Antenna units, array antennas, radar sensors and electronic equipment

Abstract

The embodiments of the present application relate to the field of wireless communication technology, and disclose an antenna unit, an array antenna, a radar sensor, and an electronic device. The antenna unit includes a dielectric layer and a radiating portion, wherein the dielectric layer is provided with a ground plane; the radiating portion is provided on a side of the dielectric layer away from the ground plane; the radiating portion includes a first radiating edge and a second radiating edge that are relatively arranged, and the direction of the current after the radiating portion is fed is from the first radiating edge to the second radiating edge; a first short-circuit structure connected to the ground plane is provided on the radiating portion, the first short-circuit structure is located in the direction of current flow, and a current channel is left on the first short-circuit structure; part of the current flows directly from the current channel to the second radiating edge, and part of the current flows to the first radiating edge under the blocking effect of the first short-circuit structure. The antenna unit, array antenna, radar sensor, and electronic device provided by the embodiments of the present application can realize the wide-beam radiation characteristics of the antenna, so as to achieve effective coverage of the detection area.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of wireless communication technology, and in particular to an antenna unit, an array antenna, a radar sensor, and an electronic device. Background Art

[0002] In addition to its applications in high-end aerospace electronics, radar technology is also widely used in daily life. For example, in recent years, as cars continue to move towards intelligence and electrification, automotive vision systems are also equipped with radar sensors to meet the needs of surrounding detection and autonomous driving.

[0003] To effectively implement blind spot detection and collision avoidance warnings, radar sensors installed in automotive vision systems require a wide field of view (FOV). A wide FOV enables the vehicle's vision system to better detect the surroundings, front, back, and sides. This, in turn, requires the radar sensor's antenna to have a wide beam radiation characteristic. Therefore, achieving this wide beam radiation characteristic for effective coverage of the detection area is a critical issue. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide an antenna unit, an array antenna, a radar sensor and an electronic device that can realize the wide-beam radiation characteristics of the antenna so as to achieve effective coverage of the detection area.

[0005] In order to solve the above technical problems, an embodiment of the present application provides an antenna unit, including a dielectric layer and a radiating portion; the dielectric layer is provided with a ground plane; the radiating portion is arranged on a side of the dielectric layer away from the ground plane; the radiating portion includes a first radiating edge and a second radiating edge arranged opposite to each other, and the direction of the current after the radiating portion is fed is from the first radiating edge to the second radiating edge; a first short-circuit structure connected to the ground plane is provided on the radiating portion, the first short-circuit structure is located in the current flow direction, and a current channel is left on the first short-circuit structure; part of the current flows directly to the second radiating edge from the current channel, and part of the current flows to the first radiating edge under the blocking effect of the first short-circuit structure.

[0006] An embodiment of the present application also provides an array antenna, comprising a plurality of the above-mentioned antenna units, wherein the dielectric layers of the plurality of antenna units are integrally arranged, and the radiating parts of the plurality of antenna units are arranged in an array on the integrally arranged dielectric layer, and the plurality of radiating parts located on the same straight line are connected together via a transmission line.

[0007] An embodiment of the present application further provides a radar sensor including the above-mentioned array antenna.

[0008] An embodiment of the present application further provides an electronic device including the above-mentioned radar sensor.

[0009] The antenna unit, array antenna, radar sensor and electronic equipment provided in the embodiments of the present application are provided with a first short-circuit structure located in the direction of current flow on the radiating part, and a current channel is left on the first short-circuit structure. Through the blocking effect formed by the first short-circuit structure, part of the current formed by the radiating part after feeding flows to the first radiating edge, while the other part can flow directly to the second radiating edge through the current channel. As a result, the reverse electric fields at the two radiating edges become symmetrical, and the corresponding magnetic currents are reversed. Therefore, the antenna unit can be equivalent to the superposition of reverse binary arrays, and the final radiation pattern presents a shape with convex sides and concave normal. As a result, the radiation pattern of the antenna unit changes from the highest point at 0° to the highest point near ±45°, realizing the wide beam radiation characteristics of the antenna, so as to achieve effective coverage of the detection area.

