Deep groove waveguide antenna of E-plane waveguide feeder line

Abstract

The invention discloses a deep groove waveguide antenna of an E-plane waveguide feeder line, which comprises the E-plane feeder line, the deep groove waveguide feeder line and a transition structure, one end of the E-plane feeder line is connected with the middle position of the deep groove waveguide feeder line through the transition structure, the transition structure comprises a through hole and an impedance conversion structure, the deep groove waveguide feeder line comprises a first radiation structure and a second radiation structure, the first radiation structure and the second radiation structure are in point symmetry with respect to the center point of the through hole. The antenna is wide in working bandwidth, good in deflection resistance of the maximum gain beam directional angle of the pitching surface, good in aperture efficiency and low in side lobe.

Description

Technical Field

[0001] The present invention relates to a deep slot waveguide antenna, in particular to a deep slot waveguide antenna with an E-plane waveguide feeder, belonging to the technical field of antennas. Background Art

[0002] Deep-slot waveguides (single-layer waveguide antennas) are an antenna design based on a waveguide structure. Compared to traditional multi-layer or complex antennas, they offer advantages such as simple structure, low processing costs, and ease of integration. In recent years, with the development of technologies such as 5G / 6G communications, millimeter-wave radar, and satellite communications, single-layer waveguide antennas have garnered widespread attention due to their superior performance in high-frequency bands. The following analyzes their prospects from the perspectives of technical advantages, application areas, research hotspots, and future trends.

[0003] Chinese Patent Publication No. CN118610743A discloses an E-plane waveguide antenna structure comprising a first structural layer, a second structural layer, and an E-plane waveguide antenna assembly. The first structural layer defines an annular groove, a first waveguide channel, and multiple radiating slots, each of which communicates with the first waveguide channel. The inner wall of the annular groove is provided with multiple cylindrical portions, which are spaced apart to form an electromagnetic bandgap structure. The second structural layer is stacked on the first structural layer and defines a second waveguide channel. The first and second waveguide channels communicate with each other to form a waveguide cavity. The E-plane waveguide antenna assembly is located within the waveguide cavity and has a wide side and a narrow side. Both sides are perpendicular to the extension direction of the E-plane waveguide antenna assembly, and the wide side is greater than or equal to twice the narrow side. This E-plane waveguide antenna structure exhibits excellent signal transmission performance.

[0004] The E-plane waveguide antenna assembly of this solution has a wide side and a narrow side, and the wide side requires two layers of waveguide antenna boards to be welded.

[0005] Chinese Patent Publication No. CN117941173A discloses an open waveguide antenna and a system having the open waveguide antenna, comprising: an electromagnetic (EM) transition portion having a transition region, a signal feeding interface, and an open waveguide section, the EM transition portion being configured to couple EM energy from the signal feeding interface to a guided waveguide mode of EM energy via the transition region to reach the open waveguide section; and a leaky waveguide antenna portion being configured and arranged to radiate electromagnetic energy received from the open waveguide section; wherein the EM transition portion is electromagnetically coupled to the leaky waveguide antenna portion, and the EM transition portion is configured to support electromagnetic energy transfer from the signal feeding structure to the leaky waveguide antenna portion.

[0006] This solution is a deep-groove waveguide antenna. The feed line does not need to be welded, but the turning structure will cause leakage of the antenna. The structure of this solution can reduce the leakage of electromagnetic waves, but it cannot be processed and manufactured.

[0007] Chinese Patent Publication No. CN102084538B discloses a waveguide and transmission line in a gap between parallel conductive surfaces. This novel approach is advantageous when frequencies are so high that existing transmission lines and waveguides have excessive losses or cannot be cost-effectively manufactured within the required tolerances. Therefore, the new technology aims to replace coaxial lines, hollow cylindrical waveguides, microstrip lines, and other substrate-constrained transmission lines at high frequencies. A microwave device is implemented using a narrow gap between two parallel surfaces of conductive material by using a texture or multilayer structure on one of the surfaces. The field resides primarily in the gap, not in the texture or multilayer structure itself, resulting in minimal losses. The microwave device further includes one or more conductive elements, such as metallic ridges or grooves on one of the two surfaces, or metallic strips within the multilayer structure between the two surfaces. Waves propagate along the conductive elements. No metallic connection is required between the two metal surfaces. At least one of the surfaces is provided with a device to inhibit wave propagation between the surfaces except along the ridges, grooves, or strips. At very high frequencies, gap waveguides can be implemented in IC packages or within the chip itself.

