Beam-reconfigurable millimeter-wave array antenna

Abstract

This invention relates to the field of wireless communication technology and discloses a beam-reconfigurable millimeter-wave array antenna, comprising a radiating component and a feeding component. The radiating component includes four groups of radiating elements arranged in a 2×2 array on a first substrate. The feeding component includes a second substrate and a third substrate stacked together. A first and second power branch, both T-shaped and facing each other, are provided on the third substrate. A third and fourth power branch, also T-shaped and facing each other, are provided on the second substrate. Both ends of the power branch heads are output ports. Each of the third and fourth power branches has two input ports respectively connected to the output ports of the first and second power branches. The outputs of the third and fourth power branches face the radiating elements and feed signals into them. This beam-reconfigurable millimeter-wave array antenna can achieve beam reconfiguration with a relatively simple structure and has high gain.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically, to a beam-reconfigurable millimeter-wave array antenna. Background Technology

[0002] With the development of 5G communication technology, low-frequency bands are increasingly unable to meet the demands of communication. To address the scarcity of spectrum resources, the 24.75 to 27.5 GHz band has been allocated to 5G millimeter-wave communication systems, and the trend towards higher frequencies is becoming increasingly apparent. Due to the higher frequency, millimeter-wave antennas have relatively shorter transmission distances, thus requiring higher gain to maximize transmission range. Achieving high gain for millimeter-wave antennas involves constructing antenna arrays, which is a primary research direction. Traditional millimeter-wave antenna arrays have narrow beams, while beam reconfiguration can effectively expand the antenna's radiation range; therefore, multi-beam implementation is also a crucial research area for millimeter-wave antennas. Summary of the Invention

[0003] This invention was made to solve the above-mentioned technical problems, and its purpose is to provide a beam-reconfigurable millimeter-wave array antenna that can achieve beam reconfiguration with a relatively simple structure while having high gain.

[0004] To achieve the above objectives, the present invention provides a beam-reconfigurable millimeter-wave array antenna, comprising a radiating component and a feeding component; wherein the radiating component comprises a first substrate and four sets of radiating elements arranged in a 2×2 array thereon; the feeding component comprises a second substrate and a third substrate stacked together, wherein a first power branch and a second power branch with T-shaped heads facing each other are provided on the third substrate, and a third power branch and a fourth power branch with T-shaped heads facing each other are provided on the second substrate, wherein both ends of the heads of the power branches are output ports, and each of the third power branch and the fourth power branch has two input ports respectively connected to the output ports of the first power branch and the second power branch, wherein the output ends of the third power branch and the fourth power branch face the radiating elements and feed signals into the radiating elements.

[0005] Preferably, the first substrate, the second substrate, and the third substrate are stacked sequentially, and metal layers are provided on both sides of the second substrate and the third substrate. The power branch is a substrate integrated waveguide structure composed of metal layers and metal vias penetrating the substrate. The output end of the first power branch is connected to the tail ends of the third power branch and the fourth power branch via metal pillars. The output end of the second power branch is provided with metal gaps facing the middle of the third power branch and the fourth power branch respectively. The output ends of the third power branch and the fourth power branch are provided with metal gaps facing the radiating unit.

[0006] Preferably, each of the radiation units includes a total of four metal radiators distributed in a 2×2 array; the output ends of the third power branch and the fourth power branch are H-shaped branches, and metal slots facing the metal radiators are respectively provided at the four ends of the H-shaped branch.

[0007] Preferably, the metal radiator is a "wisdom" character-shaped metal patch.

[0008] Preferably, parasitic patches are provided on the outer periphery of the metal radiator.

[0009] Preferably, a metal fence is provided on the outer periphery of the radiation unit. The metal fence is a strip-shaped metal plate, and one end of it is inserted into the first substrate.

[0010] Preferably, signal guiding holes formed by metal vias are provided in the power branch, and the signal guiding holes are at least provided at the positions where the electromagnetic waves in the power branch turn.

[0011] Preferably, the head of the first power branch is perpendicular to the heads of the third power branch and the fourth power branch; the head of the second power branch is perpendicular to the heads of the third power branch and the fourth power branch.

[0012] Preferably, the thicknesses of the first substrate, the second substrate, and the third substrate are 0.787 mm.

