Method for correcting phase error of slot antenna and slot antenna

Abstract

The present invention relates to a method for correcting the phase error of a slot antenna and a slot antenna. The method for correcting the phase error of a slot antenna includes: obtaining the phase difference error value between two adjacent slot antennas; opening a concave window structure above the slot antenna, and the central position of the concave window structure is determined by the phase difference error value between two adjacent slot antennas, so that the equivalent phase center of the slot antenna provided with the concave window structure coincides with the geometric center. By setting a concave window structure above the slot antenna, the present invention corrects the equivalent phase center of the slot antenna to coincide with the geometric center, so as to optimize the angle measurement performance of the radar antenna. In addition, the radiation pattern and amplitude of the radar antenna can also be finely adjusted by adjusting the position and shape of the concave window structure.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave communication, and particularly to a method for correcting phase error of a slot antenna and a slot antenna. Background Art

[0002] In recent years, with the rapid growth of China's economy, the number of automobiles has increased significantly. With the rapid development of the autopilot level, as a sensor, the index requirement for the angular resolution of radar has been increasing day by day. Multi-chip cascading can meet the current angular resolution requirement by increasing the number of channels. Therefore, multi-chip cascading has become the development trend of 77GHz automotive millimeter-wave radar sensors. Considering the wiring loss and the overall board layout, the antenna form is no longer limited to the antenna on the PCB board, and the metal slot antenna has gradually become popular. The angular resolution of the millimeter-wave radar has also been improved from one dimension to two dimensions. The structural form of the antenna is relatively diverse, especially the metal slot antenna. Its asymmetric design increases the design flexibility, but also brings the position deviation between the equivalent phase center and the geometric center. As a channel unit, the error of the equivalent phase center of the antenna will cause the degradation of the radar angle measurement performance, thus affecting the angle measurement indexes in two dimensions. At the same time, considering that the width of the metal slot antenna is limited by the working wavelength and the adjacent antenna spacing is limited by the array form, neither of them can be adjusted. If the edge spacing between adjacent antennas is not large enough, it will lead to spatial coupling, which will deteriorate the amplitude-phase consistency. Therefore, correspondingly, the requirement for the channel consistency of the antenna is also more stringent. Summary of the Invention

[0003] In order to overcome the problems in the above-mentioned prior art, such as the non-PCB board antenna with asymmetric design having an equivalent phase center deviation and poor channel consistency of the antenna, which leads to the degradation of the radar angle measurement performance, the present invention provides a method for correcting the phase error of a slot antenna.

[0004] To solve the above technical problems, the technical solution of the present invention is as follows:

[0005] A method for correcting the phase error of a slot antenna includes the following steps:

[0006] Obtain the phase difference error value between two adjacent slot antennas;

[0007] Open a concave window structure above the slot antenna, and the central position of the concave window structure is determined by the phase difference error value between two adjacent slot antennas, so that the equivalent phase center and the geometric center of the slot antenna provided with the concave window structure coincide.

[0008] Further, as a preferred technical solution, the setting of the concave window structure specifically includes:

[0009] Set an initial concave window structure above the slot antenna and obtain the central value of the initial concave window structure;

[0010] Adjust the center offset value of the initial concave window structure according to the phase difference error value between two adjacent slot antennas until the phase difference error value between two adjacent slot antennas with the initial concave window structure is within the first range;

[0011] Obtain the determined center offset value of the initial concave window structure, obtain the determined center value of the initial concave window structure, and thus obtain the concave window structure.

[0012] Furthermore, as a preferred technical solution, the obtaining of the phase difference error value between two adjacent slot antennas specifically includes:

[0013] Calculate the ideal phase difference between two adjacent slot antennas;

[0014] Calculate the phase difference between two adjacent slot antennas, and combine the ideal phase difference between two adjacent slot antennas to obtain the phase difference error value between two adjacent slot antennas.

