Millimeter wave array antenna with high radiation efficiency

Abstract

The invention relates to a millimeter wave high-radiation-efficiency array antenna technology, in particular to a millimeter wave high-radiation-efficiency array antenna which sequentially comprises a radiation slot layer, a resonant coupling layer and a waveguide feed layer from top to bottom, the array antenna is composed of 16 * 16 antenna sub-arrays, and each antenna sub-array comprises 2 * 2 radiation slot units. The scale of the array antenna is 32 * 32 radiation slot units. The antenna array is compact in structure, wide in broadband and high in radiation efficiency.

Description

Technical Field

[0001] The present invention relates to a millimeter wave high radiation efficiency array antenna technology, and in particular to a millimeter wave high radiation efficiency array antenna. Background Art

[0002] With the rapid development of military and civilian communication technologies, the demand for communication system capacity has increased dramatically. In the millimeter wave frequency band, spectrum resources are particularly abundant. It has the characteristics of microwaves and far infrared waves, and has the advantages of narrow beam, wide bandwidth, and high reliability. Therefore, millimeter wave technology is widely used in radar, remote sensing, communication, automobile and other fields. At the same time, millimeter wave antenna technology and millimeter wave device performance have made great progress.

[0003] Antennas that work in the millimeter wave frequency band are called millimeter wave antennas. The gain of a single antenna is limited and often cannot meet the needs of signal transmission in a specific direction. Therefore, the industry often uses multiple unit antennas to form an array antenna to obtain high gain. As the number of unit antenna arrays increases, the corresponding feeding network scale also increases. Traditional microstrip patch antennas produce serious surface wave effects in the millimeter wave frequency band, and high dielectric loss becomes unacceptable. The all-metal waveguide slot antenna has no dielectric loss, high power capacity, and can be completed by machining. It is widely used in the fields of communications and radar.

[0004] However, the existing millimeter-wave waveguide slot antennas still have shortcomings such as narrow bandwidth and large size. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention proposes a millimeter-wave high radiation efficiency array antenna. The array antenna includes a radiation slot layer, a resonant coupling layer, and a waveguide feeding layer from top to bottom. The array antenna is composed of 16×16 antenna subarrays, each antenna subarray includes 2×2 radiation slot units. Therefore, the array antenna has a total of 32×32 radiation slot units.

[0006] Furthermore, the radiation slot layer consists of 32×32 radiation slot units, each radiation slot unit includes a first slot and a second slot, the first slot and the second slot are rectangular slots that are perpendicular to each other and overlap, the length of the first slot is greater than the length of the second slot and the width of the first slot is less than the width of the second slot.

[0007] Furthermore, the length, width and thickness of the first gap are 5.2 mm, 4.8 mm and 1.55 mm, and the length, width and thickness of the second gap are 2.2 mm, 5.5 mm and 1 mm.

[0008] Furthermore, the resonant coupling layer is composed of 16×16 resonant cavities, including a bowtie-type coupling gap arranged at the center of each resonant cavity, and a boss is arranged on both sides of the resonant cavity corresponding to the narrowest position of the bowtie-type coupling gap.

[0009] Furthermore, the bowtie-type coupling gap has a length of 3.8 mm, a size of 2.1 mm at the widest point, a size of 1.3 mm at the narrowest point, and a thickness of 0.7 mm.

[0010] Furthermore, the waveguide feeding layer is composed of a one-to-two equal-power stage cascade, ultimately forming a one-to-256 waveguide feeding network.

[0011] Furthermore, the one-sixteenth waveguide feeding network includes four T-shaped ridges and three straight ridges, and every two antenna substructures are merged using one lateral end of the T-shaped ridge, and the two lateral ends of the T-shaped ridge are merged together. The ends of every two T-shaped ridges are connected to one end of an straight ridge, and one end of three straight ridges are connected together, and one end of one straight ridge serves as the feed and port of the 4×4 antenna array.

[0012] Furthermore, the vertical part of the T-shaped ridge adopts a transformation structure, that is, the vertical part is formed by splicing two sections of metal structures with different lengths, widths and thicknesses.

[0013] Furthermore, the length, width and thickness of the transverse part of the T-shaped ridge are 5.7mm, 1.4mm and 0.65mm respectively, the length, width and thickness of the vertical part connected to the transverse structure are 8.8mm, 1.25mm and 0.65mm respectively, and the length, width and thickness of another section of the vertical part are 3mm, 1.25mm and 0.4mm respectively; the length, width and thickness of the I-shaped ridge are 6.2mm, 1.6mm and 0.2mm respectively.

