Waveguide slot array and waveguide slot antenna

Abstract

The application discloses a waveguide slot array and a waveguide slot antenna, and relates to the technical field of antennas. The waveguide slot array comprises a plurality of first waveguide tubes and a plurality of second waveguide tubes which are identical in structure, each of the first waveguide tubes is respectively provided with a plurality of first waveguide slots, and each of the second waveguide tubes is respectively provided with a plurality of second waveguide slots; wherein the first waveguide tubes and the second waveguide tubes are alternately arranged along a first direction, the first waveguide tubes and the second waveguide tubes are staggered along a second direction, so that the corresponding first waveguide slots and the second waveguide slots are staggered along the second direction, and the first direction intersects with the second direction. The waveguide slot array provided by the application can improve the isolation of the corresponding waveguide slot antenna.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antennas, in particular to a waveguide slot array and a waveguide slot antenna. BACKGROUND

[0002] The waveguide slot antenna refers to a kind of aperture antenna with slot on the wall of waveguide tube or cavity resonator, and electromagnetic wave is radiated to external space through the slot.It is light in weight, simple in processing, easy to realize low sidelobe, and can meet the engineering requirements of high reliability, and is widely used in radar field.

[0003] At present, the waveguide slot antenna often includes multiple antenna units, and the isolation degree of the antenna unit is a key factor affecting the performance of the waveguide slot antenna. SUMMARY

[0004] The main purpose of the present application is to provide a waveguide slot array and a waveguide slot antenna, to improve the isolation degree of the waveguide slot antenna.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a waveguide slot array, which comprises a plurality of first waveguide tubes and a plurality of second waveguide tubes with the same structure, each of the first waveguide tubes is provided with a plurality of first waveguide slots, and each of the second waveguide tubes is provided with a plurality of second waveguide slots.

[0006] The first waveguide tubes and the second waveguide tubes are arranged alternately along a first direction, and the first waveguide tubes and the second waveguide tubes are arranged staggeredly along a second direction, so that the corresponding first waveguide slots and the second waveguide slots are arranged staggeredly along the second direction, wherein the first direction intersects with the second direction.

[0007] In an embodiment, the staggered distance of the first waveguide tubes and the second waveguide tubes is 0.5 to 3 times of the slot spacing, wherein the slot spacing is the spacing between the centers of two adjacent first waveguide slots in the second direction.

[0008] In an embodiment, the first waveguide tubes and the second waveguide tubes are ridge waveguide tubes respectively.

[0009] In an embodiment, the first waveguide slots on the first waveguide tubes are arranged alternately, and the second waveguide slots on the second waveguide tubes are arranged alternately.

[0010] In an embodiment, the first waveguide tubes and the second waveguide tubes respectively extend along the second direction, and the distance between the same side edges of adjacent first waveguide tubes and second waveguide tubes along the first direction is half of the working wavelength.

[0011] The distance between the centers of two adjacent first waveguide slots and the distance between the centers of two adjacent second waveguide slots are less than one operating wavelength, respectively.

[0012] In a second aspect, the present application provides a waveguide slot antenna, comprising:

[0013] A horizontal turntable for rotating to drive a structure located thereon to rotate synchronously;

[0014] A plurality of phase shifters located on the horizontal turntable, each of the phase shifters being configured to receive a radio frequency input signal;

[0015] The waveguide slot array according to the first aspect is located on the horizontal turntable, and each of the first waveguides and each of the second waveguides is connected to a corresponding phase shifter.

[0016] In an embodiment, the waveguide slot antenna further comprises a circular polarizer, the circular polarizer comprising an adhesive medium layer and a plurality of printed circuit boards, the adhesive medium layer being located between two adjacent printed circuit boards and configured to bond the two adjacent printed circuit boards, opposite surfaces of each printed circuit board being printed with a first metal pattern layer of a first shape and a second metal pattern layer of a second shape, so that the reflected wave between the first metal pattern layer and the second metal pattern layer of the printed circuit board has an initial phase of a target angle, wherein the first shape is different from the second shape, and the target angle is greater than 0° and less than or equal to 90°.

[0017] In an embodiment, the first metal pattern layer comprises a first metal line, a second metal line, a third metal line, a fourth metal line and a fifth metal line connected in sequence, the first metal line, the third metal line and the fifth metal line extend along a first direction, the second metal line and the fourth metal line extend along a second direction, the first metal line and the fifth metal line are symmetric to the center line of the third metal line, and the second metal line and the fourth metal line are symmetric to the center line of the third metal line.

[0018] In an embodiment, the second metal pattern layer is a straight metal pattern layer.