[0008] This solution adopts the principle of electromagnetic band gap and is implemented through gap ridge waveguide. It does not require welding, but there will be a lot of small pillars, which will affect the life of the mold and increase the difficulty of manufacturing. The small pillars are easy to break, affecting the yield.

[0009] In summary, conventional cavity waveguide-fed antenna structures require two-part soldering (SMT or conductive adhesive), resulting in a complex manufacturing process and low yield. Conventional deep-slot waveguides are all implemented using side feeding, but this results in a narrow operating bandwidth. In particular, due to the asymmetry of the antenna's radiation structure, the angle of the maximum gain beam in the elevation plane deflects with frequency. Center-fed solutions often employ complex transition structures in the middle of the radiating plane, resulting in low energy in the center of the antenna and high energy at the ends, resulting in low antenna aperture efficiency. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a deep slot waveguide antenna with an E-plane waveguide feeder, which has a wide working bandwidth, good anti-deflection performance of the maximum gain beam pointing angle in the elevation plane, good aperture efficiency and low side lobes.

[0011] In order to solve the above technical problems, the technical solution adopted by the present invention is: A deep slot waveguide antenna with an E-plane waveguide feeder comprises an E-plane feeder, a deep slot waveguide feeder and a transition structure, wherein one end of the E-plane feeder is connected to the middle position of the deep slot waveguide feeder via the transition structure, the transition structure comprises a through hole and an impedance transformation structure, and the deep slot waveguide feeder comprises a first radiating structure and a second radiating structure, wherein the first radiating structure and the second radiating structure are point-symmetrical about the center point of the through hole.

[0012] Furthermore, the first radiating structure and the second radiating structure respectively include a first step, a second step, a first blind hole, a second blind hole, a third blind hole and a cut corner, the first step and the second step are arranged in sequence along the through hole toward the two ends of the deep slot waveguide feeder, and the height of the first step is higher than the height of the second step, the first blind hole, the second blind hole and the third blind hole are arranged in sequence along the through hole toward the two ends of the deep slot waveguide feeder, and the first blind hole and the third blind hole are arranged on one side of the first radiating structure or the second radiating structure, the second blind hole is arranged on the other side of the first radiating structure or the second radiating structure, and the cut corners are arranged at both ends of the deep slot waveguide feeder.

[0013] Furthermore, the E-plane feeder is equally divided into the upper half of the E-plane feeder and the lower half of the E-plane feeder. The lower half of the E-plane feeder is arranged on the upper side of the first layer board, the upper half of the E-plane feeder is arranged on the lower side of the second layer board, and the deep groove waveguide feeder is arranged on the upper side of the second layer board.

[0014] Furthermore, the width of the E-plane feeder is 1.27 mm, the height of the E-plane feeder is 2.54 mm, the depth of the deep slot waveguide feeder is 3.7 mm, and the width of the deep slot waveguide feeder is 2 mm.

[0015] Furthermore, the through hole is a horn hole whose width gradually decreases from bottom to top, the length of the upper end of the through hole is 2 mm, and the width of the upper end of the through hole is 0.85 mm. The impedance transformation structure is a stepped structure arranged at the end of the E-plane feeder and located below the through hole. The length of the impedance transformation structure is 1.24 mm, and the height of the impedance transformation structure is 0.58 mm.

