Pattern Reconfigurable Millimeter-Wave Antenna

Abstract

The present invention relates to the field of wireless communication technology, and discloses a reconfigurable millimeter wave antenna, comprising: a radiation component composed of 2×2 array radiation units on a first substrate; a T-shaped first power divider on the first substrate, with the two ends of the head arranged between the radiation units; a II-shaped first feeding branch on the second substrate, with a cross coupling slot facing the radiation unit at the end, and a straight coupling slot facing the head of the first power divider in the middle; an I-shaped second power divider on the fourth substrate, with the other end arranged facing the middle of four radiation units and a straight coupling slot; an I-shaped second feeding branch on the third substrate, with a straight coupling slot facing the radiation unit at the end, and a straight coupling slot facing the second power divider in the middle. The reconfigurable millimeter wave antenna can realize different radiation patterns when fed by different feeding networks, thereby realizing the switching of narrow beam and wide scanning angle in one antenna.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and more specifically, to a millimeter-wave antenna with reconfigurable radiation patterns. Background Art

[0002] With the rapid development of communication systems, Sub 6 of the first phase of 5G has been commercialized currently, and the millimeter-wave band is about to become the selected band for the second phase. It is currently expected that the operating bands of vehicle-mounted millimeter-wave antennas include the 24 GHz band and the 77 GHz band. Vehicle-mounted antennas in the millimeter-wave band need both narrow beams that can accurately locate to effectively overcome multipath interference and co-channel interference, and wide scanning angles to establish communication connections with multiple surrounding devices. However, these two indicators are mutually restrictive in traditional single antennas. The narrow-beam antennas reported so far mainly achieve this by designing large-scale antenna arrays or using special materials with high prices to correct the radiation electric field. The methods for achieving wide scanning angles mainly include wide half-power beam widths and reconfigurable antennas with scannable beams. Among them, wide half-power beam widths will result in low gains, and scannable reconfigurable antennas require complex feeding networks to control the phase, introducing greater losses. Therefore, it is very important to study a millimeter-wave antenna with high gain that can achieve narrow beams and wide scanning angles.

[0003] In addition, the antenna aperture efficiency is an important indicator for measuring the relationship between the antenna gain and the antenna area. Some of the reported millimeter-wave antennas use large feeding networks to achieve high gain, but sacrifice the planar size, resulting in low antenna aperture efficiency. It is very important to increase the antenna gain and further improve the antenna aperture efficiency under the condition of studying the effective area. Summary of the Invention

[0004] The purpose of the present invention is to provide a millimeter-wave antenna with reconfigurable radiation patterns to at least solve one of the above technical problems.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a reconfigurable millimeter wave antenna, comprising: a radiation component, arranged on a first substrate, comprising a 2×2 array of radiation units, each of the radiation units comprising a 2×2 array of cross-coupling slots and metal vias arranged on the periphery of four cross-coupling slots; a first power divider, arranged on the first substrate, being a "T"-shaped structure formed by metal vias, the tail being a feeding end, and the two ends of the head being arranged between the radiation units; a first feeding branch, arranged on a second substrate, being a "II"-shaped structure formed by metal vias, and the four ends being provided with cross-coupling slots facing the radiation units. , two middle parts are provided with a straight coupling slot facing the two ends of the head of the first power divider; the second power divider is arranged on the fourth substrate, which is an "I"-shaped structure formed by a metal via, one end of which is a feeding end, and the other end is arranged at a position facing the middle parts of the four radiation units and an straight coupling slot is arranged at the end; the second feeding branch is arranged on the third substrate, which is an "I"-shaped structure formed by a metal via, and the four ends are provided with a straight coupling slot facing the radiation unit, and the middle part is arranged to face the straight coupling slot of the second power divider; wherein the first substrate, the second substrate, the third substrate, and the fourth substrate are stacked together in sequence.

[0006] Preferably, the upper and lower surfaces of the first substrate, the second substrate, the third substrate and the fourth substrate are all covered with a metal layer; the first power divider, the first feeding branch, the second power divider and the second feeding branch are substrate integrated waveguide structures.

[0007] Preferably, the metal vias of the first power divider form a ring-shaped "T"-shaped structure, and three metal vias are further provided in the middle of the head thereof.

[0008] Preferably, the metal via of the second feeding branch forms a ring-shaped "I"-shaped structure, and two metal vias are arranged in the middle thereof.

[0009] Preferably, an excitation component is also provided on the side of the radiation component away from the second feeding branch; the excitation component has a refractive index of zero, includes a fifth substrate and a plurality of excitation units provided thereon, and the excitation units include metal rings provided on the upper and lower surfaces of the fifth substrate, and a plurality of metal vias that penetrate the fifth substrate and connect the metal rings on the upper and lower surfaces.