[0015] Furthermore, as a preferred technical solution, the ideal phase difference between two adjacent slot antennas is calculated by the following formula:

[0016]

[0017] where Δph represents the ideal phase difference between two adjacent slot antennas, d represents the equivalent phase center spacing between two adjacent slot antennas, λ represents the air wavelength, and θ represents the electromagnetic wave incident angle.

[0018] Furthermore, as a preferred technical solution, during the calculation of the ideal phase difference between two adjacent slot antennas, it is defaulted that the equivalent phase center of the slot antenna coincides with the geometric center.

[0019] Furthermore, as a preferred technical solution, the calculation of the phase difference between two adjacent slot antennas specifically includes:

[0020] Obtain the phase curves of two adjacent slot antennas through simulation or actual measurement;

[0021] Perform a difference operation on the phase curves of two adjacent slot antennas to obtain the phase difference between two adjacent slot antennas.

[0022] Furthermore, as a preferred technical solution, the first range is set to be less than or equal to 5°; that is, the phase difference error curve between two adjacent slot antennas fluctuates within a range of 5° around 0.

[0023] Furthermore, as a preferred technical solution, the obtaining of the determined center offset value specifically includes the following steps:

[0024] Set the center offset value of the initial concave window structure;

[0025] Calculate the ideal phase difference between two adjacent slot antennas with an initial concave window structure according to the center offset value of the initial concave window structure;

[0026] When the phase difference error value between the ideal phase difference of two adjacent slot antennas with an initial concave window structure and the phase difference of the two adjacent slot antennas is within a first range, determine that the determined center offset value of the initial concave window structure is half of the set center offset value of the initial concave window structure.

[0027] Furthermore, as a preferred technical solution, the width and length of the initial concave window structure are the same as the width and length of the slot antenna, and the depth of the initial concave window structure is set to 0.3 - 1.5 mm.

[0028] Furthermore, as a preferred technical solution, the slot antenna is an asymmetric wide - plane longitudinal slot antenna.

[0029] A slot antenna includes a metal cavity layer, a slot layer disposed above the metal cavity layer, and a correction layer disposed above the slot layer. A first concave window structure is provided on the correction layer, and the first concave window structure is located above the slot on the slot layer for correcting the equivalent phase center of the slot antenna so that the equivalent phase center of the slot antenna coincides with the geometric center.

[0030] Furthermore, as a preferred technical solution, a second concave window structure having the same structure as the first concave window structure is further provided on the correction layer. The second concave window structure is located on both sides of the slot on the slot layer for correcting the spatial coupling of the slot antenna so that the channel amplitudes of the slot antenna are consistent.

[0031] Furthermore, as a preferred technical solution, both the first concave window structure and the second concave window structure can be square - shaped, circular - shaped, trapezoidal - shaped or elliptical - shaped; neither the first concave window structure nor the second concave window structure blocks all the slots on the slot layer.

[0032] Furthermore, as a preferred technical solution, the first concave window structure can be obtained by using the phase error correction method of a slot antenna according to any one of claims 1 - 10.

[0033] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0034] The present invention corrects the equivalent phase center of the slot antenna to coincide with the geometric center by providing a concave window structure above the slot antenna, thereby optimizing the angle - measuring performance of the radar antenna.

[0035] In addition, the radiation pattern of the radar antenna can be finely adjusted by adjusting the position and shape of the concave window structure to further optimize the angular resolution of the radar antenna. Description of the Drawings

[0036] Figure 1 It is a flowchart of the steps of a method for correcting the phase error of a slot antenna provided by the present invention.

[0037] Figure 2 It is a flowchart of the steps for setting the concave window structure of a method for correcting the phase error of a slot antenna provided by the present invention.

[0038] Figure 3 It is a flowchart of the steps for calculating the phase difference error value in a method for correcting the phase error of a slot antenna provided by the present invention.

[0039] Figure 4 It is a flowchart of the steps for calculating the central offset value determined for the initial concave window structure in a method for correcting the phase error of a slot antenna provided by the present invention.

