Symmetrically fed waveguide antenna array unit and waveguide antenna array

Abstract

Disclosed in the present invention are a symmetrically fed waveguide antenna array unit and a waveguide antenna array. The symmetrically fed waveguide antenna array unit comprises a 180° E-plane power divider, a first E-plane feeder line, a second E-plane feeder line, a first E-plane to H-plane waveguide converter, a second E-plane to H-plane waveguide converter, an H-plane waveguide, and a radiation slot array. The differential symmetrical feed and equal-split symmetrical feed solutions of the present invention have the advantages of wide operating bandwidth, symmetrical radiation patterns, and flexible variation of the physical aperture size of an antenna, and can solve multiple pain point problems. In the present invention, a symmetrical feed network is more compact by optimizing impedance matching, so that the solution has a wide range of application scenarios. In terms of implementation, in addition to being implemented by welding after metallization of two layers of injection-molded parts, the invention can also be implemented by means of metallization of the same-layer injection-molded parts and a thin copper sheet, thereby significantly reducing the thickness of the antenna.

Description

A feed-through waveguide antenna array element and a waveguide antenna array Technical Field

[0001] This invention relates to an antenna array unit and a waveguide antenna array, particularly a feed-through waveguide antenna array unit and a waveguide antenna array, belonging to the field of antenna technology. Background Technology

[0002] A waveguide antenna is a type of antenna that uses a waveguide structure to transmit and radiate electromagnetic waves. As a structure that guides electromagnetic waves, the waveguide is typically filled with air or a vacuum, but can also be other dielectric materials. Waveguide antennas generally have high directivity and gain, and are therefore widely used in radar, satellite communications, microwave measurement, radio broadcasting, and television.

[0003] Chinese Patent Publication No. CN108336507A discloses a feed-through-wave C-shaped waveguide antenna array for Ku-band satellite communication. It includes a metal C-shaped waveguide power divider, with a metal C-shaped waveguide antenna radiating element located between the two ports of the power divider. The inner wall of the power divider is equipped with a feed metal diaphragm and a metal disk. It also includes a coaxial adapter, which is inserted into the power divider via a metal probe. This design features a simple antenna structure, small size, and ease of fabrication, achieving broadband impedance matching while simultaneously achieving miniaturization and broadband performance. Furthermore, this design achieves a relative bandwidth of 8.2% with a VSWR < 2, a large main lobe gain, and small side lobes, thus improving radiation efficiency.

[0004] The current solution is too large to be miniaturized and requires a large number of layers. The inner wall of the antenna C-shaped waveguide power divider needs to have a feeding metal diaphragm and a metal disk. A coaxial adapter is also needed to insert the metal through a metal probe. This solution is too expensive in the 77GHz band and requires extremely high processing precision for this part.

[0005] Chinese Patent Publication No. CN113904097A discloses a waveguide antenna, radar, and automobile. The waveguide antenna includes an antenna body, a radiating slot group, and a beam-expanding radiating slot. The antenna body includes a radiating array, and the radiating slot group is disposed on the radiating array, forming an antenna that generates radiated signals. The beam-expanding radiating slots are disposed on the radiating array and located on both sides of the radiating slot group. The beam-expanding radiating slots generate radiated signals by cutting current on the radiating array. The radiated signals from the beam-expanding radiating slots are superimposed with the radiated signals from the radiating slot group to widen the beamwidth of the waveguide antenna. This solution solves the problem of narrow beamwidth in existing waveguide antennas.

[0006] This approach can result in high sidelobes in certain directions. To save costs, a side-fed approach is required. When the antenna frequency deviates from the center frequency, the H-plane beam pointing angle of the antenna will deviate by 0°, resulting in a narrower operating bandwidth. If a center-fed approach is used, it will increase costs, installation costs, and reduce yield.