[0010] Preferably, each position on the fifth substrate facing the radiation unit is provided with 3×3 excitation units.

[0011] Preferably, the metal ring is a rectangular ring.

[0012] As can be seen from the above description and practice, the two feeding networks of the reconfigurable millimeter-wave antenna according to the present invention are integrated together and use the same radiation component. When different ports are excited, different radiation patterns can be achieved, realizing pattern reconfigurability, and thus realizing the switching between narrow beams and wide scanning angles in one antenna. In addition, the radiation component in this embodiment adopts a high-order mode slot antenna, which can effectively reduce the planar size of the antenna compared with the traditional horn antenna, and can also make each slot obtain equal excitation, weakening the beam offset caused by the unbalanced excitation of the feeding network unit. In addition, the slot antenna has symmetry, making it easier to achieve dual polarization and improving the frequency band utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Perspective view of the reconfigurable millimeter-wave antenna according to an embodiment of the present invention.

[0014] Figure 2 Structural schematic diagram of the first substrate according to an embodiment of the present invention.

[0015] Figure 3 Structural schematic diagram of the second substrate according to an embodiment of the present invention.

[0016] Figure 4 Structural schematic diagram of the third substrate according to an embodiment of the present invention.

[0017] Figure 5 Structural schematic diagram of the fourth substrate according to an embodiment of the present invention.

[0018] Figure 6 Structural schematic diagram of the fifth substrate according to an embodiment of the present invention.

[0019] Figure 7 Schematic diagram of the feeding path of the reconfigurable millimeter-wave antenna according to an embodiment of the present invention.

[0020] Figure 8a and Figure 8b The S parameters and phase differences of the first feeding network according to an embodiment of the present invention, respectively.

[0021] Figure 9a and Figure 9b The S parameters and phase differences of the second feeding network according to an embodiment of the present invention, respectively.

[0022] Figure 10a and Figure 10b Performance diagram of the reconfigurable millimeter-wave antenna according to an embodiment of the present invention.

[0023] Figure 11The radiation patterns of the reconfigurable millimeter-wave antenna related to an embodiment of the present invention when feeding frequency signals of 76 GHz and 80 GHz through two feeding ports respectively.

[0024] The reference numerals in the figure are:

[0025] 1. First substrate; 2. Second substrate; 3. Third substrate; 4. Fourth substrate; 5. Fifth substrate; 6. Radiation unit; 7. First power divider; 8. First feeding branch; 9. Second power divider; 10. Second feeding branch; 11. Excitation unit. Detailed implementation manners

[0026] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in various 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 thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0027] In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures denote the same or similar parts, and thus repeated descriptions thereof will be omitted. It should be noted that in the present disclosure, the terms "including", "configured with", and "disposed on" are used to mean an open inclusion, and mean that there may be additional elements, components, etc. in addition to the listed elements, components, etc.; the terms "first", "second", etc. are only used as labels and are not limitations on the number or order of their objects; the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present invention.

[0028] Unless otherwise clearly defined and limited, the terms "installed", "connected", and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In this embodiment, a reconfigurable millimeter-wave antenna with reconfigurable radiation patterns is disclosed. Figure 1The perspective structure of the pattern-reconfigurable millimeter-wave antenna is shown; Figures 2 - 6 The surface structures of the first substrate to the fifth substrate in the pattern-reconfigurable millimeter-wave antenna are respectively shown; Figure 7 The feeding path of the pattern-reconfigurable millimeter-wave antenna is shown in the form of a simplified diagram.

[0030] Please refer to Figures 1 - 7 , the pattern-reconfigurable millimeter-wave antenna includes a first substrate 1, a second substrate 2, a third substrate 3, and a fourth substrate 4 stacked together, and metal layers are covered on the upper and lower surfaces of the four substrates. A radiation component is provided on the first substrate 1, and the radiation component adopts a high-order mode slot antenna. As Figure 2 shown, the radiation component includes four radiation units 6 arranged in a 2×2 array, and each radiation unit 6 includes four cross-coupled slots arranged in a 2×2 array and metal vias provided on the outer periphery of the four cross-coupled slots. The radiation component is fed through two feeding networks, and when fed through the first feeding network and the second feeding network respectively, the radiation component will generate different forms of radiation patterns.