[0040] Figure 5 It is a schematic diagram of a slot antenna used in a method for correcting the phase error of a slot antenna provided by the present invention.

[0041] Figure 6 It is a schematic diagram of the "window" structure of a slot antenna used in a method for correcting the phase error of a slot antenna provided by the present invention.

[0042] Figure 7 It is a schematic diagram of the equivalent phase center and geometric center of a slot antenna before setting the concave window structure in a method for correcting the phase error of a slot antenna provided by the present invention.

[0043] Figure 8 It is a schematic diagram of the equivalent phase center and geometric center of a slot antenna after setting the concave window structure in a method for correcting the phase error of a slot antenna provided by the present invention.

[0044] Figure 9 It is a schematic diagram of the equivalent phase center and geometric center of two adjacent slot antennas before setting the concave window structure in a method for correcting the phase error of a slot antenna provided by the present invention.

[0045] Figure 10 It is a schematic diagram of the equivalent phase center and geometric center of two adjacent slot antennas after setting the concave window structure in a method for correcting the phase error of a slot antenna provided by the present invention.

[0046] Figure 11 It is a phase difference curve diagram taking the spacing of 1.5λ as an example for two adjacent slot antennas before setting the concave window structure in a method for correcting the phase error of a slot antenna provided by the present invention.

[0047] Figure 12The difference between the phase difference calculated according to different phase centers before the concave window structure is set for two adjacent slot antennas in a phase error correction method for a slot antenna provided by the present invention and the ideal phase difference.

[0048] Figure 13 The difference between the phase difference calculated according to different phase centers after the concave window structure is set for two adjacent slot antennas in a phase error correction method for a slot antenna provided by the present invention and the ideal phase difference.

[0049] Figure 14 A cross-sectional view of a slot antenna provided by the present invention.

[0050] Figure 15 A schematic structural diagram of two adjacent slot antennas of a slot antenna provided by the present invention before the concave window structure is set.

[0051] Figure 16 A schematic structural diagram of two adjacent slot antennas of a slot antenna provided by the present invention after the concave window structure is set.

[0052] Figure 17 A cross-section of two adjacent slot antennas of a slot antenna provided by the present invention after the concave window structure is set.

[0053] Figure 18 The azimuth plane pattern of two adjacent slot antennas of a slot antenna provided by the present invention before the concave window structure is set, taking a spacing of 2λ as an example.

[0054] Figure 19 The azimuth plane pattern of two adjacent slot antennas of a slot antenna provided by the present invention after the concave window structure is set, taking a spacing of 2λ as an example.

[0055] Figure 20 The phase difference error curve graph of two adjacent slot antennas of a slot antenna provided by the present invention before / after the concave window structure is set, taking a spacing of 2λ as an example.

[0056] The drawings are only for illustrative purposes and should not be construed as a limitation of this patent; for better illustration of this embodiment, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted; the same or similar reference numerals correspond to the same or similar components; the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation of this patent. Detailed implementation manners

[0057] The following elaborates on the preferred embodiments of the present invention in conjunction with the drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined..

[0058] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and cannot be construed as a limitation of this patent.

[0059] In addition, if there are terms such as "first", "second", etc., they are only for descriptive purposes, mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components, and cannot be construed as indicating or implying relative importance.

[0060] Embodiment 1

[0061] This embodiment discloses a method for correcting the phase error of a slot antenna to overcome the problems in the prior art that the non-PCB board antenna with an asymmetric design has an equivalent phase center deviation, which affects the decline of the radar angle measurement performance.

[0062] A method for correcting the phase error of a slot antenna in this embodiment is directed to a slot antenna with an asymmetric structure. Due to the asymmetry of the structure, this type of slot antenna will bring asymmetry to the radiation field, resulting in the deviation of the equivalent phase center of the slot antenna from the geometric center, and further affecting the angle measurement performance of the slot antenna. Therefore, it is necessary to correct the equivalent phase center of the slot antenna with an asymmetric structure.

[0063] Please refer to Figure 1 , which shows a flowchart of the steps of a method for correcting the phase error of a slot antenna provided in this embodiment.