[0014] Furthermore, two adjacent antennas in each column of the antenna array are merged through an I-shaped ridge to form a 2×1 antenna array, every two 2×1 antenna arrays are merged through an I-shaped ridge to form a 2×2 antenna array, every two 2×2 antenna arrays are merged through an I-shaped ridge to form a 2×4 antenna array, and finally two 2×4 antenna arrays are merged through an I-shaped ridge to form a 4×4 antenna array, and the output end of the I-shaped ridge is converted into a WR-28 standard waveguide by transforming the step through the step.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Firstly, the present invention adopts the combination of ridge waveguide and conventional waveguide, so that the feeding network structure is compact, and a single-layer feeding network can complete the feeding of the entire array antenna;

[0017] Secondly, the working bandwidth of the present invention is wide, and the relative bandwidth of the present invention reaches 10.5%, which is a significant improvement compared with the relative bandwidth of the existing rectangular waveguide slot antenna of about 3%;

[0018] Finally, the present invention has high radiation efficiency, with an overall in-band gain of 37.7 dB and a radiation efficiency of more than 85%, which is higher than that of existing dielectric waveguide antennas. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 An exploded diagram of an antenna subarray of a millimeter-wave high radiation efficiency array antenna according to the present invention;

[0020] Figure 2 A side view of an antenna subarray of a millimeter-wave high radiation efficiency array antenna according to the present invention;

[0021] Figure 3 A top view of a one-sixteenth feeding network in a millimeter-wave high radiation efficiency array antenna of the present invention;

[0022] Figure 4 It is a side view of a one-sixteenth antenna subarray in a millimeter-wave high radiation efficiency array antenna of the present invention;

[0023] Figure 5 An exploded diagram of a one-sixteenth antenna subarray in a millimeter-wave high radiation efficiency array antenna of the present invention;

[0024] Figure 6 This is a structural diagram of converting a non-standard waveguide into a standard waveguide in a millimeter-wave high radiation efficiency array antenna of the present invention;

[0025] Figure 7 A side view of a waveguide slot array antenna of a millimeter wave high radiation efficiency array antenna according to the present invention;

[0026] Figure 8 It is an oblique view of a waveguide slot array antenna of a millimeter wave high radiation efficiency array antenna of the present invention;

[0027] Fig. 9 A gain diagram that can be realized as the frequency changes for a millimeter wave high radiation efficiency array antenna of the present invention;

[0028] Fig.10 A millimeter wave high radiation efficiency array antenna standing wave diagram of the present invention;

[0029] Fig.11 A low-frequency azimuth and elevation diagram of a millimeter-wave high-radiation-efficiency array antenna of the present invention;

[0030] Fig.12 The present invention provides a millimeter wave high radiation efficiency array antenna intermediate frequency azimuth and elevation diagram;

[0031] Fig.13 A high frequency azimuth and elevation diagram of a millimeter wave high radiation efficiency array antenna of the present invention;

[0032] Fig.14 A typical 3D radiation pattern of a millimeter-wave high radiation efficiency array antenna of the present invention;

[0033] Among them, 1. the first gap; 2. the second gap; 3. the resonant cavity; 4. the boss; 5. the bowtie coupling gap; 6. the waveguide feeding layer; 7. the T-shaped ridge; 8. the ridge transformation section; 9. the first protrusion of the feeding layer; 10. the straight ridge; 11. the second protrusion of the feeding layer; 14. the waveguide feeding layer of the antenna subarray; 15. the resonant coupling layer of the antenna subarray; 16. the radiation gap layer of the antenna subarray antenna; 17. the non-standard waveguide transformation standard waveguide transformation step; 18. the WR-28 standard waveguide output port; 19. the waveguide feeding network and port; 20. the antenna array output port. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The present invention proposes a millimeter-wave high radiation efficiency array antenna, which includes a radiation slot layer, a resonant coupling layer, and a waveguide feeding layer from top to bottom. The array antenna includes a radiation slot layer, a resonant coupling layer, and a waveguide feeding layer from top to bottom. The array antenna is composed of 16×16 antenna subarrays, each antenna subarray includes 2×2 radiation slot units, and therefore, the array antenna has a scale of 32×32 radiation slot units.