[0031] Specifically referring to Figure 2 and Figure 3 , the first feeding network includes a first power divider 7 and a first feeding branch 8. Among them, the first power divider 7 is provided on the first substrate 1 and is a ring-shaped "T" structure formed by several metal vias. Its tail part, as the input end (i.e., the feeding end), can be connected to the feeding wire, and the head part forms two output ends and is coupled to the first feeding branch 8. Through the first power divider 7, the feeding signal can be split into two. The first feeding branch 8 is provided on the second substrate 2 and is a "Ⅱ" structure formed by several metal vias. For details, see Figure 3 , the first feeding branch 8 includes a total of two left and right rectangular rings formed by metal vias, and the two rectangular rings constitute the first feeding branch 8 of the "Ⅱ" structure. Two one-dimensional coupling slots facing the two output ends of the head part of the first power divider 7 are provided in the middle of the first feeding branch 8. The one-dimensional coupling slot is arranged horizontally to serve as the input port of the first feeding branch 8 and receives the feeding signal output by the first power divider 7 through the coupling method; a cross-coupled slot is provided at each of the four end parts of the first feeding branch 8, and the cross-coupled slot faces each radiation unit 6 respectively to serve as the output port of the first feeding branch 8 and feed the radiation unit 6 through the coupling form. Among them, the input end of the first power divider 7 is denoted as port one.

[0032] Referring to Figure 4 and Figure 5, the second feeding network includes a second power divider 9 and a second feeding branch 10. Among them, the second power divider 9 is arranged on the fourth substrate 4 and is an annular "I" - shaped structure formed by several metal vias. One end of it is used as the input end (i.e., the feeding end) and can be connected to the feeding line, the other end is the output end, and a linear coupling slot is arranged in the middle. This linear coupling slot is arranged at a position facing the middle parts of the four radiation units 6 and is arranged horizontally. The second feeding branch 10 is arranged on the third substrate 3 and is a "Gong" - shaped structure formed by several metal vias. See Figure 4 , one vertical linear coupling slot is respectively arranged at its four end parts. This linear coupling slot faces the four radiation units 6 respectively to serve as the output ports of the second feeding branch 10 and feed the radiation units 6 in a coupling manner. Among them, the input end of the second power divider 9 is denoted as the two - port.

[0033] Please combine Figures 7 - 9b and Figure 11 , Figure 11 shows the radiation patterns of the reconfigurable millimeter - wave antenna when feeding 76GHz and 80GHz frequency signals through two feeding ports respectively. In Figure 8a and Figure 8b , Port 1 is a one - port, and Port a, Port b, Port c, Port d are the four output ports of the first feeding network respectively; in Figure 9a and Figure 9b , Port 2 is a two - port, and Port e, Port f, Port g, Port h are the four output ports of the second feeding network respectively. In the first feeding network, a T - to - H - shaped feeding path is adopted, which can make each radiation unit 6 obtain feeding signals with the same phase and amplitude, realizing further narrowing of the half - power beam (less than 10°), and the side lobe is less than - 15dB. See Figure 11 , the half - power beam width of the narrow beam of the one - port is less than 10° in both the XOZ plane and the YOZ plane, the side lobe is less than - 15dB, and the cross - polarization is less than - 30dB. In the second feeding network, an I - to - H - type feeding path is adopted, so that each radiation unit 6 obtains feeding signals with equal amplitude and there is a 180° phase difference between adjacent radiation units 6, thereby realizing narrow beams in four different directions and improving the scanning range of the antenna (a scanning angle of 30°). See Figure 11 , the radiation patterns of the two - port in the XOZ plane and the YOZ plane both present double beams, where there is a 30° offset between the two peaks, broadening the scanning angle, and the side lobe is also less than - 15dB, and the cross - polarization is less than - 28dB.

[0034] In addition, the above antenna structure integrates two feeding networks and uses the same radiation component. When different ports are excited, different radiation patterns can be achieved, realizing pattern reconfigurability, and thus enabling switching between narrow beams and wide scanning angles in one antenna. Additionally, the radiation component in this embodiment adopts a high-order mode slot antenna, which can effectively reduce the planar size of the antenna compared to traditional horn antennas. At the same time, it can also ensure that each slot receives equal excitation, weakening the beam offset caused by unbalanced excitation of the feeding network by the unit. Moreover, the slot antenna has symmetry, making it easier to achieve dual polarization and improve the frequency band utilization rate.

[0035] The above first power divider 7, first feeding branch 8, second power divider 9, and second feeding branch 10 all adopt a structural form of arranging continuous metal vias on the substrate, forming a substrate integrated waveguide structure, which can reduce the external dimensions of the feeding network. Additionally, setting the first power divider 7 and the radiation component on the same substrate further reduces the external dimensions of this pattern-reconfigurable millimeter-wave antenna.

[0036] In addition, referring to Figure 2 and Figure 4 , in this embodiment, three metal vias are also arranged in the middle of the head of the first power divider 7 to improve its coupling effect with the first feeding branch 8; two metal vias are also arranged in the middle of the second feeding branch 10 to improve its coupling effect with the second power divider 9.