[0019] In an embodiment, the second metal pattern layer comprises a sixth metal line, a seventh metal line and an eighth metal line, the sixth metal line and the seventh metal line extend along a first direction, respectively, and the eighth metal line extends along a second direction, the eighth metal line is located between the sixth metal line and the seventh metal line and connects the sixth metal line and the seventh metal line.

[0020] In an embodiment, a distance between the first metal pattern layer and the second metal pattern layer is one-eighth of a working wavelength of a center frequency.

[0021] The waveguide slot array includes a plurality of first waveguide tubes and a plurality of second waveguide tubes, each of the first waveguide tubes is respectively provided with a plurality of first waveguide slots, each of the second waveguide tubes is respectively provided with a plurality of second waveguide slots, and the first waveguide tubes and the second waveguide tubes are staggered by being arranged alternately, so that the corresponding first waveguide slots and the second waveguide slots are staggered, the relative distance between the corresponding first waveguide slots and the second waveguide slots can be pulled apart, the direct coupling between the adjacent first waveguide slots and the second waveguide slots can be reduced, the electromagnetic field directions of the adjacent first waveguide slots and the second waveguide slots can be offset partially, the energy crosstalk between the first waveguide slots and the second waveguide slots can be reduced effectively, and thus the isolation of the corresponding waveguide slot antenna can be improved.

[0022] The waveguide slot antenna includes a horizontal turntable, a plurality of phase shifters, and the waveguide slot array, each of the phase shifters and the waveguide slot array is arranged on the horizontal turntable, so that the horizontal turntable can drive the phase shifters and the waveguide slot array to rotate, that is, the entire waveguide slot antenna rotates, and thus the horizontal plane scanning of the waveguide slot antenna is realized in a mechanical scanning mode. The scanning of the elevation plane of the waveguide slot antenna can be realized by the phase shifters distributing specific phase combinations, that is, the elevation tracking can be realized in an electrical scanning mode. The waveguide slot antenna is scanned in a combination of the mechanical scanning and the electrical scanning, so that the system has a fast acquisition capability and a certain stable tracking capability. Compared with the two-dimensional arrangement of the electrical scanning antenna in the related art, a large number of components are saved, and only one horizontal turntable is needed, which greatly simplifies the structure compared with the two-dimensional turntable of the mechanical scanning antenna. In addition, the isolation of each antenna unit of the waveguide slot antenna is good, and the waveguide slot antenna has high performance. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The structure diagram of the waveguide slot array in an embodiment of the present application;

[0025] Figure 2 The correlation diagram of the staggered distance and the isolation;

[0026] Figure 3 Fig. 1 is a structural schematic diagram of a rectangular waveguide in the related art;

[0027] Figure 4 Fig. 2 is a structural schematic diagram of a ridge waveguide;

[0028] Figure 5 Fig. 3 is a structural schematic diagram of a waveguide slot antenna in an embodiment of the present application;

[0029] Figure 6 Fig. 4 is a schematic diagram of a mechanical scanning principle of the waveguide slot antenna in the embodiment of the present application;

[0030] Figure 7 Fig. 5 is a schematic diagram of an electrical scanning principle of the waveguide slot antenna in the embodiment of the present application;

[0031] Figure 8 Fig. 6 is a structural schematic diagram of a circular polarizer in an embodiment of the present application;

[0032] Figure 9 Fig. 7 is an exploded structural schematic diagram of the circular polarizer in the embodiment of the present application.

[0033] Brief Description of the Drawings:

[0034] 1-waveguide slot array, 11-first waveguide, 111-first waveguide slot, 12-second waveguide, 121-second waveguide slot, 2-horizontal turntable, 3-phase shifter, 4-circular polarizer, 41-printed circuit board, 411-first metal pattern layer, 4111-first metal line, 4112-second metal line, 4113-third metal line, 4114-fourth metal line, 4115-fifth metal line, 412-second metal pattern layer, 4121-sixth metal line, 4122-seventh metal line, 4123-eighth metal line, 42-adhesive medium layer.

[0035] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0037] It should be noted that if the embodiments of the present application involve directionality indication (such as up, down, left, right, front, back, …), the directionality indication is only used to explain the relative position relationship, motion condition and the like between components in a certain posture, and if the certain posture changes, the directionality indication also changes accordingly.

[0038] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of a person skilled in the art, and when the combination of technical solutions is contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0039] As described in the background, the waveguide slot antenna refers to a kind of aperture antenna with a slot on the wall of waveguide tube or cavity resonator, and electromagnetic wave is radiated to the outside space through the slot. It is light in weight, simple in processing, easy to realize low sidelobe, and can meet the engineering requirements of high reliability, and is widely used in radar field.

[0040] At present, the waveguide slot antenna often includes multiple antenna units, and the isolation degree of the antenna unit is a key factor affecting the performance of the waveguide slot antenna.