[0064] A method for correcting the phase error of a slot antenna disclosed in this embodiment, as Figure 1 shown, includes the following steps:

[0065] S101. Obtain the phase difference error value between two adjacent slot antennas.

[0066] In this embodiment, the slot antennas used all have the same structure.

[0067] As a preferred embodiment, the slot antenna in this embodiment is described by taking an asymmetric wide-plane longitudinal slot antenna as an example, and specifically, reference can be made to Figure 5As shown, the figure shows a schematic diagram of the slot antenna used in the phase error correction method of the slot antenna in this embodiment. There is a certain deviation between its equivalent phase center and the geometric center, as Figure 7 shown.

[0068] Then, in this step, it is necessary to first obtain the phase difference error value between two adjacent slot antennas to obtain a basis for optimizing the equivalent phase center of the slot antenna pair.

[0069] S102. Open a concave window structure above the slot antenna so that the phase difference error value between two adjacent slot antennas provided with the concave window structure is within a first range, thereby making the equivalent phase center of the slot antenna provided with the concave window structure coincide with the geometric center.

[0070] In this step, it is necessary to set a concave window structure above the slot antenna. The specific parameters of the concave window structure can be determined by virtual simulation or by setting it on multiple slot antennas and then determining according to the simulation results. By setting the concave window structure, the phase difference error value between two adjacent slot antennas is corrected within the first range, thereby making the equivalent phase center of the slot antenna provided with the concave window structure coincide with the geometric center. See Figure 5 and Figure 7 shown.

[0071] Please refer to Figure 2 , the figure shows a flowchart of the setting steps of a concave window structure of a slot antenna provided in this embodiment.

[0072] As Figure 2 shown, the setting of the concave window structure specifically includes:

[0073] S201. Set an initial concave window structure above the slot antenna and obtain the center value of the initial concave window structure.

[0074] In this step, it is necessary to set an initial concave window structure above the slot antenna. The width and length of the initial concave window structure can be the same as those of the slot antenna, and the depth of the initial concave window structure is set within 0.3 - 1.5 mm, and it does not block all the slots on the slot antenna. Through the set initial concave window structure, its center value can be directly obtained.

[0075] S201. Adjust the center offset value of the initial concave window structure according to the phase difference error value between two adjacent slot antennas until the phase difference error value between two adjacent slot antennas provided with the initial concave window structure is within the first range.

[0076] In this step, referring to step S201, since the width and length of the initial concave window structure can be the same as those of the slot antenna, the geometric center of the initial concave window structure coincides with the geometric center of the original slot antenna, thus obtaining the central value of the initial concave window structure. After setting the initial concave window structure, if the position and shape of the initial concave window structure are adjusted, the geometric center of the initial concave window structure can be changed, thereby achieving the purpose of changing the equivalent phase center of the slot antenna.

[0077] Therefore, in this step, it is necessary to adjust the central offset value of the initial concave window structure according to the phase difference error value between two adjacent slot antennas, and then calculate the phase difference error value between two adjacent slot antennas until the phase difference error value between two adjacent slot antennas with the initial concave window structure is within the first range.

[0078] In this embodiment, the first range is set to be less than or equal to 5°.

[0079] It can also be understood that: the phase difference error curve between two adjacent slot antennas is a curve that fluctuates around 0 within a range of 5°, that is Figure 12 the dotted line shown in

[0080] S203. Obtain the determined central offset value of the initial concave window structure, obtain the determined central value of the initial concave window structure, and thus obtain the concave window structure.

[0081] Specifically, in this step, through step S202, the determined central offset value of the initial concave window structure that makes the phase difference error value between two adjacent slot antennas with the initial concave window structure within the first range can be obtained, and then the determined central value of the initial concave window structure is obtained according to the determined central offset value of the initial concave window structure, thereby obtaining the concave window structure. The equivalent phase centers of two adjacent slot antennas with the concave window structure coincide with the geometric centers, as can be seen in Figure 6 and Figure 8 shown.