[0037] In this embodiment, in order to improve the gain of the antenna, further narrow the beam, and improve the aperture efficiency, an excitation component is also arranged on the side of the radiation component away from the second feeding branch 10. Please refer to Figure 1 and Figure 6 , the excitation component includes a fifth substrate 5 and a number of excitation units 11 arranged thereon. The fifth substrate 5 is arranged above the first substrate 1. Each excitation unit 11 includes metal rings arranged on the upper and lower surfaces of the fifth substrate 5 and a number of metal vias passing through the fifth substrate 5 and connecting the metal rings on the upper and lower surfaces. The middle of the metal ring is a hollow structure. By arranging the excitation units 11 on the fifth substrate 5, a new structure with zero refractive index can be formed, and the transmittance is relatively high, which can effectively correct the electric field of the radiation component, make the radiation field face the same direction, and improve the gain of the antenna. Additionally, the metal ring is a rectangular ring, which is convenient for arranging a larger array of excitation units 11 on the fifth substrate 5. In this embodiment, 3×3 of the above excitation units 11 are arranged at each position of the fifth substrate 5 facing the radiation unit 6, forming a symmetric excitation component, which is convenient for realizing dual polarization.

[0038] Figure 10a and Figure 10bThe performance of the pattern-reconfigurable millimeter-wave antenna is shown. The impedance matching of both feeding ports covers the frequency band of 76 - 80 GHz, the isolation is greater than 25 dB, the maximum gain of port 1 is 22.5 dBi, and the maximum gain of port 2 is 18.3 dBi. The maximum aperture efficiency of port 1 is 59%, and the maximum aperture efficiency of port 2 is 91.5%. Compared with traditional millimeter-wave antennas, both the gain and aperture efficiency have been improved.

[0039] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A millimeter-wave antenna with reconfigurable radiation pattern, characterized in that, include: A radiation component, disposed on a first substrate, comprising a 2×2 array of radiation units, each of the radiation units comprising a 2×2 array of cross-coupling slots and metal vias disposed on the periphery of four cross-coupling slots; A first power divider is provided on the first substrate and is a "T"-shaped structure formed by metal vias, with a tail portion being a feeding end and two ends of a head portion being provided between the radiation units; The first feeding branch is provided on the second substrate and is a "Ⅱ"-shaped structure formed by metal vias, and four ends are provided with cross coupling slots facing the radiation unit, and two middle parts are provided with straight coupling slots facing the two ends of the first power divider head; The second power divider is provided on the fourth substrate and is an "I"-shaped structure formed by metal vias, one end of which is a feeding end, and the other end is provided at a position facing the middle of the four radiation units and a straight coupling gap is provided at the end; The second feeding branch is arranged on the third substrate and is an "I"-shaped structure formed by metal vias, and the four ends are provided with a straight coupling slot facing the radiation unit, and the middle part is arranged facing the straight coupling slot of the second power divider; wherein The first substrate, the second substrate, the third substrate and the fourth substrate are stacked together in sequence.

2. The millimeter wave antenna with reconfigurable directional pattern as claimed in claim 1, characterized in that: The upper and lower surfaces of the first substrate, the second substrate, the third substrate, and the fourth substrate are all covered with a metal layer; The first power divider, the first feeding branch, the second power divider, and the second feeding branch are substrate integrated waveguide structures.

3. The millimeter wave antenna with reconfigurable directional pattern as claimed in claim 2, characterized in that: The metal vias of the first power divider form a ring-shaped "T" structure, and three metal vias are arranged in the middle of the head thereof.

4. The millimeter wave antenna with reconfigurable directional pattern as claimed in claim 2, characterized in that: The metal vias of the second feeding branch form a ring-shaped "I"-shaped structure, and two metal vias are arranged in the middle.

5. The millimeter wave antenna with reconfigurable directivity pattern according to any one of claims 1 to 4, characterized in that: An excitation component is also provided on a side of the radiation component away from the second feeding branch; The excitation component has a refractive index of zero and includes a fifth substrate and a plurality of excitation units disposed thereon. The excitation units include metal rings disposed on the upper and lower surfaces of the fifth substrate and a plurality of metal vias penetrating the fifth substrate and connecting the metal rings on the upper and lower surfaces.

6. The millimeter wave antenna with reconfigurable directional pattern as claimed in claim 5, characterized in that: Each position on the fifth substrate facing the radiation unit is provided with 3×3 excitation units.

7. The millimeter wave antenna with reconfigurable directional pattern as claimed in claim 6, characterized in that: The metal ring is a rectangular ring.

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