A waveguide slot antenna, antenna array, detection device and information system

Abstract

The utility model relates to antenna technical field, especially in a waveguide slot antenna, antenna array, detection equipment and information system. Waveguide slot antenna includes slow wave structure and radiating structure, and slow wave structure includes the serpentine cavity and first feed coupling slit formed by the first rectangular straight waveguide unit and multiple connecting waveguide units of multiple parallel settings, and radiating structure includes multiple parallel settings second rectangular straight waveguide unit, second feed coupling slit and radiating slot, and second feed coupling slit is coupled with first feed coupling slit, and slow wave structure feeds into electromagnetic wave to radiating structure through first and second feed coupling slit, and radiating structure radiates electromagnetic wave outward through radiating slot, can realize the reduction of the beam's minor lobe under the high frequency application scene, improves antenna gain and energy utilization efficiency.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology, and in particular to a waveguide slot antenna, antenna array, detection device, and information system. Background Technology

[0002] Waveguide slot antennas are commonly used in beam scanning scenarios. In typical waveguide slot antennas, a single slot is usually formed on a rectangular straight waveguide, with the slot centers arranged along a straight line to form a slot radiation array. When using this approach, to achieve beam scanning, multiple slot array antennas are usually connected in parallel via a power divider. The disadvantages of this approach are: firstly, the beam is relatively wide, making precise directivity impossible; secondly, the combination of multiple antenna arrays significantly increases the overall size and complexity; and thirdly, the introduction of the power divider inevitably leads to power loss, resulting in a reduction in antenna gain. Utility Model Content

[0003] To overcome the shortcomings of the aforementioned beam-scanning antenna schemes, such as wide beamwidth, large size, and low gain, it is necessary to solve the technical problem of how to obtain a narrower beam direction, smaller antenna size, and higher antenna gain in beam-scanning antennas.

[0004] To address the aforementioned technical problems, a waveguide slot antenna, a corresponding antenna array, a detection device, and a signal system are proposed herein.

[0005] The waveguide slot antenna proposed here includes a slow-wave structure and a radiating structure; The slow-wave structure includes multiple first rectangular straight waveguide units and multiple connecting waveguide units; the multiple first rectangular straight waveguide units are arranged in parallel, and adjacent first rectangular straight waveguide units are connected by the connecting waveguide units to form a serpentine cavity; the slow-wave structure is distributed along the plane containing the narrow side of the first rectangular straight waveguide unit; a first feed coupling slot is formed on the narrow side of the first rectangular straight waveguide unit; The radiating structure includes multiple second rectangular straight waveguide units; the narrow side of the second rectangular straight waveguide unit is correspondingly disposed on the narrow side of the first rectangular straight waveguide unit; the second rectangular straight waveguide unit has a second feed coupling slot on one of its narrow sides, and the second feed coupling slot is coupled to the first feed coupling slot; a set of radiating slots is formed on the other narrow side of the second rectangular straight waveguide unit. The slow-wave structure feeds electromagnetic waves into the radiating structure through the first and second feed coupling gaps, and the radiating structure radiates electromagnetic waves outward through the radiation gaps.

[0006] An antenna array, including the waveguide slot antenna as described above, is also proposed here.

[0007] A detection device is also proposed herein, comprising an antenna array for transmitting detection signals and / or receiving return signals of detection signals, the antenna array comprising the waveguide slot antenna as described above.

[0008] An information system, including a detection device and a signal processing device, is also proposed here. The detection device includes a radio frequency front-end assembly and an antenna array; the detection device is used to detect a target by transmitting a detection signal based on frequency scanning and receiving a return signal of the detection signal; The radio frequency front-end component includes at least one of a signal amplification module, a mixing module, and a filtering module; the radio frequency front-end component is used to preprocess the probe signal before transmission and to preprocess the returned signal of the probe signal after reception. The antenna array includes a waveguide slot antenna as described above, and the antenna array is used to transmit a detection signal and / or receive a return signal of the detection signal; The signal processing device includes a processing and analysis module; the signal processing device is used to obtain target detection information based on the detection signal and the return signal, the detection information including one or more of the target's distance information, position information and spatial information.

[0009] The technical solution provided here has the following beneficial effects: 1. By opening a set of radiating slots on a rectangular straight waveguide, the number of radiating elements is increased and the beamwidth is reduced without having to increase the antenna size. This effectively reduces the antenna size for the same number of radiating elements and beamwidth. 2. By using a slow-wave structure instead of a traditional power divider or power divider network for power feeding, a wide-angle frequency sweep is achieved, reducing power loss and improving antenna gain; 3. By creating radiation slots on the narrow side of a rectangular straight waveguide, the spacing between adjacent slots on adjacent rectangular straight waveguides meets the low sidelobe requirement, thereby reducing beam sidelobes and improving antenna gain and energy utilization efficiency in high-frequency applications. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0011] Figure 1 This is a three-dimensional schematic diagram of the cross-section of a rectangular waveguide; Figure 2This is a three-dimensional schematic diagram of a serpentine waveguide structure; Figure 3 A planar schematic diagram of a slow-wave structure of a waveguide slot antenna provided in an embodiment of this application; Figure 4 for Figure 4 Enlarged structural diagram of region Z in the middle; Figure 5 This application provides a schematic diagram of the structure of a second rectangular straight waveguide unit for a waveguide slot antenna. Figure 6 This is a planar schematic diagram of a slow-wave structure provided in an embodiment of this application; Figure 7A The figure shows the Taylor distribution curve of the radiation excitation amplitude of the slit. Figure 7B The image shown corresponds to Figure 7A The normalized admittance distribution curve of the gap; Figure 8A A planar schematic diagram of a waveguide slot antenna provided for an embodiment of this application; Figure 8B A schematic planar view of another waveguide slot antenna provided in an embodiment of this application; Figure 8C A schematic planar view of another waveguide slot antenna provided in an embodiment of this application; Figure 9A A side view showing the coupling of the first and second power supply coupling slots through a coupling cavity, as provided in an embodiment of this application. Figure 9B A top view showing the coupling of the first and second power supply coupling slots through a coupling cavity, as provided in the embodiments of this application. Figure 9C A side view of another first power supply coupling slot and a second power supply coupling slot coupled through a coupling cavity, provided in an embodiment of this application; Figure 9D A top view of another first power supply coupling slot and a second power supply coupling slot coupled through a coupling cavity, provided in an embodiment of this application; Figure 10A A schematic diagram of the layering of a three-layer metal waveguide slot antenna provided in an embodiment of this application; Figure 10B for Figure 10A A layered schematic diagram from another perspective of the embodiment; Figure 11 This is the frequency scan pattern of the waveguide slot antenna along the extension direction in the embodiments of this application; Figure 12A This is the radiation pattern of the waveguide slot antenna in the embodiment of this application at a frequency of frequency scanning; Figure 12B This is the radiation pattern of the waveguide slot antenna in this application embodiment at another frequency of the frequency scan; Figure 13 This is a structural block diagram of the detection device provided in the embodiments of this application; Figure 14 A structural block diagram of the information system provided in the embodiments of this application; Figure 15 This is a structural block diagram of the signal processing apparatus provided in the embodiments of this application; Figure 16 A three-dimensional structural diagram of a slow-wave structure provided in an embodiment of this application; Figure 17 This is a three-dimensional structural diagram of another slow-wave structure provided in an embodiment of this application.

