Opposite-fed waveguide antenna array unit and waveguide antenna array

Abstract

The invention discloses an opposite-feed waveguide antenna array unit and a waveguide antenna array. The opposite-feed waveguide antenna array unit comprises a 180-degree E-plane power divider, a first E-plane feeder, a second E-plane feeder, a first E-plane-H-plane waveguide converter, a second E-plane-H-plane waveguide converter, an H-plane waveguide and a radiation slot array. The differential feed and equant feed scheme has the advantages of wide working bandwidth, symmetrical directional diagrams, flexible change of the physical aperture of the antenna and the like, the problem of more pain points can be solved, the feed network of feed is more compact by optimizing impedance matching, the scheme has a larger application scene, and in the aspect of implementation, the application range of the antenna is widened. The antenna can be realized by welding after two layers of injection molding parts are metalized, and can also be realized by metalizing the same layer of injection molding parts and one layer of thin copper sheet, so that the thickness of the antenna can be obviously reduced.

Description

Technical Field

[0001] The present invention relates to an antenna array unit and a waveguide antenna array, in particular to a fed waveguide antenna array unit and a waveguide antenna array, belonging to the technical field of antennas. Background Art

[0002] Waveguide antenna is a type of antenna that uses waveguide structure to transmit and radiate electromagnetic waves. Waveguide, as a structure for guiding electromagnetic waves, is usually filled with air or vacuum, or other dielectrics. Waveguide antennas usually have high directivity and gain, so they are widely used in radar, satellite communications, microwave measurement, radio broadcasting and television.

[0003] Chinese patent publication number CN108336507A discloses a fed traveling wave C-shaped waveguide antenna array for Ku-band satellite communications, including a metal C-shaped waveguide power divider, a metal C-shaped waveguide antenna radiation unit is arranged between the two ports of the metal C-shaped waveguide power divider, a feeding metal diaphragm and a metal disc are arranged on the inner wall of the metal C-shaped waveguide power divider, and further includes a coaxial adapter, which is inserted into the metal C-shaped waveguide power divider through a metal probe. The antenna of the present invention has a simple structure, a small size, and is easy to process and shape, and realizes broadband impedance matching, that is, it takes into account both miniaturization and broadband. In addition, the relative bandwidth of the VSWR<2 of the present invention can reach 8.2%, and the main lobe gain is large, the side lobe is small, and the radiation efficiency is improved.

[0004] This solution is too high to be miniaturized and requires a large number of layers to be implemented. A feeding metal diaphragm and a metal disc are required on the inner wall of the antenna's C-shaped waveguide power divider, and a coaxial adapter is required to insert the metal through a metal probe. This solution is too expensive in the 77GHz frequency band and requires extremely high processing accuracy for this part.

[0005] Chinese patent publication number CN113904097A discloses a waveguide antenna, radar and automobile. The waveguide antenna includes an antenna body, a radiation slot group and a beam expansion radiation slot. The antenna body includes a radiation array. The radiation slot group is arranged on the radiation array and constitutes an antenna that generates radiation signals with the antenna body. The beam expansion radiation slot is arranged on the radiation array and located on both sides of the radiation slot group. The beam expansion radiation slot generates a radiation signal by cutting the current on the radiation array. The radiation signal of the beam expansion radiation slot is superimposed on the radiation signal of the radiation slot group to widen the beam width of the waveguide antenna. The waveguide antenna provided by the present application solves the problem of narrow beam of existing waveguide antennas.

[0006] This solution will cause the antenna to have higher side lobes in certain directions. If you want to save costs, you need to use a side-feed solution. When the antenna frequency deviates from the center frequency, the H-plane beam pointing angle of the antenna will deviate from 0°, causing the antenna's operating bandwidth to become narrower. If a center-feed solution is used, it will increase costs, increase installation costs, and reduce yields.

[0007] Chinese patent publication number CN216055193U discloses a millimeter wave flat waveguide array antenna. The millimeter wave flat waveguide array antenna includes a radiation array plate, a feed plate and an output waveguide plate. The radiation array plate, the feed plate and the output waveguide plate are all made of low-warping and low-deformation electroplatable plastic as the base material, and are subjected to high-speed and high-precision injection molding; then the surface of the molded component is subjected to plasma treatment; then a metal layer is vacuum sputtered, and the metal layer is a silver metal layer sputtered on a copper substrate; finally, solder paste is printed on the intermittent or dislocated welding area, and reflow furnace welding is performed, thereby achieving continuous closed welding of the waveguide cavity. The present application has a simple process, fast welding, high production efficiency, and greatly reduced costs.