[0007] Chinese Patent Publication No. CN216055193U discloses a millimeter-wave planar waveguide array antenna. The millimeter-wave planar waveguide array antenna includes a radiating array plate, a feed plate, and an output waveguide plate. All three plates are made of low-warpage, low-deformation electroplatable plastic as the substrate material and are injection molded using high-speed, high-precision injection molding. The surface of the molded components is then subjected to plasma treatment; subsequently, a metal layer is vacuum sputtered, consisting of a copper substrate with a sputtered silver metal layer. Finally, solder paste is printed in intermittently or staggered soldering areas, followed by reflow oven soldering, thereby achieving continuous closed soldering of the waveguide cavity. This solution features a simple process, rapid soldering, high production efficiency, and significantly reduced costs.

[0008] This scheme uses a center-fed method, which leads to an increase in the number of antenna layers and the number of antenna installations, resulting in a decrease in antenna production yield.

[0009] In summary, the existing technology has the following drawbacks:

[0010] 1. Side-feed schemes result in a narrower operating bandwidth for waveguide antennas and an asymmetrical radiation pattern;

[0011] 2. Conventional offset slots can cause the antenna's radiation pattern to have higher sidelobes at certain angles;

[0012] 3. Conventional center-feed schemes use three-layer waveguide antennas, which are costly;

[0013] 4. Conventional waveguide antennas contain other components in addition to the main signal, which can cause large ripples at large angles in multi-channel antennas. The conventional solution is to use absorbing materials to absorb these components.

[0014] 5. Conventional two-cavity designs typically have an even number of radiation ports. Summary of the Invention

[0015] The technical problem to be solved by the present invention is to provide a feed-through waveguide antenna array unit and waveguide antenna array that have extended operating bandwidth, symmetrical radiation pattern, low angular sidelobes, and low cost.

[0016] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0017] A feed-through waveguide antenna array unit includes a 180-degree E-plane power divider, a first E-plane feed line, a second E-plane feed line, a first E-plane to H-plane waveguide converter, a second E-plane to H-plane waveguide converter, an H-plane waveguide, and a radiating slot array. The first output port of the 180-degree E-plane power divider is connected to one end of the first E-plane feed line, the other end of the first E-plane feed line is connected to the input end of the first E-plane to H-plane waveguide converter, the output end of the first E-plane to 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 feed line, the other end of the second E-plane feed line is connected to the input end of the second E-plane to H-plane waveguide converter, the output end of the second E-plane to H-plane waveguide converter is connected to the other end of the H-plane waveguide, and the radiating slot array is disposed on the upper side of the H-plane waveguide. The first E-plane feed line and the second E-plane feed line are of equal length, and the radiating slot array includes an even number of radiating ports.

[0018] Furthermore, the first E-plane to H-plane waveguide converter and the second E-plane to H-plane waveguide converter are provided with impedance matching steps.

[0019] Furthermore, the even number of radiation ports is four, and they are sequentially designated as the first radiation port, the second radiation port, the third radiation port, and the fourth radiation port. The dimensions 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-to-center distance between the first radiation port, the second radiation port, the third radiation port, and the fourth radiation port is 3.3mm.

[0020] Furthermore, the H-plane waveguide includes a first rectangular portion, a first trapezoidal protrusion, a second trapezoidal protrusion, and a second rectangular portion. One end of the first rectangular portion is connected to one end of the first trapezoidal protrusion, the other end of the first trapezoidal protrusion is connected to one end of the second trapezoidal protrusion, and the other end of the second trapezoidal protrusion is connected to one end of the second rectangular portion. The first trapezoidal protrusion protrudes to one side of the H-plane waveguide, and the second trapezoidal protrusion protrudes to the other side of the H-plane waveguide. The first trapezoidal protrusion and the second trapezoidal protrusion are point-symmetric about the center point of the H-plane waveguide. The first rectangular portion and the second rectangular portion are offset to both sides along the length direction of the H-plane waveguide, and the first rectangular portion and the second rectangular portion are also point-symmetric about the center point of the H-plane waveguide.

