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

Abstract

The invention discloses a high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feed, particularly relates to the technical field of wireless communication, and solves the problems that an antenna array in the prior art adopts a single-layer gap waveguide feed technology, the sizes of a metal ridge and a metal pin are limited by a small unit interval at high frequency, high processing precision is needed, and the antenna array is inconvenient to use. The high gain needs more antenna units, and huge pressure is applied to the layout and design of a single-layer feed network; according to the technical scheme, a substrate layer and a metal feed layer are stacked up and down, a metal patch unit is arranged on the upper surface of the substrate layer, and a wave guide metal ridge and a plurality of periodically arranged metal columns are arranged above the metal feed layer. The high-order mode TM30 mode of the metal patch unit is used as a radiation mode, and high gain is achieved.

Description

Technical Field

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

[0002] As communication systems develop, the demand for high-speed transmission is growing. The millimeter wave band is seen as one of the promising options to meet these requirements due to its sufficient bandwidth and easy integration. The 60GHz band (57-64GHz) has attracted much attention because it provides a large amount of bandwidth necessary for real-time high data rate transmission, especially for application scenarios such as high-definition video streaming. However, signals operating in this frequency band are mainly affected by large losses caused by atmospheric absorption. Therefore, 60GHz wireless systems need to use high-gain antennas to minimize propagation losses.

[0003] At present, there are many forms of antennas that can achieve high gain, such as traditional lens antennas, reflector antennas and horn antennas, but 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 optional alternative to achieve high gain, because it combines 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 an increase in side lobes, which needs to be avoided as much as possible in directional antennas. Side lobes 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 with the increase of frequency, the low efficiency problem caused by dielectric loss becomes increasingly obvious. The rectangular waveguide feeding network has the advantage of low loss, but the existing waveguide antenna is mainly prepared by layered disassembly 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 the 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 smaller 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 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 the metal pin, 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 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 unit size and unit spacing of the patch antenna, 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 of the present invention comprises a substrate layer and a metal feeding layer stacked up and down. The upper surface of the substrate layer is provided with 64 metal patch units arranged in an 8×8 periodic pattern. A waveguide metal ridge and a plurality of periodically arranged metal columns are provided above the metal layer. By utilizing the high-order mode TM of the metal patch unit 30 The mode is used as the radiation mode to achieve high gain. Since the size of the patch unit and the distance between units using the high-order mode radiation are large, it provides greater design space and freedom for the gap waveguide feeding network, and only one layer of feeding network is needed to realize the feeding of all patch units.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is specifically: 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 feeding layer, and the waveguide metal ridges are used to transmit electromagnetic waves; the metal columns and the 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 unit size of the metal radiation patch is 4.4mm×4.4mm, and the distance between units is 6mm. The unit size and unit distance of the patch antenna are large, and 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.

[0011] Furthermore, three symmetrically distributed transverse gaps are provided in the middle area of ​​the metal patch to achieve sidelobe suppression. The first gap and the third gap are located at the edge of the patch and are equal in size, 1.2mm×0.9mm. The second gap 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, 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 a plurality of 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 to achieve 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 gap waveguide conversion section, and a step-shaped structure is provided at the connection between the rectangular waveguide-ridge gap 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 angle 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 gap waveguide feeding, which adopts the high-order mode TM30 mode of the patch antenna as its radiation mode, greatly improving the array gain without adding additional antenna units, thereby avoiding the use of a more complex feeding network.

[0020] 2. The present invention provides a high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding, which adopts low-loss gap waveguide feeding. Due to the use of high-order modes of patches, the antenna units and unit spacing are larger, the gap waveguide has a higher design space and controllability, the distance between metal columns and metal ridges can be larger, and the difficulty and cost are reduced during CNC processing, and the product yield is improved.