[0008] This solution adopts mid-feed, which will lead to an increase in the number of antenna layers and an increase in the number of antenna installations, resulting in a decrease in the antenna production yield.

[0009] In summary, the prior art has the following defects: 1. The side-feed scheme will result in a narrow working bandwidth of the waveguide antenna and an asymmetric radiation pattern; 2. Conventional bias slots can cause the antenna’s radiation pattern to have high side lobes at certain angles; 3. The conventional center-feed solution uses a three-layer waveguide antenna, which is costly; 4. Conventional waveguide antennas have other components in addition to the main signal, which will cause the multi-channel antenna to have larger ripples at large angles. The conventional solution is to use absorbing materials to absorb the components; 5. The conventional two-layer cavity scheme generally has an even number of radiation ports. Summary of the invention

[0010] The technical problem to be solved by the present invention is to provide a fed waveguide antenna array unit and a waveguide antenna array, which have extended working bandwidth, symmetrical directional patterns, low angular side lobes and low cost.

[0011] In order to solve the above technical problems, the technical solution adopted by the present invention is: A fed waveguide antenna array unit comprises a 180-degree E-plane power divider, a first E-plane feeder, a second E-plane feeder, a first E-plane-H-plane waveguide converter, a second E-plane-H-plane waveguide converter, an H-plane waveguide and a radiation slot array, wherein a first output port of the 180-degree E-plane power divider is connected to one end of the first E-plane feeder, the other end of the first E-plane feeder is connected to an input end of the first E-plane-H-plane waveguide converter, the output end of the first E-plane-H-plane waveguide converter is connected to one end of the H-plane waveguide, the second output port of the 180-degree E-plane power divider is connected to one end of the second E-plane feeder, the other end of the second E-plane feeder is connected to the input end of the second E-plane-H-plane waveguide converter, the output end of the second E-plane-H-plane waveguide converter is connected to the other end of the H-plane waveguide, the radiation slot array is arranged on the upper side of the H-plane waveguide, the first E-plane feeder and the second E-plane feeder are equal in length, and the radiation slot array comprises an even number of radiation ports.

[0012] Furthermore, the first E-plane-H-plane waveguide converter and the second E-plane-H-plane waveguide converter are provided with impedance matching steps.

[0013] Furthermore, the number of the even-numbered radiation ports is four and they are, respectively, the first radiation port, the second radiation port, the third radiation port and the fourth radiation port. The sizes of the first radiation port, the second radiation port, the third radiation port and the fourth radiation port are all 0.9*2.2*1.7mm, and the center distance between the first radiation port, the second radiation port, the third radiation port and the fourth radiation port is 3.3mm.

[0014] Further, the H-plane waveguide includes a first rectangular portion, a first trapezoidal protruding portion, a second trapezoidal protruding portion, and a second rectangular portion, one end of the first rectangular portion is connected to one end of the first trapezoidal protruding portion, the other end of the first trapezoidal protruding portion is connected to one end of the second trapezoidal protruding portion, the other end of the second trapezoidal protruding portion is connected to one end of the second rectangular portion, the first trapezoidal protruding portion protrudes toward one side of the H-plane waveguide, the second trapezoidal protruding portion protrudes toward the other side of the H-plane waveguide, and the first trapezoidal protruding portion and the second trapezoidal protruding portion are point-symmetrical about the center point of the H-plane waveguide, the first rectangular portion and the second rectangular portion are staggered to both sides in the length direction of the H-plane waveguide, and the first rectangular portion and the second rectangular portion are also point-symmetrical about the center point of the H-plane waveguide.