[0021] A feed-through waveguide antenna array unit includes a 180-degree E-plane power divider, a first E-plane feed line, a second E-plane feed line, a first E-plane to H-plane waveguide converter, a second E-plane to H-plane waveguide converter, an H-plane waveguide, and a radiating slot array. The first output port of the 180-degree E-plane power divider is connected to one end of the first E-plane feed line, and the other end of the first E-plane feed line is connected to the input end of the first E-plane to H-plane waveguide converter. The output end of the first E-plane to 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 feed line, and the other end of the second E-plane feed line is connected to the input end of the second E-plane to H-plane waveguide converter. The output end of the second E-plane to H-plane waveguide converter is connected to the other end of the H-plane waveguide. The radiating slot array is disposed on the upper side of the H-plane waveguide. The first E-plane feed line and the second E-plane feed line have a length difference X such that the phase difference of the signals passing through the two feed lines is 180 degrees. The radiating slot array includes an odd number of radiating ports.

[0022] Furthermore, the number of the odd-numbered radiation ports is three, and they are, in order, the fifth radiation port, the sixth radiation port, and the seventh radiation port.

[0023] Furthermore, the H-plane waveguide includes a third rectangular portion, a third trapezoidal protrusion portion, and a fourth rectangular portion. One end of the third rectangular portion is connected to one end of the third trapezoidal protrusion portion, and the other end of the third trapezoidal protrusion portion is connected to one end of the fourth rectangular portion. The third trapezoidal protrusion portion protrudes to 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 protrusion portion.

[0024] Furthermore, the fifth, sixth, and seventh radiation ports are rectangular slit radiation ports.

[0025] Furthermore, the fifth, sixth, and seventh radiation ports are rectangular horn-shaped radiation ports.

[0026] A waveguide antenna array includes an even number of feed waveguide antenna array elements, which are divided into two groups. One group of feed waveguide antenna array elements serves as a signal transmitting unit group, and the other group serves as a signal receiving unit group.

[0027] Compared with the prior art, the present invention has the following advantages and effects:

[0028] 1. This invention adopts a counter-feed scheme to extend the working bandwidth of the antenna. Because the feed has high symmetry, the radiation pattern can be guaranteed to be symmetrical.

[0029] 2. This invention employs a counter-feed differential power supply scheme. During transmission, the signal is split into positive and negative paths for transmission; this process is called differential transmission. Because the two signals have different polarities, they can cancel out some interference during transmission, thus ensuring more stable signal transmission and preventing any sidelobes from deteriorating due to interference.

[0030] 3. The feed network of this invention is relatively compact and is on the same side of the waveguide antenna, so only two layers of waveguides are needed to achieve this, which reduces the cost and eliminates one layer of installation.

[0031] 4. This invention adopts a counter-feed differential power supply scheme. During transmission, 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 cancel out some of the interference during transmission, thereby making the signal transmission more stable and ensuring that all angle sidelobes will not deteriorate due to these interferences.

[0032] 5. This invention is applicable to both even-numbered and odd-numbered radiation ports, and can be implemented on a single metallized injection molded part and a single thin copper sheet, or on two metallized injection molded parts. Attached Figure Description

[0033] Figure 1 is a schematic diagram of an embodiment 1 of the feed-through waveguide antenna array unit of the present invention.

[0034] Figure 2 is a planar schematic diagram of an embodiment 1 of the feed-through waveguide antenna array unit of the present invention.

[0035] Figure 3 is a schematic diagram of the operating bandwidth simulation of an embodiment 1 of the feed-through waveguide antenna array unit of the present invention.

[0036] Figure 4 is a simulation diagram of the radiation pattern of an embodiment 1 of the feed-through waveguide antenna array unit of the present invention.

[0037] Figure 5 is a schematic diagram of an embodiment 2 of the feed-through waveguide antenna array unit of the present invention.

[0038] Figure 6 is a schematic diagram of the operating bandwidth simulation of an embodiment 2 of the feed-through waveguide antenna array unit of the present invention.

[0039] Figure 7 is a simulation diagram of the radiation pattern of an embodiment 2 of the feed-through waveguide antenna array unit of the present invention.

[0040] Figure 8 is a schematic diagram of an embodiment 3 of the feed-through waveguide antenna array unit of the present invention.

[0041] Figure 9 is a schematic diagram of the operating bandwidth simulation of an embodiment 3 of the feed-through waveguide antenna array unit of the present invention.