[0013] According to the above description and practice, the beam reconfigurable millimeter-wave array antenna of the present invention can achieve an impedance bandwidth in the 24.75 - 27.5 GHz millimeter-wave band, achieving relatively wide bandwidth performance; the specific structure of the dual-port feeding network also makes the isolation between the two ports of this antenna less than -30 dB, and the isolation performance has been greatly improved compared with traditional antennas. In addition, the dual-port feeding network structure enables the antenna to achieve the function of beam reconfiguration. Compared with traditional antennas with a single radiation pattern, this antenna can adapt to more complex application scenarios and can achieve different signal transmission effects according to requirements. Furthermore, the antenna can achieve high-gain performance. Compared with traditional array antennas with no more than 4 units, this antenna realizes an antenna array scale of 4×4 through a two-layer feeding network and achieves high-gain performance within the working frequency band. In addition, the present invention can achieve good radiation pattern performance. Compared with traditional array antennas where the side lobes are relatively large, which affects the main lobe gain, this antenna reduces the side lobes of the radiation pattern by adding parasitic patches and metal fences beside the radiation patches, making the side lobe level of the antenna array below -10 dB. Description of the Drawings

[0014] Figure 1a and Figure 1bThe figures shown are a three-dimensional structural diagram and an exploded view of a beam-reconfigurable millimeter-wave array antenna according to one embodiment of the present invention.

[0015] Figure 2 This is a top view of the first substrate involved in one embodiment of the present invention.

[0016] Figure 3 This is a top view of the second substrate involved in one embodiment of the present invention.

[0017] Figure 4 This is a top view of the third substrate involved in one embodiment of the present invention.

[0018] Figure 5a and Figure 5b The diagrams show the structure and phase distribution of the power supply network when power is supplied through the first port and the second port, respectively, in one embodiment of the present invention.

[0019] Figure 6 This is an S-parameter diagram of two power supply ports involved in one embodiment of the present invention.

[0020] Figure 7 This is a schematic diagram illustrating the isolation between two power supply ports in one embodiment of the present invention.

[0021] Figure 8 This is a gain diagram of a beam-reconfigurable millimeter-wave array antenna according to one embodiment of the present invention.

[0022] Figure 9a and Figure 9b These are the antenna radiation patterns when the antenna is fed through the first port and the second port, respectively, in one embodiment of the present invention.

[0023] The attached figures are labeled as follows:

[0024] 11. First substrate; 12. Second substrate; 13. Third substrate; 21. First power branch; 22. Second power branch; 23. Third power branch; 24. Fourth power branch; 25. Metal gap; 26. H-shaped branch; 27. Signal guide hole; 28. Metal pillar; 31. Metal radiator; 32. Parasitic patch; 33. Metal fence; 34. Mounting slot; 41. First port; 42. Second port. Detailed Implementation

[0025] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0026] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. It should be noted that in this disclosure, the terms "comprising," "configured with," and "set in" are used to indicate an open-ended inclusion, meaning that additional elements / components / etc. may exist besides those listed; the terms "first," "second," etc., are used only as labels and are not intended to limit the number or order of objects; the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0027] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] This embodiment discloses a beam-reconfigurable millimeter-wave array antenna. Figure 1a shows the three-dimensional structure of the antenna. Figure 1b The exploded structure of the antenna is shown; Figure 2 The top view of the first substrate is shown; Figure 3 The top view of the second substrate is shown; Figure 4 The top view of the third substrate is shown; Figure 5a The structure and phase distribution of the feeding network when the antenna is fed through the first port are shown; Figure 5b The structure and phase distribution of the feeding network when the antenna is fed through the second port are shown.

[0029] Please refer to Figures 1a-5b, in this embodiment, the beam-reconfigurable millimeter-wave array antenna includes a radiation component and a feeding component. The radiation component includes a first substrate 11 and a total of four groups of radiation units arranged in a 2×2 array thereon; the feeding component includes: a second substrate 12 and a third substrate 13 stacked together, a third power branch 23 and a fourth power branch 24 provided on the second substrate 12, and a first power branch 21 and a second power branch 22 provided on the third substrate 13. Among them, the first power branch 21, the third power branch 23, and the fourth power branch 24 can form a feeding network, and the second power branch 22, the third power branch 23, and the fourth power branch 24 can form another feeding network. For details, see Figure 5a and Figure 5b , these two feeding networks can feed different forms of signals into the radiation component, and finally form two different forms of radiation patterns: a side double-conical beam and a single-conical beam.