[0082] Through the above steps, this embodiment can adjust the equivalent phase center of the slot antenna to make it coincide with the geometric center, thereby improving the angle measurement performance of the slot antenna.

[0083] Please refer to Figure 3 , which shows the flowchart of the calculation steps of the phase difference error value in a method for correcting the phase error of a slot antenna provided in this embodiment.

[0084] As Figure 3 shown, the calculation of the phase difference error value between two adjacent slot antennas specifically includes:

[0085] S301. Calculate the ideal phase difference between two adjacent slot antennas.

[0086] In this step, the ideal phase difference between two adjacent slot antennas is calculated by the following formula:

[0087]

[0088] where Δph represents the ideal phase difference between two adjacent slot antennas, d represents the equivalent phase center spacing between two adjacent slot antennas, λ represents the air wavelength, and θ represents the electromagnetic wave incident angle.

[0089] In this embodiment, during the calculation of the ideal phase difference between two adjacent slot antennas, it is defaulted that the equivalent phase center of the slot antenna coincides with the geometric center. Therefore, the above d can also represent the geometric center spacing between two adjacent slot antennas.

[0090] S302. Calculate the phase difference between two adjacent slot antennas.

[0091] In this step, the calculation of the phase difference between two adjacent slot antennas specifically includes:

[0092] Obtain the phase curves of two adjacent slot antennas through simulation or actual measurement.

[0093] Perform a difference operation on the phase curves of two adjacent slot antennas to obtain the phase difference between two adjacent slot antennas.

[0094] For example, if the obtained phase curves of two adjacent slot antennas are ph1 and ph2 respectively, then the phase difference between two adjacent slot antennas is obtained by the following formula:

[0095] ∧oh′ = ph1 - phλ (2)

[0096] where Δph′ represents the phase difference between two adjacent slot antennas.

[0097] In this step, the phase difference curve graph of two adjacent slot antennas can be seen in Figure 11 as shown. The figure shows the phase difference curve graph of two adjacent slot antennas with a spacing of 1.5λ as an example.

[0098] S303. Combine the ideal phase difference between two adjacent slot antennas to obtain the phase difference error value between two adjacent slot antennas.

[0099] This step is specifically: perform a difference operation on the ideal phase difference between two adjacent slot antennas calculated in step S301 and the phase difference between two adjacent slot antennas calculated in step S302, so as to obtain the phase difference error value between two adjacent slot antennas.

[0100] For example, extract the ideal phase difference Δph between two adjacent slot antennas, extract the phase difference Δph′ between two adjacent slot antennas, and the phase difference error value between two adjacent slot antennas is obtained by the following formula:

[0101] Δerror ph = Δph - Δph′ (3)

[0102] Wherein, Δerror-ph represents the phase difference error value between two adjacent slot antennas.

[0103] Please refer to Figure 4 , which shows the flowchart of the calculation steps of the determined center offset value of the initial concave window structure in a phase error correction method for a slot antenna provided in this embodiment.

[0104] As Figure 4 shown, the obtaining of the determined center offset value specifically includes the following steps:

[0105] S401. Set the center offset value of the initial concave window structure.

[0106] In this step, the center offset value of the initial concave window structure can be determined according to the phase difference error value Δerror-ph between two adjacent slot antennas calculated in the above step S303.

[0107] For example, assume that the center offset value of the initial concave window structure is ΔΔd.

[0108] S402. Calculate the ideal phase difference between two adjacent slot antennas with the initial concave window structure according to the center offset value of the initial concave window structure.

[0109] In this step, the ideal phase difference between two adjacent slot antennas with the initial concave window structure can be calculated by formula (1), specifically as follows:

[0110]

[0111] Wherein, Δph″ represents the ideal phase difference between two adjacent slot antennas with the initial concave window structure.

[0112] S403. When the phase difference error value between the ideal phase difference between two adjacent slot antennas with the initial concave window structure and the phase difference between two adjacent slot antennas is within the first range, determine that the determined center offset value of the initial concave window structure is half of the center offset value of the set initial concave window structure.

