High gain high order mode patch array antenna based on single-layer ridge gap waveguide feed

Abstract

The application discloses a high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding, and particularly relates to the technical field of wireless communication, and solves the technical problem that in the prior art, an antenna array adopts a single-layer gap waveguide feeding technology, at high frequencies, a smaller unit spacing limits the size of a metal ridge and a metal pin, high machining precision is required, more antenna units are required for high gain, and great pressure is exerted on the layout and design of a single-layer feeding network; a technical scheme is as follows: one substrate layer and one metal feeding layer are arranged in a stack, the substrate layer is provided with metal patch units on the upper surface, and the metal feeding layer is provided with a waveguide metal ridge and a plurality of periodically arranged metal columns above the metal feeding layer; the high-order mode TM 30 of the metal patch units is used as a radiation mode to achieve high gain.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding. Background Art

[0002] With the development of communication systems, the demand for high-speed transmission is increasing. The millimeter wave band is considered a promising option for meeting these requirements due to its ample bandwidth and ease of integration. The 60 GHz band (57-64 GHz) has attracted much attention because it provides the large bandwidth necessary for real-time high-data-rate transmission, especially for applications such as high-definition video streaming. However, signals operating in this frequency band are primarily affected by significant losses caused by atmospheric absorption. Therefore, 60 GHz wireless systems require high-gain antennas to minimize propagation losses.

[0003] Currently, there are various antenna forms that achieve high gain, such as traditional lens antennas, reflector antennas, and horn antennas. However, these antennas have disadvantages such as large size, high manufacturing cost, and difficulty in integration. The emergence of high-order mode patch antennas has become an alternative to achieve high gain, as they combine the advantages of microstrip antennas such as low profile, light weight, low cost, and easy integration. High-order mode patch antennas have high directivity due to their large radiation aperture, but this is accompanied by increased sidelobes, which is something that needs to be avoided as much as possible in directional antennas. Sidelobes can usually be suppressed by engraving transverse grooves on the patch.

[0004] To achieve high-gain and high-efficiency antenna arrays, a low-loss feeding network is necessary. Substrate integrated waveguide (SIW) feeding and rectangular waveguide feeding are two commonly used feeding technologies in millimeter wave feeding networks. SIW feeding is widely used in planar antenna arrays due to its compact size and high design freedom, but as the frequency increases, the low efficiency problem caused by dielectric loss becomes increasingly apparent. The rectangular waveguide feeding network has the advantage of low loss, but the existing waveguide antenna is mainly prepared by layered disassembly processing, and then assembled layer by layer through surface mounting technology. Good electrical contact is required between the surfaces of adjacent manufactured parts, which places high requirements on the flatness of the connection surface, resulting in a sharp increase in manufacturing costs.

[0005] The gap waveguide is an all-metal waveguide structure based on the electromagnetic bandgap principle. It has the advantages of low loss and does not require very good electrical contact between the metal layers, which reduces the precision requirements for processing and array formation. Therefore, it has been widely used in the design and manufacture of millimeter wave antenna arrays. At present, in gap waveguide-fed antenna arrays at higher frequencies such as the 60GHz band or the W band, an additional back cavity layer is required to reduce the complexity and processing difficulty of the feeding network, resulting in increased manufacturing costs and prone to misalignment during the assembly process. Therefore, some antenna arrays use single-layer gap waveguide feeding technology, but at high frequencies, the small unit spacing of the antenna limits the size of the metal ridges and metal pins, requiring high processing precision. In addition, high gain usually requires more antenna units, which puts great pressure on the layout and design of the single-layer feeding network. Summary of the Invention

[0006] Therefore, the present invention solves the technical problem that the antenna array in the prior art adopts the single-layer gap waveguide feeding technology, but at high frequencies, the small unit spacing of the antenna limits the size of the metal ridge and metal pins, requiring high processing precision. In addition, high gain usually requires more antenna units, which puts great pressure on the layout and design of the single-layer feeding network. The present invention provides a 60GHz frequency band high-gain high-order mode patch antenna array based on a single-layer ridge gap waveguide. By adopting the high-order mode of the patch antenna, the gain of the antenna unit is improved, thereby greatly improving the array gain without increasing the number of antenna units. At the same time, due to the large size and unit spacing of the patch antenna unit, the gap waveguide feeding network has a higher design space and degree of freedom, which greatly promotes the implementation of the single-layer ridge gap waveguide feeding network.