[0042] Figure 10 is a simulation diagram of the radiation pattern of an embodiment 3 of the feed-through waveguide antenna array unit of the present invention.

[0043] Figure 11 is a schematic diagram of a waveguide antenna array according to the present invention. Detailed Implementation

[0044] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0045] Example 1

[0046] As shown in Figures 1 and 2, a feed-through waveguide antenna array unit of the present invention includes 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 to H-plane waveguide converter 4, a second E-plane to H-plane waveguide converter 5, an H-plane waveguide 6, and a radiating slot array 7. The 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 the input port of the first E-plane to H-plane waveguide converter 4. The output of the waveguide converter 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 feed line 3. The other end of the second E-plane feed line 3 is connected to the input of the second E-plane-H-plane waveguide converter 5. The output of the second E-plane-H-plane waveguide converter 5 is connected to the other end of the H-plane waveguide 6. The radiating slot array 7 is located 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 are of equal length. The radiating slot array 7 contains an even number of radiating ports.

[0047] The signal of this invention is fed into the input terminal of the 180-degree E-plane power divider 1. After passing through the 180-degree E-plane power divider 1, the energy is divided into two signals with a phase difference of 180 degrees. The two signals pass through the first E-plane feed line 2 and the second E-plane feed line 3 of the same length, and then through the waveguide conversion of the first E-plane to H-plane waveguide converter 4 and the second E-plane to H-plane waveguide converter 5 before being fed into the H-plane waveguide 6.

[0048] The first E-plane to H-plane waveguide converter 4 and the second E-plane to H-plane waveguide converter 5 are equipped with impedance matching steps. Conventional feedback schemes result in a significantly larger longitudinal dimension of the antenna (in the direction of the central axis of the parallel radiating element), approximately one wavelength. This invention achieves a compact feedback scheme by miniaturizing the E-plane to H-plane waveguide converter. The E-plane waveguide is directly converted to the H-plane waveguide, which only increases the size by about 1 mm in width of the E-plane waveguide and about 2 mm on both sides, or about half a wavelength. However, the impedance matching of the antenna will be mismatched at this time. This invention adds an impedance matching step to the E-plane to H-plane waveguide converter to optimize the performance of the E-plane to H-plane waveguide converter and achieve lossless energy transmission. At the same time, the horizontal plane of the antenna can also be miniaturized by reducing the structure of the E-plane power divider. The minimum spacing between the channels on both sides of the E-plane power divider is a processable spacing of 1 mm. Simultaneously, the impedance matching step structure is optimized to achieve lossless energy transmission.

[0049] The number of even-numbered radiation ports is four, namely, the first radiation port 8, the second radiation port 9, the third radiation port 10, and the fourth radiation port 11. The dimensions 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-to-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.

[0050] H-plane waveguide 6 includes a first rectangular portion 12, a first trapezoidal protrusion 13, a second trapezoidal protrusion 14, and a second rectangular portion 15. One end of the first rectangular portion 12 is connected to one end of the first trapezoidal protrusion 13, the other end of the first trapezoidal protrusion 13 is connected to one end of the second trapezoidal protrusion 14, and the other end of the second trapezoidal protrusion 14 is connected to one end of the second rectangular portion 15. The first trapezoidal protrusion 13 protrudes to one side of the H-plane waveguide 6, and the second trapezoidal protrusion 14 protrudes to the other side of the H-plane waveguide 6. The first trapezoidal protrusion 13 and the second trapezoidal protrusion 14 are point-symmetric about the center point of the H-plane waveguide 6. The first rectangular portion 12 and the second rectangular portion 15 are offset 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-symmetric about the center point of the H-plane waveguide 6.

[0051] To reduce the sidelobes of the antenna, the second and third radiating ports 9 and 10 need to have higher energy, while the first and fourth radiating ports 8 and 11 need to have lower energy. Therefore, the H-plane waveguide 6 is bent into a trapezoidal shape, and the distance between the radiating ports and the waveguide axis is controlled by the bending angle. The second and third radiating ports 9 and 10 require more energy, so the bending angle (i.e., the angle between the waist and the base of the trapezoid) is 30°-60°. The first and fourth radiating ports 8 and 11 require less energy, so the waveguide cavity only needs to be moved away from the first and fourth radiating ports 8 and 11.