[0113] This step can be to replace the ideal phase difference between two adjacent slot antennas with the initial concave window structure in formula (4) with the ideal phase difference between two adjacent slot antennas in formula (3), then:

[0114] Δerror-ph = Δph″ - Δph′ (5)

[0115] At this time, by estimating and adjusting the value of Δd, its iterative calculation formulas (4) and (5) are used until the result calculated by formula (5) is within the first range, that is, to obtain Figure 12 the dotted line shown in

[0116] In this embodiment, the first range is set to be less than or equal to 5°. It can also be understood that: the phase difference error curve of two adjacent slot antennas is a curve fluctuating within a range of 5° around 0, that is, Figure 12 the dotted line shown in

[0117] Therefore, in this embodiment, if the asymmetric slot antenna does not have a concave window structure, then there is a certain deviation between its equivalent phase center and the geometric center. As Figure 9 shown, the difference between its phase difference and the ideal phase difference is as Figure 12 shown, with a sloped curve superimposed, indicating that its equivalent phase center does not overlap with the geometric center. After setting the concave window structure, the equivalent phase center of the slot antenna is corrected so that its equivalent phase center overlaps with the geometric center. As Figure 10 shown, the difference between its phase difference and the ideal phase difference tends to zero. As Figure 13 shown, the curve of the difference between the phase difference and the ideal phase difference only fluctuates slightly, indicating that its equivalent phase center overlaps with the geometric center.

[0118] Embodiment 2

[0119] This embodiment discloses a method for correcting the phase error of a slot antenna, which further discloses the shape and position adjustment range of the initial concave window structure on the basis of Embodiment 1.

[0120] In this embodiment, the width and length of the initial concave window structure are the same as those of the slot antenna, and the depth of the initial concave window structure is set to 0.3 - 1.5 mm.

[0121] Then, during the adjustment process, its length has no influence on the phase center, while the width and height have a slight influence on the phase center. Therefore, after obtaining the concave window structure through Embodiment 1, that is, after determining the center position of the concave window structure, the width and height of the concave window structure can be finely adjusted to make the coincidence degree of the positions of the equivalent phase center and the geometric center of the slot antenna higher. That is, the structure of formula (5) in Embodiment 1 tends to zero.

[0122] In addition, in this embodiment, generally speaking, the width of the concave window structure is also limited by the spacing between two adjacent slot antennas. As a preferred embodiment, the width of the concave window structure should at least not block the slots of the slot antenna, and at most be the same as the width of the slot antenna. The maximum width adjustment range generally does not exceed 4 mm, and the height adjustment range is 0.5 - 1.5 mm. Specifically, it still needs to be adjusted according to the specifications of the slot antenna.

[0123] Embodiment 3

[0124] This embodiment discloses a slot antenna. It uses the phase error correction method of a slot antenna in Embodiment 1 to set a concave window structure above the slot antenna and adjust the position of the concave window structure to correct the equivalent phase center of the slot antenna to coincide with the geometric center, so as to optimize the angle measurement performance of the radar antenna.

[0125] Please refer to Figure 14 , which shows a cross-sectional view of a slot antenna provided in this embodiment.

[0126] As Figure 14 shown, a slot antenna disclosed in this embodiment includes a metal cavity layer 1 with a cavity 11, a slot layer 2 arranged above the metal cavity layer 1, and a correction layer 3 arranged above the slot layer 2. A first concave window structure 31 is provided on the correction layer 3. The first concave window structure 31 is located above the slot 21 on the slot layer 2. The first concave window structure 31 is used to correct the equivalent phase center of the slot antenna so that the equivalent phase center of the slot antenna coincides with the geometric center, thereby optimizing the angle measurement performance of the radar antenna.