[0010] In some embodiments, the first short-circuit structure is parallel to the first radiation edge and the second radiation edge, so that the first short-circuit structure can effectively block the passage of current, thereby allowing part of the current to flow toward the first radiation edge.

[0011] In some embodiments, the first short-circuit structure includes at least one row of first metal vias, each row including at least two first metal vias, wherein the first metal vias connect the radiating portion and the ground plane. Thus, by arranging the first metal vias on the radiating portion, a first short-circuit structure can be formed to block current from passing through.

[0012] In some embodiments, two adjacent first metal vias in the same row are spaced apart to form a current channel. This allows the current channel to be positioned to accommodate other structures on the radiating portion, such as the feed structure. Furthermore, the first metal vias on either side of the current channel can still block current flow.

[0013] In some embodiments, the radiating portion further includes a first non-radiating edge and a second non-radiating edge disposed opposite each other, each of which is provided with a second short-circuit structure connected to a ground plane. This second short-circuit structure can thus cut off current flow at the non-radiating edge of the radiating portion, thereby facilitating miniaturization of the antenna unit.

[0014] In some embodiments, the second short-circuit structure includes a plurality of second metal vias, which are sequentially arranged along the extension direction of the first non-radiating edge or the second non-radiating edge. In this way, by arranging the second metal vias on the radiating portion, a second short-circuit structure is formed to cut off current at the non-radiating edge of the radiating portion.

[0015] In some embodiments, the antenna unit further includes a feed portion, which is perpendicularly connected to the first radiating edge, with the current path opposing the feed portion. Thus, by adjusting the position of the feed portion to correspond to the position of the current path, the final radiation phase of the antenna unit can be changed to obtain the desired radiation pattern characteristics.

[0016] In some embodiments, the feed portion is connected to the center of the first radiating edge, so that the electric field strength of the radiating edge of the radiating portion is symmetrically distributed about the center, thereby ultimately obtaining a directional pattern with uniform gain distribution.

[0017] In some embodiments, a slot is provided on the first radiating edge, extending from the first radiating edge toward the second radiating edge, and the feed portion is disposed within the slot. This slot allows for the introduction of a new resonant unit at the feed portion of the radiating portion, thereby achieving impedance matching between the radiating portion and the feed portion of the antenna unit and reducing radiation signal loss at the feed portion of the radiating portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0019] Figure 1 is a schematic diagram of the structure of a beamforming wide beam array antenna used in some situations;

[0020] Figure 2 is a schematic diagram of a top view of the antenna unit provided in some embodiments of the present application;

[0021] Figure 3 This is a schematic diagram of the current flow on the radiating portion when no short-circuit structure is provided in some cases;

[0022] Figure 4 This is a schematic diagram of the current flow on the radiating portion when a short-circuit structure and a current channel are provided in some embodiments of the present application;

[0023] Figure 5 This is a schematic diagram of the electric field direction at the radiating edge of the radiating portion when no short-circuit structure is provided in some cases;

[0024] Figure 6 This is a schematic diagram of the electric field direction at the radiating edge of the radiating portion when a short-circuit structure and a current channel are provided in some embodiments of the present application;

[0025] Figure 7 is a schematic top view of another antenna unit provided in some embodiments of the present application;

[0026] Figure 8 is a schematic top view of another antenna unit provided in some embodiments of the present application;

[0027] Figure 9 is a schematic top view of another antenna unit provided in some embodiments of the present application;

[0028] Figure 10 is a directional pattern of an antenna unit provided in some embodiments of the present application;

[0029] Figure 11 is a return loss graph of an antenna unit provided in some embodiments of the present application;

[0030] Figure 12 is a schematic structural diagram of an array antenna provided in some embodiments of the present application;

[0031] Figure 13 is a schematic structural diagram of another array antenna provided in some embodiments of the present application;

[0032] Figure 14 is a structural diagram of another array antenna provided in some embodiments of the present application;