[0052] Figure 3 is a simulation diagram of the operating bandwidth of Embodiment 1 of the fed-beam waveguide antenna array unit of the present invention, and Figure 4 is a simulation diagram of the radiation pattern of Embodiment 1 of the fed-beam waveguide antenna array unit of the present invention. As can be seen from Figures 3 and 4, Embodiment 1 of the fed-beam waveguide antenna array unit of the present invention exhibits good performance in the 74-81 GHz frequency band, good antenna pattern consistency in the 76-79 GHz frequency band, and the elevation beam pointing angle is all within 0°, with antenna sidelobes all less than -20 dB.

[0053] Example 2

[0054] As shown in Figure 5, a counter-fed waveguide antenna array unit includes 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 to H-plane waveguide converter 4, a second E-plane to H-plane waveguide converter 5, an H-plane waveguide 6, and a radiating slot array 7. The 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 the input port of the first E-plane to H-plane waveguide converter 4, and the output port of the first E-plane to H-plane waveguide converter 4 is connected to the H-plane waveguide 6. One end of the first E-plane feed line 2 is connected to the second output port of the 180-degree E-plane power divider 1, which 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 disposed 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 such that the phase difference of the signals passing through the two feed lines is 180 degrees. The radiation slot array 7 contains an odd number of radiation ports.

[0055] The signal of this invention is fed into the input terminal of the 180-degree E-plane power divider 1. After passing through the 180-degree E-plane power divider 1, the energy is divided into two signals with a phase difference of 180 degrees. The two signals pass through the first E-plane feed line 2 and the second E-plane feed line 3 with a length difference of X, so that the two signals have the same phase when they reach the first E-plane to H-plane waveguide converter 4 and the second E-plane to H-plane waveguide converter 5, and are symmetrically fed into the H-plane waveguide 6.

[0056] The number of odd-numbered radiation ports is three, namely the fifth radiation port 16, the sixth radiation port 17, and the seventh radiation port 18. The fifth radiation port 16, the sixth radiation port 17, and the seventh radiation port 18 are rectangular slit radiation ports.

[0057] H-plane waveguide 6 includes a third rectangular portion 19, a third trapezoidal protrusion 20, and a fourth rectangular portion 21. One end of the third rectangular portion 19 is connected to one end of the third trapezoidal protrusion 20, and the other end of the third trapezoidal protrusion 20 is connected to one end of the fourth rectangular portion 21. The third trapezoidal protrusion 20 protrudes to one side of the H-plane waveguide 6. The third rectangular portion 19 and the fourth rectangular portion 21 are symmetrically arranged at both ends of the third trapezoidal protrusion 20.

[0058] Figure 6 shows a simulation diagram of the operating bandwidth of Embodiment 2 of the fed-beam waveguide antenna array unit of the present invention, and Figure 7 shows a simulation diagram of the radiation pattern of Embodiment 2 of the fed-beam waveguide antenna array unit of the present invention. As can be seen from Figures 6 and 7, Embodiment 2 of the fed-beam waveguide antenna array unit of the present invention exhibits good performance in the 74-81 GHz frequency band, good antenna pattern consistency in the 76-79 GHz frequency band, and the elevation beam pointing angle is all within 0°, with antenna sidelobes all less than -20 dB.

[0059] Example 3

[0060] As shown in Figure 8, a counter-fed waveguide antenna array unit includes 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 to H-plane waveguide converter 4, a second E-plane to H-plane waveguide converter 5, an H-plane waveguide 6, and a radiating slot array 7. The 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 the input port of the first E-plane to H-plane waveguide converter 4, and the output port of the first E-plane to H-plane waveguide converter 4 is connected to the H-plane waveguide 6. One end of the first E-plane feed line 2 is connected to the second output port of the 180-degree E-plane power divider 1, which 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 disposed 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 such that the phase difference of the signals passing through the two feed lines is 180 degrees. The radiation slot array 7 contains an odd number of radiation ports.

