenna provided in an embodiment of the present application;

[0032] Figure 3 A schematic diagram of the structure of another antenna provided in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of the structure of another antenna provided in an embodiment of the present application;

[0034] Figure 5 A schematic diagram of the structure of another antenna provided in an embodiment of the present application;

[0035] Figure 6 A schematic diagram of the structure of another antenna provided in an embodiment of the present application;

[0036] Figure 7A schematic diagram of the structure of an impedance transformation unit in an antenna provided in an embodiment of the present application;

[0037] Figure 8 A schematic structural diagram of another impedance transformation portion in an antenna provided in an embodiment of the present application;

[0038] Fig. 9 A schematic diagram of the electric field strength distribution of an antenna provided in an embodiment of the present application;

[0039] Fig.10 for Figure 1 Schematic diagram of impedance bandwidth of the antenna shown;

[0040] Fig.11 A schematic diagram of the impedance bandwidth of an antenna provided in an embodiment of the present application;

[0041] Fig.12 for Figure 1 Schematic diagram of the radiation efficiency of the antenna shown;

[0042] Fig.13 A schematic diagram of the radiation efficiency of an antenna provided in an embodiment of the present application;

[0043] Fig.14 A schematic diagram of the radiation pattern and sidelobe level of an antenna operating at 76 GHz provided in an embodiment of the present application;

[0044] Fig.15 A schematic diagram of the radiation pattern and sidelobe level of an antenna operating at 78.5 GHz provided in an embodiment of the present application;

[0045] Fig.16 A schematic diagram of the radiation pattern and sidelobe level of an antenna operating at 81 GHz provided in an embodiment of the present application;

[0046] Fig.17 A schematic diagram of a partial structure of a radar provided in an embodiment of the present application.

[0047] In the figure: 100 - antenna; 110 - feeding part; 120 - impedance transformation part; 130 - first matching part; 140 - radiation part; 150 - second matching part; 160 - central axis;

[0048] 121- impedance transformation element;

[0049] 141-radiation structure; 142-radiation unit;

[0050] 200-Radar RF IC main board; 210-PCB board; 220-RF chip. DETAILED DESCRIPTION

[0051] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0052] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0053] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0054] It should be understood that the terms used in the description of the various examples herein are only for describing specific examples and are not intended to be limiting. As used in the description of the various examples, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0055] In this application, "at least one" means one, two or more, and "more" means more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0056] It should also be understood that in the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a sliding connection, a detachable connection, or an integral connection, etc.; it can be a direct connection or an indirect connection through an intermediate medium.

[0057] It should also be understood that the term “comprise” (also known as “includes,” “including,” “comprises” and / or “comprising”) when used in this specification specifies the presence of stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0058] It should be understood that the "one embodiment", "another embodiment", "a possible design" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment or implementation are included in at least one embodiment of the present application. Therefore, "in one embodiment of the present application" or "in another embodiment of the present application", "a possible design" appearing in various places throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0059] It should also be understood that the specific values ​​mentioned in the embodiments of the present application do not limit the specific dimensions of specific features or structures. The relevant values ​​may be examples for easy understanding, or they may be the theoretically optimal theoretical values ​​of a certain feature. In practice, the relevant dimensions may be a range of the value appended thereto, for example, the range may be ±10% of the optimal theoretical value, or ±20% of the optimal theoretical value, and in practice, the corresponding technical effect can be achieved.

[0060] The vertical in the embodiments of the present application includes some situations similar to vertical, for example, the situation where the angle between lines, lines and planes, and planes is 80° to 100° can also be understood as vertical, rather than strictly limiting the angle between the two to 90° to be vertical. Similarly, the parallel in the embodiments of the present application also includes situations similar to parallel, that is, the situation where the angle between lines, lines and planes, and planes is 0° to 10° can also be understood as parallel.