[0033] Figure 15 This is a comparison diagram of the directional patterns of a single wide-beam array antenna and two wide-beam array antenna units provided in some embodiments of the present application;

[0034] Figure 16 This is a comparison diagram of the directional patterns of a single wide-beam array antenna and three beamforming antennas provided in some embodiments of the present application;

[0035] Figure 17 This is a comparison diagram of the directional patterns of two wide-beam array antennas and three beamforming array antennas provided in some embodiments of the present application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below with reference to the accompanying drawings. However, it will be understood by those skilled in the art that in each embodiment of the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can be implemented. The division of the following embodiments is for convenience of description and should not constitute any limitation on the specific implementation of the present application. The various embodiments can be combined with each other and referenced to each other under the premise of no contradiction.

[0037] Radar technology is used to detect objects within a target area. In the automotive field, with the upgrade and evolution of autonomous driving functions such as lane change assistance, automatic navigation, automatic parking, and emergency automatic braking, the vehicle installation rate of millimeter-wave corner radar has also increased rapidly. Corner radar is a radar sensor installed at the side corner of the car, at a 45° angle to the front and rear of the car body. Based on the installation method of the corner radar, it is necessary to design a wide-beam millimeter-wave radar antenna with a directional pattern gain peak of around ±45° to meet the detection needs of the front, rear, and side areas of the car body.

[0038] In some cases, in order to achieve a directional pattern with a maximum gain of around ±45°, the antenna usually adopts the form of beamforming, with a structure such as Figure 1 As shown. The radiating patch 10 is connected via a transmission line 20 to form a branch, and the three branches are fed by a one-to-three power divider 30. During the design, the phase and amplitude ratio of the three branches are first simulated, and then the microstrip power divider is used for simulation to achieve the phase and amplitude required for each of the three branches. Finally, the microstrip power divider is connected to the radiating branch, and then optimized and adjusted to achieve the required angular radar pattern. This beamforming method requires three branches, the antenna size is too large, and a one-to-three power divider is required, so the design is relatively complicated.

[0039] Some embodiments of the present application provide a wide-beam antenna unit structure, where a single antenna unit can meet the requirements of the angular radar pattern.

[0040] like Figure 2 As shown, the antenna unit 100 provided in some embodiments of the present application includes a dielectric layer 110 and a radiating portion 120, and the dielectric layer 110 is provided with a ground plane 111 ( Figure 6 Radiating portion 120 is disposed on the side of dielectric layer 110 away from ground plane 111. Radiating portion 120 includes a first radiating edge 121 and a second radiating edge 122 positioned opposite each other. When powered, current flows from first radiating edge 121 to second radiating edge 122. A first short-circuit structure 130 connected to ground plane 111 is provided on radiating portion 120. First short-circuit structure 130 is located in the direction of current flow and defines a current path 140. Part of the current flows directly through current path 140 to second radiating edge 122, while part of the current flows toward first radiating edge 121, blocked by first short-circuit structure 130.

[0041] The dielectric layer 110 is the basis for supporting the radiation part 120 in the antenna unit 100 . The dielectric layer 110 may be made of FR-4 material with a dielectric constant of 4.4. The ground plane 111 of the dielectric layer 110 may be realized by providing a grounded metal layer on one side of the dielectric layer 110 .

[0042] The radiating portion 120 is the radiating portion of the antenna unit 100, which plays the role of transmitting signals to the outside world and receiving external signals. The radiating portion 120 can be made of metal, such as copper metal. The radiating portion 120 can be in the form of a metal patch, and the shape of the metal patch can be a regular shape such as a square, rectangle, circle, or an irregular shape. The radiating portion 120 can also be in the form of a metal branch. The feeding form of the radiating portion 120 can be microstrip feeding, coaxial feeding or other feeding forms. Figure 3 As shown (arrows indicate current flow direction), after the radiating portion 120 is fed, the generated current flows from the first radiating edge 121 (the edge connected to the feeding structure) to the second radiating edge 122 .