[0061] The signal of this invention is fed into the input terminal of the 180-degree E-plane power divider 1. After passing through the 180-degree E-plane power divider 1, the energy is divided into two signals with a phase difference of 180 degrees. The two signals pass through the first E-plane feed line 2 and the second E-plane feed line 3 with a length difference of X, so that the two signals have the same phase when they reach the first E-plane to H-plane waveguide converter 4 and the second E-plane to H-plane waveguide converter 5, and are symmetrically fed into the H-plane waveguide 6.

[0062] The number of odd-numbered radiation ports is three, namely 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.

[0063] H-plane waveguide 6 includes a fifth rectangular portion 25, a fourth trapezoidal protrusion 26, and a sixth rectangular portion 27. One end of the fifth rectangular portion 25 is connected to one end of the fourth trapezoidal protrusion 26, and the other end of the fourth trapezoidal protrusion 26 is connected to one end of the sixth rectangular portion 27. The fourth trapezoidal protrusion 26 protrudes to one side of the H-plane waveguide 6. The fifth rectangular portion 25 and the sixth rectangular portion 27 are symmetrically arranged at both ends of the fourth trapezoidal protrusion 26.

[0064] Figure 9 shows a simulation diagram of the operating bandwidth of Embodiment 3 of the fed-beam waveguide antenna array unit of the present invention, and Figure 10 shows a simulation diagram of the radiation pattern of Embodiment 3 of the fed-beam waveguide antenna array unit of the present invention. As can be seen from Figures 9 and 10, Embodiment 3 of the fed-beam waveguide antenna array unit of the present invention exhibits good performance in the 74-81 GHz frequency band, good antenna pattern consistency in the 76-79 GHz frequency band, and the elevation beam pointing angle is all within 0°, with antenna sidelobes all less than -20 dB.

[0065] Example 4

[0066] As shown in Figure 11, a waveguide antenna array comprises an even number of fed-beam waveguide antenna array elements. These elements are divided into two groups: one group serves as the signal transmitting unit group, and the other group serves as the signal receiving unit group. The input terminal of the 180-degree E-plane power divider 1 of each fed-beam waveguide antenna array element is connected to the waveguide converter on the chip port via an E-plane waveguide feed line. The signal is transmitted through the waveguide converter on the chip port to the E-plane waveguide feed line, and then fed into the fed-beam waveguide antenna array element through the 180-degree E-plane power divider 1. This embodiment uses a 4-transmit, 4-receive model, employing a compact fed-beam scheme. The overall antenna size is not increased compared to traditional center-fed or side-fed systems. Since differential feeding can cancel out some interference during transmission, it improves the consistency between the antenna elements. As shown in the figure, the differential feeding scheme improves consistency by approximately 2 dB compared to the conventional scheme.

[0067] This invention employs a counter-feed scheme to extend the antenna's operating bandwidth. Because the feed has high symmetry, it ensures the symmetry of the radiation pattern. The invention uses a differential feed scheme, where the signal is split into positive and negative paths during transmission; this process is called differential transmission. Since the two signals have different polarities, they can cancel out some interference during transmission, resulting in more stable signal transmission and ensuring that all angular sidelobes are not degraded by interference. The counter-feed network of this invention is relatively compact and located on the same side of the waveguide antenna, thus requiring only two waveguide layers, reducing cost and eliminating one installation layer. The invention is applicable to both even and odd-numbered radiating ports, and can be implemented on a single metallized injection-molded part and a single thin copper sheet, or on two metallized injection-molded parts.