[0012] In the attached figures: 100 - slow wave structure; 110 - first rectangular straight waveguide unit; 120 - connecting waveguide unit; 111 - first feed coupling slot; α - first tilt angle; 130 - first metal layer; 131 - serpentine groove; 140 - second metal layer; 141 - feed coupling via slot; 150 - third metal layer; 151 - rectangular groove; 200 - radiation slot; 210 - second rectangular straight waveguide unit; 211 - second feed coupling slot; 212 - radiation slot; β - second tilt angle; 300 - information system; 310 - detection device; 311 - radio frequency front-end assembly; 3111 - signal amplification module; 3112 - mixer module; 3113 - filter module; 312 - antenna array; 320 - signal processing device; 321 - processing and analysis module; 1201 - first connecting waveguide unit; 1202 - second connecting waveguide unit; coupling part 23. Detailed Implementation

[0013] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0014] It should be noted that the terms "vertical," "horizontal," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0016] A waveguide structure is an electromagnetic energy transmission device that uses waveguide walls to enclose a waveguide cavity within which electromagnetic energy is transmitted. A rectangular waveguide is a common waveguide structure, such as... Figure 1 As shown, the cavity of a rectangular waveguide typically has a rectangular cross-section with a wide side 'a' and a narrow side 'b', where 'a' > 'b'. The waveguide structure is usually positioned in electronic devices with the wide side 'a' as the base. It should be noted that the wide and narrow sides of a waveguide are common technical terms in this field, not specific definitions used herein.

[0017] Regardless of whether the waveguide is laid out with wide side a or narrow side b, the plane containing the corresponding bottom surface can be called the waveguide's distribution plane or layout plane.

[0018] When a slot is made in the wall of the waveguide, electromagnetic waves entering the waveguide cavity can radiate outward from the slot, thus forming a waveguide slot antenna.

[0019] Waveguide slot antennas are often used in beam scanning, but existing waveguide slot antenna schemes have relatively wide beams, resulting in a large overall size and complexity when constructing antenna arrays. Furthermore, the use of power dividers leads to power loss, which in turn reduces antenna gain.

[0020] To overcome the aforementioned shortcomings, a waveguide slot antenna is needed that can be applied to beam scanning scenarios, addressing the technical challenges of narrowing the beam, reducing antenna size, and improving antenna gain. Therefore, a waveguide slot antenna is proposed here, comprising a slow-wave structure and a radiating structure. The slow-wave structure includes multiple first rectangular straight waveguide units and multiple connecting waveguide units; the multiple first rectangular straight waveguide units are arranged in parallel, and adjacent first rectangular straight waveguide units are connected by the connecting waveguide units to form a serpentine cavity; the slow-wave structure is distributed along the plane containing the narrow side of the first rectangular straight waveguide unit; a first feed coupling slot is formed on the narrow side of the first rectangular straight waveguide unit; The radiating structure includes multiple second rectangular straight waveguide units; the narrow side of the second rectangular straight waveguide unit is correspondingly disposed on the narrow side of the first rectangular straight waveguide unit; the second rectangular straight waveguide unit has a second feed coupling slot on one of its narrow sides, and the second feed coupling slot is coupled to the first feed coupling slot; a set of radiating slots is formed on the other narrow side of the second rectangular straight waveguide unit. The slow-wave structure feeds electromagnetic waves into the radiating structure through the first and second feed coupling gaps, and the radiating structure radiates electromagnetic waves outward through the radiation gaps.

[0021] Figure 2 A specific embodiment of a waveguide slot antenna is shown from the slow-wave structure side, having a slow-wave structure 100 and a radiating structure 200, wherein the slow-wave structure 100 includes a plurality of mutually parallel first rectangular straight waveguide elements 110 and a plurality of connecting waveguide elements 120, and the radiating structure 200 includes a plurality of second rectangular straight waveguide elements 210.

[0022] In one specific implementation, such as Figure 3 As shown, the slow-wave structure 100 includes multiple first rectangular straight waveguide units 110 and multiple connecting waveguide units 120; the multiple first rectangular straight waveguide units 110 are parallel to each other, and adjacent first rectangular straight waveguide units 110 are connected by connecting waveguide units 120 to form a through serpentine cavity; the slow-wave structure 100 is distributed along the plane containing the narrow side of the first rectangular straight waveguide units 110, as shown in the figure. Figure 3 The planar schematic shown represents the waveguide wall where the narrow side of the first rectangular straight waveguide unit 110 is located, and a first feed coupling slot 111 is provided on this narrow side.

[0023] It is important to note that the waveguide slot antennas shown in the accompanying figures should be understood as representing the relationship between the waveguide cavity structure and the slots, rather than the waveguide's outer wall structure or external contour. For example, the spacing S refers to the distance between the cavities of adjacent first rectangular straight waveguide units, not the distance between the outer walls of the waveguide.

[0024] In one specific implementation, such as Figure 5 As shown, the radiation structure 200 includes a second rectangular straight waveguide unit 210. The second rectangular straight waveguide unit 210 has a second feed coupling slot 211 on one narrow side and a set of radiation slots 212 on the other narrow side.

[0025] In an embodiment, a set of radiation slots 212 may include 2, 3, 4 or more radiation slots.

[0026] like Figure 3As shown, the slow wave structure 100 is distributed on the plane of the narrow side of the radiating structure 200. When the antenna is deployed, the narrow side of the second rectangular straight waveguide unit 210 of the radiating structure 200 is correspondingly set on the narrow side of the first rectangular straight waveguide unit, and the second feed coupling slot 211 is coupled with the first feed coupling slot 111. Thus, the electromagnetic waves in the slow wave structure 100 are fed into the second rectangular straight waveguide unit through the first and second feed coupling slots 111 and 211, and radiated outward through the radiating slot 212.

[0027] Along the extension direction, the centers of adjacent first feed coupling slots 111 are spaced by a distance d. In the beam scanning field, to eliminate beam grating lobes, the distance d theoretically needs to satisfy the following condition: d≤ d max ； in, d max To eliminate the maximum spacing value of the grid lobes, θ Maximum scanning angle; λ Let λ be the spatial wavelength and N be the number of array elements. From the above formula, it can be seen that when other parameters remain constant, the larger the maximum scanning angle, the smaller the maximum spacing value for eliminating grating lobes.

[0028] Assuming the maximum scanning angle reaches ±90 degrees, and the number of array elements is sufficiently large, i.e., (1-1 / N) is close to equal to 1, then... d max Approximately 1 / 2 λ Therefore, the spacing between array elements is no greater than 1 / 2. λ At the same time, it can reduce the generation of grating lobes during large-angle scanning, effectively shape the beam, and further improve the antenna gain.

[0029] When the operating frequency is high, the corresponding operating wavelength is small. d max The operating wavelength is smaller; while when the operating wavelength is lower, the corresponding operating wavelength is larger. d max Relatively large.