[0043] The radiation portion 120 is provided with a first short-circuit structure 130, which is electrically connected to the ground plane 111 of the dielectric layer 110, and plays a role in changing the electric field radiation characteristics of the radiation portion 120. Figure 4 As shown (arrows indicate current flow), the presence of the first short-circuit structure 130 blocks a portion of the current generated by the radiating portion 120 after power is fed, allowing the current to flow through other areas of the radiating portion 120 toward the first radiating edge 121. Thus, by providing the first short-circuit structure 130 on the radiating portion 120, the opposing electric fields at the two radiating edges of the radiating portion 120 are transformed into the same direction. The arrows at the two radiating edges of the radiating portion 120 in the figure indicate the direction of the generated electric fields. In practice, the first short-circuit structure 130 can be implemented by providing a grounded short-circuit via, a grounded short-circuit gap, a grounded short-circuit pin, or a grounded metal plane on the radiating portion 120.

[0044] It should be noted that in the microstrip antenna, the two radiation edges of the radiation portion 120 along the signal propagation direction, namely the first radiation edge 121 and the second radiation edge 122, can be equivalent to two gaps to generate radiation in space. Figure 5 As shown in the figure, in the absence of a short-circuit structure, the electric fields at the two equivalent gaps are in opposite directions, and the corresponding magnetic currents are in the same direction. Therefore, it can be equivalent to the superposition of two unidirectional arrays, forming the maximum radiation in the normal direction.

[0045] In the antenna unit 100 provided in some embodiments of the present application, a first short-circuit structure 130 is provided on the radiating portion 120 in the direction of current flow, and a current channel 140 is left on the first short-circuit structure 130. Due to the blocking effect formed by the first short-circuit structure 130, part of the current generated by the radiating portion 120 after being fed flows to the first radiating edge 121, while the other part can flow directly to the second radiating edge 122 through the current channel 140, thereby making the reverse electric fields at the two radiating edges become the same direction (i.e., both facing downward in the paper direction), as shown in FIG. Figure 6As shown, the corresponding magnetic currents are in opposite directions. Therefore, the antenna unit 100 is equivalent to a stack of two inverted arrays, resulting in a directional pattern with convex sides and a concave normal. This shifts the radiation pattern of the antenna unit 100 from a peak at 0° to a peak near ±45°, achieving wide-beam radiation characteristics for effective coverage of the detection area.

[0046] That is to say, by providing a first short-circuit structure 130 on the radiating portion 120 that is electrically connected to the ground plane 111 of the dielectric layer 110, the radiation characteristics of the directional pattern of the antenna unit 100 can be changed, so that the directional pattern of the antenna unit 100 changes from the original directional pattern that is high in the middle and low on both sides to a directional pattern that is convex on both sides and concave in the middle, thereby widening the beam width of the antenna unit 100.

[0047] In some embodiments of the present application, the first short-circuit structure 130 is parallel to the first radiating edge 121 and the second radiating edge 122. The present application designs the first short-circuit structure 130 to be parallel to the first radiating edge 121 and the second radiating edge 122 to better block the current from flowing toward the second radiating edge 122.

[0048] To ensure that the first short-circuit structure 130 effectively blocks current, it can be distributed along the extending direction of the radiating edge of the radiating portion 120. At the same time, a current channel 140 is left along the distribution direction of the first short-circuit structure 130. This allows the first short-circuit structure 130 to effectively block current while also allowing some current to pass through the current channel 140 and reach the second radiating edge 122. The radiation pattern characteristics of the antenna unit 100 can be adjusted by adjusting the distribution position of the first short-circuit structure 130. For example, by adjusting the position of the first short-circuit structure between the first radiating edge 121 and the second radiating edge 122, the phase of the antenna unit's radiated signal can be adjusted.

[0049] Of course, in other embodiments, the first short-circuit structure 130 may not be parallel to the first radiation edge 121 and the second radiation edge 122 , as long as it can block the current from flowing toward the first radiation edge 121 .