[0015] A fed waveguide antenna array unit comprises a 180-degree E-plane power divider, a first E-plane feeder, a second E-plane feeder, a first E-plane-H-plane waveguide converter, a second E-plane-H-plane waveguide converter, an H-plane waveguide and a radiation slot array, wherein a first output port of the 180-degree E-plane power divider is connected to one end of the first E-plane feeder, the other end of the first E-plane feeder is connected to an input end of the first E-plane-H-plane waveguide converter, the output end of the first E-plane-H-plane waveguide converter is connected to one end of the H-plane waveguide, the second output port of the 180-degree E-plane power divider is connected to one end of the second E-plane feeder, the other end of the second E-plane feeder is connected to the input end of the second E-plane-H-plane waveguide converter, the output end of the second E-plane-H-plane waveguide converter is connected to the other end of the H-plane waveguide, the radiation slot array is arranged on the upper side of the H-plane waveguide, the length difference X between the first E-plane feeder and the second E-plane feeder makes the phase difference of signals passing through the two feeders 180 degrees, and the radiation slot array comprises an odd number of radiation ports.

[0016] Further, the number of the odd-numbered radiation ports is three and they are the fifth radiation port, the sixth radiation port and the seventh radiation port, respectively.

[0017] Further, the H-plane waveguide includes a third rectangular portion, a third trapezoidal protruding portion and a fourth rectangular portion, one end of the third rectangular portion is connected to one end of the third trapezoidal protruding portion, the other end of the third trapezoidal protruding portion is connected to one end of the fourth rectangular portion, the third trapezoidal protruding portion protrudes toward one side of the H-plane waveguide, and the third rectangular portion and the fourth rectangular portion are symmetrically arranged at both ends of the third trapezoidal protruding portion.

[0018] Furthermore, the fifth radiation opening, the sixth radiation opening and the seventh radiation opening are rectangular slit radiation openings.

[0019] Furthermore, the fifth radiation port, the sixth radiation port and the seventh radiation port are rectangular trumpet-shaped radiation ports.

[0020] A waveguide antenna array comprises an even number of fed waveguide antenna array units, wherein the even number of fed waveguide antenna array units are evenly divided into two groups, one group of fed waveguide antenna array units is used as a signal transmitting unit group, and the other group of fed waveguide antenna array units is used as a signal receiving unit group.

[0021] Compared with the prior art, the present invention has the following advantages and effects: 1. The present invention adopts a counter-feeding scheme to expand the working bandwidth of the antenna, because the feeding has a high degree of symmetry, which can ensure the symmetry of the directional pattern; 2. The present invention adopts a differential feeding scheme in the pair feeding. During the transmission process, the signal will be divided into positive and negative paths for transmission. This process is called differential transmission. Since the polarities of the two signals are different, they can offset some interference in the transmission process, so that the signal is transmitted more stably, ensuring that all angular side lobes will not be deteriorated due to these interferences; 3. The feed network of the present invention is relatively compact and is on the same side of the waveguide antenna, so only two layers of waveguide are needed to achieve it, which reduces the cost and reduces the installation of one layer; 4. The present invention adopts a differential feeding scheme. During the transmission process, the signal is divided into positive and negative paths for transmission. This process is called differential transmission. Since the polarities of the two signals are different, they can offset some interference in the transmission process, so that the signal is transmitted more stably, ensuring that all angular side lobes will not be deteriorated due to these interferences. 5. The present invention is applicable to both an even number of radiation ports and an odd number of radiation ports, and can be implemented on a metallized injection molded part with a layer of thin copper sheet or on a two-layer metallized injection molded part. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of embodiment 1 of a fed waveguide antenna array unit of the present invention.

[0023] Figure 2 It is a plan schematic diagram of embodiment 1 of a fed waveguide antenna array unit of the present invention.

[0024] Figure 3 It is a schematic diagram of the working bandwidth simulation of Example 1 of a fed waveguide antenna array unit of the present invention.

[0025] Figure 4 It is a simulation schematic diagram of the directional diagram of Example 1 of a fed waveguide antenna array unit of the present invention.

[0026] Figure 5 It is a schematic diagram of embodiment 2 of a fed waveguide antenna array unit of the present invention.

[0027] Figure 6 It is a schematic diagram of the working bandwidth simulation of Example 2 of a fed waveguide antenna array unit of the present invention.

[0028] Figure 7 It is a simulation schematic diagram of the directional pattern of Example 2 of a fed waveguide antenna array unit of the present invention.

[0029] Figure 8 It is a schematic diagram of Example 3 of a fed waveguide antenna array unit of the present invention.