[0030] The inventors discovered that in the existing scheme, the wide side a of the waveguide must be greater than 1 / 2 wavelength, and the slot of the waveguide slot antenna is opened on the wide side a. At this time, when constructing an antenna array using multiple wide side slot antennas of the waveguide, in order to ensure that the requirement of reducing the spacing of the grating lobes is met, the large scanning angle of the antenna will be sacrificed or the number of array elements will be increased, and the effect of reducing the grating lobes is limited.

[0031] In this scheme, by opening a first feed coupling slot on the narrow side of the first rectangular straight waveguide, the beam grating lobes radiating outward through the slot can be reduced without sacrificing the maximum scanning angle of the antenna or adding more array elements.

[0032] The waveguide slot antenna includes a slow-wave structure and a radiating structure. A first feed coupling slot is formed on the slow-wave structure, and a second feed coupling slot is formed on the second rectangular straight waveguide of the radiating structure. The first feed coupling slot is defined from the slow-wave structure side, and the second feed coupling slot is defined from the radiating structure side.

[0033] In some embodiments, the first power supply coupling gap and the second power supply coupling gap can be two relatively independent gaps that are coupled to each other; in some embodiments, the first power supply coupling gap and the second power supply coupling gap can also be the same through gap, which are the same through gap defined on different sides.

[0034] Therefore, the "first" and "second" power supply coupling gaps are not a limitation on the number of coupling gaps in this scheme, but rather a definition based on different structural aspects.

[0035] In some embodiments, when the waveguide walls of the narrow sides of the slow-wave structure and the radiating structure are implemented by the same metal layer, the through-slot opened on the metal layer is both the first feed coupling slot and the second feed coupling slot, realizing the feeding of energy from the serpentine cavity of the slow-wave structure to the rectangular straight waveguide cavity of the radiating structure.

[0036] In the electromagnetic field, coupling, broadly speaking, refers to the transfer of energy. The second feed coupling gap is coupled to the first feed coupling gap, meaning that the second feed coupling gap can transfer the energy radiated from the first feed coupling gap into the radiating structure. Energy transfer between cavities can be achieved through direct or indirect connections between different cavities; energy transfer between cavities can also be achieved by setting coupling components, such as coupling cavities, coupling devices, and coupling circuits; coupling can also be achieved through capacitive coupling, inductive coupling, common impedance, etc. The "coupling" in this scheme includes, but is not limited to, the coupling methods listed above.

[0037] By creating a set of two or more radiating slots on a rectangular straight waveguide, the number of radiating elements is increased without changing the size of the rectangular straight waveguide, thereby reducing the beamwidth and reducing the required antenna size for the same number of radiating elements. Placing the radiating slots on the narrow side of the waveguide makes it easier for the spacing between adjacent slots on adjacent rectangular straight waveguides to meet the low sidelobe requirement. This is especially beneficial for high-frequency applications where smaller spacing between adjacent slots is required, thus reducing sidelobes and improving antenna gain and energy efficiency. By using a slow-wave structure instead of a traditional power divider or power divider network for feeding, power loss is reduced and antenna gain is improved.

[0038] According to the foregoing d max As can be seen from the formula, d max Compared to λ The multiple is (1-1 / N) / (1+|sinθ|), where |sinθ| takes values ​​from 0 to 1, N is the number of array elements, the minimum value of N is 2, and the theoretical maximum value can approach infinity. When the number of array elements is very large and |sinθ| is 1, d max Approximately 1 / 2 λ When the number of array elements is 2 and |sinθ| is 1, d max Approximately 1 / 4 λ When the number of array elements is very large and |sinθ| is 0, d max Approximately λ .

[0039] For example, when the scanning angle is ±90 degrees and the number of array elements is large, the maximum value of the element spacing is approximately 1 / 2. λ For example, when the scanning angle is ±90 degrees and the number of array elements is 2, the maximum value of the element spacing is approximately 1 / 4. λ For example, when the scanning angle is set to its extreme value of 0 degrees and the number of array elements is very large, the maximum value of the element spacing is approximately... λ .

[0040] In some embodiments of this scheme, the spacing between the first feed coupling gaps on adjacent first rectangular straight waveguide units along the extension direction is not less than 1 / 4 of the spatial wavelength and not greater than the spatial wavelength.

[0041] In some embodiments of this scheme, the spacing of the first feed coupling slots on adjacent first rectangular straight waveguide units along the extension direction is approximately 1 / 2 spatial wavelength.

[0042] In some embodiments of this scheme, the spacing between the first feed coupling gaps on adjacent first rectangular straight waveguide units along the extension direction is not less than 1 / 4 of the spatial wavelength and not greater than 1 / 2 of the spatial wavelength.

[0043] like Figure 3 As shown, within the distribution plane, the outline of the slow-wave structure 100 meanders like a snake. Generally speaking, like the meandering movement of a snake, the direction of the meandering or extending straight line is defined as the extension direction of the slow-wave structure, that is, as... Figure 3 The direction B shown is defined as the longitudinal direction, which is also the longitudinal direction of the narrow side of the first rectangular straight waveguide unit 110, and is shown as direction A in the figure; there is a gap S between two adjacent first rectangular straight waveguide units 110; the center-to-center distance of the first feed coupling slots 111 respectively provided on the adjacent first rectangular straight waveguide units 110 is d.

[0044] The connecting waveguide unit 120 of the slow-wave structure 100 has a bend, which allows for the connection of the same-side ends of parallel adjacent first rectangular straight waveguide units 110. In this embodiment, the connecting waveguide unit 120 of the slow-wave structure can be configured as follows: Figure 3 The structure shown can be either arc-shaped or rectangular. The former can reduce the voltage standing wave ratio, reduce losses, and correspondingly increase the antenna gain compared to the latter. The connecting waveguide unit 120 can also have other shapes that can achieve connection, not limited to arc or rectangle, and the connecting waveguide unit 120 can also be a combination of different morphological structures.

[0045] Each first feed coupling slot of the slow wave structure is respectively disposed on a first rectangular straight waveguide unit. The center of each first feed coupling slot is arranged on a first straight line, which is parallel to the extension direction of the slow wave structure. The extension direction represents the direction in which the serpentine cavity extends meanderingly.

[0046] In a specific embodiment, each first feed coupling slot 111 is respectively disposed on a first rectangular straight waveguide unit 110, specifically including two cases: the first case is that the first feed coupling slot 111 and the first rectangular straight waveguide unit are disposed in a one-to-one correspondence, that is, each first feed coupling slot 111 is located on a first rectangular straight waveguide unit 110, and each first rectangular straight waveguide unit 110 is provided with a first feed coupling slot 111; the second case is that the first feed coupling slot 111 and the first rectangular straight waveguide unit are disposed in a one-to-many manner, that is, not every rectangular straight waveguide unit 110 is provided with a first feed coupling slot unit 111, for example, a first feed coupling slot unit 111 can be provided on every other rectangular straight waveguide unit 110.