[0007] The inventive concept of the present invention is as follows: The 60GHz band high-gain high-order mode patch antenna array based on a single-layer ridge gap waveguide comprises a substrate layer and a metal feed layer stacked one above the other. The upper surface of the substrate layer is provided with 64 metal patch units arranged in an 8×8 periodic pattern. Above the metal layer are waveguide metal ridges and several periodically arranged metal pillars. By utilizing the high-order modes TM of the metal patch units, the high-order modes TM 30 The high-order mode is used as the radiation mode to achieve high gain. Since the patch units that utilize high-order mode radiation are larger in size and distance between units, it provides greater design space and freedom for the gap waveguide feeding network. Only one layer of feeding network is needed to feed all patch units.

[0008] In order to achieve the above-mentioned invention objectives, the present invention adopts a technical solution specifically as follows: a high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding, comprising a substrate layer and a metal feeding layer stacked from top to bottom; the upper surface of the substrate layer is provided with 64 metal radiation patch units arranged in an 8×8 array periodically, and the lower surface is provided with a metal ground; a plurality of periodically arranged metal columns and waveguide metal ridges are provided above the feed layer, and the waveguide metal ridges are used to transmit electromagnetic waves; the metal columns and waveguide metal ridges are combined to form a ridge gap waveguide feeding network;

[0009] Furthermore, the metal ground is provided with coupling gaps, the number and position of which correspond to the metal patch units, for coupling electromagnetic waves to the metal patches.

[0010] Furthermore, the metal radiating patch unit size is 4.4mm x 4.4mm, with a 6mm inter-unit spacing. The larger unit size and inter-unit spacing of the patch antenna provide greater design freedom and flexibility for the gap waveguide feed network, greatly facilitating the implementation of a single-layer ridge gap waveguide feed network.

[0011] Furthermore, three symmetrically distributed transverse slots are provided in the middle area of ​​the metal patch to achieve sidelobe suppression. The first and third slots are located on the edge sides of the patch and are equal in size, measuring 1.2mm×0.9mm. The second slot is located in the center of the patch and is 1.1mm×0.9mm in size.

[0012] Furthermore, there is an air gap between the metal column and the lower surface of the substrate layer; the size of the air gap is 0.05mm-1mm.

[0013] Furthermore, the height of the waveguide metal ridge is lower than the height of the metal column.

[0014] Furthermore, the waveguide metal ridge coupling end is located directly below each radiation patch unit and is connected to the rectangular waveguide-ridge gap waveguide conversion section through a 1-to-64 metal power divider; the waveguide metal ridge is composed of a metal ridge coupling end, a rectangular waveguide-ridge gap waveguide conversion section and a T-type ridge gap waveguide power divider, the rectangular waveguide-ridge gap waveguide conversion section is connected to the T-type ridge gap waveguide power divider, and the T-type ridge gap waveguide power divider is connected to the metal ridge coupling end, and the number of metal ridge coupling ends corresponds to the number of radiation patch units.

[0015] Furthermore, the 1-to-64 metal power divider is composed of several T-shaped ridge gap waveguide power dividers. The signal is transmitted to the inner side of the waveguide metal ridge through the 1-to-64 metal power divider, thereby achieving equal amplitude and in-phase feeding of the metal radiation patch unit.