[0016] Furthermore, the contact surface between the first step and the second step is a step-shaped contact surface, the first length of the first step surface from the end of the first step close to the through hole to the step-shaped contact surface is 4.7 mm, the second length of the first step surface from the end of the first step close to the through hole to the second step surface of the step-shaped contact surface is 3.9 mm, the first length of the second step surface from the end of the second step close to the through hole to the first step surface of the step-shaped contact surface is 1.1 mm, and the second length of the second step surface from the end of the second step close to the through hole to the second step surface of the step-shaped contact surface is 1.9 mm.

[0017] Furthermore, the length of the first blind hole is 2.4 mm, the width of the first blind hole is 0.6 mm, and the end of the first blind hole close to the through hole is flush with the end of the first step close to the through hole. The length of the second blind hole is 2.3 mm, the width of the second blind hole is 0.7 mm, and the end of the second blind hole away from the through hole is flush with the second step surface. The length of the third blind hole is 1.6 mm, the width of the third blind hole is 0.6 mm, and the length of the second step surface is 0.6 mm. The end of the third blind hole away from the through hole is flush with the end of the cut corner close to the through hole. The bottom surfaces of the first blind hole, the second blind hole and the third blind hole are flush with the bottom surface of the deep slot waveguide feeder.

[0018] Furthermore, the cutting angle is 45°.

[0019] Furthermore, a choke slot is provided on each side of the deep slot waveguide feeder, the width of the choke slot is 0.6 mm, the depth of the choke slot is 0.8 mm, and the length of the choke slot is equal to the length of the deep slot waveguide feeder.

[0020] Compared with the prior art, the present invention has the following advantages and effects: 1. The present invention is based on a center-feed solution. The transition to the antenna's radiation structure does not require a conventional baffle or a complex transition structure. Direct coupling and simultaneous radiation are achieved, resulting in a high antenna aperture efficiency. 2. The radiation structure of the present invention can be realized with a blind hole height of less than 1 mm in the deep-trench waveguide. Compared with the partition solution, the processing difficulty is reduced. The plastic metallization solution can reduce the difficulty of electroplating. 3. The present invention uses cutting angles at both ends of the radiation to adjust the amplitude and phase distribution of the electric field of the antenna aperture, achieving a low sidelobe effect without increasing the physical size of the antenna in the elevation direction; 4. Compared with the traditional side-feed solution, the center-feed solution of the present invention has a wider working bandwidth of the antenna, especially the maximum gain beam pointing angle in the elevation plane, which will not deflect with changes in frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a perspective view of a deep slot waveguide antenna of an E-plane waveguide feeder of the present invention.

[0022] Figure 2 It is a schematic diagram of a deep slot waveguide antenna of an E-plane waveguide feeder of the present invention.

[0023] Figure 3 Schematic diagram of the first layer of the present invention.

[0024] Figure 4 Schematic diagram of the second layer board of the present invention.

[0025] Figure 5This is a schematic diagram of the S parameters of a deep slot waveguide antenna of an E-plane waveguide feeder of the present invention at different gaps.

[0026] Figure 6 This is a schematic diagram of the 77 GHz radiation pattern of a deep slot waveguide antenna of an E-plane waveguide feeder of the present invention at different gaps.

[0027] Figure 7 It is a schematic diagram of the directional patterns of a deep slot waveguide antenna of an E-plane waveguide feeder of the present invention at different frequency points. DETAILED DESCRIPTION

[0028] In order to elaborate on the technical solutions adopted by the present invention to achieve the predetermined technical purpose, the technical solutions 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 some embodiments of the present invention, not all embodiments, and the technical means or technical features in the embodiments of the present invention can be replaced without creative work. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0029] like Figure 1 、 Figure 2 and Figure 3 As shown, a deep slot waveguide antenna with an E-plane waveguide feeder of the present invention includes an E-plane feeder 1, a deep slot waveguide feeder 2, and a transition structure 3. One end of the E-plane feeder 1 is connected to the middle position of the deep slot waveguide feeder 2 through the transition structure 3. The E-plane feeder 1 and the deep slot waveguide feeder 2 are perpendicular to each other and the E-plane feeder 1 is located below the deep slot waveguide feeder 2. One end of the E-plane feeder 1 is connected to the midpoint of the deep slot waveguide feeder 2 through the transition structure 3 to form a center feed structure. The transition structure 3 includes a through hole 4 and an impedance transformation structure 5. The deep slot waveguide feeder 2 includes a first radiating structure and a second radiating structure. Since the phase difference of the power divider from the E-plane feeder 1 to the deep slot waveguide feeder 2 is 180°, the first radiating structure and the second radiating structure are point-symmetrical about the center point of the through hole 4.