[0047] In the first case, each first rectangular straight waveguide unit is provided with a first feed coupling slot 111. Therefore, the first feed coupling slots on adjacent first rectangular straight waveguide units can have a small spacing, approximately the sum of the narrow side width of the first rectangular straight waveguide unit and the spacing S. In the second case, the spacing between the first feed coupling slots on adjacent first rectangular straight waveguide units is several times that in the first case. When applied to high-frequency scenarios, a smaller spacing between slots is required to meet certain conditions. d max In this case, the first approach can be used if the application is to eliminate grating lobes in non-high-frequency scenarios. d max When the beam size is large, or when the requirement to reduce beam grating lobes is not high, the second approach can be adopted.

[0048] The first power supply coupling slots can be arranged on the same straight line parallel to the extension direction, or they can be arranged on different straight lines parallel to the extension direction. Specifically, their arrangement is determined based on the center of the first power supply coupling slot.

[0049] When the first power supply coupling gaps are arranged in a straight line, such as Figure 3 As shown, the center of the first feed coupling gap 111 is located on a first straight line, which is parallel to the extension direction of the slow wave structure 100.

[0050] In some embodiments, the first straight line may be a straight line connecting the centers of each first rectangular straight waveguide unit; the first straight line may also be other straight lines parallel to the extension direction B of the slow wave structure 100.

[0051] When the first feed coupling slots are arranged on different straight lines, at least a portion of the slot centers of the first feed coupling slots are arranged on the first straight line, and at least a portion of the slot centers of the first feed coupling slots are arranged on the second straight line. Both the first and second straight lines are parallel to the extension direction of the slow-wave structure, and the first and second straight lines do not coincide. The extension direction represents the direction in which the serpentine cavity meanders. The case of being located on two straight lines is illustrated here, but it is not limited to two straight lines. There may also be a third, fourth, or more straight lines for arranging the first feed coupling slots.

[0052] The following explanation uses two straight lines as an example. Figure 6 As shown, the first feed coupling slots 111 are distributed on a first straight line and a second straight line parallel to the extension direction, respectively. The first feed coupling slots 111 distributed along the first straight line and the first feed coupling slots 111 distributed along the second straight line are respectively spaced on the first rectangular straight waveguide unit 110.

[0053] It should be noted that the spacing d between the first feed coupling slots on adjacent first rectangular straight waveguide units is the distance between the centers of the two first feed coupling slots along the extension direction, rather than the straight-line distance between the centers of the two slots.

[0054] like Figure 4 The first feed coupling slot 111 shown has a first tilt angle α, which represents the angle between the first feed coupling slot 111 and the longitudinal centerline of the first rectangular straight waveguide unit 110.

[0055] When all the first feed coupling slots 111 are arranged on the same straight line, the first feed coupling slots 111 distributed along the straight line have different first tilt angles, so that the radiation effect of the first feed coupling slots 111 distributed along the first straight line is stronger at the middle position of the slow wave structure than at the two sides.

[0056] Electromagnetic waves radiated from the first feed coupling slot 111 enter the cavity of the second rectangular straight waveguide through the second feed coupling slot, and finally radiate outward through the radiation slot. The radiated electromagnetic waves have a strong beam directionality in space. To reduce beam sidelobes and achieve frequency-based beam scanning, the radiation excitation of the first feed coupling slot needs to satisfy a certain distribution, such as Taylor distribution, Chebyshev distribution, Gaussian distribution, Villeneuve distribution, etc. These distributions are collectively referred to as the low sidelobe synthesis method for array antennas. These distributions all result in the radiation effect of the first feed coupling slot 111, distributed along the first straight line, being stronger at the middle position of the slow-wave structure than at the two sides.

[0057] According to equivalent circuit theory, a set of rectangular slot waveguides with N slots can be equivalent to a parallel admittance circuit, where N is a natural number greater than or equal to 2, corresponding to N equivalent normalized admittances g1, g2, ... g N and equivalent normalized loss admittance g L Assuming the radiation efficiency is η and the total input power is... P in The total radiated power is P r The power loss is P L , No. i The radiated power on each slit is f i ,in i = 1, 2, ... N.

[0058] When the slot spacing is equal and transmission loss and mutual coupling between straight waveguide segments are neglected, the following relationship is satisfied: The equivalent normalized admittance g of the Nth gap N The following relationship must be satisfied: The equivalent normalized admittance of the (N-1)th gap satisfies the following relationship: The equivalent normalized admittance of the i-th gap satisfies the following relationship: Due to the radiation power on the radiation slit f i Proportional to the square of the radiated excitation amplitude, when the antenna radiated efficiency η is determined, the power parameter of each radiated slot can be derived from the distribution relationship satisfied by the radiated excitation amplitude. The equivalent normalized admittance value of each radiated slot can be obtained using the power parameter, and then the tilt angle of the radiated slot can be determined using the equivalent normalized admittance value.

[0059] Generally speaking, the distribution relationship is a function of one or more radiation parameters, including but not limited to the number of slits, the number of sidelobes, and the sidelobe level.

[0060] When the distribution is a Taylor distribution, the distribution is a function of the number of slits, the number of sidelobes, and the sidelobe level. The sidelobe level represents the power ratio of the maximum sidelobe value to the maximum main lobe value. For example, when the sidelobe level is 30dB, it means that the sidelobe is 30dB lower than the main lobe.

[0061] In one specific embodiment, the number of gaps is used as... M The number of side lobes is indicated by... K Indicates that the sidelobe level is used B The identifier and the radiative excitation of the slit conform to the distribution function. F , F yes M , K and B One or more functions in the list, with specific steps including: Based on the fact that the radiation excitation amplitude of the radiative slot satisfies the function F, and based on predetermined design parameters, such as the pre-set values ​​of the number of sidelobes K and the sidelobe level B, the normalized radiative excitation amplitudes of this group of slots are calculated as follows: A 1, A 2, ..., A M ; The normalized radiated power is obtained by squared-and normalized the amplitude of the normalized slit radiation excitation. , ,......, ; Multiplying the normalized radiated power by the radiated efficiency η yields the actual normalized radiated power value for each slot, considering antenna loss. , ,......, ; Using the sum of these actual normalized radiated power values, the actual normalized loss radiated power value is calculated to be 1 - ( + + ...... + ); Pick f i Equal to the actual normalized radiated power value of each slit, taken as P L It equals the actual normalized loss radiated power value, according to the formula To calculate the equivalent normalized admittance on each gap; The slot angle of each slot is calculated using the slot tilt angle formula for waveguide slot antennas. The formula for the slot tilt angle is as follows: In the above formula, This represents the weighted normalized admittance distribution of each waveguide element in the antenna; a represents the wide side dimension of the waveguide; b represents the narrow side dimension of the waveguide. Indicates the waveguide wavelength; Indicates spatial wavelength; This indicates the angle of inclination of the inclined gap relative to the longitudinal direction.

[0062] This method can be used to calculate the tilt angle of a row or column of slits, such that the radiation excitation amplitude on the row or column of slits satisfies the distribution relationship F.

[0063] In some embodiments, this calculation method can be used to calculate the first tilt angle of the first feed coupling slot and / or the second tilt angle of the radiation slot.

[0064] In some embodiments, the first tilt angle of the first feed coupling slot is determined based on the radiation excitation amplitude of the first feed coupling slot and the normalized admittance formula, wherein the radiation excitation amplitude of the first feed coupling slot satisfies the low sidelobe synthesis method of the antenna array along the first straight line.