[0036] In this embodiment, a millimeter wave high radiation efficiency array antenna is composed of 16×16 identical antenna subarrays, each antenna subarray includes 2×2 identical radiation slot units, and therefore, one of the antenna units is first described in this embodiment.

[0037] like Figure 1-2 As shown, along the vertical negative direction of the first plane (i.e., the negative direction of the Z axis), the antenna subarrays are sequentially stacked as a radiation slot layer, a resonant coupling layer, and a waveguide feeding layer, wherein:

[0038] The radiation slot layer includes two rectangular slots which are perpendicular to each other and overlap each other, the rectangular projection centers of the two slots overlap, the length of the first slot 1 is greater than the length of the second slot 2, and the width of the first slot 1 is less than the width of the second slot 2. The two radiation rectangular cavities work in different working frequency bands, effectively improving the working bandwidth; as an optional implementation, in this embodiment, the size of the first slot located at the top is 5.2mm×4.8mm×1.55mm (length×width×thickness), and the size of the second slot arranged vertically downward along the first slot is 2.2mm×5.5mm×1mm (length×width×thickness);

[0039] The radiation slot layer is vertically downward to form a resonant coupling layer, which includes a resonant cavity 3. A bowtie-type coupling slot 5 is arranged at the center of the resonant cavity. A boss 4 is arranged on both sides of the resonant cavity corresponding to the narrowest position of the bowtie-type coupling slot width. The two bosses divide the resonant cavity into two subspaces, that is, the two subspaces are divided by the line between the two bosses. By adjusting the height of the resonant cavity, the electromagnetic wave fed from the coupling slot layer below becomes two electromagnetic cavities with uniform wavefront phases. The actual working effect is that when the electromagnetic wave fed from the waveguide feeding layer forms four electromagnetic waves with uniform wavefront phases in the resonant cavity, the radiation slot layer above is excited respectively. Forming a one-feed-four antenna subarray; as an optional implementation, in this embodiment, the size of the resonant cavity is 9.1mm×9.1mm×1.5mm (length×width×thickness), the size of each boss is 1.8mm×1.6mm×1mm (length×width×thickness), the length of the bowtie coupling slot is 3.8mm, the widest size is 2.1mm, the narrowest size is 1.3mm, and the thickness is 0.7mm. The center of the bowtie coupling slot overlaps with the resonant cavity, and the narrowest part of the bowtie coupling slot is on the same straight line as the centers of the two bosses. The invention adopts a slot structure with a gradually changing width, which is helpful to improve the bandwidth and increase the coupling amount;

[0040] Below the bowtie coupling slot is a waveguide feeding layer 6, the waveguide cross-sectional size is 4.7 mm×2 mm, and the waveguide of the antenna subarray adopts a non-standard waveguide due to the compact structure of the feeding network design.

[0041] In the present invention, the antenna subarray includes antenna substructures and feeding networks from top to bottom, and each substructure includes a radiation slot layer, a resonant coupling layer, and a waveguide feeding layer from top to bottom. A one-sixteenth feeding network in a millimeter-wave high radiation efficiency array antenna is as follows: Figure 3 As shown, every four antenna substructures are fed through a T-shaped ridge 7. Figure 4 The feeding structure is as follows Figure 5The 8×8 radiation slot unit shown is fed, and every two T-shaped ridges in the feeding structure are connected by a straight ridge 10, and the two straight ridges are connected together by another straight ridge to obtain an output of a feeding network. A feeding network and an antenna substructure arranged on the feeding network form an antenna unit. Two adjacent antennas in each column of the antenna array are merged through a straight ridge to form a 2×1 antenna array, and every two 2×1 antenna arrays are merged through a straight ridge to form a 2×2 antenna array. Every two 2×2 antenna arrays are merged through a straight ridge to form a 2×4 antenna array. Finally, two 2×4 antenna arrays are merged through a straight ridge to form a 4×4 antenna array. The output end of the straight ridge converts the feeding estuary into a WR-28 standard waveguide through a step by transforming the step. Each straight ridge divides the power evenly into two parts. The power of the array antenna is divided into 16 and input into each antenna unit. In each antenna unit, the straight ridge divides the power evenly into two parts, and the T-shaped ridge divides the power evenly into four parts. That is, the power of each antenna substructure is equivalent to 1 / 256 of the input power. Figures 4-5 This embodiment provides an antenna subarray in an antenna array, which includes, from bottom to top, a waveguide feeding layer 14 of the antenna subarray, a resonant coupling layer 15 of the antenna subarray, and a radiation slot layer 16 of the antenna subarray antenna.