[0050] In some embodiments of the present application, the first short-circuit structure 130 includes at least one row of first metal through-holes 131 , each row includes at least two first metal through-holes 131 , and the first metal through-holes 131 in the same row are arranged sequentially along the extension direction of the first radiation edge 121 and the second radiation edge 122 .

[0051] like Figure 2As shown, the first short-circuit structure 130 can be a row of first metal vias 131 disposed on the radiating portion 120. In other embodiments, the first short-circuit structure 130 can also be multiple rows of first metal vias 131 disposed on the radiating portion 120, with the multiple rows of first metal vias 131 arranged sequentially along the current flow direction. The electrical connection between the first metal vias 131 and the ground plane of the dielectric layer 110 can be achieved by providing metal vias or adding short-circuit pins at locations on the dielectric layer 110 corresponding to the first metal vias 131.

[0052] The location of the radiation portion 120 where the first metal vias 131 are located will block the passage of current, while the location of the current channel 140 where the first metal vias 131 are not located allows the current to pass normally and eventually reach the second radiation edge 122 .

[0053] In some embodiments of the present application, two adjacent first metal vias 131 in the same row are spaced apart to form a current channel 140 .

[0054] In other words, the current channel 140 blocks the metal vias 131 in the same row. Thus, when the first short-circuit structure 130 is provided on the radiating portion 120, space can be adaptively reserved for the current channel 140, so that the current channel 140 corresponds to the location of other structures on the radiating portion 120, such as the feed structure. At the same time, the first metal vias 131 on either side of the current channel 140 can still block current from passing through.

[0055] In other embodiments, the current channel 140 may be reserved at the outermost position of the first metal vias 131 in the same row. Furthermore, the current channel 140 may be positioned at a position offset from the feed structure. In practice, the position of the current channel 140 and the feed structure may be adjusted based on the desired radiation pattern characteristics of the antenna unit 100 to obtain radiation patterns with different phases for the antenna unit 100.

[0056] In some embodiments of the present application, the number of first metal vias 131 may be determined based on the size of the radiating portion 120 and the desired radiation pattern characteristics of the antenna unit 100. If the radiating portion 120 is relatively small, the number of first metal vias 131 may be reduced accordingly. The desired radiation pattern characteristics of the antenna unit 100 can be achieved by adjusting the size of the first metal vias 131 and the distance between adjacent first metal vias 131.

[0057] like Figure 2 As shown, the first metal through holes 131 can be arranged in a row of six on the radiation portion 120, as shown in FIG. Figure 7As shown, four first metal vias 131 may be arranged in a row on the radiation portion 120 , wherein two first metal vias 131 are spaced apart to form a current channel 140 .

[0058] In addition, the first metal through holes 131 on both sides of the current channel 140 can be symmetrically distributed on the radiation portion 120 to uniformly introduce a short-circuit structure into the antenna unit 100, thereby facilitating the debugging of the antenna unit 100 so as to ultimately obtain the desired directional radiation characteristics.

[0059] In some embodiments, the plurality of first metal vias 131 in the same row may be distributed along a straight line on the radiation portion 120, or the plurality of first metal vias 131 in the same row may be distributed in a zigzag pattern on the radiation portion 120 ( Figure 8 As shown), this may depend on the specific size of the radiating portion 120 and the desired directional radiation characteristics of the antenna unit 100.

[0060] like Figure 9 As shown, in some embodiments of the present application, the radiation portion 120 further includes a first non-radiation edge 123 and a second non-radiation edge 124 arranged opposite to each other, and a second short-circuit structure 150 connected to the ground plane 111 is provided at both the first non-radiation edge 123 and the second non-radiation edge 124 .

[0061] The second short-circuit structure 150 serves to cut off the current at the non-radiating edge of the radiating portion 120. By introducing the second short-circuit structure 150, the current cutoff at the non-radiating edge of the radiating portion 120 can be artificially controlled. This facilitates controlling the relative distance between the two non-radiating edges of the radiating portion 120, thereby facilitating a miniaturized design of the antenna unit 100.