[0065] In some embodiments, when the waveguide slot antenna needs to perform frequency scanning along the longitudinal direction, the second tilt angle of the radiating slot is determined based on the radiating excitation amplitude of the radiating slot and the normalized admittance formula, wherein the radiating excitation amplitude of the radiating slot along the longitudinal direction satisfies the low sidelobe synthesis method of the antenna array.

[0066] In some embodiments, such as Figure 7AAs shown, the radiative excitation amplitude of the slits satisfies the Taylor distribution method in the extension direction or longitudinal direction. Accordingly, the normalized admittance of each slit along the extension direction or longitudinal direction can be derived. Figure 7B As shown.

[0067] Each second rectangular straight waveguide unit is provided with a set of radiation slots, and each set of radiation slots includes n radiation slots, where n is a natural number greater than or equal to 2; the centers of the radiation slots are respectively arranged along the longitudinal center line of the narrow side of the second rectangular straight waveguide unit, and along n straight lines parallel to the extension direction.

[0068] By opening a set of radiation slots on multiple parallel second rectangular straight waveguide units 210, the beam directivity can be further improved, the antenna size can be reduced, and the antenna gain can be increased compared to a waveguide slot antenna with only a single slot.

[0069] The radiation array is composed of various groups of radiation slots, wherein each array element is arranged according to a certain rule. The center of the array element is arranged along the extension direction on n straight lines parallel to the extension direction, where n is equal to the number of each group of radiation slots and n is a natural number greater than or equal to 2. The center of the array element is arranged along the longitudinal direction on the longitudinal center line of each second rectangular straight waveguide unit 210.

[0070] Figure 7A , 7B Two specific embodiments are shown, wherein the centers of the radiating slots 212 are respectively arranged on the longitudinal center line of each second rectangular straight waveguide unit 210 and on 6 straight lines parallel to the extension direction, and each group of radiating slots 212 on each second rectangular straight waveguide unit includes 6 radiating slots 212.

[0071] The radial slot has a second tilt angle, which represents the angle between the radial slot and the longitudinal center line of the narrow side; the same group of radial slots has different second tilt angles, and the second tilt angles of adjacent radial slots are angled in opposite directions relative to the longitudinal center line of the narrow side.

[0072] like Figure 5 As shown, the radiating slot 212 has a second tilt angle β, which is the angle relative to the longitudinal centerline of the narrow side. Adjacent radiating slots in the same group have a tilt angle along the longitudinal direction. Since the radiating slots are located on the longitudinal centerline of the second rectangular straight waveguide, the spacing is... d’ That is, the distance between the longitudinal centerlines of adjacent second rectangular straight waveguides.

[0073] In some embodiments, when d’When the wavelength is equal to half the waveguide wavelength, the phase difference of the electromagnetic waves between adjacent radiating slots is 180 degrees. At this time, the second tilt angle β of the adjacent slots is opposite to the longitudinal centerline. When the second tilt angle β of the adjacent slots differs by 180 degrees, it cancels out the 180-degree phase difference caused by the longitudinal spacing, making the phase difference of the electromagnetic waves between the adjacent radiating slots 0 degrees. At this time, the beam formed by this set of radiating slots points perpendicular to the plane where the slots are located, achieving the effect of in-phase excitation. When the second tilt angle of the adjacent radiating slots forms an angle in opposite directions relative to the longitudinal centerline of the narrow side, that is, when the second tilt angle β of the adjacent slots differs by equal to or close to 180 degrees, when... Figure 5 As shown, at this time, the adjacent radiation gaps are in the shape of an "eight" or approximately the shape of an "eight".

[0074] In some embodiments, d’ It can be different from 1 / 2 waveguide wavelength; for example, it can be less than or greater than 1 / 2 waveguide wavelength. Generally, when using a standing wave design, the longitudinal spacing of the radiation slots is taken as close to 1 / 2 waveguide wavelength; when using a traveling wave design, it is less than or greater than 1 / 2 waveguide wavelength.

[0075] The electromagnetic wave in the second rectangular straight waveguide can be a traveling wave or a standing wave.

[0076] In some embodiments, the electromagnetic wave in the second rectangular straight waveguide is a traveling wave, and an end-fed coupling method can be used. At one end of the second rectangular straight waveguide along the longitudinal direction A, the electromagnetic wave signal is coupled through a slow-wave structure, and a matching load is connected at the end, such as... Figure 8B and 8C As shown. The spacing between adjacent radiating slots on each second rectangular straight waveguide is set. d The value is not less than 1 / 4 of the waveguide wavelength and not greater than 3 / 4 of the waveguide wavelength, so that the reflected waves generated by each radiation gap will not produce a large standing wave due to the superposition of waves in the same direction.

[0077] In some embodiments, the electromagnetic wave in the second rectangular straight waveguide is a standing wave. The coupling method is end-fed or center-fed. A short-circuit load is connected to the end of the second rectangular straight waveguide or a short-circuit surface is formed at the end of the second rectangular straight waveguide. The center distance d between adjacent radiating slots on each second rectangular straight waveguide is set to be approximately 1 / 2 waveguide wavelength, so that the radiating slot is located at the peak of the standing wave current.

[0078] In some embodiments, the second rectangular straight waveguide end refers to a position approximately 1 / 4 of the waveguide wavelength away from the center of the radiation slot furthest from the feed end in the longitudinal direction A when using end-feed coupling.

[0079] When the waveguide slot antenna needs to perform frequency scanning along the longitudinal direction, the second tilt angle of the same group of radiating slots should be such that the radiation effect of the group of radiating slots along the longitudinal centerline of the second rectangular straight waveguide unit is stronger at the middle position of the second rectangular straight waveguide unit than at the two ends.

[0080] In order to ensure that the radiation effect along the longitudinal centerline of the second rectangular straight waveguide unit is stronger at the middle position than at both ends, the second tilt angle of the radiation slot is determined based on the radiation excitation amplitude and normalized admittance formula of the radiation slot. The radiation excitation amplitude of the radiation slot along the longitudinal centerline direction satisfies the low sidelobe synthesis method of the antenna array.

[0081] The second tilt angle of the radial slit can be calculated and derived using the method described above.

[0082] According to the aforementioned d max As can be seen from the formula, d max Compared to λ The multiple is (1-1 / N) / (1+|sinθ|), where |sinθ| takes values ​​from 0 to 1, N is the number of array elements, the minimum value of N is 2, and the theoretical maximum value can approach infinity. When the number of array elements is very large and |sinθ| is 1, d max Approximately 1 / 2 λ When the number of array elements is 2 and |sinθ| is 1, d max Approximately 1 / 4 λ When the number of array elements is very large and |sinθ| is 0, d max Approximately λ .

[0083] This applies not only to determining the spacing of the first feed coupling slots along the extension direction on the slow-wave structure, but also to determining the spacing of the radiation slots along the extension direction to reduce or eliminate beam gratings in that direction.

[0084] When beam scanning is performed laterally, the spacing between adjacent radiating slots along the extension direction in a radiation array composed of multiple sets of radiating slots should satisfy the following: d ≤ d max .