[0041] In order to solve the above problems, as shown in Figure 1 The present application provides a waveguide slot array 1, which includes a plurality of first waveguide tubes 11 and a plurality of second waveguide tubes 12, each first waveguide tube 11 is provided with a plurality of first waveguide slots 111, and each second waveguide tube 12 is provided with a plurality of second waveguide slots 121. The first waveguide tube 11 and the second waveguide tube 12 can be rectangular waveguide tubes extending along the second direction, so as to facilitate processing and analysis. The arrangement mode of each first waveguide slot 111 on the first waveguide tube 11 can be the same as the arrangement mode of each second waveguide slot 121 on the second waveguide tube 12.

[0042] The first waveguide tube 11 and the second waveguide tube 12 are alternately arranged along the first direction, and the first waveguide tube 11 and the second waveguide tube 12 are arranged in a staggered manner along the second direction, so that the corresponding first waveguide slot 111 and second waveguide slot 121 are arranged in a staggered manner along the second direction, wherein the first direction intersects the second direction.

[0043] It should be noted that the first direction is the X-axis direction, and the second direction is the Y-axis direction. The first waveguide 11 and the second waveguide 12 have the same structure, and the shape, size and slit arrangement of the first waveguide 11 and the second waveguide 12 are the same. If the first waveguide 11 and the second waveguide 12 are not arranged in the second direction, the first waveguide slit 111 and the second waveguide slit 121 are arranged in the same row, and the first waveguide slit 111 and the second waveguide slit 121 in the same row exist. In the case of the first waveguide 11 and the second waveguide 12 arranged in the second direction, the first waveguide slit 111 and the second waveguide slit 121 in the same row are the corresponding first waveguide slit 111 and the second waveguide slit 121.

[0044] The first waveguide 11 and the second waveguide 12 are arranged in the first direction, and the first waveguide 11 and the second waveguide 12 are arranged in the second direction, so that the corresponding first waveguide slit 111 and the second waveguide slit 121 are arranged in the second direction, and the staggered arrangement can pull apart the relative distance between the corresponding first waveguide slit 111 and the second waveguide slit 121, reduce the direct coupling between the adjacent first waveguide slit 111 and the second waveguide slit 121, and make the electromagnetic field directions of the adjacent first waveguide slit 111 and the second waveguide slit 121 partially offset each other, which can effectively reduce the energy crosstalk between the first waveguide slit 111 and the second waveguide slit 121, thereby improving the isolation of the corresponding waveguide slit antenna.

[0045] Exemplarily, as shown in Figure 2 The design bandwidth of the corresponding waveguide slit antenna is Ka high frequency band 27.5-30GHz, and it can be seen that the isolation of the waveguide slit antenna is obviously improved with the increase of the staggered distance d3.

[0046] The waveguide slit array 1 includes a plurality of first waveguides 11 and a plurality of second waveguides 12, each first waveguide 11 is provided with a plurality of first waveguide slits 111, and each second waveguide 12 is provided with a plurality of second waveguide slits 121. By arranging the first waveguide 11 and the second waveguide 12 alternately, the first waveguide 11 and the second waveguide 12 are arranged in the second direction, so that the corresponding first waveguide slit 111 and the second waveguide slit 121 are arranged in the second direction, the relative distance between the corresponding first waveguide slit 111 and the second waveguide slit 121 can be pulled apart, the direct coupling between the adjacent first waveguide slit 111 and the second waveguide slit 121 can be reduced, and the electromagnetic field directions of the adjacent first waveguide slit 111 and the second waveguide slit 121 can be partially offset each other, which can effectively reduce the energy crosstalk between the first waveguide slit 111 and the second waveguide slit 121, thereby improving the isolation of the corresponding waveguide slit antenna.

[0047] In an embodiment, the misalignment distance between the first waveguide 11 and the second waveguide 12 is 0.5 to 3 times of a gap distance, where the gap distance is a distance between centers of two first waveguide slots 111 adjacent in the second direction. As shown in FIG. 1, the misalignment distance between the first waveguide 11 and the second waveguide 12 is d1 in FIG. 1, and the gap distance is d2 in FIG. 1. Figure 1 In an embodiment, the misalignment distance between the first waveguide 11 and the second waveguide 12 is 0.5 to 3 times of a gap distance, where the gap distance is a distance between centers of two first waveguide slots 111 adjacent in the second direction. As shown in FIG. 1, the misalignment distance between the first waveguide 11 and the second waveguide 12 is d1 in FIG. 1, and the gap distance is d2 in FIG. 1. Figure 1 In an embodiment, the misalignment distance between the first waveguide 11 and the second waveguide 12 is 0.5 to 3 times of a gap distance, where the gap distance is a distance between centers of two first waveguide slots 111 adjacent in the second direction. As shown in FIG. 1, the misalignment distance between the first waveguide 11 and the second waveguide 12 is d1 in FIG. 1, and the gap distance is d2 in FIG. 1. Figure 1 In an embodiment, the misalignment distance between the first waveguide 11 and the second waveguide 12 is 0.5 to 3 times of a gap distance, where the gap distance is a distance between centers of two first waveguide slots 111 adjacent in the second direction. As shown in FIG. 1, the misalignment distance between the first waveguide 11 and the second waveguide 12 is d1 in FIG. 1, and the gap distance is d2 in FIG. 1.