[0062] In actual situations, the second short-circuit structure 150 can be implemented by providing a grounded short-circuit via, a grounded short-circuit gap, a grounded short-circuit pin, or a grounded metal plane on the radiation portion 120 .

[0063] In some embodiments of the present application, the second short-circuit structure 150 includes a plurality of second metal vias 151 , and the plurality of second metal vias 151 are sequentially arranged along the extension direction of the first non-radiating edge 123 or the second non-radiating edge 124 .

[0064] The electrical connection between the second metal through hole 151 and the ground plane 111 of the dielectric layer 110 can be achieved by providing a short-circuit via hole or adding a short-circuit pin at a position corresponding to the second metal through hole 151 on the dielectric layer 110 .

[0065] like Figure 9As shown, the second short-circuit structure 150 is similar to the first short-circuit structure 130 and can be implemented using multiple metal vias connecting the radiating portion 120 and the ground plane 111. Furthermore, the second metal vias 151 forming the second short-circuit structure 150 are arranged sequentially along the extension direction of the non-radiating edge of the radiating portion 120, thereby completely covering the non-radiating edge of the radiating portion 120 and better blocking the current at the non-radiating edge.

[0066] like Figure 9 As shown, the second metal vias 151 at the two non-radiating edges remain corresponding and can be symmetrically distributed on the radiation portion 120 .

[0067] By symmetrically distributing the second metal vias 151 on the radiating portion 120, a new short-circuit structure can be uniformly introduced into the antenna unit 100, thereby stabilizing the directivity pattern of the antenna unit 100. This also facilitates debugging of the antenna unit 100, and by rationally arranging the short-circuit structure positions, the antenna unit 100 can be miniaturized.

[0068] In some embodiments of the present application, the antenna unit 100 further includes a feeding portion 160 . The feeding portion 160 is vertically connected to the first radiation edge 121 , and the current channel 140 is opposite to the feeding portion 160 .

[0069] The feeder 160 feeds the radiating element 120, enabling it to radiate signals. Depending on the feeding method, the feeder 160 can take different forms. For example, in direct feeding, the feeder 160 can use a microstrip or coaxial line. In coupled feeding, the feeder 160 can use an independent radiating patch or a parasitic patch.

[0070] By vertically connecting the feeding portion 160 to the first radiating edge 121 of the radiating portion 120 , current on the feeding portion 160 can flow directly to the radiating portion 120 and flow from the first radiating edge 121 to the second radiating edge 122 of the radiating portion 120 .

[0071] Furthermore, by aligning the current path 140 on the radiating portion 120 with the feeding portion 160, current loss in the radiating portion 120 can be reduced, facilitating the signal's passage through the first short-circuit structure 130 on the radiating portion 120 and reaching the second radiating edge 122. This also facilitates controlling the radiation pattern characteristics of the antenna unit 100, ensuring that the maximum gain of the antenna unit 100 occurs near ±45°, thereby achieving wide-beam radiation characteristics for the antenna unit 100.

[0072] In some embodiments of the present application, the feeding portion 160 is connected to the center of the first radiation edge 121 .

[0073] like Figure 9As shown, the feed portion 160 is located at the center of the first radiating edge 121. Meanwhile, the current channel 150 can be kept opposite to the feed portion 160. In other embodiments, the feed portion 160 can also be located at any position on either side of the center of the first radiating edge 121.

[0074] By connecting the feed portion 160 to the center of the first radiation edge 121 , the electric field strength at the two radiation edges of the radiation portion 120 can be kept symmetrical about the center, which is beneficial for the antenna unit 100 to form a directional pattern with uniform gain distribution.

[0075] In some embodiments of the present application, a slot 125 is provided on the first radiation edge 121 . The slot 125 extends from the first radiation edge 121 toward the second radiation edge 122 . The feeding portion 160 is provided in the slot 125 .