[0042] In this embodiment, the T-shaped ridge is a metal ridge, and the vertical portion of the T-shaped ridge adopts a transformation structure, that is, two sections of metal structures with different lengths, widths, and thicknesses are spliced ​​to form the vertical portion. For example, in this embodiment Figure 4 A ridge transformation segment 8 is provided at the tail of the middle T-shaped ridge 7, and the ridge transformation segment 8 of one T-shaped ridge 7 and the ridge transformation segment 8 of another T-shaped ridge are connected by a straight ridge 10. A first feed layer protrusion 9 is provided in the middle of the T-shaped ridge, and a second feed layer protrusion 11 is provided at the connection between the two T-shaped ridges and the straight ridge 10. These two protrusions serve as standing wave regulators, and those skilled in the art can obtain better matching performance by optimizing the sizes of the two protrusions; as an optional implementation, in this embodiment, the length, width and thickness of the horizontal part of the T-shaped ridge are 5.7mm, 1.4mm, and 0.65mm, respectively, the length, width and thickness of the part connected to the horizontal structure in the vertical part are 8.8mm, 1.25mm, and 0.65mm, respectively, and the length, width and thickness of another section of the vertical part are 3mm, 1.25mm, and 0.4mm, respectively; the length, width and thickness of the straight ridge are 6.2mm, 1.6mm, and 0.2mm, respectively. In this embodiment, the length, width and thickness of the straight ridge are 6.2 mm, 1.6 mm and 0.2 mm respectively. The invention uses a waveguide metal ridge to help achieve low wave impedance at the same size, laying the foundation for using only a single-layer feeding network for the entire array.

[0043] from Figures 4-5It can be seen that each feeding network is used to feed the 4×4 radiating slot unit, and the output of each antenna unit is a waveguide feed port, which is also a branch port of the next-level power divider. Through a one-to-two power stage cascade method, the entire array is finally formed.

[0044] like Figure 5 , two adjacent antennas in each column of the antenna array are merged through a straight ridge to form a 2×1 antenna array, every two 2×1 antenna arrays are merged through a straight ridge to form a 2×2 antenna array, every two 2×2 antenna arrays are merged through a straight ridge to form a 2×4 antenna array, and finally two 2×4 antenna arrays are merged through a straight ridge to form a 4×4 antenna array. The output end of the straight ridge is converted into a WR-28 standard waveguide through a step by transforming the step; the feeding port of the entire array is set at the center of the array, and a conversion structure is used to convert the non-standard waveguide of the straight ridge into a WR-28 standard waveguide. The conversion structure is a step structure, one end of the structure in the horizontal direction matches the non-standard waveguide, and one end in the numerical direction matches the standard waveguide, such as Figure 6 The waveguide feeding network and port 19 of the entire array are non-standard waveguides, which are converted to the WR-28 standard waveguide output port 18 through the non-standard waveguide conversion standard waveguide conversion step 17. In this way, subsequent measurements and system integration are convenient. The present invention performs impedance change through the non-standard waveguide conversion standard waveguide conversion step 17, which is helpful for energy transmission. When designing this step, technicians in this field consider the maximum transmission energy for design.

[0045] like Figures 7-8 A 4×4 antenna array consisting of 16 antenna subarrays is given. The two antenna subarrays in the first column and the second column in the first row are connected by a vertical straight-line ridge to form a first unit. Then the first unit and the first unit formed by the two antenna subarrays in the first column and the second column in the second row are connected by a vertical straight-line ridge to form a horizontal second unit. Then the second unit is connected to the second unit formed by the two antenna subarrays in the third column and the fourth column of the first row and the two antenna subarrays in the third column and the fourth column of the second row through a vertical straight-line ridge to form a third unit. Finally, the third unit is connected to the third unit formed by the antenna units in the third row and the fourth row through a horizontal straight-line ridge to form a 4×4 antenna array. Each unit is then output through the waveguide output port only in the center of the array.