[0030] like Figure 4 As shown, the first radiation structure and the second radiation structure respectively include a first step 6, a second step 7, a first blind hole 8, a second blind hole 9, a third blind hole 10 and a cut corner 11. The first step 6 and the second step 7 are sequentially arranged along the through hole 4 toward the two ends of the deep slot waveguide feeder 2, and the height of the first step 6 is higher than the height of the second step 7. The first blind hole 8, the second blind hole 9 and the third blind hole 10 are sequentially arranged along the through hole 4 toward the two ends of the deep slot waveguide feeder 2, and the first blind hole 8 and the third blind hole 10 are arranged on one side of the first radiation structure or the second radiation structure, and the second blind hole 9 is arranged on the other side of the first radiation structure or the second radiation structure. The cut corners 11 are arranged at both ends of the deep slot waveguide feeder 2.

[0031] The E-plane feeder 1 is divided into the upper part of the E-plane feeder and the lower part of the E-plane feeder. The lower part of the E-plane feeder is arranged on the upper side of the first layer board 12, the upper part of the E-plane feeder is arranged on the lower side of the second layer board 13, and the deep slot waveguide feeder 2 is arranged on the upper side of the second layer board 13.

[0032] The width of the E-plane feed line 1 is 1.27 mm, the height of the E-plane feed line 1 is 2.54 mm, the depth of the deep slot waveguide feed line 2 is 3.7 mm, and the width of the deep slot waveguide feed line 2 is 2 mm.

[0033] The through hole 4 is a horn hole whose width gradually decreases from bottom to top. The length of the upper end of the through hole 4 is 2 mm, and the width of the upper end of the through hole 4 is 0.85 mm. The impedance transformation structure 5 is a stepped structure arranged at the end of the E-plane feeder 1 and is located below the through hole 4. The length of the impedance transformation structure 5 is 1.24 mm, and the height of the impedance transformation structure 5 is 0.58 mm.

[0034] The contact surface between the first step 6 and the second step 7 is a stepped contact surface. The first length of the first step 6 from the end close to the through hole 4 to the first step surface of the stepped contact surface is 4.7 mm, the second length of the first step 6 from the end close to the through hole 4 to the second step surface of the stepped contact surface is 3.9 mm, the first length of the second step 7 from the end close to the through hole 4 to the first step surface of the stepped contact surface is 1.1 mm, and the second length of the second step 7 from the end close to the through hole 4 to the second step surface of the stepped contact surface is 1.9 mm.

[0035] The length of the first blind hole 8 is 2.4 mm, the width of the first blind hole 8 is 0.6 mm, and the end of the first blind hole 8 close to the through hole 4 is flush with the end of the first step 6 close to the through hole 4. The length of the second blind hole 9 is 2.3 mm, the width of the second blind hole 9 is 0.7 mm, and the end of the second blind hole 9 away from the through hole 4 is flush with the second step surface. The length of the third blind hole 10 is 1.6 mm, the width of the third blind hole 10 is 0.6 mm, and the length of the second step surface is 0.6 mm. The end of the third blind hole 10 away from the through hole 4 is flush with the end of the cut corner 11 close to the through hole 4. The bottom surfaces of the first blind hole 8, the second blind hole 9, and the third blind hole 10 are flush with the bottom surface of the deep slot waveguide feeder 2.

[0036] The angle of the cut corner 11 is 45°.