[0048] It can be understood that the relative distance between the corresponding first waveguide slot 111 and the second waveguide slot 121 is positively correlated with the misalignment distance between the first waveguide 11 and the second waveguide 12, and within a certain range, the greater the relative distance between the corresponding first waveguide slot 111 and the second waveguide slot 121, that is, the greater the misalignment distance between the first waveguide 11 and the second waveguide 12, the better the isolation of the waveguide slot antenna is improved. However, the greater the misalignment distance between the first waveguide 11 and the second waveguide 12, the greater the size of the waveguide slot array 1, and the oversized waveguide slot array 1 is not conducive to the miniaturization of the waveguide slot antenna. Therefore, the misalignment distance between the first waveguide 11 and the second waveguide 12 is 0.5 to 3 times of the gap distance, which can significantly improve the isolation of the corresponding waveguide slot antenna, and the size of the waveguide slot array 1 will not be too large.

[0049] In an embodiment, the first waveguide 11 and the second waveguide 12 respectively extend along the first direction, and the distance between the same side edges of the adjacent first waveguide 11 and the second waveguide 12 along the second direction is half of the working wavelength. The distance between the centers of the two adjacent first waveguide slots 111 and the distance between the centers of the two adjacent second waveguide slots 121 are respectively less than one working wavelength.

[0050] In an embodiment, the first waveguide 11 and the second waveguide 12 respectively extend along the first direction, and the distance between the same side edges of the adjacent first waveguide 11 and the second waveguide 12 along the second direction is half of the working wavelength. The distance between the centers of the two adjacent first waveguide slots 111 and the distance between the centers of the two adjacent second waveguide slots 121 are respectively less than one working wavelength. Figure 1 In an embodiment, the first waveguide 11 and the second waveguide 12 respectively extend along the first direction, and the distance between the same side edges of the adjacent first waveguide 11 and the second waveguide 12 along the second direction is half of the working wavelength. The distance between the centers of the two adjacent first waveguide slots 111 and the distance between the centers of the two adjacent second waveguide slots 121 are respectively less than one working wavelength. Figure 1 In an embodiment, the first waveguide 11 and the second waveguide 12 respectively extend along the first direction, and the distance between the same side edges of the adjacent first waveguide 11 and the second waveguide 12 along the second direction is half of the working wavelength. The distance between the centers of the two adjacent first waveguide slots 111 and the distance between the centers of the two adjacent second waveguide slots 121 are respectively less than one working wavelength. Figure 1 In an embodiment, the first waveguide 11 and the second waveguide 12 respectively extend along the first direction, and the distance between the same side edges of the adjacent first waveguide 11 and the second waveguide 12 along the second direction is half of the working wavelength. The distance between the centers of the two adjacent first waveguide slots 111 and the distance between the centers of the two adjacent second waveguide slots 121 are respectively less than one working wavelength.

[0051] Among them, when considering the scanning range of the waveguide slot antenna in the pitch plane, the distance between the adjacent first waveguide tubes 11 and the second waveguide tubes 12 is a key factor. From the antenna array theory, it can be known that the spacing between adjacent antenna units will affect the beam scanning characteristics. For the waveguide slot antenna, in order to achieve a wider scanning range in the pitch plane (such as + / -60°), it is necessary to control the distance between the adjacent first waveguide tubes 11 and the second waveguide tubes 12. When d3 is approximately half the working wavelength, the interference principle between the antenna units can be used to achieve a wider scanning range. According to the directional pattern product theorem, the directional pattern of the antenna array is the product of the unit antenna directional pattern and the array factor directional pattern. In the pitch plane direction, a suitable d3 can make the array factor directional pattern vary within a wider angle range, thereby achieving a wider scanning angle.

[0052] Grating lobes are unwanted side lobes in the antenna pattern. Their level can be comparable to or even higher than that of the main lobe, severely impacting antenna performance. To avoid or reduce the level of grating lobes, d2 needs to be limited. According to antenna theory, when the spacing between adjacent slots is less than one operating wavelength, the grating lobe situation in the antenna pattern can be effectively improved. Therefore, by limiting the distance between the centers of two adjacent first waveguide slots 111 and the distance between the centers of two adjacent second waveguide slots 121 to less than one operating wavelength, the appearance of grating lobes can be avoided or their level can be reduced, thereby improving the performance of the corresponding waveguide slot antenna.