[0030] Fig. 9It is a schematic diagram of the working bandwidth simulation of Example 3 of a fed waveguide antenna array unit of the present invention.

[0031] Fig.10 It is a simulation schematic diagram of the directional diagram of Example 3 of a fed waveguide antenna array unit of the present invention.

[0032] Fig.11 It is a schematic diagram of a waveguide antenna array of the present invention. DETAILED DESCRIPTION

[0033] In order to elaborate on the technical scheme adopted by the present invention to achieve the predetermined technical purpose, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only partial embodiments of the present invention, rather than all embodiments, and the technical means or technical features in the embodiments of the present invention can be replaced without paying creative work. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0034] Example 1. Figure 1 As shown, a fed waveguide antenna array unit of the present invention comprises a 180-degree E-plane power divider 1, a first E-plane feed line 2, a second E-plane feed line 3, a first E-plane-H-plane waveguide converter 4, a second E-plane-H-plane waveguide converter 5, an H-plane waveguide 6 and a radiation slot array 7, wherein a first output port of the 180-degree E-plane power divider 1 is connected to one end of the first E-plane feed line 2, and the other end of the first E-plane feed line 2 is connected to an input end of the first E-plane-H-plane waveguide converter 4, and the first E-plane-H-plane waveguide converter The output end of the device 4 is connected to one end of the H-plane waveguide 6, the second output port of the 180-degree E-plane power divider 1 is connected to one end of the second E-plane feeder 3, the other end of the second E-plane feeder 3 is connected to the input end of the second E-plane-H-plane waveguide converter 5, the output end of the second E-plane-H-plane waveguide converter 5 is connected to the other end of the H-plane waveguide 6, the radiation slot array 7 is arranged on the upper side of the H-plane waveguide 6, the first E-plane feeder 2 and the second E-plane feeder 3 are equal in length, and the radiation slot array 7 includes an even number of radiation ports.

[0035] The signal of the present invention is fed from the input end of the 180-degree E-plane power divider 1, and after passing through the 180-degree E-plane power divider 1, the energy is equally divided into two signals with a phase difference of 180 degrees. The two signals pass through a first E-plane feed line 2 and a second E-plane feed line 3 of the same length, and then undergo waveguide conversion through a first E-plane-H-plane waveguide converter 4 and a second E-plane-H-plane waveguide converter 5 before being fed into an H-plane waveguide 6.

[0036] The first E-plane-H-plane waveguide converter 4 and the second E-plane-H-plane waveguide converter 5 are provided with impedance matching steps. Conventional feeding schemes will cause the longitudinal size of the antenna (parallel to the central axis direction of the radiation unit) to be significantly larger, about one wavelength. The present invention realizes a compact feeding scheme by miniaturizing the E-plane-H-plane waveguide converter. The E-plane waveguide is first directly transferred to the H-plane waveguide. At this time, the size only increases the width of the E-plane waveguide by about 1mm, and the bilateral increase is about 2mm, that is, about half a wavelength. However, the impedance matching of the antenna will verify mismatch at this time. The present invention adds an impedance matching step in the E-plane-H-plane waveguide converter to optimize the performance of the E-plane-H-plane waveguide converter and realize lossless transmission of energy. At the same time, the horizontal plane of the antenna can also be miniaturized by reducing the E-plane power divider structure. The minimum channel spacing on both sides of the E-plane power divider is a processable spacing of 1mm. At the same time, the impedance matching step structure is optimized to realize lossless transmission of energy.

[0037] The number of even-numbered radiation ports is four and they are the first radiation port 8, the second radiation port 9, the third radiation port 10 and the fourth radiation port 11, respectively. The sizes of the first radiation port 8, the second radiation port 9, the third radiation port 10 and the fourth radiation port 11 are all 0.9*2.2*1.7mm, and the center distance between the first radiation port 8, the second radiation port 9, the third radiation port 10 and the fourth radiation port 11 is 3.3mm.