[0061] With the development of intelligent driving technology, the requirements of Advanced Driving Assistance System (ADAS) for body sensors are getting higher and higher. ADAS is an active safety technology that uses various sensors installed on the car to collect environmental data inside and outside the car at the first time, and perform technical processing such as identification, detection and tracking of static and dynamic objects, so that the driver can be aware of possible dangers in the fastest time to attract attention and improve safety.

[0062] The sensors used by ADAS mainly include cameras, radars, lasers and ultrasound, which can detect light, electromagnetic waves or other variables used to monitor the status of the vehicle. They are usually located on the front and rear bumpers, side-view mirrors and windshield of the vehicle.

[0063] Millimeter wave radar, as a sensor device that senses Doppler effect electromagnetic waves, is increasingly being used in ADAS. Millimeter wave radar generally consists of mounting structure and bottom shell, radar RF IC motherboard, and antenna cover, among which the MIMO antenna array is integrated into the RF IC motherboard.

[0064] As an electromagnetic wave transceiver, the antenna is particularly important in the millimeter-wave radar RF front end. It determines some key indicators of the radar system. Improving the performance of the antenna can improve the detection capability of the radar system.

[0065] In recent years, automotive millimeter-wave radar has developed rapidly, and broadband automotive radar with a 5GHz operating bandwidth and operating in the 76GHz to 81GHz millimeter-wave frequency band has become a new focus of automotive radar technology.

[0066] Figure 1 This is a schematic diagram of the structure of a conventional comb antenna provided in an embodiment of the present application. In the related art, vehicle-mounted millimeter wave radar antennas are mostly used Figure 1 In the comb antenna form shown, multiple staggered radiating units 142 are connected in series through a feeding line to form a comb array. Each radiating unit 142 is designed to have a different width according to a certain rule to achieve a low sidelobe level of the radiation pattern, but conventional comb antenna arrays cannot meet the above requirements.

[0067] In order to provide an antenna with high bandwidth and low sidelobe level. The present application embodiment provides an antenna, referring to Figure 2 , Figure 2 This is a schematic diagram of the structure of an antenna provided in an embodiment of the present application. Figure 2 As shown, the antenna in the embodiment of the present application includes a feeding part 110, an impedance transformation part 120, a first matching part 130, a radiating part 140 and a second matching part 150 connected in sequence. Specifically, one end of the feeding part 110 is connected to one end of the impedance transformation part 120, the other end of the impedance transformation part 120 is connected to one end of the first matching part 130, the other end of the first matching part 130 is connected to one end of the radiating part 140, and the other end of the radiating part 140 is connected to the second matching part 150. Among them, the other end of the feeding part 110 can be used to connect to the feeding network. The feeding part 110 can select a microstrip line with an intrinsic impedance of 50 ohms, and the operating frequency range of the antenna includes 76 GHz to 81 GHz.

[0068] The antenna has a central axis 160, which passes through the feeding portion 110, the impedance transformation portion 120, the first matching portion 130, the radiation portion 140 and the second matching portion 150. Figure 2 Taking the antenna shown as an example, the central axis 160 refers to the center line of the antenna in the horizontal direction. In the embodiment of the present application, the antenna is not a symmetrical structure, so the central axis 160 refers to a line passing through the antenna, and does not limit the antenna to be symmetrical about the central axis 160.

[0069] In the embodiment of the present application, the radiation portion 140 is centrosymmetric about its center, and the radiation portion 140 includes a radiation structure 141, each radiation structure 141 includes two radiation units 142, and the center lines of any two adjacent radiation units 142 are offset in opposite directions from the central axis 160. That is, the radiation portion 140 is a centrosymmetric structure, and the radiation structure 141 on the radiation portion 140 is centrosymmetric about the center of the radiation portion 140.

[0070] Each radiation structure 141 includes two radiation units 142 , and there is a certain offset between the center line of each radiation unit 142 and the central axis 160 , that is, the center line of each radiation unit 142 does not overlap with the central axis 160 .