[0053] In one embodiment, the first waveguide tube 11 and the second waveguide tube 12 are ridge waveguide tubes. Figure 3 and Figure 4 As shown, Figure 3 It is a common rectangular waveguide in the related art. Figure 4 It is a ridge waveguide, which adds a ridge-shaped structure inside the rectangular waveguide.

[0054] Ridge waveguides incorporate a ridged structure within the waveguide. For example, in a rectangular ridge waveguide, a ridge is added to the center of the waveguide's wide edge or at other suitable locations. The ridges can be rectangular, triangular, or in a variety of other shapes. The presence of these ridges alters the electromagnetic field distribution within the waveguide.

[0055] The ridge waveguide changes the electromagnetic field distribution due to its special structure, so that the cutoff frequency is reduced, the frequency band is widened, and thus the operating frequency range of the ridge waveguide is wide. Moreover, the electromagnetic field distribution inside the ridge waveguide is beneficial to reducing the reflection and scattering of electromagnetic waves on the wall of the waveguide, reducing energy loss, and improving the efficiency of signal transmission. Therefore, the first waveguide 11 and the second waveguide 12 are respectively provided as ridge waveguides, which is beneficial to improving the frequency range supported by the waveguide slot array 1 and the efficiency of signal transmission. In addition, the first waveguide 11 and the second waveguide 12 are respectively provided as ridge waveguides, which is also beneficial to limiting the distance d3 between adjacent waveguides in the first waveguide 11 and the second waveguide 12 to about half a working wavelength, and making the distance d2 between adjacent first waveguide slots 111 and adjacent second waveguide slots 121 less than one working wavelength, so as to facilitate the corresponding waveguide slot antenna to obtain a wider scanning range in the elevation plane and avoid or reduce the level of grating lobes.

[0056] In one embodiment, as shown in FIG. 1, the first waveguide slots 111 on the first waveguide 11 are staggered, and the second waveguide slots 121 on the second waveguide 12 are staggered. Figure 1

[0057] The first waveguide slots 111 on the first waveguide 11 are staggered, and the second waveguide slots 121 on the second waveguide 12 are staggered.

[0058] In this embodiment, by staggering the first waveguide slots 111 on the first waveguide 11, the direct coupling between adjacent first waveguide slots 111 can be reduced, and by staggering the second waveguide slots 121 on the second waveguide 12, the direct coupling between adjacent second waveguide slots 121 can be reduced, thereby improving the isolation of the corresponding waveguide slot antenna.

[0059] In one embodiment, as shown in FIG. 1, the first waveguide slots 111 on the first waveguide 11 are staggered, and the second waveguide slots 121 on the second waveguide 12 are staggered. Figure 5

[0060] ​​The horizontal turntable 2 is used for rotation to drive the structure located on the horizontal turntable 2 to rotate synchronously. Each phase shifter 3 is located on the horizontal turntable 2, and each phase shifter 3 is used to receive a radio frequency input signal; each first waveguide tube 11 and each second waveguide tube 12 in the waveguide slot array 1 correspond to each phase shifter 3, respectively.

[0061] The horizontal turntable 2 is a mechanical device that can rotate around a vertical axis. The horizontal turntable 2 can include a base, a turntable, a drive system, and a positioning system. The base is usually a stable platform that provides solid support for the entire turntable. The turntable is the part where the object to be rotated is placed, and it is connected to the base through bearings and other components to ensure smooth rotation. The drive system includes a motor, a reducer, and other components. The motor provides power, and the reducer is used to adjust the speed and torque, allowing the turntable to rotate at the appropriate speed and force. The positioning system is used to accurately control the rotation angle of the turntable. The positioning system can include photoelectric encoders, rotary transformers, and other devices that can accurately feedback the position information of the turntable.

[0062] The phase shifter 3 is an electronic device that can change the phase of a signal. Its basic principle is to change the length, capacitance, inductance, and other parameters of the signal transmission path to achieve phase change. For example, in a simple transmission line phase shifter, the signal passes through transmission lines of different lengths. Because the lengths of the transmission lines are different, the time it takes for the signal to propagate is different, resulting in a change in phase. In the waveguide slot antenna, by connecting each phase shifter 3 to each first waveguide tube 11 and each second waveguide tube 12, respectively, each phase shifter 3 can control the phase of the corresponding antenna element based on the input radio frequency input signal, thereby adjusting the direction of the waveguide slot antenna beam. In addition, by changing the phase of each antenna element in the waveguide slot antenna, beam scanning, focusing, and other functions can be achieved, improving the coverage range and signal reception quality of the communication system.