[0038] The H-plane waveguide 6 includes a first rectangular portion 12, a first trapezoidal protruding portion 13, a second trapezoidal protruding portion 14, and a second rectangular portion 15. One end of the first rectangular portion 12 is connected to one end of the first trapezoidal protruding portion 13, the other end of the first trapezoidal protruding portion 13 is connected to one end of the second trapezoidal protruding portion 14, and the other end of the second trapezoidal protruding portion 14 is connected to one end of the second rectangular portion 15. The first trapezoidal protruding portion 13 protrudes toward one side of the H-plane waveguide, and the second trapezoidal protruding portion 14 protrudes toward the other side of the H-plane waveguide. The first trapezoidal protruding portion 13 and the second trapezoidal protruding portion 14 are point-symmetrical about the center point of the H-plane waveguide 6. The first rectangular portion 12 and the second rectangular portion 15 are staggered to both sides in the length direction of the H-plane waveguide 6, and the first rectangular portion 12 and the second rectangular portion 15 are also point-symmetrical about the center point of the H-plane waveguide 6.

[0039] It is necessary to reduce the side lobes of the antenna, and to achieve higher energy for the second radiation port 9 and the third radiation port 10, and weaker energy for the first radiation port 8 and the fourth radiation port 11. Therefore, the H-plane waveguide is bent in a trapezoidal shape and the distance between the radiation port and the central axis of the waveguide is controlled by the bending angle. The second radiation port 9 and the third radiation port 10 require greater energy, so the bending angle (that is, the inclination angle between the waist and the bottom edge of the trapezoid) is 30°-60°. The energy required for the first radiation port 8 and the fourth radiation port 11 is relatively weak, and it is only necessary to move the waveguide cavity away from the first radiation port 8 and the fourth radiation port 11.

[0040] Figure 3 1 is a schematic diagram of a simulation of the working bandwidth of a fed waveguide antenna array unit according to Embodiment 1 of the present invention. Figure 4 FIG. 1 is a schematic diagram of a simulation of the directional pattern of a feed waveguide antenna array unit according to Embodiment 1 of the present invention. Figure 3 and Figure 4 It can be seen that the embodiment 1 of the fed waveguide antenna array unit of the present invention has good performance in the 74-81 GHz frequency band, and the antenna direction in the 76-79 GHz frequency band Figure 1 The alignment is good and the consistency is good, and the antenna sidelobes are all less than -20dB.

[0041] Example 2. Figure 5 As shown, a fed waveguide antenna array unit comprises a 180-degree E-plane power divider 1, a first E-plane feed line 2, a second E-plane feed line 3, a first E-plane-H-plane waveguide converter 4, a second E-plane-H-plane waveguide converter 5, an H-plane waveguide 6 and a radiation slot array 7, wherein a first output port of the 180-degree E-plane power divider 1 is connected to one end of the first E-plane feed line 2, the other end of the first E-plane feed line 2 is connected to an input end of the first E-plane-H-plane waveguide converter 4, and an output end of the first E-plane-H-plane waveguide converter 4 is connected to the H-plane waveguide 6. The first E-plane feed line 2 and the second E-plane feed line 3 are connected to one end of the first E-plane power divider 1, the second output port of the 180-degree E-plane power divider 1 is connected to one end of the second E-plane feed line 3, the other end of the second E-plane feed line 3 is connected to the input end of the second E-plane-H-plane waveguide converter 5, the output end of the second E-plane-H-plane waveguide converter 5 is connected to the other end of the H-plane waveguide 6, the radiation slot array 7 is arranged on the upper side of the H-plane waveguide 6, the first E-plane feed line 2 and the second E-plane feed line 3 have a length difference X so that the phase difference of the signals passing through the two feed lines is 180 degrees, and the radiation slot array 7 includes an odd number of radiation ports.

[0042] The signal of the present invention is fed from the input end of the 180-degree E-plane power divider 1, and is equally divided into two signals with a phase difference of 180 degrees through the 180-degree E-plane power divider 1. The two signals pass through a first E-plane feed line 2 and a second E-plane feed line 3 with a length difference of X, so that the two signals have the same phase when reaching the first E-plane-H-plane waveguide converter 4 and the second E-plane-H-plane waveguide converter 5, and are symmetrically fed into the H-plane waveguide 6.

[0043] The number of odd-numbered radiation openings is three and they are, in order, the fifth radiation opening 16, the sixth radiation opening 17 and the seventh radiation opening 18. The fifth radiation opening 16, the sixth radiation opening 17 and the seventh radiation opening 18 are rectangular slit radiation openings.