[0071] It should be noted that the offset in the embodiment of the present application refers to translation, that is, the center line of the radiation unit 142 is parallel to the central axis 160. The center lines of any two adjacent radiation units 142 are offset from the central axis 160 in different directions, which means that the center lines of the two adjacent radiation units 142 are respectively located on both sides of the central axis 160. Any two adjacent radiation units 142 include two radiation units 142 in the same radiation structure 141, and also include adjacent radiation units 142 in two adjacent radiation structures 141.

[0072] In the embodiment of the present application, the impedance transformation unit 120 is provided to increase the bandwidth of the antenna. By providing a radiation unit 140 composed of a plurality of radiation units 142 and arranging two adjacent radiation units 142 to offset the central axis 160 in opposite directions, the amplitude of each radiation unit 142 can be adjusted to reduce the side lobe of the antenna.

[0073] In one embodiment of the present application, the amount by which the center line of the radiation unit 142 is offset from the central axis 160 is negatively correlated with the distance from the radiation unit 142 to the center of the radiation portion 140 .

[0074] In other words, the farther the distance between the radiation unit 142 and the center of the radiation portion 140 is, the smaller the offset of the center line of the radiation unit 142 from the central axis 160 is; the closer the distance between the radiation unit 142 and the center of the radiation portion 140 is, the larger the offset of the center line of the radiation unit 142 from the central axis 160 is. Since the radiation portion 140 is a centrally symmetrical structure, the offset of the radiation units 142 located on both sides of the center of the radiation portion 140 is negatively correlated with the distance from the radiation unit 142 to the center of the radiation portion 140. It should be noted that when the radiation portion 140 includes only one radiation structure 141, the offsets of the two radiation units 142 in the radiation structure 141 are the same and the offset directions are opposite. In the embodiment of the present application, the radiation portion 140 generally includes multiple radiation structures 141.

[0075] Example 1, reference Figure 3 , Figure 3 This is a schematic diagram of the structure of another antenna provided in an embodiment of the present application. Figure 3 As shown, Figure 3 The antenna shown includes a feeding portion 110, an impedance transformation portion 120, a first matching portion 130, a radiation portion 140, and a second matching portion 150 which are connected in sequence. Figure 3 and Figure 2 The antennas shown differ in that Figure 3 In the antenna shown, the radiating portion 140 includes two radiating structures 141. Figure 3 The two radiation structures 141 are respectively referred to as the first radiation structure and the second radiation structure in the order from left to right in the figure. The two radiation units 142 in the first radiation structure are respectively referred to as the first radiation unit and the second radiation unit in the order from left to right in the figure, and the two radiation units 142 in the second radiation structure are respectively referred to as the third radiation unit and the fourth radiation unit in the order from left to right in the figure.

[0076] like Figure 3 As shown, the center line of the first radiation unit is located at the lower side of the central axis 160, the first radiation unit is offset downward relative to the central axis 160, and the offset between the center line of the first radiation unit and the central axis 160 is referred to as the first offset. The center line of the second radiation unit is located at the upper side of the central axis 160, the second radiation unit is offset upward relative to the central axis 160, and the offset between the center line of the second radiation unit and the central axis 160 is referred to as the second offset. The center line of the third radiation unit is located at the lower side of the central axis 160, the first radiation unit is offset downward relative to the central axis 160, and the offset between the center line of the first radiation unit and the central axis 160 is referred to as the third offset. The center line of the fourth radiation unit is located at the upper side of the central axis 160, the fourth radiation unit is offset upward relative to the central axis 160, and the offset between the center line of the second radiation unit and the central axis 160 is referred to as the fourth offset.

[0077] In the embodiment of the present application, since the offset of the center line of the radiation unit 142 from the central axis 160 is negatively correlated with the distance from the radiation unit 142 to the center of the radiation portion 140, the second offset is greater than the first offset, and the third offset is greater than the fourth offset. Since the radiation portion 140 is a centrally symmetrical structure, the first offset is equal to the fourth offset, and the second offset is equal to the third offset.