[0085] For example, when the scanning angle is ±90 degrees and the number of array elements is large. d max Approximately 1 / 2 λ For example, when the scanning angle is ±90 degrees and the number of array elements is 2, dmax Approximately 1 / 4 λ .

[0086] In some embodiments, the center-to-center distance between adjacent radiation slots located on adjacent second rectangular straight waveguide units is not less than 1 / 4 of the spatial wavelength and not greater than the spatial wavelength.

[0087] In some embodiments, the center-to-center distance between adjacent radiation slots located on adjacent second rectangular straight waveguide units is not less than 1 / 4 of the spatial wavelength and not greater than 1 / 2 of the spatial wavelength.

[0088] In some embodiments, the center-to-center spacing of adjacent radiation slots on adjacent second rectangular straight waveguide units is approximately equal to 1 / 2 of the spatial wavelength.

[0089] In the waveguide slot antenna proposed here, a slow-wave structure feeds the radiating structure. The slow-wave structure includes a first rectangular straight waveguide unit with a first feed coupling slot on its narrow side. The radiating structure includes a second rectangular straight waveguide unit with a second feed coupling slot on its narrow side. By placing the narrow side of the second rectangular straight waveguide unit on the narrow side of the first rectangular straight waveguide unit, the second feed coupling slot is coupled with the first feed coupling slot. This allows electromagnetic energy from the slow-wave structure to be fed into the second rectangular straight waveguide unit through the first and second feed coupling slots and radiated outward through the radiating slot.

[0090] In some embodiments, the first power supply coupling gap and the second power supply coupling gap are coupled by aligning and connecting the gaps; in some embodiments, the first power supply coupling gap and the second power supply coupling gap are coupled by partially aligning and connecting the gaps; in some embodiments, the first power supply coupling gap and the second power supply coupling gap are coupled by connecting the gaps through a coupling structure.

[0091] like Figure 8A , 8B As shown in Figure 8C, the projections of the first and second feed coupling gaps on the distribution plane coincide, and the gaps are aligned and connected vertically.

[0092] In some embodiments, the projections of the first power supply coupling slot and the second power supply coupling slot on the distribution plane do not completely coincide, and the first power supply coupling slot and the second power supply coupling slot are coupled through a coupling cavity.

[0093] like Figure 9A and 9B As shown in Figures 9C and 9D, a coupling cavity is provided between the first power supply coupling gap 111 and the second power supply coupling gap 211, and the first power supply coupling gap and the second power supply coupling gap are respectively connected to the coupling cavity to achieve coupling.

[0094] like Figure 9A and 9B As shown, the projections of the first power supply coupling gap 111 and the second power supply coupling gap 211 on the distribution plane are parallel to each other and do not overlap.

[0095] like Figure 9C and 9D As shown, the projections of the first power supply coupling gap 111 and the second power supply coupling gap 2111 on the distribution plane partially overlap, and the gaps are locally aligned and connected vertically.

[0096] like Figures 9A-9D The illustration shows a specific implementation where the projections of the first and second feed coupling gaps on the distribution plane do not coincide, but it is not limited to this. When the first and second feed coupling gaps are coupled through a coupling structure, they can have other positional relationships. For example, they can also be parallel and have overlapping parts on the distribution plane.

[0097] The slow-wave structure can feed and couple the second rectangular waveguide element at either the middle or end of the second rectangular straight waveguide element. Therefore, the second feed coupling slot can be located at either the middle or end of the second rectangular straight waveguide element.

[0098] In some implementations of slow-wave structures, such as Figures 16 to 17 As shown, the connecting waveguide unit includes a first connecting waveguide unit 1201 and a second connecting waveguide unit 1202. The first rectangular straight waveguide unit 110 has a first end and a second end in its longitudinal direction A. The first end is connected to the first connecting waveguide unit 1201, and the second end is connected to the second connecting waveguide unit 1202. Both the first connecting waveguide unit 1201 and the second connecting waveguide unit 1202 include a turning portion, and at least one of the first connecting waveguide unit 1201 and the second connecting waveguide unit 1202 further includes a coupling portion 23. The coupling portion 23 extends along a direction perpendicular to or inclined to the layout surface of the first rectangular straight waveguide unit 110, so that the layout surface of the turning portion of the first connecting waveguide unit 1201 and / or the second connecting waveguide unit 1202 is not on the same plane as the layout surface within the first rectangular straight waveguide unit 110.

[0099] In some embodiments, such as Figure 17 As shown, in the slow-wave structure, at least one of the first connecting waveguide unit 1201 and the second connecting waveguide unit 1202 connected to the first rectangular straight waveguide unit 110 has a coupling portion 23. Figure 17For example, the first connecting waveguide unit 1201 has a coupling portion 23, which extends obliquely or vertically relative to the layout surface within the first rectangular straight waveguide unit 110, such that at least one of the first connecting waveguide unit 1201 and the second connecting waveguide unit 1202 ( Figure 17 For example, the layout surface of the turning part of the first connecting waveguide unit 1201 is not on the same plane as the layout surface of the first rectangular straight waveguide unit 110. That is, the first rectangular straight waveguide unit 110 has only the second connecting waveguide unit 1202 in the longitudinal direction A along its layout surface, thereby reducing the size of the entire slow wave structure in the longitudinal direction A while meeting the requirements of large-angle scanning.

[0100] In some embodiments, at least one of the first connecting waveguide unit 1201 or the second connecting waveguide unit 1202 may be arranged on another plane parallel to the arrangement surface of the first rectangular straight waveguide unit 110; or, it may be arranged on another plane intersecting the arrangement surface of the first rectangular straight waveguide unit 110.

[0101] Although the layout surface of the turning portion of at least one of the first connecting waveguide unit 1201 and the second connecting waveguide unit 1202 is not on the same plane as the layout surface in the first rectangular straight waveguide unit 110, it is connected to the first rectangular straight waveguide unit 110 through the coupling part 23, thereby reducing the height while still satisfying the transmission characteristics of the slow wave structure.

[0102] Please refer to the previous description for the definition of the layout surface.

[0103] Typically, within the distribution plane or layout plane of a serpentine waveguide structure, the first rectangular straight waveguide unit and the connecting waveguide unit are connected in the longitudinal direction A and located within the same layout plane (or their layout planes overlap).

[0104] The size of waveguide slot antennas is often limited by installation space, such as Figure 8B and 8C As shown, the slow-wave structure extends beyond the outer contour of the radiating structure, which may affect the application and installation of the waveguide slot antenna.

[0105] By “folding back” the connecting waveguide unit 120 relative to the layout surface of the first rectangular straight waveguide unit 110 and maintaining communication through the coupling part 23, the slow wave structure can be adapted.

[0106] In some embodiments, the coupling portion 23 can be implemented by providing a communicating cavity; in some embodiments, in order to achieve better coupling, a recessed or protruding structure can be provided in the coupling portion 23 to reduce coupling loss.

[0107] like Figure 8A ,8B As shown in Figures 8 and 8C, specific implementations are illustrated where the second feed coupling slot is located in the middle or at the end of the second rectangular straight waveguide unit.