[0037] like Figure 2 As shown, a choke slot 14 is provided on each side of the deep slot waveguide feeder 2 to reduce surface waves and adjust the antenna's horizontal plane pattern. The choke slot 14 is 0.6 mm wide and 0.8 mm deep, and its length is equal to that of the deep slot waveguide feeder 2.

[0038] In a deep slot waveguide antenna of an E-plane waveguide feeder of the present invention, the other end of the E-plane feeder 1 is connected to the excitation port on the side of the first layer board 12 and the second layer board 13. The antenna signal is fed into the E-plane feeder 1 from the excitation port, and then enters the deep slot waveguide feeder 2 from the other end of the E-plane feeder 1 through the transition structure 3. The signal is equally divided into two signals with a phase difference of 180° in the deep slot waveguide feeder 2 and radiated through the first radiation structure and the second radiation structure.

[0039] The deep slot waveguide antenna of the E-plane waveguide feeder of the present invention can be realized by a two-layer structure in the 77GHz frequency band, and the deep slot structure only requires a single layer. When the two-layer structure E-plane feeder is cut in the middle, the current is not cut, so there is very little leakage of electromagnetic waves, and it can be installed by hot melting, screwing and other processes.

[0040] like Figure 5 The figure shows a schematic diagram of the S parameters of a deep slot waveguide antenna of an E-plane waveguide feeder of the present invention at different gaps. The S11 of the waveguide conversion in the three cases is below -12.5dB in the frequency band of 75-81GHz and below -15dB in the frequency band of 76-79GHz.

[0041] like Figure 6 The figure shows a schematic diagram of the 77GHz radiation pattern of a deep slot waveguide antenna with an E-plane waveguide feeder of the present invention at different gaps. The peak gain of the antenna is 15.5dB at a gap of 0mm, and the peak gain of the antenna is 15.35dB at a gap of 0.2mm, which only decreases by 0.15dB. The elevation sidelobe of the antenna decreases from -23dB at a gap of 0mm to -20dB at a gap of 0.2mm, which is a small difference. The radiation pattern of the antenna is relatively smooth, indicating that there is no leakage of electromagnetic waves. It can be seen that the antenna can operate normally without achieving a gap of 0mm. The present invention has a large redundancy in the assembly between the two layers of the waveguide antenna.

[0042] like Figure 7 The figure shows a schematic diagram of the directional pattern of a deep slot waveguide antenna with an E-plane waveguide feeder of the present invention at different frequencies. The antenna peak gain is around 15.5dB, the antenna has good frequency consistency, and the side lobes are basically between -21dB and -23dB. Because the antenna is a center-fed solution, the antenna is structurally symmetrical. The antenna's elevation plane directional pattern at different frequencies is well symmetrical, and the maximum beam pointing angle is 0°.

[0043] The present invention is based on a center-feed solution, and the transition to the antenna's radiation structure does not require the use of conventional baffles or complex transition structures. Radiation is achieved while directly coupling, so the antenna has a high aperture efficiency. The radiation structure of the present invention can be achieved when the height of the blind hole in the deep-groove waveguide is less than 1 mm. Compared with the baffle solution, the processing difficulty is reduced, and the plastic metallization solution is used to reduce the difficulty of electroplating. The present invention uses cutting angles at both ends of the radiation to adjust the amplitude and phase distribution of the antenna aperture electric field, and achieves a low sidelobe effect without increasing the physical size of the antenna in the elevation direction. Compared with the traditional side-feed solution, the center-feed solution of the present invention has a wider working bandwidth of the antenna, especially the maximum gain beam pointing angle in the elevation plane, which will not deflect with changes in frequency.

[0044] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A deep slot waveguide antenna with an E-plane waveguide feeder, characterized in that: It includes an E-plane feeder, a deep slot waveguide feeder and a transition structure. One end of the E-plane feeder is connected to the middle position of the deep slot waveguide feeder through the transition structure. The transition structure includes a through hole and an impedance transformation structure. The deep slot waveguide feeder includes a first radiation structure and a second radiation structure. The first radiation structure and the second radiation structure are point-symmetrical about the center point of the through hole.