[0030] Specifically, in this embodiment, each radiation unit is composed of a total of four metal radiators 31 arranged in a 2×2 array. After receiving the feeding signal, it can realize high-gain signal radiation. Each metal radiator 31 is a "wisdom" - shaped metal patch in this embodiment, which is pasted or printed on the first substrate 11. The metal patch has many intersecting branches, which can further improve the gain.

[0031] In addition, traditional array antennas have the problem that the side lobes are relatively large, which in turn affects the main lobe gain. In this antenna, several circular parasitic patches 32 are also provided on the outer periphery of the metal radiator 31, and a metal fence 33 is provided on the outer periphery of the radiation unit, which can reduce the side lobes of the radiation pattern of this antenna, making the side lobe level of the antenna array below -10 dB. Specifically, a circle of parasitic patches 32 is provided on the outer periphery of two vertically adjacent metal radiators 31; mounting grooves 34 are provided on the first substrate 11 on the outer periphery of the radiation unit and between adjacent radiation units. The metal fence 33 is a strip-shaped metal plate, and one side of it is inserted into the mounting groove 34.

[0032] Specifically, the first power branch 21 and the second power branch 22 with T - shapes and facing heads are provided on the third substrate 13. The tails of the two are the feeding ports of the antenna, denoted as the first port 41 and the second port 42 respectively, which can be connected to the feeding wire of the antenna; the heads of the two are arranged in parallel, and both ends are output terminals for feeding signals into the third power branch 23 and the fourth power branch 24 on the second substrate 12. The third power branch 23 and the fourth power branch 24 with T - shapes and facing heads are provided on the second substrate 12. The two ends of the heads of the two form a total of four groups of output ports facing the radiation units respectively. The tails of the two are the input terminals facing the output ports of the first power branch 21, and the middle parts of the two are the input terminals facing the output terminals of the second power branch 22.

[0033] In this embodiment, the four power branches are essentially 1-to-2 power dividers. The first power branch 21 splits the signal received at the first port 41 into two and feeds them into the third power branch 23 and the fourth power branch 24. Each of these branches then splits the signal into two, forming a total of four signals with the same phase, which can then be transmitted to each radiating element to achieve a double-cone beam radiation pattern. The second power branch 22 splits the signal received at the second port 42 into two and feeds them into the third power branch 23 and the fourth power branch 24. Each of these branches then splits the signal into two, forming a total of four signals. The two upper signals have a 180° phase difference with the two lower signals, achieving a single-beam radiation pattern.

[0034] In this embodiment, all four power branch circuits adopt a substrate integrated waveguide structure, which can achieve signal transmission in the 24.75-27.5GHz frequency band with a small volume and low loss, which can indirectly improve the antenna gain to a certain extent. Specifically, metal layers are provided on both sides of the second substrate 12 and the third substrate 13. The four power branch circuits are channels for electromagnetic wave transmission formed by metal vias and metal layers through the second substrate 12 and the third substrate 13. Taking the first power branch circuit 21 as an example, it is a T-shaped channel surrounded by metal vias. The electromagnetic wave fed in through the first port 41 can be confined to the middle of the third substrate 13, and then the electromagnetic wave is split through several metal vias on the substrate, ultimately achieving a power splitting effect of one to two.

[0035] The output of the first power branch 21 is connected to the tail ends of the third power branch 23 and the fourth power branch 24 via metal pillars 28, forming a transmission structure that converts a substrate integrated waveguide structure to a coaxial structure and then back to a substrate integrated waveguide structure. This allows the four output ends of the third power branch 23 and the fourth power branch 24 to generate signals with the same phase. The output of the second power branch 22 is provided with metal slots 25 facing the middle of the third power branch 23 and the fourth power branch 24 respectively. These metal slots 25 are parallel to the tail ends of the third power branch 23 and the fourth power branch 24, so two signals with a phase difference of 180° can be formed on the upper and lower sides of the metal slots 25. In use, the signal in the second power branch 22 can be fed into the third power branch 23 and the fourth power branch 24 in a slot-coupled differential form through the metal slots 25, ultimately forming a total of four signals, of which the two upper signals have a phase difference of 180° with the two lower signals.