[0127] Preferably, the first concave window structure 31 in this embodiment can be square, circular, trapezoidal or elliptical. The specific shape is not limited, as long as it does not block all the slots 31 on the slot layer 3 and can correct the equivalent phase center of the slot antenna so that the equivalent phase center of the slot antenna coincides with the geometric center.

[0128] As a preferred embodiment, the first concave window structure 31 in this embodiment can be obtained by using the phase error correction method of a slot antenna described in Embodiment 1, and this embodiment will not repeat the description.

[0129] Embodiment 4

[0130] This embodiment discloses a slot antenna. It uses the phase error correction method of a slot antenna in Embodiment 1 to set a concave window structure above the slot antenna and adjust the position of the concave window structure to correct the equivalent phase center of the slot antenna to coincide with the geometric center, thereby optimizing the angle measurement performance of the radar antenna. At the same time, concave window structures are also set on both sides above the slot antenna to improve the spatial coupling of the slot antenna, thereby achieving the purpose of improving the amplitude consistency of the radar antenna.

[0131] Please refer to Figure 16 , in the figure, there is a schematic structural diagram of two adjacent slot antennas of a slot antenna provided in this embodiment after setting the concave window structure.

[0132] Please refer to Figure 17 , in the figure, there is a cross-sectional view of two adjacent slot antennas of a slot antenna provided in this embodiment after setting the concave window structure.

[0133] As Figure 16 - 17 shown, a slot antenna disclosed in this embodiment includes a metal cavity layer 1 having a cavity 11, a slot layer 2 provided above the metal cavity layer 1, and a correction layer 3 provided above the slot layer 2. A first concave window structure 31 and a second concave window structure 32 are provided on the correction layer 3. The first concave window structure 31 is located above the position where the slot 21 on the slot layer 2 is located. The first concave window structure 31 is used to correct the equivalent phase center of the slot antenna so that the equivalent phase center of the slot antenna coincides with the geometric center, thereby optimizing the angle measurement performance of the radar antenna. The second concave window structure 32 has the same structure as the first concave window structure 31 and is located on both sides of the position where the slot 1 on the slot layer 2 is located. The second concave window structure 32 is used to correct the spatial coupling of the slot antenna so that the channel amplitudes of the slot antenna are consistent.

[0134] In this embodiment, since it is for two adjacent slot antennas, therefore, the second concave window structure 32 is located on the opposite sides and between two adjacent slot antennas, that is, three second concave window structures 32 are opened, and the three second concave window structures 32 are periodically arranged.

[0135] For example, please refer to Figure 15 , in the figure, there is a schematic structural diagram of two adjacent slot antennas of a slot antenna provided in this embodiment before setting the concave window structure. At the same time, please refer to Figure 18 , in the figure, there is an azimuth plane pattern of two adjacent slot antennas of a slot antenna provided in this embodiment before setting the concave window structure with a spacing of 2λ as an example. It can be seen from this figure that before the concave window structure is set on the slot antenna, due to spatial coupling, the jitter is obvious and there is a situation of amplitude inconsistency.

[0136] However, please refer to Figure 19, the figure shows the azimuth pattern of a pair of adjacent slot antennas provided in this embodiment with a concave window structure at a spacing of 2λ. It can be seen from this figure that after the concave window structure is set on the slot antenna, the simulation curve is smooth and the amplitude consistency of the slot antenna is significantly improved.

[0137] Refer again to Figure 20 , the figure shows the phase difference error curve of a pair of adjacent slot antennas provided in this embodiment before / after setting the concave window structure at a spacing of 2λ. It can be seen from this figure that after the concave window structure is set on the slot antenna, the phase consistency of the slot antenna is significantly improved.