[0021] 3. The high-gain high-order mode patch array antenna based on single-layer ridge gap waveguide feeding provided by the present invention only requires a single-layer feeding network, avoiding the disadvantage of misalignment during assembly that may be caused by multi-layer feeding. The antenna radiation layer adopts low-profile, low-cost PCB technology, the upper and lower layers have simple structures, and no good electrical contact is required. Only reserved threaded holes are required for fixing, and the overall assembly process is simple. Compared with the prior art, the present invention has the advantages of low processing difficulty, low profile, high gain, high efficiency, etc., and has high commercial practicality. 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 drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded 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 It is a 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 of 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 of the present invention;

[0029] Figure 6 The figure shows a schematic diagram of the structure of a one-to-two power divider of the present invention;

[0030] Figure 7 The figure shows a schematic diagram of the structure of a rectangular waveguide-ridge gap waveguide conversion 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] Fig. 9 Shown are the radiation patterns of the 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] Fig.10 The figure shows the 8×8 array gain curve of the 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 arrangement. The working mode of the metal radiation patch unit 2 is TM 30 The length and width w1 of the patch are equal, both are 4.4 mm, and the spacing D of the metal radiation patch unit 2 is set to 6 mm, that is, 1.2λ 0 . 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 on the edge side of the patch and are equal in size. 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 coupling slots 31 of the same number as the metal radiation patch unit 2. Each coupling slot 31 is located directly below each metal radiation patch unit 2. A number of positioning holes 51 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 has 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 52, the size and position of which correspond to the positioning holes 51. 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, spacing p is 1.6mm, and air gap g is 0.05mm. The dispersion curve formed according to the proposed size is shown in Figure 4, where mode 1, mode 2 and mode 3, in the frequency range of 42-80.9GHz, electromagnetic waves cannot propagate in the array formed by periodic metal columns, and are in a stopband state. In this frequency range, electromagnetic waves will propagate along the waveguide metal ridge 42 between the electromagnetic band gap structure formed by the periodic metal columns 41 on both sides. Since an air gap is allowed between the upper surface of the metal column 41 and the metal ground 3, there is no need for the two to be closely fitted or electrically connected, and at the same time, a certain degree of unevenness is allowed between the substrate layer 1 and the feed layer 4, so that the assembly tolerance is greatly increased, and only screw assembly is required, and the assembly difficulty is low. In addition, since the antenna unit size and unit spacing in the present invention are large, the metal column 41 and the waveguide metal ridge 42 in the feed layer 4 can be designed with larger sizes, which allows a larger diameter milling cutter to be used during processing, greatly reducing the processing difficulty.

[0039] The structure diagram 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 as shown in FIG. Figure 6 and Figure 7 As shown. The structure of the T-shaped ridge gap waveguide power divider 423 includes a section of T-shaped metal ridge and metal pillars 41 arranged around it. The rectangular waveguide-ridge gap waveguide conversion section 422 includes a stepped transition section from the rectangular waveguide opening at the flange interface 44 to the ridge gap waveguide 42, with one step, the first step transition section is lower than the waveguide metal ridge 42 in height, has the same width as the waveguide metal ridge 42, and partially extends 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. Fig. 9 The radiation pattern of the antenna array at 60GHz is shown in the figure. The in-band radiation pattern is good, the side lobe is less than 14dB, and the cross polarization is less than -35dB. The gain diagram of the antenna array shown in the figure shows that the in-band gain is greater than 29.5dBi, the peak gain is 30.3dBi, the aperture efficiency is greater than 78%, and the highest reaches 95%.

[0041] The present invention combines a ridge gap waveguide with a high-order mode patch antenna, and utilizes the high-gain characteristic of the high-order mode patch antenna to greatly improve the gain of the array without increasing the number of antenna units, thereby avoiding the use of a more complex feeding network. At the same time, the characteristics of the large unit size and large unit spacing of the high-order mode patch antenna are utilized, so that the design and processing difficulty of the ridge gap waveguide feeding network is greatly reduced, and feeding can be achieved with only a single feeding layer.

[0042] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

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 (2) 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 arranged 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), the waveguide metal ridges (42) being used to transmit electromagnetic waves; and a raised metal frame (43) is provided on the outer periphery of the feed layer (4).

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 holes (51) and the positioning holes (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 the TM30 mode, and each of the metal radiation patch units (2) is provided with three transverse gaps (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 position of the coupling slots (31) correspond to the metal radiation patch unit (2), and are used to couple electromagnetic waves to the metal 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 radiation patch unit (2) and is connected to the rectangular waveguide-ridge gap waveguide conversion section (422) through 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 arranged outside 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 1:64 power divider; and a step-shaped structure is arranged 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.

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