[0076] like Figure 9 As shown, the antenna unit 100 may be fed by a microstrip, that is, the antenna unit 100 further includes a microstrip line, the radiation portion 120 is provided with a slot 125 , and the microstrip line is provided in the slot 125 .

[0077] The slit 125 provided on the radiating portion 120 transforms the closed edge of the radiating portion 120 into an open edge. The slit 125 can change the electric field radiation characteristics at the first radiating edge of the radiating portion 120. The capacitive structure formed by the slit 125 introduces a new resonance in the radiating portion 120, thereby facilitating impedance matching between the radiating portion 120 and the feeding portion 160 of the antenna unit 100, thereby reducing radiation signal loss at the feeding connection of the antenna unit 100.

[0078] Figure 10 The directional patterns of the antenna units provided in some embodiments of the present application are shown. It can be seen that the directional patterns are convex on both sides and concave in the middle, indicating that the beam width of the antenna unit can be widened by setting the first metal via 131 on the radiating portion 120. Figure 11 The return loss diagram of the antenna unit provided in some embodiments of the present application is shown. It can be seen that the bandwidth in which the return loss S11 of the antenna unit is less than -10dB (decibel) can cover 75GHz (gigahertz) to 77.5GHz.

[0079] Some embodiments of the present application further provide an array antenna comprising a plurality of antenna units 100, where antenna units 100 are the antenna units described in the aforementioned embodiments. The dielectric layer 111 of the plurality of antenna units 100 is integrally arranged, and the radiating portions 120 of the plurality of antenna units 100 are arranged in an array on the integrally arranged dielectric layer 111. The plurality of radiating portions 120 located on the same straight line are connected together via a transmission line 200.

[0080] In addition, if Figure 12 and Figure 13 As shown, the radiation portion 120 may be arranged on one side of the transmission line 200, or as shown in FIG. Figure 14 As shown, radiating elements 120 can also be arranged on both sides of the transmission line 200. When multiple radiating elements 120 are distributed on one side of each transmission line 200, the distance between two adjacent radiating elements 120 can be one wavelength. When multiple radiating elements 120 are distributed on both sides of each transmission line 200, the distance between two adjacent radiating elements 120 on the same side of the transmission line 200 can be half a wavelength. Both configurations ultimately achieve an antenna pattern with a peak point near ±45°.

[0081] It should be noted that, since a single antenna unit 100 can achieve wide beam radiation characteristics, it can be directly arrayed. Figure 12 The single wide beam array antenna shown can also be Figure 13 The structure shown can further improve the antenna gain by connecting two single arrays through a one-to-two power splitter.

[0082] exist Figure 1 In the wide-beam array antenna achieved through beamforming shown in the figure, first, the amplitude and phase distribution ratios of the same power divider vary at different frequencies. Second, the power divider is easily affected by the surrounding electromagnetic environment and manufacturing errors, causing the final amplitude and phase ratios to vary, thus easily producing a radiation pattern that does not meet expectations. Furthermore, the array antenna using three beamforming branches is relatively wide. Given the limited PCB (Printed Circuit Board) area, the radar's multi-input multi-output (MIMO) TRX channels (transmitter and receive channels) can only be reduced, which will reduce the radar's angle resolution performance.

[0083] Tests have shown that, under the same resonant frequency, the width of a single wide-beam array antenna is 1.45mm, two wide-beam array antennas is 4.1mm, and three beamforming wide-beam array antennas is 7.1mm. Therefore, a radiating element with wide-beam radiation characteristics can be used to form an array to achieve a miniaturized wide-beam millimeter-wave radar antenna.

[0084] Figure 15 The comparison of the directional patterns of a single wide beam array antenna and two wide beam array antennas is shown. Figure 15 It can be seen that the gain of the two wide-beam array antennas is slightly improved compared to the single wide-beam array antenna. Figure 16 and Figure 17The following diagrams compare the radiation patterns of a single wide-beam array antenna, two wide-beam array antennas, and a three-beam-forming wide-beam array antenna. While the gain of the two wide-beam array antennas is comparable to that of the three-beam-forming array antenna, the two wide-beam array antennas offer greater advantages in miniaturization and stability. While the gain of a single wide-beam array antenna is slightly lower than that of a three-beam-forming wide-beam array antenna, its area is only about one-fifth of the three-beam-forming array antenna. Therefore, when gain requirements are low but the PCB area is small, a single wide-beam array antenna offers a clear advantage.