[0046] like Fig. 9 As shown in FIG. 1 , the achievable gain diagram of the waveguide slot array antenna in this embodiment with frequency variation can be obtained, and its gain has high flatness in the entire band, and the gain reaches more than 37.8 dB, and the radiation efficiency in the entire band reaches more than 85%, as shown in FIG. Fig.10As shown, the matching performance in the entire band is excellent, and the VSWR is less than 1.6. Fig.11 Low frequency azimuth and elevation diagrams of waveguide slot array antennas, Fig.12 Waveguide slot array antenna intermediate frequency azimuth and elevation diagram, Fig.13 High frequency azimuth and elevation diagrams of waveguide slot array antennas and Fig.14 As shown in the typical 3D radiation pattern of the waveguide slot array antenna, there is no distortion problem in the radiation pattern and the side lobes are all less than -13dB.

[0047] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "outside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0048] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "rotation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A millimeter-wave high radiation efficiency array antenna, a millimeter-wave high radiation efficiency array antenna, the array antenna includes a radiation slot layer, a resonant coupling layer, and a waveguide feeding layer from top to bottom. The array antenna is composed of 16×16 antenna subarrays, each antenna subarray includes 2×2 radiation slot units, so the array antenna scale is 32×32 radiation slot units.

2. The millimeter wave high radiation efficiency array antenna according to claim 1, characterized in that: The radiation slot layer consists of 32×32 radiation slot units, each of which includes a first slot and a second slot. The first slot and the second slot are rectangular slots that are perpendicular to each other and overlap. The length of the first slot is greater than the length of the second slot and the width of the first slot is less than the width of the second slot.

3. The millimeter wave high radiation efficiency array antenna according to claim 2, characterized in that: The length, width and thickness of the first gap are 5.2 mm, 4.8 mm and 1.55 mm, and the length, width and thickness of the second gap are 2.2 mm, 5.5 mm and 1 mm.

4. The millimeter wave high radiation efficiency array antenna according to claim 1, characterized in that: The resonant coupling layer is composed of 16×16 resonant cavities, including a bowtie-type coupling gap arranged at the center of each resonant cavity, and a boss is arranged on both sides of the resonant cavity corresponding to the narrowest position of the bowtie-type coupling gap.

5. The millimeter wave high radiation efficiency array antenna according to claim 4, characterized in that: The bow tie coupling gap length is 3.8mm, the widest dimension is 2.1mm, the narrowest dimension is 1.3mm, and the thickness is 0.7mm.

6. The millimeter wave high radiation efficiency array antenna according to claim 1, characterized in that: The waveguide feeding layer is composed of a one-to-two equal-power stage cascade, ultimately forming a one-to-256 waveguide feeding network.

7. The millimeter wave high radiation efficiency array antenna according to claim 6, characterized in that: The one-sixteenth waveguide feeding network includes four T-shaped ridges and three straight ridges. Every two antenna substructures are merged using one lateral end of the T-shaped ridge, and the two lateral ends of the T-shaped ridge are merged together. The ends of every two T-shaped ridges are connected to one end of a straight ridge, and one end of three straight ridges are connected together, and one end of one straight ridge serves as the feed and port of the 4×4 antenna array.

8. The millimeter wave high radiation efficiency array antenna according to claim 7, characterized in that: The vertical part of the T-shaped ridge adopts a transformation structure, that is, two sections of metal structures with different lengths, widths and thicknesses are spliced ​​together to form the vertical part.

9. The millimeter wave high radiation efficiency array antenna according to claim 8, characterized in that: The length, width and thickness of the horizontal part of the T-shaped ridge are 5.7mm, 1.4mm and 0.65mm respectively; the length, width and thickness of the vertical part connected to the horizontal structure are 8.8mm, 1.25mm and 0.65mm respectively; the length, width and thickness of the other section of the vertical part are 3mm, 1.25mm and 0.4mm respectively; the length, width and thickness of the I-shaped ridge are 6.2mm, 1.6mm and 0.2mm respectively.

10. The millimeter wave high radiation efficiency array antenna according to claim 7, characterized in that: Two adjacent antennas in each column of the antenna array are merged through a straight-line ridge to form a 2×1 antenna array, every two 2×1 antenna arrays are merged through a straight-line ridge to form a 2×2 antenna array, every two 2×2 antenna arrays are merged through a straight-line ridge to form a 2×4 antenna array, and finally two 2×4 antenna arrays are merged through a straight-line ridge to form a 4×4 antenna array. The output end of the straight-line ridge is converted into a WR-28 standard waveguide by transforming the step to feed and port.

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