[0078] Example 2, reference Figure 4 , Figure 4 This is a schematic diagram of the structure of another antenna provided in an embodiment of the present application. Figure 4 As shown, Figure 4The antenna shown includes a feeding portion 110, an impedance transformation portion 120, a first matching portion 130, a radiation portion 140, and a second matching portion 150 which are connected in sequence. Figure 4 and Figure 2 The antennas shown differ in that Figure 4 In the antenna shown, the radiating portion 140 includes three radiating structures 141. Figure 4 The radiation structures 141 in the figure are respectively referred to as the first radiation structure, the second radiation structure and the third radiation structure in the order from left to right in the figure. Figure 4 The radiation units 142 in the figure are respectively called the first radiation unit, the second radiation unit, the third radiation unit, the fourth radiation unit, the fifth radiation unit and the sixth radiation unit in order from left to right in the figure.

[0079] like Figure 4 As shown, the center lines of the first radiation unit, the third radiation unit, and the fifth radiation unit are all located below the central axis 160, and the first radiation unit, the third radiation unit, and the fifth radiation unit are all offset downward relative to the central axis 160. The offset between the center line of the first radiation unit and the central axis 160 is referred to as a first offset, the offset between the center line of the third radiation unit and the central axis 160 is referred to as a third offset, and the offset between the center line of the fifth radiation unit and the central axis 160 is referred to as a fifth offset.

[0080] The center lines of the second radiation unit, the fourth radiation unit, and the sixth radiation unit are all located on the upper side of the central axis 160, and the second radiation unit, the fourth radiation unit, and the sixth radiation unit are all offset upward relative to the central axis 160. The offset between the center line of the second radiation unit and the central axis 160 is referred to as a second offset, the offset between the center line of the fourth radiation unit and the central axis 160 is referred to as a fourth offset, and the offset between the center line of the sixth radiation unit and the central axis 160 is referred to as a sixth offset.

[0081] In the embodiment of the present application, the offset of the center line of the radiation unit 142 from the central axis 160 is negatively correlated with the distance from the radiation unit 142 to the center of the radiation portion 140. Therefore, the third offset is greater than the second offset, and the second offset is greater than the first offset; the fourth offset is greater than the fifth offset, and the fifth offset is greater than the sixth offset. Since the radiation portion 140 is a centrally symmetrical structure, the first offset is equal to the sixth offset, the second offset is equal to the fifth offset, and the third offset is equal to the fourth offset.

[0082] Example 3, reference Figure 5 and Figure 6 , Figure 5 A schematic diagram of the structure of another antenna provided in an embodiment of the present application is shown. Figure 6A schematic diagram of the structure of another antenna provided in an embodiment of the present application. Figure 5 and Figure 6 As shown, the antenna includes a feeding part 110, an impedance transformation part 120, a first matching part 130, a radiation part 140 and a second matching part 150 which are connected in sequence. Figure 5 and Figure 2 The antennas shown differ in that Figure 5 In the antenna shown, the radiating portion 140 includes four radiating structures 141 . Figure 6 and Figure 2 The antennas shown differ in that Figure 6 In the antenna shown, the radiating portion 140 includes eight radiating structures 141 .

[0083] Similar to the structure introduced in the above example, Figure 5 and Figure 6 In the figure, the closer the radiation unit 142 is to the center of the radiation unit 140, the greater its offset. That is, the entire radiation unit 140 is a centrosymmetric structure, and the offset of the radiation unit 142 gradually increases from any end of the radiation unit 140 to the center of the radiation unit 140. However, the offset directions of any two adjacent radiation units 142 are opposite.

[0084] In one embodiment of the present application, Figures 2 to 6 As shown, the length of the radiation structure 141 is (0.8-1.2)λ, where λ is the propagation wavelength of the electromagnetic wave corresponding to the working frequency of the antenna in the dielectric substrate. Specifically, the length of the radiation structure 141 can be set to 0.8λ, 0.9λ, λ, 1.1λ or 1.2λ.