[0036] Metal slots 25 facing the radiating units are provided at the output ends of the third power branch 23 and the fourth power branch 24. The signals within these slots can be transmitted to the radiating units in a differential coupling manner to achieve signal radiation. Furthermore, since each radiating unit has four metal radiators 31, H-shaped branches 26 are provided at the output ends of the third power branch 23 and the fourth power branch 24, forming a local one-to-four power divider. Metal slots 25 facing the metal radiators 31 are provided at the four ends of each H-shaped branch 26, allowing the signal to be transmitted to each metal radiator 31. To achieve better radiation performance, the four sets of radiating units are positioned relatively close together. Correspondingly, the heads of the third power branch 23 and the fourth power branch 24 are designed with bent structures to provide more branch structures while achieving power division, thereby feeding each metal radiator 31. In this embodiment, the head of the first power branch 21 is perpendicular to the heads of the third power branch 23 and the fourth power branch 24; the head of the second power branch 22 is perpendicular to the heads of the third power branch 23 and the fourth power branch 24, which can achieve better isolation between the two power supply ports.

[0037] In addition, in this embodiment, a signal guiding hole 27 formed by a metal via is provided in each power branch, wherein the signal guiding hole 27 is provided at least at the position where the electromagnetic wave turns in the power branch, which can guide the electromagnetic wave to turn and split, thereby reducing the loss of electromagnetic wave in the power branch.

[0038] See details Figure 3 and Figure 4 A signal guiding hole 27 is provided at the intersection of the head and tail of the first power branch 21, which can split the electromagnetic wave transmitted from the tail into two, reducing signal concentration in that local area. A signal guiding hole 27 is also provided near the outer periphery of the bend at the head of the first power branch 21, which can guide the electromagnetic wave to change direction and reduce signal concentration at this point, achieving optimal power splitting effect while reducing losses. Since the structure of the second power branch 22 is similar to that of the first power branch 21, the position of the signal guiding hole 27 on the second power branch 22 is similar to that of the signal guiding hole 27 in the first power branch 21, and will not be described in detail further.

[0039] A signal guiding hole 27 is provided near the outer periphery at the bend of the third power branch 23 to guide the electromagnetic wave and reduce signal accumulation at this location. A signal guiding hole 27 is also provided at the entrance in the middle of the H-shaped branch 26 and at the middle of both sides, which can split the transmitted electromagnetic wave in two, achieving current splitting and reducing signal accumulation in this local area, ultimately achieving optimal power splitting effect while reducing losses. Since the structure of the fourth power branch 24 is similar to that of the third power branch 23, the position of the signal guiding hole 27 on the fourth power branch 24 is similar to that in the third power branch 23, and will not be described in detail further.

[0040] The first substrate 11, second substrate 12, and third substrate 13 mentioned above are all Rogers 5880 dielectric substrates, with a thickness of 0.787 mm, a dielectric constant of 2.2, and a loss of 0.0009. Tests were conducted on the beam-reconfigurable millimeter-wave array antenna of the above type, with an operating frequency band of 24.75-27.5 GHz. For detailed performance information, please refer to [link to relevant documentation]. Figures 6 to 9b .in, Figure 6 The S-parameters of the two feed ports are shown, and the reflection coefficients of both feed ports are less than -10dB in the operating frequency band. Figure 7 The isolation between the two feed ports is shown, and the isolation between the two feed ports is less than -33dB within the operating frequency band; Figure 8 The gain of the beam-reconfigurable millimeter-wave array antenna is shown. In the operating frequency band, when the first port 41 is excited, the antenna gain is about 17.9 dBi, with a gain fluctuation of less than 1 dBi. When the second port 42 is excited, the antenna gain is about 21.1 dBi, with a gain fluctuation of less than 1.6 dBi. Figure 9a The radiation patterns of the antenna at three frequency points of 24.8 GHz, 26 GHz and 27.5 GHz are shown when the antenna is fed through the first port 41. As can be seen from the figure, when the first port 41 is excited, the antenna radiation pattern presents a lateral double cone beam and achieves a sidelobe level of less than -10 dB and a cross polarization of less than -18 dB. Figure 9b The radiation patterns of the antenna at three frequency points of 24.8 GHz, 26 GHz and 27.5 GHz are shown when the antenna is fed through the second port 42. As can be seen from the figure, when the second port 42 is excited, the antenna radiation pattern presents a single conical beam, the sidelobe level of the pattern is suppressed to below -10 dB, and cross polarization of less than -20 dB is achieved.