[0044] The H-plane waveguide 6 includes a third rectangular portion 19, a third trapezoidal protruding portion 20 and a fourth rectangular portion 21. One end of the third rectangular portion 19 is connected to one end of the third trapezoidal protruding portion 20, and the other end of the third trapezoidal protruding portion 20 is connected to one end of the fourth rectangular portion 21. The third trapezoidal protruding portion 20 protrudes toward one side of the H-plane waveguide 6, and the third rectangular portion 19 and the fourth rectangular portion 21 are symmetrically arranged at both ends of the third trapezoidal protruding portion 20.

[0045] like Figure 6 FIG. 1 is a schematic diagram of a simulation of the working bandwidth of a feed waveguide antenna array unit according to Embodiment 2 of the present invention. Figure 7 FIG. 1 is a schematic diagram of a simulation of the directional pattern of a second embodiment of a fed waveguide antenna array unit of the present invention. Figure 6 and Figure 7 It can be seen that the embodiment 2 of the fed waveguide antenna array unit of the present invention has good performance in the 74-81 GHz frequency band, and the antenna direction in the 76-79 GHz frequency band is Figure 1 The alignment is good and the consistency is good, and the antenna sidelobes are all less than -20dB.

[0046] Example 3. Figure 8 As shown, a fed waveguide antenna array unit comprises a 180-degree E-plane power divider 1, a first E-plane feed line 2, a second E-plane feed line 3, a first E-plane-H-plane waveguide converter 4, a second E-plane-H-plane waveguide converter 5, an H-plane waveguide 6 and a radiation slot array 7, wherein a first output port of the 180-degree E-plane power divider 1 is connected to one end of the first E-plane feed line 2, the other end of the first E-plane feed line 2 is connected to an input end of the first E-plane-H-plane waveguide converter 4, and an output end of the first E-plane-H-plane waveguide converter 4 is connected to the H-plane waveguide 6. The first E-plane feed line 2 and the second E-plane feed line 3 are connected to one end of the first E-plane power divider 1, the second output port of the 180-degree E-plane power divider 1 is connected to one end of the second E-plane feed line 3, the other end of the second E-plane feed line 3 is connected to the input end of the second E-plane-H-plane waveguide converter 5, the output end of the second E-plane-H-plane waveguide converter 5 is connected to the other end of the H-plane waveguide 6, the radiation slot array 7 is arranged on the upper side of the H-plane waveguide 6, the first E-plane feed line 2 and the second E-plane feed line 3 have a length difference X so that the phase difference of the signals passing through the two feed lines is 180 degrees, and the radiation slot array 7 includes an odd number of radiation ports.

[0047] The signal of the present invention is fed from the input end of the 180-degree E-plane power divider 1, and is equally divided into two signals with a phase difference of 180 degrees through the 180-degree E-plane power divider 1. The two signals pass through a first E-plane feed line 2 and a second E-plane feed line 3 with a length difference of X, so that the two signals have the same phase when reaching the first E-plane-H-plane waveguide converter 4 and the second E-plane-H-plane waveguide converter 5, and are symmetrically fed into the H-plane waveguide 6.

[0048] The number of odd-numbered radiation ports is three and they are the fifth radiation port 22, the sixth radiation port 23 and the seventh radiation port 24. The fifth radiation port 22, the sixth radiation port 23 and the seventh radiation port 24 are rectangular horn-shaped radiation ports.

[0049] The H-plane waveguide 6 includes a third rectangular portion 19, a third trapezoidal protruding portion 20 and a fourth rectangular portion 21. One end of the third rectangular portion 19 is connected to one end of the third trapezoidal protruding portion 20, and the other end of the third trapezoidal protruding portion 20 is connected to one end of the fourth rectangular portion 21. The third trapezoidal protruding portion 20 protrudes toward one side of the H-plane waveguide 6, and the third rectangular portion 19 and the fourth rectangular portion 21 are symmetrically arranged at both ends of the third trapezoidal protruding portion 20.