[0085] In the embodiment of the present application, the main operating frequency range of the antenna is 76 GHz to 81 GHz. For example, the operating frequency of the antenna can be 76 GHz, 78.5 GHz, and 81 GHz. Among them, the lengths of the radiation structures 141 of antennas with different operating frequencies are also different. In the embodiment of the present application, the length of the radiation structure 141 is generally set to λ, that is, the length of the radiation structure 141 is set to the propagation wavelength of the electromagnetic wave corresponding to the operating frequency of the antenna in the dielectric substrate.

[0086] In one embodiment of the present application, Figures 2 to 6 As shown, the two radiation units 142 in the radiation structure 141 have the same length and width. Taking the length of the radiation structure 141 as λ as an example, the length of each radiation unit 142 is 0.5λ, that is, the length of each radiation unit 142 is half of the propagation wavelength of the electromagnetic wave corresponding to the working frequency of the antenna in the dielectric substrate.

[0087] In an embodiment of the present application, the width of the radiation unit 142 is greater than 0.25λ.

[0088] In one embodiment of the present application, the maximum offset of the radiation unit 142 from the central axis 160 is less than 0.1λ. In the embodiment of the present application, the specific offset of each radiation unit 142 is not limited, and the offset of the radiation unit 142 is adjusted mainly to reduce the side lobe of the antenna. Those skilled in the art can set the specific offset of each radiation unit 142 according to actual needs, and keep the maximum offset of all radiation units 142 from the central axis 160 less than 0.1λ.

[0089] In one embodiment of the present application, Figures 1 to 6 As shown, the center line of the feeding part 110 and the center line of the impedance transformation part 120 are both coincident with the central axis 160. That is, the feeding part 110 and the impedance transformation part 120 are symmetrical about the central axis 160 (in the figure, they are symmetrical about the central axis 160 from top to bottom). Accordingly, when setting the antenna, the center line of the feeding part 110 and the center line of the impedance transformation part 120 can be set on the same straight line, and the center line of the feeding part 110 and the center line of the impedance transformation part 120 are used as the central axis 160 of the antenna, and then the overall structure of the radiating part 140 is determined according to the offset of each radiating unit 142.

[0090] In an embodiment of the present application, the first matching portion 130 and the second matching portion 150 have the same length and width. Since the first matching portion 130 and the second matching portion 150 are respectively connected to the two ends of the radiating portion 140, the first matching portion 130 and the second matching portion 150 are set to have the same length and width, so as to better achieve the matching with the radiating portion 140.

[0091] In one embodiment of the present application, the first matching portion 130 and the second matching portion 150 are centrally symmetrical about the center of the radiation portion 140. Figures 1 to 6 As shown, the first matching portion 130 has a certain offset relative to the central axis 160, and the second matching portion 150 also has a certain offset relative to the central axis 160. The first matching portion 130 and the second matching portion 150 are arranged to be centrally symmetrical about the center of the radiation portion 140, so the first matching portion 130 and the second matching portion 150 have the same offset, but opposite offset directions. In this arrangement, the overall structure formed by the first matching portion 130, the radiation portion 140 and the second matching portion 150 is also a centrally symmetrical structure.

[0092] In an embodiment of the present application, the width of the first matching portion 130, the width of the second matching portion 150 and the width of the radiation unit 142 are all equal. That is, it can be understood that the first matching portion 130, the radiation unit 142 and the second matching portion 150 are all structures of the same width, but the offset amount and offset direction of each structure relative to the central axis 160 are different.

[0093] In one embodiment of the present application, Figures 1 to 6 As shown, the width of the impedance transformation part 120 is greater than the width of the feeding part 110 and less than the width of the first matching part 130. That is, the width of the impedance transformation part 120 is set between the width of the feeding part 110 and the width of the first matching part 130.