[0041] The beam-reconfigurable millimeter-wave array antenna in this embodiment achieves an impedance bandwidth of 24.75-27.5 GHz millimeter-wave frequency band, realizing a wide bandwidth performance. The specific structure of the dual-port feed network also makes the isolation between the two ports of this antenna less than -30 dB, which is a significant improvement in isolation performance compared to traditional antennas. In addition, the dual-port feed network structure enables the antenna to achieve beam reconfiguration. Compared to traditional single-radiating antennas, this antenna can adapt to more complex application scenarios and can achieve different signal transmission effects according to requirements. Furthermore, this antenna can achieve high gain performance. Compared to traditional array antennas with no more than 4 elements, this antenna achieves a 4×4 antenna array scale through two layers of feed networks, achieving high gain performance within the operating frequency band. In addition, this invention can achieve good radiation pattern performance. Compared to the problem of large sidelobes affecting the main lobe gain of traditional array antennas, this antenna reduces the sidelobes of the radiation pattern by adding parasitic patches 32 and metal fences 33 next to the radiating patches, making the sidelobe level of the antenna array below -10 dB.

[0042] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A beam-reconfigurable millimeter-wave array antenna, characterized in that, It includes a radiation component and a feeding component; Wherein the radiation component includes a first substrate and a total of four groups of radiation units arranged in a 2×2 array thereon; the feeding component includes a second substrate and a third substrate stacked together. On the third substrate, there are a first power branch path and a second power branch path in a T shape with their heads facing each other. On the second substrate, there are a third power branch path and a fourth power branch path in a T shape with their heads facing each other. Both ends of the heads of the four power branch paths are output ports. On both the third power branch path and the fourth power branch path, there are two input ports respectively connected to the output ports of the first power branch path and the second power branch path. The output ends of the third power branch path and the fourth power branch path face the radiation units respectively and feed signals into the radiation units; the head of the first power branch path is perpendicular to the heads of the third power branch path and the fourth power branch path; the head of the second power branch path is perpendicular to the heads of the third power branch path and the fourth power branch path; the output end of the first power branch path is connected to the tails of the third power branch path and the fourth power branch path via a metal column; the output end of the second power branch path has metal gaps facing the middle parts of the third power branch path and the fourth power branch path respectively; the output ends of the third power branch path and the fourth power branch path have metal gaps facing the radiation units; the output ends of the third power branch path and the fourth power branch path are H-shaped branches, and there are metal gaps facing the radiation units respectively at the four end parts of the H-shaped branches.

2. The beam reconfigurable millimeter-wave array antenna according to claim 1, wherein the first substrate, the second substrate, and the third substrate are stacked together in sequence. Metal layers are provided on both sides of the second substrate and the third substrate. The power branch path is a substrate integrated waveguide structure composed of a metal layer and metal vias penetrating the substrate.

3. The beam reconfigurable millimeter-wave array antenna according to claim 2, wherein each of the radiation units includes a total of four metal radiators arranged in a 2×2 array; the four metal radiators are arranged opposite to the four end parts of the H-shaped branches.

4. The beam reconfigurable millimeter-wave array antenna according to claim 3, wherein the metal radiator is a "wisdom" - shaped metal patch.

5. The beam reconfigurable millimeter-wave array antenna according to claim 3, wherein a parasitic patch is provided on the outer periphery of the metal radiator.

6. The beam reconfigurable millimeter-wave array antenna according to claim 1, wherein a metal fence is provided on the outer periphery of the radiation unit. The metal fence is a strip-shaped metal plate, and one end of it is inserted into the first substrate.

7. The beam reconfigurable millimeter-wave array antenna according to claim 2, wherein signal guiding holes formed by metal vias are provided in the power branch path, and the signal guiding holes are at least provided at the positions where the electromagnetic waves turn in the power branch path.

8. The beam reconfigurable millimeter-wave array antenna according to claim 7, wherein the thicknesses of the first substrate, the second substrate, and the third substrate are 0.787 mm.

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