[0063] In satellite communication, beam scanning during fast aiming and tracking usually occurs mainly in one dimension, so the high scanning speed caused by electronic scanning only needs to occur in one dimension, while the other dimension can use mechanical scanning with slower speed. For example, Figure 1 and Figure 6As shown, by arranging each phase shifter 3 and waveguide slot array 1 on the horizontal turntable 2, the horizontal turntable 2 can drive each phase shifter 3 and waveguide slot array 1 to rotate, that is, drive the entire waveguide slot antenna to rotate, so as to realize the horizontal plane scanning of the waveguide slot antenna in a mechanical scanning manner. As for the elevation tracking, the scanning in the elevation plane of the waveguide slot antenna can be realized by the specific phase combination distributed by each phase shifter 3. The waveguide slot antenna realizes scanning in a combination of mechanical scanning and electrical scanning, so that the system has the ability of fast acquisition and certain stable tracking ability. Moreover, the two-dimensional arrangement of the waveguide slot antenna in the embodiment saves a large number of components compared with the electrical scanning antenna in the related art, and only one horizontal turntable 2 is needed, which greatly simplifies the structure compared with the two-dimensional turntable of the mechanical scanning antenna in the related art. Meanwhile, the antenna adopts the low-profile waveguide slot form, which greatly improves the working bandwidth compared with the VICTS antenna with the same low profile but a bandwidth of less than 5%.

[0064] The electrical scanning principle block diagram of the present application is shown in Figure 7 , taking an 8*8 antenna array as an example. The waveguide slot antenna includes 8 antenna sub-arrays (antenna units), and each antenna sub-array contains 8 antenna elements (waveguide slots). A phase shifter 3 is connected behind each sub-array, and the phase shifter 3 can control the phase state of the antenna sub-array connected with the phase shifter 3. It is assumed that the phase of the phase shifter 31 is , the phase of the phase shifter 32 is , and the phase of the phase shifter 3i is The corresponding antenna beam inclination θ can be calculated by the following formula.

[0065]

[0066] In the above formula, k is the free space beam, and d is the distance between adjacent antenna elements. It should be noted that when d is d2 in Figure 1 , the calculated antenna beam inclination is the horizontal antenna beam inclination, and when d is d3 in Figure 1 , the calculated antenna beam inclination is the vertical antenna beam inclination, and the final antenna beam inclination is determined by the horizontal antenna beam inclination and the vertical antenna beam inclination. The scanning angle of the waveguide slot antenna in the horizontal plane is completely controlled by the mechanical turntable, and presents an equivalent relationship, that is, the angle of the turntable rotation is the angle of the horizontal scanning of the antenna beam, as shown in Figure 7 .

[0067] It should be further noted that since the waveguide slot antenna includes the waveguide slot array 1 in any of the above embodiments, the isolation of each antenna unit of the waveguide slot antenna in the embodiment is good, and the waveguide slot antenna has high performance.

[0068] The waveguide slot antenna comprises a horizontal rotating table 2, a plurality of phase shifters 3 and the waveguide slot array 1, the phase shifters 3 and the waveguide slot array 1 are arranged on the horizontal rotating table 2, so that the horizontal rotating table 2 can drive the phase shifters 3 and the waveguide slot array 1 to rotate, that is, the entire waveguide slot antenna rotates, thereby realizing horizontal plane scanning of the waveguide slot antenna in a mechanical scanning mode. The scanning of the waveguide slot antenna in the elevation plane can be realized by the phase shifters 3 distributing specific phase combinations, that is, the elevation tracking can be realized in an electric scanning mode. The waveguide slot antenna realizes scanning in a combination of mechanical scanning and electric scanning, so that the system has fast acquisition capability and certain stable tracking capability. Compared with the two-dimensional arrangement of the electric scanning antenna in the related art, a large number of components are saved, and only one horizontal rotating table 2 is needed, which greatly simplifies the structure compared with the two-dimensional rotating table of the mechanical scanning antenna. In addition, the isolation of each antenna unit of the waveguide slot antenna is good, and the waveguide slot antenna has high performance.

[0069] In one embodiment, as shown in Figure 8 and Figure 9 The waveguide slot antenna further comprises a circular polarizer 4, the circular polarizer 4 comprises a bonding medium layer 42 and a plurality of printed circuit boards 41, the bonding medium layer 42 is located between adjacent two printed circuit boards 41, the bonding medium layer 42 is used for bonding the adjacent two printed circuit boards 41, and opposite surfaces of the printed circuit board 41 are respectively printed with a first metal pattern layer 411 of a first shape and a second metal pattern layer 412 of a second shape, so that reflected waves between the first metal pattern layer 411 and the second metal pattern layer 412 of the printed circuit board 41 have an initial phase of a target angle, wherein the first shape is different from the second shape, and the target angle is greater than 0° and less than or equal to 90°.