[0094] In one embodiment of the present application, the impedance transformation unit 120 includes a first end and a second end, the first end is connected to the feeding unit 110, and the second end is connected to the first matching unit 130. The length of the impedance transformation unit 120 is (0.2-0.3)λ. Figure 2 As shown, the impedance transformation unit 120 is a primary structure, such as Figures 3 to 6 As shown, the impedance transformation part 120 is a two-stage structure. When the impedance transformation part 120 is a one-stage structure, the length of the impedance transformation part 120 can be set to (0.2-0.3)λ, where λ is the propagation wavelength of the electromagnetic wave corresponding to the working frequency of the antenna in the dielectric substrate.

[0095] In one embodiment of the present application, when the impedance transformation part 120 is a primary structure, the length of the impedance transformation part 120 can be set to 0.25λ, that is, the length of the impedance transformation part 120 is one quarter of the propagation wavelength of the electromagnetic wave corresponding to the working frequency of the antenna in the dielectric substrate.

[0096] In an embodiment of the present application, the impedance transformation part 120 includes a first end and a second end, the first end is connected to the feeding part 110, and the second end is connected to the first matching part 130. When the impedance transformation part 120 is a multi-stage structure, the width of the impedance transformation part 120 gradually increases from the first end to the second end, and the length of the impedance transformation part 120 can be set to (0.4-0.6)λ.

[0097] For example, Figures 3 to 6 As shown, when the impedance transformation part 120 is a two-stage structure, the length of the impedance transformation part 120 can be set to 0.5λ, wherein the length of each stage of the impedance transformation part 120 is 0.25λ.

[0098] Of course, the impedance transformation part 120 can also be configured to be composed of a structure with more levels. In one embodiment of the present application, the impedance transformation part 120 includes a plurality of impedance transformation members 121 connected in sequence, and the width of the impedance transformation member 121 gradually increases from the first end to the second end. That is, from the first end to the second end, the width of the impedance transformation part 120 changes gradually.

[0099] In one embodiment of the present application, Figures 3 to 6As shown, the impedance transformation part 120 includes a first impedance transformation part 121 and a second impedance transformation part 121 . The first impedance transformation part 121 is connected to the feeding part 110 , and the second impedance transformation part 121 is connected to the first matching part 130 . The width of the second impedance transformation part 121 is greater than that of the first impedance transformation part 121 .

[0100] In one embodiment of the present application, refer to Figure 7 , Figure 7 A schematic diagram of the structure of an impedance transformation unit 120 in an antenna provided in an embodiment of the present application. Figure 7 FIG. 4 shows a schematic diagram of a partial structure of an antenna, such as Figure 7 As shown, the impedance transformation part 120 is a gradual structure, the side of the impedance transformation part 120 is a straight line, and the side is located between the first end and the second end. That is, the width of the impedance transformation part 120 gradually increases in a linear gradual form.

[0101] In one embodiment of the present application, refer to Figure 8 , Figure 8 This is a schematic structural diagram of another impedance transformation unit 120 in an antenna provided in an embodiment of the present application. Figure 8 FIG. 4 shows a schematic diagram of a partial structure of an antenna, such as Figure 8 As shown, the impedance transformation part 120 is a gradual structure, the side of the impedance transformation part 120 is a curve, and the side is located between the first end and the second end. That is, the width of the impedance transformation part 120 gradually increases in a curved gradual form.

[0102] In the embodiment of the present application, by providing an impedance transformation unit 120 and setting the impedance transformation unit 120 as a multi-level structure or a structure with a gradually changing width, it is beneficial to increase the bandwidth of the antenna.

[0103] Next, an antenna and Figure 1 The performance of the antenna shown is analyzed.

[0104] refer to Fig. 9 , Fig. 9 A schematic diagram of the electric field strength distribution of an antenna provided in an embodiment of the present application, Fig. 9 for Figure 5 Schematic diagram of the electric field strength distribution of the antenna shown in Figure . Fig. 9 As shown, from Fig. 9 It can be seen that in the area corresponding to the radiation portion 140, each offset radiation unit 142 generates a strong electric field in the offset direction, thereby generating radiation.