[0085] Some embodiments of the present application further provide a radar sensor, including an array antenna, which is the array antenna in the above embodiment.

[0086] In addition, some embodiments of the present application further provide an electronic device including the radar sensor in the above embodiments. The function of the electronic device is described below using the anti-collision warning function.

[0087] When electronic equipment is used for vehicle collision avoidance warning, it can obtain scene information collected by the radar sensor within the vehicle's driving area, obtain obstacle information contained in the radar sensor's detection area, and then generate a target warning signal based on the obstacle information of the target obstacle to determine when the warning trigger conditions are met.

[0088] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and that in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. An antenna unit, characterized in that: include: a dielectric layer provided with a ground plane; A radiating portion is provided on a side of the dielectric layer away from the ground plane; the radiating portion includes a first radiating edge and a second radiating edge that are arranged opposite to each other, and the direction of current flowing from the first radiating edge to the second radiating edge after the radiating portion is fed; The radiation portion is provided with a first short-circuit structure connected to the ground plane, the first short-circuit structure is located in the current flow direction, and a current channel is left on the first short-circuit structure; Part of the current flows directly from the current channel to the second radiation edge, and part of the current flows to the first radiation edge under the blocking effect of the first short-circuit structure.

2. The antenna unit according to claim 1, wherein: The first short-circuit structure is parallel to the first radiation edge and the second radiation edge.

3. The antenna unit according to claim 1, wherein: The first short-circuit structure includes at least one row of first metal vias, each row includes at least two first metal vias, and the first metal vias connect the radiation portion and the ground plane.

4. The antenna unit according to claim 3, wherein: Two adjacent first metal through holes in the same row are spaced apart to form the current channel.

5. The antenna unit according to any one of claims 1 to 4, characterized in that: The radiation portion further includes a first non-radiation edge and a second non-radiation edge that are oppositely disposed. A second short-circuit structure connected to the ground plane is disposed at both the first non-radiation edge and the second non-radiation edge.

6. The antenna unit according to claim 5, wherein: The second short-circuit structure includes a plurality of second metal through-holes, and the plurality of second metal through-holes are sequentially arranged along the extending direction of the first non-radiating edge and the second non-radiating edge.

7. The antenna unit according to claim 1, wherein: The device further includes a feeding portion, wherein the feeding portion is vertically connected to the first radiation edge, and the current channel is opposite to the feeding portion.

8. The antenna unit according to claim 7, wherein: The feed portion is connected to the center of the first radiation edge.

9. The antenna unit according to claim 7, wherein: A slot is provided on the first radiation edge, the slot extends from the first radiation edge toward the second radiation edge, and the feeding portion is provided in the slot.

10. An array antenna, characterized in that: include: The antenna units according to any one of claims 1 to 9, wherein the dielectric layers of the plurality of antenna units are integrally arranged, the radiating parts of the plurality of antenna units are arranged in an array on the integrally arranged dielectric layer, and the plurality of radiating parts located on the same straight line are connected together via a transmission line.

11. The array antenna according to claim 10, wherein: A plurality of the radiation portions are distributed on one side of each of the transmission lines, and the distance between two adjacent radiation portions is one wavelength; or A plurality of the radiation portions are distributed on both sides of each transmission line, and the distance between two adjacent radiation portions on the same side of the transmission line is half a wavelength.

12. The array antenna according to claim 11, wherein: A plurality of the radiation parts are distributed on both sides of each transmission line, and the radiation parts on both sides of the same transmission line are staggered.

13. A radar sensor, characterized in that: include: The array antenna according to any one of claims 10 to 12.

14. An electronic device, characterized in that: include: The radar sensor according to claim 13.

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