[0138] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for correcting the phase error of a slot antenna, characterized in that It includes the following steps: Obtain the phase difference error value between two adjacent slot antennas; Open a concave window structure above the slot antenna, and the central position of the concave window structure is determined by the phase difference error value between two adjacent slot antennas, so that the equivalent phase center of the slot antenna provided with the concave window structure coincides with the geometric center; The setting of the concave window structure specifically includes: Set an initial concave window structure above the slot antenna and obtain the central value of the initial concave window structure; Adjust the central offset value of the initial concave window structure according to the phase difference error value between two adjacent slot antennas until the phase difference error value between two adjacent slot antennas provided with the initial concave window structure is within a first range; Obtain the determined central offset value of the initial concave window structure, obtain the determined central value of the initial concave window structure, and thus obtain the concave window structure; Wherein, the width of the initial concave window structure is the same as the width of the slot antenna, and the length of the initial concave window structure is the same as the length of the slot antenna.

2. A method for correcting the phase error of a slot antenna according to claim 1, characterized in that, The obtaining of the phase difference error value between two adjacent slot antennas specifically includes: Calculate the ideal phase difference between two adjacent slot antennas; Calculate the phase difference between two adjacent slot antennas; Combine the ideal phase difference between two adjacent slot antennas to obtain the phase difference error value between two adjacent slot antennas.

3. A method for correcting the phase error of a slot antenna according to claim 2, characterized in that, The ideal phase difference between two adjacent slot antennas is calculated by the following formula: ； Among them, represents the ideal phase difference between two adjacent slot antennas, represents the equivalent phase center spacing between two adjacent slot antennas, λ represents the air wavelength, and θ represents the incident angle of the electromagnetic wave.

4. A method for correcting the phase error of a slot antenna according to claim 3, characterized in that During the calculation of the ideal phase difference between two adjacent slot antennas, it is defaulted that the equivalent phase center of the slot antenna coincides with the geometric center.

5. A method for correcting the phase error of a slot antenna according to claim 2, characterized in that, The calculation of the phase difference between two adjacent slot antennas specifically includes: Obtain the phase curves of two adjacent slot antennas through simulation or actual measurement; Perform a difference operation on the phase curves of two adjacent slot antennas to obtain the phase difference between two adjacent slot antennas.

6. A method for correcting the phase error of a slot antenna according to claim 1, characterized in that The first range is set to be less than or equal to 5°; that is, the phase difference error curve between two adjacent slot antennas fluctuates within a range of 5° around 0.

7. A method for correcting the phase error of a slot antenna according to claim 2, characterized in that, The obtaining of the determined central offset value specifically includes the following steps: Set the central offset value of the initial concave window structure; Calculate the ideal phase difference between two adjacent slot antennas with the initial concave window structure according to the central offset value of the initial concave window structure; When the phase difference error value between the ideal phase difference between two adjacent slot antennas with the initial concave window structure and the phase difference between two adjacent slot antennas is within the first range, determine that the determined central offset value of the initial concave window structure is half of the set central offset value of the initial concave window structure.

8. A phase error correction method for a slot antenna according to claim 1, characterized in that, The width and length of the initial concave window structure are the same as the width and length of the slot antenna, and the depth of the initial concave window structure is set to 0.3 - 1.5 mm.

9. A method for correcting the phase error of a slot antenna according to claim 1, characterized in that, The slot antenna is an asymmetric wide planar longitudinal slot antenna.

10. A slot antenna, characterized in that, It includes a metal cavity layer, a slot layer provided above the metal cavity layer, and a correction layer provided above the slot layer. A first concave window structure is provided on the correction layer, and the first concave window structure is located above the slot on the slot layer for correcting the equivalent phase center of the slot antenna so that the equivalent phase center of the slot antenna coincides with the geometric center; The first concave window structure is obtained by using a phase error correction method for a slot antenna according to any one of claims 1 - 9.

11. A slot antenna according to claim 10, wherein, A second concave window structure having the same structure as the first concave window structure is further provided on the correction layer. The second concave window structure is located on both sides of the gap on the gap layer for correcting the spatial coupling of the slot antenna so that the channel amplitudes of the slot antenna are consistent.

12. A slot antenna according to claim 11, characterized in that, Both the first concave window structure and the second concave window structure can be square, circular, trapezoidal or elliptical; neither the first concave window structure nor the second concave window structure blocks all the gaps on the gap layer.

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