[0105] In order to better demonstrate the antenna performance effect brought by the antenna of the present invention, the comparison Figure 1 A conventional comb antenna is shown. Fig.10 and Fig.11 , Fig.10 for Figure 1 The impedance bandwidth diagram of the antenna shown is Fig.11 The impedance bandwidth diagram of an antenna provided in an embodiment of the present application is as follows. Fig.10 As shown, Figure 1 When the conventional comb antenna array shown works in the range of 76 GHz to 81 GHz, its antenna bandwidth is 76.14 GHz to 79.8 GHz, and its antenna bandwidth frequency band is less than 4 GHz, which does not meet the bandwidth requirement of 5 GHz.

[0106] It should be noted that antenna bandwidth mainly refers to impedance bandwidth, which is generally measured by satisfying the return loss index of less than -10dB in the operating frequency band. An antenna that meets the requirements means that the return loss index of the antenna must be less than -10dB within the 5GHz bandwidth of the operating frequency range of 76GHz to 81GHz.

[0107] The impedance bandwidth of the antenna in the embodiment of the present application is as follows: Fig.11 As shown, within the range of 76 GHz to 81 GHz, the return loss index of the antenna in the embodiment of the present application is less than -10 dB, which meets the 5 GHz bandwidth requirement of 76 GHz to 81 GHz.

[0108] refer to Fig.12 and Fig.13 , Fig.12 for Figure 1 Schematic diagram of the radiation efficiency of the antenna shown, Fig.13 A schematic diagram of the radiation efficiency of an antenna provided in an embodiment of the present application. Fig.12 As shown, Figure 1 The radiation efficiency of the conventional comb antenna shown in the figure is about 0.73 to 0.8 in the operating frequency range of 76 GHz to 81 GHz. Fig.13 As shown, the radiation efficiency of the antenna of the embodiment of the present application is about 0.86 to 0.9 in the operating frequency range of 76 GHz to 81 GHz. The radiation efficiency of the antenna of the embodiment of the present application is about 10% higher than that of the conventional comb antenna array in the prior art.

[0109] refer to Fig.14 , Fig.15 and Fig.16 , Fig.14 A schematic diagram of the radiation pattern and sidelobe level of an antenna operating at 76 GHz provided in an embodiment of the present application. Fig.15 A schematic diagram of the radiation pattern and sidelobe level of an antenna operating at 78.5 GHz provided in an embodiment of the present application. Fig.16 A schematic diagram of the radiation pattern and sidelobe level of an antenna operating at 81 GHz provided in an embodiment of the present application.

[0110] like Fig.14 , Fig.15 and Fig.16 As shown, in the operating frequency range of 76 GHz to 81 GHz, the level of the side lobe is better than -19 dB. By setting the structure of the antenna to the antenna structure introduced in the embodiment of the present application, a good low side lobe characteristic is achieved.

[0111] In one embodiment of the present application, an antenna array is further provided, which includes a plurality of antennas in any one of the above embodiments.

[0112] In one embodiment of the present application, a radar is also provided, referring to Fig.17 , Fig.17 A schematic diagram of a partial structure of a radar provided in an embodiment of the present application. Fig.17 As shown, the radar includes a radar RF IC mainboard 200. Specifically, the radar RF IC mainboard 200 includes a PCB board 210, a RF chip 220 and the antenna array in the above embodiment. The antenna array includes multiple antennas 100. The antenna array and the RF chip 220 are both arranged on the PCB 210 board, and the antenna array is connected to the RF chip 220.

[0113] In one embodiment of the present application, a vehicle is further provided, on which the radar in the above embodiment is provided.