[0050] like Fig. 9 FIG. 1 is a schematic diagram of a simulation of the working bandwidth of a feed waveguide antenna array unit according to Embodiment 3 of the present invention. Fig.10 FIG. 1 is a schematic diagram of a simulation of the directional pattern of Embodiment 3 of a fed waveguide antenna array unit of the present invention. Fig. 9 and Fig.10 It can be seen that the embodiment 3 of the fed waveguide antenna array unit of the present invention has good performance in the 74-81 GHz frequency band, and the antenna direction in the 76-79 GHz frequency band is Figure 1 The alignment is good and the consistency is good, and the antenna sidelobes are all less than -20dB.

[0051] Example 4. Fig.11 As shown, a waveguide antenna array comprises an even number of feed waveguide antenna array units, and the even number of feed waveguide antenna array units are evenly divided into two groups, one group of feed waveguide antenna array units is used as a signal transmitting unit group, and the other group of feed waveguide antenna array units is used as a signal receiving unit group. The input end of the 180-degree E-plane power divider 1 of each feed waveguide antenna array unit is connected to the waveguide converter on the chip port through the E-plane waveguide feeder. The signal is transmitted to the E-plane waveguide feeder through the waveguide converter on the chip port, and then fed into the feed waveguide antenna array unit through the 180-degree E-plane power divider 1. This embodiment adopts a 4-transmit 4-receive model and a compact feed solution. The size of the antenna is not increased compared to traditional center feed or side feed. Since differential feeding can offset some interference during transmission, the consistency between the antennas of each unit can be improved. As shown in the figure, the consistency of the feed differential solution can be improved by about 2dB compared to the ordinary solution.

[0052] The present invention adopts a counter-feeding scheme to expand the working bandwidth of the antenna. Since the feeding is highly symmetrical, the symmetry of the directional pattern can be guaranteed. The present invention adopts a differential feeding scheme in the counter-feeding. During the transmission process, the signal will be divided into positive and negative paths for transmission. This process is called differential transmission. Since the polarities of the two signals are different, they can offset each other's partial interference in the transmission process, so that the signal is transmitted more stably, ensuring that all angular side lobes will not be deteriorated by these interferences; the feeding network of the present invention is relatively compact and is on the same side of the waveguide antenna, so only two layers of waveguide are needed to achieve it, which reduces the cost and reduces the installation of one layer; the present invention adopts a differential feeding scheme for feeding, and during the transmission process, the signal will be divided into positive and negative paths for transmission, and this process is called differential transmission; since the polarities of the two signals are different, they can offset each other's partial interference in the transmission process, so that the signal is transmitted more stably, ensuring that all angular side lobes will not be deteriorated by these interferences; the present invention is suitable for both an even number of radiation ports and an odd number of radiation ports, and can be implemented on a layer of metallized injection molded parts and a layer of thin copper sheet, or on two layers of metallized injection molded parts.

[0053] The differential pair feeding and equal pair feeding schemes of the present invention have many advantages such as wide working bandwidth, symmetrical directional pattern and flexible change of antenna physical aperture size, which can solve many pain points. The present invention makes the feeding network of the pair feeding more compact by optimizing impedance matching, so that the scheme has a larger application scenario. From the implementation point of view, in addition to being realized by welding after metallizing two layers of injection molding parts, it can also be realized by metallizing the same layer of injection molding parts and a layer of thin copper sheet, which can significantly reduce the thickness of the antenna. The H-plane waveguide can be either a cavity waveguide or a ridge waveguide.

[0054] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A fed waveguide antenna array unit, characterized in that: The invention comprises a 180-degree E-plane power divider, a first E-plane feeder, a second E-plane feeder, a first E-plane-H-plane waveguide converter, a second E-plane-H-plane waveguide converter, an H-plane waveguide and a radiation slot array, wherein a first output port of the 180-degree E-plane power divider is connected to one end of the first E-plane feeder, the other end of the first E-plane feeder is connected to the input end of the first E-plane-H-plane waveguide converter, the output end of the first E-plane-H-plane waveguide converter is connected to one end of the H-plane waveguide, the second output port of the 180-degree E-plane power divider is connected to one end of the second E-plane feeder, the other end of the second E-plane feeder is connected to the input end of the second E-plane-H-plane waveguide converter, the output end of the second E-plane-H-plane waveguide converter is connected to the other end of the H-plane waveguide, the radiation slot array is arranged on the upper side of the H-plane waveguide, the first E-plane feeder and the second E-plane feeder are of equal length, and the radiation slot array comprises an even number of radiation ports.