[0108] The waveguide slot antenna proposed herein comprises multiple stacked metal layers, and the waveguide slot antenna is formed by creating grooves and slots in the metal layers.

[0109] Waveguide slot antennas, which are constructed by stacking multiple metal layers, are easier to manufacture and install compared to traditional waveguide slot antennas formed by connecting and enclosing metal walls.

[0110] In some embodiments, the waveguide slot antenna includes first, second, and third metal layers stacked sequentially, wherein: The first metal layer is adjacent to the second metal layer. The first metal layer has a serpentine groove on the side adjacent to the second metal layer, so that it fits tightly with the second metal layer to form the serpentine cavity. A through-hole for power feeding coupling is provided on the second metal layer to realize the first and second coupling power feeding gaps through the power feeding coupling through-hole; The third metal layer is adjacent to the second metal layer. The third metal layer has a plurality of spaced rectangular grooves on the side adjacent to the second metal layer, so as to fit tightly with the second metal layer to form the second rectangular straight waveguide unit; the third metal layer is provided with the radiation slot.

[0111] In some embodiments, such as Figure 10A and 10B As shown, the waveguide slot antenna includes first, second, and third metal layers 130, 140, and 150 stacked together. The solid boundaries of the serpentine cavity and the rectangular waveguide are formed by the solid structure of the metal layers.

[0112] like Figure 10B As shown, the first metal layer 130 has a serpentine groove 131 on the side adjacent to the second metal layer 140, so as to form the serpentine cavity by tightly adhering the first metal layer 130 and the second metal layer 140; as Figure 10A and 10B As shown, a through-hole 141 is formed on the second metal layer 140 to realize the first and second coupling feed gaps through the through-hole 141; as Figure 10A and 10B As shown, the third metal layer 150 has a plurality of spaced rectangular grooves 151 on the side adjacent to the second metal layer 140, so as to form the second rectangular straight waveguide unit 210 by the close contact between the second metal layer 140 and the third metal layer 150. The third metal layer 150 is provided with the radiation slot 212.

[0113] For example, the first metal layer 130 and the second metal layer 140 each have corresponding serpentine grooves 131 on their respective adjacent sides, so as to form the serpentine cavity by tightly fitting the first metal layer 130 and the second metal layer 140 together. A through-hole feed coupling via 141 is formed on the second metal layer 140 to realize the first and second coupling feed gaps. The third metal layer 150 and the second metal layer 140 each have a plurality of spaced and corresponding rectangular grooves 151 on their respective adjacent sides, so as to form the second rectangular straight waveguide unit 210 by tightly fitting the second metal layer 140 and the third metal layer 150 together. The third metal layer 150 has the radiation gap 212.

[0114] For example, the second metal layer 140 has a serpentine groove 131 on the side adjacent to the first metal layer 130, which is used to form the serpentine cavity by tightly fitting the first metal layer 130 and the second metal layer 140 together. A through-hole feed coupling via 141 is formed on the second metal layer 140 to realize the first and second coupling feed gaps 111, 211. A plurality of spaced and corresponding rectangular grooves 151 are formed on the side of the second metal layer 140 adjacent to the third metal layer 150, which are used to form the second rectangular straight waveguide unit 210 by tightly fitting the second metal layer 140 and the third metal layer 150 together. The third metal layer 150 has the radiation gap 212.

[0115] It is worth noting that in the aforementioned embodiments, the first, second, and third metal layers 130, 140, and 150 can be formed by stacking multiple metal components as needed to meet thickness requirements. For example, due to thickness requirements, the second metal layer 140 can be formed by stacking two thinner metal components to meet the thickness requirements.

[0116] An antenna array, including the waveguide slot antenna as described above, is also proposed here.

[0117] In some embodiments of the antenna array, waveguide slot antennas are arranged along the extension direction and / or longitudinal direction to form an antenna array based on the waveguide slot antennas.

[0118] A detection device is also proposed herein, characterized by comprising an antenna array for transmitting detection signals and / or receiving return signals of the detection signals, said antenna array comprising the waveguide slot antenna as described above.

[0119] In some embodiments, such as Figure 13As shown, the detection device 310 includes a radio frequency front-end assembly 311 and an antenna array 312. The radio frequency front-end assembly is used to preprocess the detection signal before transmission and to preprocess the return signal of the detection signal after reception. The antenna array 312 is used to transmit the detection signal and / or receive the return signal.

[0120] In some embodiments, the radio frequency front-end component 311 includes at least one of a signal amplification module 3111, a mixer module 3112, and a filter module 3113.

[0121] In some specific embodiments, such as Figure 13 As shown, the radio frequency front-end component 311 includes a signal amplification module 3111, a mixing module 3112, and a filtering module 3113.

[0122] An information system, including a detection device and a signal processing device, is also proposed here. The detection device includes a radio frequency front-end assembly and an antenna array; the detection device is used to detect a target by transmitting a detection signal based on frequency scanning and receiving the return signal of the detection signal; The radio frequency front-end component includes at least one of a signal amplification module, a mixing module, and a filtering module; the radio frequency front-end component is used to preprocess the probe signal before transmission and to preprocess the returned signal of the probe signal after reception. The antenna array includes a waveguide slot antenna as described above, and the antenna array is used to transmit a detection signal and / or receive a return signal of the detection signal; The signal processing device includes a processing and analysis module; the signal processing device is used to obtain target detection information based on the detection signal and the return signal, the detection information including one or more of the target's distance information, position information and spatial information.

[0123] like Figure 14 As shown, the information system 300 includes a detection device 310 and a signal processing device 320. The detection device is used to transmit detection signals and receive return signals from the detection signals, and to perform corresponding preprocessing before transmission and after reception.

[0124] In some embodiments, the detection device, such as Figure 13 As shown, it includes a radio frequency front-end component 311 and an antenna array 312.

[0125] In some embodiments, signal processing devices such as Figure 15 As shown, the signal processing device 320 includes a processing and analysis module 321, which is used to obtain the target's detection information based on the detection signal emitted by the detection device and the return signal received by the detection device. The detection information includes one or more of the target's distance information, position information, and spatial information.

[0126] All articles and references disclosed herein, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified elements, components, parts, or steps, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute included by “may” is optional.

[0127] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the appended claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the inventors have not considered that subject matter as part of the disclosed utility model subject matter.

Claims

1. A waveguide slot antenna, characterized in that: Including slow-wave structures and radiating structures; The slow-wave structure includes multiple first rectangular straight waveguide units and multiple connecting waveguide units; the multiple first rectangular straight waveguide units are arranged in parallel, and adjacent first rectangular straight waveguide units are connected by the connecting waveguide units to form a serpentine cavity; the slow-wave structure is distributed along the plane containing the narrow side of the first rectangular straight waveguide unit; a first feed coupling slot is formed on the narrow side of the first rectangular straight waveguide unit; The radiating structure includes multiple second rectangular straight waveguide units; the narrow side of the second rectangular straight waveguide unit is correspondingly disposed on the narrow side of the first rectangular straight waveguide unit; the second rectangular straight waveguide unit has a second feed coupling slot on one of its narrow sides, and the second feed coupling slot is coupled to the first feed coupling slot; a set of radiating slots is formed on the other narrow side of the second rectangular straight waveguide unit. The slow-wave structure feeds electromagnetic waves into the radiating structure through the first and second feed coupling gaps, and the radiating structure radiates electromagnetic waves outward through the radiating gaps.