[0114] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

[0115] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0116] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the protection scope of the present application includes the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0117] Specific examples are used herein to illustrate the working principles and implementation methods of the antenna, antenna array, radar and vehicle of the present application. The description of the above embodiments is only used to help understand the specific settings and core ideas of the present application. At the same time, for those skilled in the art, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

[0118] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An antenna, characterized in that: It includes a feeding part, an impedance transformation part, a first matching part, a radiation part and a second matching part which are connected in sequence; The antenna has a central axis, and the central axis passes through the feeding part, the impedance transformation part, the first matching part, the radiation part and the second matching part; The radiation portion is centrally symmetrical about its center, and includes a radiation structure. Each of the radiation structures includes two radiation units, and center lines of any two adjacent radiation units are offset from the central axis in opposite directions.

2. The antenna according to claim 1, characterized in that The amount by which the center line of the radiation unit deviates from the central axis is negatively correlated with the distance from the radiation unit to the center of the radiation portion.

3. The antenna according to claim 2, characterized in that: The length of the radiation structure is (0.8-1.2)λ, where λ is the propagation wavelength of the electromagnetic wave corresponding to the working frequency of the antenna in the dielectric substrate.

4. The antenna according to claim 3, characterized in that: The two radiation units in the radiation structure have the same length and the same width.

5. The antenna according to claim 4, characterized in that: The width of the radiation unit is greater than 0.25λ.

6. The antenna according to claim 5, characterized in that The maximum offset of the radiation unit from the central axis is less than 0.1λ.

7. The antenna according to any one of claims 1 to 6, characterized in that: The center line of the feeding part and the center line of the impedance transformation part both coincide with the central axis.

8. The antenna according to claim 7, characterized in that: The first matching portion and the second matching portion have the same length and the same width.

9. The antenna according to claim 8, characterized in that The first matching portion and the second matching portion are centrally symmetric with respect to the center of the radiation portion.

10. The antenna according to claim 9, characterized in that: The width of the first matching portion, the width of the second matching portion, and the width of the radiation unit are all equal.

11. The antenna according to claim 7, characterized in that: The width of the impedance transformation portion is greater than the width of the feeding portion, and smaller than the width of the first matching portion.

12. The antenna according to claim 11, characterized in that The impedance transformation part includes a first end and a second end, the first end is connected to the feeding part, the second end is connected to the first matching part, and the length of the impedance transformation part is (0.2-0.3)λ.

13. The antenna according to claim 12, characterized in that: The length of the impedance transformation portion is 0.25λ.

14. The antenna according to claim 11, characterized in that The impedance transformation part includes a first end and a second end, the first end is connected to the feeding part, the second end is connected to the first matching part, the width of the impedance transformation part gradually increases from the first end to the second end, and the length of the impedance transformation part is (0.4-0.6)λ.

15. The antenna according to claim 14, characterized in that The impedance transformation portion includes a plurality of impedance transformation elements connected in sequence, and the width of the impedance transformation element gradually increases from the first end to the second end.

16. The antenna according to claim 15, characterized in that The impedance transformation part includes a first impedance transformation part and a second impedance transformation part, the first impedance transformation part is connected to the feeding part, the second impedance transformation part is connected to the first matching part, and the width of the second impedance transformation part is greater than that of the first impedance transformation part.

17. The antenna according to claim 15, characterized in that The impedance transformation portion is a gradual structure, and a side edge of the impedance transformation portion is a straight line, and the side edge is located between the first end and the second end.

18. The antenna according to claim 15, characterized in that The impedance transformation portion is a gradual structure, and a side of the impedance transformation portion is a curve, and the side is located between the first end and the second end.

19. An antenna array, characterized in that: The invention comprises a plurality of antennas according to any one of claims 1 to 18.

20. A radar, characterized in that: It comprises a PCB board, a radio frequency chip and the antenna array as claimed in claim 19, wherein the antenna array and the radio frequency chip are both arranged on the PCB board, and the antenna array is connected to the radio frequency chip.

21. A vehicle, characterized in that: Comprising the radar as claimed in claim 20.

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