2. The deep slot waveguide antenna of the E-plane waveguide feeder according to claim 1, characterized in that: The first radiation structure and the second radiation structure respectively include a first step, a second step, a first blind hole, a second blind hole, a third blind hole and a cut corner. The first step and the second step are arranged in sequence along the through hole toward the two ends of the deep slot waveguide feeder, and the height of the first step is higher than the height of the second step. The first blind hole, the second blind hole and the third blind hole are arranged in sequence along the through hole toward the two ends of the deep slot waveguide feeder, and the first blind hole and the third blind hole are arranged on one side of the first radiation structure or the second radiation structure, and the second blind hole is arranged on the other side of the first radiation structure or the second radiation structure. The cut corners are arranged at both ends of the deep slot waveguide feeder.

3. The deep slot waveguide antenna of the E-plane waveguide feeder according to claim 1, characterized in that: The E-plane feeder is equally divided into an upper part of the E-plane feeder and a lower part of the E-plane feeder. The lower part of the E-plane feeder is arranged on the upper side of the first layer board, the upper part of the E-plane feeder is arranged on the lower side of the second layer board, and the deep groove waveguide feeder is arranged on the upper side of the second layer board.

4. The deep slot waveguide antenna of the E-plane waveguide feeder according to claim 1, characterized in that: The width of the E-plane feeder is 1.27 mm, the height of the E-plane feeder is 2.54 mm, the depth of the deep slot waveguide feeder is 3.7 mm, and the width of the deep slot waveguide feeder is 2 mm.

5. The deep slot waveguide antenna of the E-plane waveguide feeder according to claim 1, characterized in that: The through hole is a horn hole whose width gradually decreases from bottom to top. The length of the upper end of the through hole is 2 mm, and the width of the upper end of the through hole is 0.85 mm. The impedance transformation structure is a stepped structure arranged at the end of the E-plane feeder and located below the through hole. The length of the impedance transformation structure is 1.24 mm, and the height of the impedance transformation structure is 0.58 mm.

6. The deep slot waveguide antenna of the E-plane waveguide feeder according to claim 1, characterized in that: The contact surface between the first step and the second step is a step-shaped contact surface, the first length of the first step surface from the end of the first step close to the through hole to the step-shaped contact surface is 4.7 mm, the second length of the first step surface from the end of the first step close to the through hole to the second step surface of the step-shaped contact surface is 3.9 mm, the first length of the second step surface from the end of the second step close to the through hole to the first step surface of the step-shaped contact surface is 1.1 mm, and the second length of the second step surface from the end of the second step close to the through hole to the second step surface of the step-shaped contact surface is 1.9 mm.

7. The deep slot waveguide antenna of the E-plane waveguide feeder according to claim 6, characterized in that: The length of the first blind hole is 2.4 mm, the width of the first blind hole is 0.6 mm, and the end of the first blind hole close to the through hole is flush with the end of the first step close to the through hole. The length of the second blind hole is 2.3 mm, the width of the second blind hole is 0.7 mm, and the end of the second blind hole away from the through hole is flush with the second step surface. The length of the third blind hole is 1.6 mm, the width of the third blind hole is 0.6 mm, and the length of the second step surface is 0.6 mm. The end of the third blind hole away from the through hole is flush with the end of the cut corner close to the through hole. The bottom surfaces of the first blind hole, the second blind hole and the third blind hole are flush with the bottom surface of the deep slot waveguide feeder.

8. The deep slot waveguide antenna of the E-plane waveguide feeder according to claim 6, characterized in that: The angle of the cutting angle is 45°.

9. The deep slot waveguide antenna of the E-plane waveguide feeder according to claim 1, characterized in that: A choke slot is provided on each side of the deep slot waveguide feeder. The width of the choke slot is 0.6 mm, the depth of the choke slot is 0.8 mm, and the length of the choke slot is equal to the length of the deep slot waveguide feeder.

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