2. The waveguide slot antenna according to claim 1, characterized in that, Each first feed coupling slot is respectively disposed on a first rectangular straight waveguide unit, and the center of each first feed coupling slot is arranged on a first straight line, which is parallel to the extension direction of the slow wave structure, and the extension direction represents the direction in which the serpentine cavity extends meanderingly.

3. The waveguide slot antenna according to claim 2, characterized in that, The first feed coupling slot has a first tilt angle, which represents the angle between the first feed coupling slot and the longitudinal centerline of the first rectangular straight waveguide unit. The first feed coupling slots distributed along the first straight line have different first tilt angles, so that the radiation effect of the first feed coupling slots distributed along the first straight line is stronger at the middle position of the slow wave structure than at the two sides.

4. The waveguide slot antenna according to claim 3, characterized in that, The first tilt angle is determined based on the radiation excitation amplitude of the first feed coupling slot and the normalized admittance formula. The radiation excitation amplitude of the first feed coupling slot along the first straight line satisfies the low sidelobe synthesis method of the antenna array.

5. The waveguide slot antenna according to claim 1, characterized in that, Each second rectangular straight waveguide unit is provided with a set of radiation slots, and each set of radiation slots includes n radiation slots, where n is a natural number greater than or equal to 2. The centers of the radiating slots are arranged along the longitudinal centerline of the narrow side of the second rectangular straight waveguide unit, and along n straight lines parallel to the extension direction of the slow wave structure, the extension direction representing the direction in which the serpentine cavity meanders.

6. The waveguide slot antenna according to claim 1 or 5, characterized in that, The radial slot has a second tilt angle, which represents the angle between the radial slot and the longitudinal center line of the narrow side; the same group of radial slots has different second tilt angles, and the second tilt angles of adjacent radial slots are angled in opposite directions relative to the longitudinal center line of the narrow side.

7. The waveguide slot antenna according to claim 6, characterized in that, The same set of radiation slots have different second tilt angles so that the radiation effect along the longitudinal centerline of the second rectangular straight waveguide unit is stronger at the middle position of the second rectangular straight waveguide unit than at the two ends.

8. The waveguide slot antenna according to claim 7, characterized in that, The second tilt angle of the radiating slot is determined based on the radiating excitation amplitude of the radiating slot and the normalized admittance formula. The radiating excitation amplitude of the radiating slot along the longitudinal centerline direction satisfies the low sidelobe synthesis method of the antenna array.

9. The waveguide slot antenna according to claim 1, characterized in that, Each first feed coupling slot is respectively disposed on a first rectangular straight waveguide unit. At least a portion of the slot centers of the first feed coupling slots are arranged on a first straight line, and at least a portion of the slot centers of the first feed coupling slots are arranged on a second straight line. The first and second straight lines are both parallel to the extension direction of the slow wave structure, and the first and second straight lines do not coincide. The extension direction represents the direction in which the serpentine cavity extends meanderingly.

10. The waveguide slot antenna according to claim 9, characterized in that, The first feed coupling slots distributed along the first straight line and the first feed coupling slots distributed along the second straight line are respectively spaced on the first rectangular straight waveguide unit.

11. The waveguide slot antenna according to claim 2 or 9, characterized in that, The spacing between the first feed coupling slots on adjacent first rectangular straight waveguide units along the extension direction is not less than 1 / 4 of the spatial wavelength and not greater than the spatial wavelength.

12. The waveguide slot antenna according to any one of claims 1-10, characterized in that, The center-to-center distance between adjacent radiation slots in the same group shall not be less than 1 / 4 waveguide wavelength and not greater than 3 / 4 waveguide wavelength.

13. The waveguide slot antenna according to any one of claims 1-10, characterized in that, The longitudinal centerline spacing between adjacent second rectangular straight waveguide units shall be no less than 1 / 4 of the spatial wavelength and no greater than the spatial wavelength.

14. The waveguide slot antenna according to any one of claims 1-10, characterized in that, The second feed coupling gap is located in the middle or at the end of the second rectangular straight waveguide unit.

15. The waveguide slot antenna according to any one of claims 1-10, characterized in that, The waveguide slot antenna comprises multiple stacked metal layers, and the waveguide slot antenna is formed by creating grooves and slots in the metal layers.

16. The waveguide slot antenna according to claim 15, characterized in that, The plurality of metal layers include a first, second, and third metal layer arranged in sequence; The first metal layer is adjacent to the second metal layer. The first metal layer has a serpentine groove on the side adjacent to the second metal layer, so that it fits tightly with the second metal layer to form the serpentine cavity. A through-hole for power feeding coupling is provided on the second metal layer to realize the first and second coupling power feeding gaps through the power feeding coupling through-hole; The third metal layer is adjacent to the second metal layer. The third metal layer has a plurality of spaced rectangular grooves on the side adjacent to the second metal layer, so as to fit tightly with the second metal layer to form the second rectangular straight waveguide unit; the third metal layer is provided with the radiation slot.

17. The waveguide slot antenna as described in any one of claims 1-16, characterized in that, The connecting waveguide unit includes a first connecting waveguide unit and a second connecting waveguide unit. The first rectangular straight waveguide unit has a first end and a second end in its longitudinal direction. The first end is connected to the first connecting waveguide unit, and the second end is connected to the second connecting waveguide unit. Both the first connecting waveguide unit and the second connecting waveguide unit include a turning portion, and at least one of the first connecting waveguide unit and the second connecting waveguide unit further includes a coupling portion. The coupling portion extends along a direction perpendicular to or inclined to the plane where the narrow side of the first rectangular straight waveguide unit is located, so that the layout surface of the turning portion of the first connecting waveguide unit and / or the second connecting waveguide unit is not on the same plane as the plane where the narrow side of the first rectangular straight waveguide unit is located.

18. An antenna array, characterized in that, Including the waveguide slot antenna as described in any one of claims 1-17.

19. A detection device, characterized in that... It includes an antenna array for transmitting probe signals and / or receiving return signals of probe signals, said antenna array including the waveguide slot antenna as described in any one of claims 1-17.

20. An information system, characterized in that... Includes detection devices and signal processing devices. The detection device includes a radio frequency front-end assembly and an antenna array; the detection device is used to detect a target by transmitting a detection signal based on frequency scanning and receiving a return signal of the detection signal; The radio frequency front-end component includes at least one of a signal amplification module, a mixing module, and a filtering module; the radio frequency front-end component is used to preprocess the probe signal before transmission and to preprocess the returned signal of the probe signal after reception. The antenna array includes a waveguide slot antenna as described in any one of claims 1-17, the antenna array being used to transmit a detection signal and / or receive a return signal of the detection signal; The signal processing device includes a processing and analysis module; the signal processing device is used to obtain target detection information based on the detection signal and the return signal, the detection information including one or more of the target's distance information, position information and spatial information.

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