2. A fed waveguide antenna array unit according to claim 1, characterized in that: The first E-plane-H-plane waveguide converter and the second E-plane-H-plane waveguide converter are provided with impedance matching steps.

3. The fed waveguide antenna array unit according to claim 1, characterized in that: The number of the even-numbered radiation ports is four and they are the first radiation port, the second radiation port, the third radiation port and the fourth radiation port, respectively. The sizes of the first radiation port, the second radiation port, the third radiation port and the fourth radiation port are all 0.9*2.2*1.7mm, and the center distance between the first radiation port, the second radiation port, the third radiation port and the fourth radiation port is 3.3mm.

4. A fed waveguide antenna array unit according to claim 3, characterized in that: The H-plane waveguide comprises a first rectangular portion, a first trapezoidal protruding portion, a second trapezoidal protruding portion, and a second rectangular portion, one end of the first rectangular portion is connected to one end of the first trapezoidal protruding portion, the other end of the first trapezoidal protruding portion is connected to one end of the second trapezoidal protruding portion, the other end of the second trapezoidal protruding portion is connected to one end of the second rectangular portion, the first trapezoidal protruding portion protrudes toward one side of the H-plane waveguide, the second trapezoidal protruding portion protrudes toward the other side of the H-plane waveguide, and the first trapezoidal protruding portion and the second trapezoidal protruding portion are point-symmetrical about the center point of the H-plane waveguide, the first rectangular portion and the second rectangular portion are staggered to both sides in the length direction of the H-plane waveguide, and the first rectangular portion and the second rectangular portion are also point-symmetrical about the center point of the H-plane waveguide.

5. A fed waveguide antenna array unit, characterized in that: The invention comprises a 180-degree E-plane power divider, a first E-plane feeder, a second E-plane feeder, a first E-plane-H-plane waveguide converter, a second E-plane-H-plane waveguide converter, an H-plane waveguide and a radiation slot array, wherein a first output port of the 180-degree E-plane power divider is connected to one end of the first E-plane feeder, the other end of the first E-plane feeder is connected to the input end of the first E-plane-H-plane waveguide converter, the output end of the first E-plane-H-plane waveguide converter is connected to one end of the H-plane waveguide, the second output port of the 180-degree E-plane power divider is connected to one end of the second E-plane feeder, the other end of the second E-plane feeder is connected to the input end of the second E-plane-H-plane waveguide converter, the output end of the second E-plane-H-plane waveguide converter is connected to the other end of the H-plane waveguide, the radiation slot array is arranged on the upper side of the H-plane waveguide, the length difference X between the first E-plane feeder and the second E-plane feeder makes the phase difference of the signals passing through the two feeders be 180 degrees, and the radiation slot array comprises an odd number of radiation ports.

6. A fed waveguide antenna array unit according to claim 5, characterized in that: The number of the odd-numbered radiation ports is three and they are the fifth radiation port, the sixth radiation port and the seventh radiation port, respectively.

7. The fed waveguide antenna array unit according to claim 6, characterized in that: The H-plane waveguide comprises a third rectangular portion, a third trapezoidal protruding portion and a fourth rectangular portion, one end of the third rectangular portion is connected to one end of the third trapezoidal protruding portion, the other end of the third trapezoidal protruding portion is connected to one end of the fourth rectangular portion, the third trapezoidal protruding portion protrudes toward one side of the H-plane waveguide, and the third rectangular portion and the fourth rectangular portion are symmetrically arranged at both ends of the third trapezoidal protruding portion.

8. The fed waveguide antenna array unit according to claim 6, characterized in that: The fifth radiation opening, the sixth radiation opening and the seventh radiation opening are rectangular slit radiation openings.

9. The fed waveguide antenna array unit according to claim 6, characterized in that: The fifth radiation port, the sixth radiation port and the seventh radiation port are rectangular trumpet-shaped radiation ports.

10. A waveguide antenna array, characterized in that: It comprises an even number of the fed waveguide antenna array units according to any one of claims 1 to 9, wherein the even number of the fed waveguide antenna array units are evenly divided into two groups, one group of the fed waveguide antenna array units is used as a signal transmitting unit group, and the other group of the fed waveguide antenna array units is used as a signal receiving unit group.

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