[0070] In the related art, adjacent metal pattern layers of the circular polarizer 4 are usually arranged at a quarter wavelength interval, because the metal pattern layers of the circular polarizer 4 are completely consistent, and the reflected electromagnetic waves between the layers are exactly opposite after passing through a distance of two quarter wavelengths, thereby ensuring smooth transmission of the electromagnetic waves. However, the total thickness of the circular polarizer 4 with this structure is relatively high, which is not conducive to reducing the volume of the circular polarizer. Taking the Ka frequency band as an example, the total thickness of the quarter wavelength circular polarizer 4 in the related art can reach 2.5 mm.

[0071] In this embodiment, a first metal pattern layer 411 with a first shape and a second metal pattern layer 412 with a second shape are respectively printed on opposite surfaces of the printed circuit board 41, so that the reflected waves between the first metal pattern layer 411 and the second metal pattern layer 412 of the printed circuit board 41 have an initial phase at a target angle, and the initial phase at the target angle corresponds to a certain spatial distance. For example, an initial phase of 90° is equivalent to the phase corresponding to a spatial distance of a quarter wavelength. By setting the first metal pattern layer 411 and the second metal pattern layer 412 with different shapes, the layer spacing between the first metal pattern layer 411 and the second metal pattern layer 412 can be compressed to at most half of the original, that is, the circular polarizer 4 can reduce the overall profile height, which is beneficial to the miniaturization and thinness of the waveguide slot antenna.

[0072] In one embodiment, as Figure 9 shown, the first metal pattern layer 411 includes a first metal wire 4111, a second metal wire 4112, a third metal wire 4113, a fourth metal wire 4114, and a fifth metal wire 4115 connected in sequence. The first metal wire 4111, the third metal wire 4113, and the fifth metal wire 4115 extend along a first direction, the second metal wire 4112 and the fourth metal wire 4114 extend along a second direction, the first metal wire 4111 and the fifth metal wire 4115 are symmetric with respect to the center line of the third metal wire 4113, and the second metal wire 4112 and the fourth metal wire 4114 are symmetric with respect to the center line of the third metal wire 4113.

[0073] As shown in the figure, the first metal pattern layer 411 is a metal pattern layer in the shape of a "Ji" character. The metal pattern layer of this shape is composed of multiple bent parts, and these bent parts play a key role in guiding electromagnetic signals and generating circular polarization characteristics.

[0074] It can be understood that the first metal pattern layer 411 includes a first metal wire 4111, a second metal wire 4112, a third metal wire 4113, a fourth metal wire 4114, and a fifth metal wire 4115 connected in sequence. Parameters such as the width, length, and the bending angle and spacing of the "Ji" character of these metal wires can be designed and adjusted to achieve specific electromagnetic performance. The "Ji" character metal pattern can excite electric field components in different directions.

[0075] In applications, the first metal pattern layer 411 can also be a metal pattern layer with other bent shapes.

[0076] In one embodiment, the second metal pattern layer 412 is a straight metal pattern layer.

[0077] In application, it was found through testing that when the first metal pattern layer 411 is a metal pattern layer in the shape of a "J" and the second metal pattern layer 412 is a straight metal pattern layer (i.e., a "I" shape), the reflected wave between the first metal pattern layer 411 and the second metal pattern layer 412 will obtain an initial phase of 90°, which is equivalent to the phase corresponding to a spatial distance of one quarter of a wavelength. The interlayer spacing between the first metal pattern layer 411 and the second metal pattern layer 412 can be compressed to half of the original, i.e., one eighth of the wavelength, thereby reducing the overall cross-sectional height of the circular polarizer 4.

[0078] In another embodiment, Figure 9 As shown, the second metal pattern layer 412 includes a sixth metal wire 4121, a seventh metal wire 4122 and an eighth metal wire 4123. The sixth metal wire 4121 and the seventh metal wire 4122 extend along the first direction respectively, the eighth metal wire 4123 extends along the second direction, and the eighth metal wire 4123 is located between the sixth metal wire 4121 and the seventh metal wire 4122, and connects the sixth metal wire 4121 and the seventh metal wire 4122.

[0079] As shown in the figure, the second metal pattern layer 412 is a metal pattern layer in the shape of an I-shaped character.

[0080] During application, it was found through testing that when the first metal pattern layer 411 is a metal pattern layer in the shape of a Chinese character "J" and the second metal pattern layer 412 is a metal pattern layer in the shape of a Chinese character "I", the reflected wave between the first metal pattern layer 411 and the second metal pattern layer 412 will also obtain an initial phase of 90°, which is equivalent to the phase corresponding to a spatial distance of one quarter of a wavelength. This can compress the interlayer spacing between the first metal pattern layer 411 and the second metal pattern layer 412 to half of the original, that is, one eighth of a wavelength, thereby reducing the overall cross-sectional height of the circular polarizer 4.