[0016] Furthermore, a flange interface connected to the WR-15 input waveguide is provided on the rectangular waveguide port side of the rectangular waveguide-ridge-slot waveguide conversion section, and a step-shaped structure is provided at the connection between the rectangular waveguide-ridge-slot waveguide conversion section and the rectangular waveguide port for achieving impedance matching.

[0017] Furthermore, the dielectric constant of the substrate is 2.2, and the loss factor is 0.0009.

[0018] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0019] 1. The present invention provides a high-gain, high-order mode patch array antenna based on single-layer ridge-slot waveguide feeding. It uses the high-order mode TM30 of the patch antenna as its radiation pattern, significantly improving the array gain without adding additional antenna units, thus avoiding the use of a more complex feeding network.

[0020] 2. This invention provides a high-gain, high-order mode patch array antenna based on a single-layer ridge-gap waveguide feed, employing low-loss gap waveguide feeding. Due to the use of patch high-order modes, the antenna elements and their spacing are larger, and the gap waveguide offers greater design flexibility and controllability. This allows for greater distances between metal pillars and ridges, reduces CNC machining difficulty and costs, and improves product yield.

[0021] 3. The present invention provides a high-gain, high-order mode patch array antenna based on a single-layer ridge-gap waveguide feed. This antenna requires only a single-layer feed network, avoiding the potential misalignment during assembly caused by multi-layer feed systems. The antenna's radiating layer utilizes low-profile, low-cost PCB technology. The upper and lower layers have a simple structure and require no electrical contact, requiring only pre-reserved threaded holes for fastening. The overall assembly process is simple. Compared to existing technologies, this invention offers advantages such as low processing difficulty, low profile, high gain, and high efficiency, resulting in high commercial applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0023] Figure 1 Shown is an exploded view of an 8×8 array of high-gain high-order mode patch array antennas based on single-layer ridge gap waveguide feeding according to the present invention;

[0024] Figure 2 Schematic diagram of the feeding layer structure of an 8×8 array of high-gain high-order mode patch array antennas based on single-layer ridge gap waveguide feeding according to the present invention;

[0025] Figure 3 Shown is an exploded view of a high-gain high-order mode patch array antenna unit based on single-layer ridge gap waveguide feeding of the present invention;

[0026] Figure 4a Schematic diagram of the ridge gap waveguide metal column unit of the present invention

[0027] Figure 4b Shown Figure 4a Schematic diagram of the dispersion curve formed by the proposed size;

[0028] Figure 5 The figure shows a schematic diagram of the exploded structure of a 2×2 sub-array of a high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to the present invention;

[0029] Figure 6 Shown is a schematic structural diagram of a one-to-two power splitter according to the present invention;

[0030] Figure 7 The figure shows a schematic structural diagram of a rectangular waveguide-ridge gap waveguide transition section of the present invention;

[0031] Figure 8 The figure shows the S11 parameter simulation and test result curve of the 8×8 array high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding of the present invention;

[0032] Figure 9 Shown are the radiation patterns of an 8×8 array of high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding of the present invention at 57 GHz and 63 GHz respectively;

[0033] Figure 10 Shown is an 8×8 array gain curve of a high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding of the present invention;

[0034] Description of reference numerals:

[0035] 1. Substrate layer; 2. Metal radiation patch unit; 21. Horizontal gap; 3. Metal ground; 31. Coupling gap; 4. Feed layer; 41. Metal column; 42. Waveguide metal ridge; 421. Metal ridge coupling end; 422. T-waveguide-ridge gap waveguide conversion section; 423. T-type ridge gap waveguide power divider; 43. Metal frame; 44. Flange interface; 51. Threaded hole; 52. Positioning hole. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] This embodiment provides a high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding, such as Figures 1 to 7 As shown, it includes a substrate layer 1 and a metal feed layer 4. The upper surface of the substrate layer 1 is provided with 64 metal radiation patch units 2, and the metal radiation patch units 2 are arranged in an 8×8 periodic pattern. The working mode of the metal radiation patch unit 2 is TM 30 Mode. The length and width w1 of the patch are equal, both are 4.4mm, and the spacing D between the metal radiation patch units 2 is set to 6mm, that is, 1.2λ0. Three symmetrically distributed transverse slots 21 are provided in the middle area of ​​the metal radiation patch unit 2 to achieve sidelobe suppression. The first slot and the third slot are located on the edge side of the patch and are equal in size, and the second slot is located in the center of the patch. A metal ground 3 is provided on the lower surface of the substrate layer 1, and the metal ground 3 is provided with the same number of coupling slots 31 as the metal radiation patch units 2. Each coupling slot 31 is located directly below each metal radiation patch unit 2. Several positioning holes 52 are provided on the outer periphery of the substrate layer 1 to facilitate assembly with the feed layer 4. The dielectric constant of the substrate layer 1 is 2.2, the loss angle is 0.0009, and the thickness is 0.5mm. The effective radiation aperture of the array composed of 64 metal radiation patch units 2 is 48mm×48mm

[0038] The metal feed layer 4 is provided with a plurality of raised metal pillars 41 and a waveguide metal ridge 42. A metal frame 43 is provided on the outer periphery of the feed layer 4. The metal frame 43 is at the same height as the metal pillar 41. The waveguide metal ridge 42 is composed of a metal ridge coupling end 421, a rectangular waveguide-ridge gap waveguide conversion section 422 and a T-shaped ridge gap waveguide power divider 423. The metal frame 43 is provided with a plurality of threaded holes 51, the size and position of which correspond to the positioning holes 52. The structure of the raised periodic metal pillar 41 is as follows: Figure 3As shown, its width w is 0.7mm, height h is 1.6mm, pitch p is 1.6mm, and air gap g is 0.05mm. The dispersion curve formed according to the proposed dimensions is shown in Figure 4. In the frequency range of 42-80.9GHz, electromagnetic waves in modes 1, 2, and 3 cannot propagate in the array formed by the periodic metal pillars, and are in a stopband state. Within this frequency range, electromagnetic waves will propagate along the waveguide metal ridge 42 between the electromagnetic band gap structure formed by the periodic metal pillars 41 on both sides. Because an air gap is allowed between the upper surface of the metal pillars 41 and the metal ground 3, there is no need for close contact or electrical connection between the two. At the same time, some unevenness in the substrate layer 1 and the feed layer 4 is allowed, which greatly increases the assembly tolerance and requires only screw assembly, reducing the assembly difficulty. In addition, due to the larger antenna unit size and unit spacing in the present invention, the metal pillars 41 and waveguide metal ridge 42 in the feed layer 4 can be designed with larger dimensions. This allows the use of a larger diameter milling cutter during processing, greatly reducing the processing difficulty.

[0039] The structure of the T-type ridge gap waveguide power divider 423 and the rectangular waveguide-ridge gap waveguide conversion section 422 on the feeding layer 4 is shown in FIG. Figure 6 and Figure 7 The T-shaped ridge-gap waveguide power divider 423 structure includes a T-shaped metal ridge and metal pillars 41 arranged around it. The rectangular waveguide-ridge-gap waveguide transition section 422 includes a stepped transition section from the rectangular waveguide opening at the flange interface 44 to the waveguide metal ridge 42. The first step transition section is lower than the waveguide metal ridge 42 and has the same width as the waveguide metal ridge 42, with a portion extending from the rectangular waveguide opening to improve matching.

[0040] like Figure 8 The S11 parameter simulation result curve of the antenna array shown in the figure shows that the antenna -10dB impedance bandwidth range is 56.5-65.6GHz, which can cover the commonly used frequency band of 57-64GHz in the 60GHz band. Figure 9 The antenna array's radiation pattern at 60 GHz is shown in the figure, with good in-band radiation patterns, sidelobes below 14 dB, and cross-polarization less than -35 dB. The antenna array's gain diagram, shown in the figure, shows in-band gain exceeding 29.5 dBi, peak gain reaching 30.3 dBi, and aperture efficiency exceeding 78%, reaching a maximum of 95%.