[0068] The differential and equal-split feed schemes of this invention have many advantages, such as wide operating bandwidth, symmetrical radiation pattern, and flexible antenna aperture size, which can solve many pain points. This invention optimizes impedance matching to make the feed network more compact, thus expanding the application scenarios of this scheme. From an implementation perspective, besides being achieved by welding after metallizing two injection-molded parts, it can also be achieved by metallizing the same injection-molded part and a thin copper sheet, significantly reducing the antenna thickness. The H-plane waveguide can be either a cavity waveguide or a ridge waveguide.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A corporate-fed waveguide antenna array unit, comprising: It includes a 180-degree E-plane power divider, a first E-plane feed line, a second E-plane feed line, a first E-plane to H-plane waveguide converter, a second E-plane to H-plane waveguide converter, an H-plane waveguide, and a radiating slot array. The first output port of the 180-degree E-plane power divider is connected to one end of the first E-plane feed line, and the other end of the first E-plane feed line is connected to the input end of the first E-plane to H-plane waveguide converter. The output end of the first E-plane to 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 feed line, and the other end of the second E-plane feed line is connected to the input end of the second E-plane to H-plane waveguide converter. The output end of the second E-plane to H-plane waveguide converter is connected to the other end of the H-plane waveguide. The radiating slot array is located on the upper side of the H-plane waveguide. The first E-plane feed line and the second E-plane feed line are of equal length. The radiating slot array contains an even number of radiating ports.

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

3. The feed-through waveguide antenna array unit according to claim 1, characterized in that: The even-numbered number of radiation ports is four, and they are named in sequence as the first radiation port, the second radiation port, the third radiation port, and the fourth radiation port. The dimensions 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-to-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 feed-through waveguide antenna array unit according to claim 3, characterized in that: The H-plane waveguide includes a first rectangular portion, a first trapezoidal protrusion, a second trapezoidal protrusion, and a second rectangular portion. One end of the first rectangular portion is connected to one end of the first trapezoidal protrusion, and the other end of the first trapezoidal protrusion is connected to one end of the second trapezoidal protrusion. The other end of the second trapezoidal protrusion is connected to one end of the second rectangular portion. The first trapezoidal protrusion protrudes to one side of the H-plane waveguide, and the second trapezoidal protrusion protrudes to the other side of the H-plane waveguide. The first trapezoidal protrusion and the second trapezoidal protrusion are point-symmetrical about the center point of the H-plane waveguide. The first rectangular portion and the second rectangular portion are offset to both sides along the length 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 feed-through waveguide antenna array element, characterized in that: The device includes a 180-degree E-plane power divider, a first E-plane feed line, a second E-plane feed line, a first E-plane to H-plane waveguide converter, a second E-plane to H-plane waveguide converter, an H-plane waveguide, and a radiating slot array. The first output port of the 180-degree E-plane power divider is connected to one end of the first E-plane feed line, and the other end of the first E-plane feed line is connected to the input of the first E-plane to H-plane waveguide converter. The output of the first E-plane to 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 feed line, and the other end of the second E-plane feed line is connected to the input of the second E-plane to H-plane waveguide converter. The output of the second E-plane to H-plane waveguide converter is connected to the other end of the H-plane waveguide. The radiating slot array is located on the upper side of the H-plane waveguide. The first E-plane feed line and the second E-plane feed line have a length difference X such that the phase difference of the signals passing through the two feed lines is 180 degrees. The radiating slot array contains an odd number of radiating ports.

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

7. A feed-through waveguide antenna array unit according to claim 6, characterized in that: The H-plane waveguide includes a third rectangular portion, a third trapezoidal protrusion portion, and a fourth rectangular portion. One end of the third rectangular portion is connected to one end of the third trapezoidal protrusion portion, and the other end of the third trapezoidal protrusion portion is connected to one end of the fourth rectangular portion. The third trapezoidal protrusion portion protrudes to 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 protrusion portion.

8. A feed-through waveguide antenna array unit according to claim 6, characterized in that: The fifth, sixth, and seventh radiation ports are rectangular slit radiation ports.

9. A feed-through waveguide antenna array unit according to claim 6, characterized in that: The fifth, sixth, and seventh radiation ports are rectangular horn-shaped radiation ports.

10. A waveguide antenna array, characterized in that: The array comprises an even number of feed waveguide antenna array elements as described in any one of claims 1-9, wherein the even number of feed waveguide antenna array elements are divided into two groups, one group of feed waveguide antenna array elements serves as a signal transmitting unit group, and the other group of feed waveguide antenna array elements serves as a signal receiving unit group.

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