[0081] It should be noted that, in application, the second metal pattern layer 412 may also be other shapes, as long as the first shape is different from the second shape and the reflected wave between the first metal pattern layer 411 and the second metal pattern layer 412 of the printed circuit board 41 has an initial phase of the target angle.

[0082] In one embodiment, the distance between the first metal pattern layer 411 and the second metal pattern layer 412 is one eighth of the operating wavelength of the center frequency.

[0083] Exemplarily, the waveguide slot antenna of the embodiment can include 4 layers of metal pattern layers. Under the condition of meeting a 10% operating bandwidth, the operating wavelength of the first metal pattern layer 411 and the second metal pattern layer 412 is reduced to one-eighth of the center frequency point, and the structure of the circular polarizer 4 is relatively compact, thereby being beneficial to realizing miniaturization and light and thin of the waveguide slot antenna. Taking the Ka frequency band as an example, the total thickness of the quarter-wave circular polarizer 4 of the related art can reach 2.5 mm, and after adopting the compact structure, the size can be compressed to 1.22 mm, about half.

[0084] The above merely describes exemplary embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made by using the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A waveguide slot array, characterized by, The waveguide slot array comprises a plurality of first waveguide tubes and a plurality of second waveguide tubes, each of the first waveguide tubes is provided with a plurality of first waveguide slots, and each of the second waveguide tubes is provided with a plurality of second waveguide slots; The first waveguide tubes and the second waveguide tubes are alternately arranged along a first direction, and the first waveguide tubes and the second waveguide tubes are staggered along a second direction, so that the corresponding first waveguide slots and the second waveguide slots are staggered along the second direction, wherein the first direction intersects the second direction; The waveguide slot array is further provided with a circular polarizer, the circular polarizer comprises an adhesive medium layer and a plurality of printed circuit boards, the adhesive medium layer is located between two adjacent printed circuit boards, and the adhesive medium layer is used for bonding the two adjacent printed circuit boards, the opposite surfaces of the printed circuit boards are respectively printed with a first metal pattern layer of a first shape and a second metal pattern layer of a second shape, so that the reflection wave between the first metal pattern layer and the second metal pattern layer of the printed circuit board has an initial phase of a target angle, wherein the first shape is different from the second shape, and the target angle is greater than 0° and less than or equal to 90°; The first metal pattern layer comprises a first metal line, a second metal line, a third metal line, a fourth metal line and a fifth metal line connected in sequence, the first metal line, the third metal line and the fifth metal line extend along a first direction, the second metal line and the fourth metal line extend along a second direction, the first metal line and the fifth metal line are symmetric to the center line of the third metal line, and the second metal line and the fourth metal line are symmetric to the center line of the third metal line; The second metal pattern layer is a straight line-shaped metal pattern layer; or The second metal pattern layer comprises a sixth metal line, a seventh metal line and an eighth metal line, the sixth metal line and the seventh metal line extend along a first direction respectively, the eighth metal line extends along a second direction, and the eighth metal line is located between the sixth metal line and the seventh metal line and connects the sixth metal line and the seventh metal line.

2. The waveguide slot array of claim 1, wherein, The staggered distance of the first waveguide tubes and the second waveguide tubes is 0.5 to 3 times of a slot interval, wherein the slot interval is the interval between the centers of two adjacent first waveguide slots in the second direction.

3. The waveguide slot array of claim 1, wherein, The first waveguide tubes and the second waveguide tubes are respectively ridge waveguide tubes.

4. The waveguide slot array of claim 1, wherein, The first waveguide slots on the first waveguide tubes are staggered, and the second waveguide slots on the second waveguide tubes are staggered.

5. The waveguide slot array of any of claims 1 to 4, wherein, The first waveguide tubes and the second waveguide tubes respectively extend along the second direction, and the distance between the same side edges of the adjacent first waveguide tubes and the second waveguide tubes along the first direction is half of a working wavelength. The distance between the centers of two adjacent first waveguide slots and the distance between the centers of two adjacent second waveguide slots are respectively less than a working wavelength.

6. A waveguide slot antenna, characterized by The waveguide slot antenna comprises: A horizontal turntable for rotating to drive a structure located thereon to rotate synchronously; a plurality of phase shifters located on the horizontal turntable, each of the phase shifters configured to receive a radio frequency input signal; the waveguide slot array of any one of claims 1 to 5, wherein each of the first waveguides and each of the second waveguides are respectively connected to each of the phase shifters.

7. The waveguide slot antenna of claim 6, wherein, a distance between the first metal pattern layer and the second metal pattern layer of the circular polarizer of the waveguide slot array is one-eighth of a working wavelength of a center frequency.

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