[0041] The present invention combines a ridge gap waveguide with a high-order mode patch antenna, utilizing the high-gain characteristics of the high-order mode patch antenna to greatly improve the gain of the array without increasing the number of antenna units, thus avoiding the use of a more complex feeding network. At the same time, the large unit size and large unit spacing of the high-order mode patch antenna are utilized to greatly reduce the design and processing difficulty of the ridge gap waveguide feeding network, and only a single feeding layer is required to achieve feeding.

[0042] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding, characterized in that: The invention comprises a substrate layer (1) and a metal feed layer (4) stacked from top to bottom; the upper surface of the substrate layer (1) is provided with a plurality of periodically arranged metal radiation patch units (2); the lower surface of the substrate layer (1) is provided with a metal ground (3); a feed layer (4) is provided below the metal ground (3); the upper surface of the feed layer (4) is provided with a plurality of periodically arranged metal columns (41) and waveguide metal ridges (42), and the waveguide metal ridges (42) are used to transmit electromagnetic waves; the outer periphery of the feed layer (4) is provided with a raised metal frame (43); the working mode of the metal radiation patch unit (2) is TM 30 The invention relates to a mold; the middle area of ​​the metal radiation patch unit (2) is provided with three symmetrically distributed transverse slots (21) for achieving sidelobe suppression, the first slot and the third slot are located at the edge side of the patch and are equal in size, and the second slot is located at the center of the patch; the lower surface of the substrate layer (1) is provided with a metal ground (3), and the metal ground (3) is provided with a number of coupling slots (31) equal to the number of the metal radiation patch units (2); each coupling slot (31) is correspondingly located directly below each metal radiation patch unit (2).

2. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 1, characterized in that: The waveguide metal ridge (42) consists of a metal ridge coupling end (421), a rectangular waveguide-ridge gap waveguide conversion section (422), and a T-shaped ridge gap waveguide power divider (423).

3. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 2, characterized in that: The metal frame (43) is provided with a threaded hole (51), and the outer side of the substrate layer (1) is provided with a positioning hole (52); the positions, sizes and numbers of the threaded hole (51) and the positioning hole (52) correspond to each other.

4. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 3, characterized in that: Each of the metal radiation patch units (2) operates in a TM30 mode, and each of the metal radiation patch units (2) is provided with three transverse slits (21).

5. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 4, characterized in that: The metal ground (3) is provided with coupling slots (31), the number and positions of the coupling slots (31) corresponding to the metal radiation patch unit (2), and are used to couple electromagnetic waves to the metal radiation patch unit (2).

6. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 5, characterized in that: There is an air gap between the metal column (41) and the lower surface of the substrate layer (1); the size of the air gap is 0.05mm-1mm.

7. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 6, characterized in that: The height of the waveguide metal ridge (42) is lower than the height of the metal column (41).

8. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 7, characterized in that: The metal ridge coupling end (421) is located below each metal radiation patch unit (2) and is connected to the rectangular waveguide-ridge gap waveguide conversion section (422) via a 1-to-64 power divider composed of a T-shaped ridge gap waveguide power divider (423).

9. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 8, characterized in that: A flange interface (44) connected to a WR-15 input waveguide is provided on the outside of the rectangular waveguide-ridge gap waveguide conversion section (422), and a signal is transmitted to the inside of the waveguide metal ridge (42) through a 1-to-64 power divider; and a stepped structure is provided at one end of the rectangular waveguide-ridge gap waveguide conversion section (422) close to the flange interface (44) for achieving impedance matching.

10. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding according to claim 8, characterized in that: There are 64 metal radiation patch units (2) in total, which are arranged in an 8×8 periodic arrangement.

Images