Millimeter wave antenna, millimeter wave antenna array, and active module

Abstract

The present application belongs to the technical field of microwave antennas. Disclosed are a millimeter wave antenna, a millimeter wave antenna array, and an active module. The millimeter wave antenna comprises: a surface choke structure, a radiation metal sheet, and a metal ground provided with a feed gap, wherein the surface choke structure comprises several metal via holes provided on a dielectric substrate 7, the dielectric substrate 7 is arranged on the metal ground, and the radiation metal sheet is electrically connected to the metal ground by means of the metal via holes; and the surface choke structure is used for suppressing the interference caused by surface waves on the radiation performance of the antenna. A surface wave choke structure is used, such that the problem of skewing of a digital array antenna pattern caused by an environmental factor and surface wave interference can be effectively solved; moreover, the surface wave choke structure is arranged inside an antenna, such that a space occupied on a base material (such as a PCB and a chip package) is reduced, and the advantage of low costs is achieved.

Description

Millimeter wave antenna, millimeter wave antenna array and active module

[0001] This application claims priority to the Chinese patent application filed on June 15, 2023 (application number: 202310711525.5). Technical Field

[0002] The present application relates to the field of microwave antenna technology, and in particular to a millimeter wave antenna, a millimeter wave antenna array, and an active module. Background Art

[0003] Currently, millimeter-wave array antennas have been widely used in the fields of automotive millimeter-wave radar and vital sign detection. Among them, digital array is the mainstream technical solution for current millimeter-wave radar. This solution performs back-end digital processing on the signals obtained by a small number of antenna units, simulates a large number of antenna units for array analysis, and has the characteristics of low cost. For example, the reference "Bailleul P KA new era in elemental digital beamforming for spaceborne communications phased arrays[J]. Proceedings of the IEEE, 2016, 104(3): 623-632" has higher requirements on the directional pattern of the antenna unit, requiring it not to be deflected or have zero points due to environmental interference, because the skew and zero point problems of the directional pattern will reduce the performance of the radar.

[0004] Due to the small size of this band, millimeter wave antennas are integrated into chip packages. The chip and the integrated circuits surrounding it are characterized by complex environments and high electromagnetic interference. Traditional antennas, such as patch antennas, as shown in the reference "Mok WC, Wong SH, Luk KM, et al. Single-layer single-patch dual-band and triple-band patch antennas [J]. IEEE transactions on antennas and propagation, 2013, 61(8): 4341-4344", are affected by the environment in the array, resulting in deterioration of radiation performance, which in turn affects the overall antenna performance, such as skewed radiation patterns.

[0005] Surface waves are a type of electromagnetic interference generated by antennas and the environment. This interference has a significant impact on the antenna radiation pattern. Usually, the solution to this problem is to add an electromagnetic band gap (EBG) around the antenna. For example, in the reference "Yang F, Rahmat-Samii Y. Microstrip antennas integrated with electromagnetic band-gap (EBG) structures: A low mutual coupling design for array applications [J]. IEEE transactions on antennas and propagation, 2003, 51(10): 2936-2946", EBG is a periodic structure that has a suppressive effect on surface wave interference.

[0006] However, EBG has the following disadvantages: First, EBG requires a large size (usually more than three times the wavelength), making it difficult to meet the high integration requirements of antenna systems; second, EBG uses high impedance to suppress surface waves, and the suppression effect on surface waves is limited and cannot be completely eliminated; finally, EBG as an electromagnetic environment itself has an impact on the radiation performance of the antenna (such as directional pattern deviation, etc.), which leads to the problem of deterioration of antenna radiation characteristics when existing millimeter-wave digital arrays are applied in complex electromagnetic environments.

[0007] Summary of the Invention

[0008] The purpose of this application is to overcome the shortcomings of the prior art, such as the large size of the EBG, which makes it difficult to meet the high integration requirements of the antenna system; the EBG uses high impedance to suppress surface waves, but the suppression effect on surface waves is limited and cannot be completely eliminated; and the EBG itself, as an electromagnetic environment, has an impact on the radiation performance of the antenna, resulting in the deterioration of the antenna radiation characteristics of the existing millimeter-wave digital array application in complex electromagnetic environments. The present application provides a millimeter-wave antenna, a millimeter-wave antenna array and an active module.

[0009] In order to achieve the above-mentioned invention objectives, this application provides the following technical solutions:

[0010] A millimeter wave antenna, comprising: a surface choke structure, a radiating metal sheet, and a metal ground provided with a feeding slot, wherein the surface choke structure is a plurality of metal vias provided on a dielectric substrate, the dielectric substrate is provided on the metal ground, and the radiating metal sheet is electrically connected to the metal ground through the metal vias;

[0011] The surface choke structure is used to suppress the interference of surface waves on the radiation performance of the antenna.

[0012] The above technical solution adopts a surface wave choke structure, which can effectively solve the problem of deflection of the digital array antenna pattern caused by environmental factors and surface wave interference. The surface wave choke structure is arranged inside the antenna, which reduces the space occupied by the substrate (such as PCB, chip package) and has the advantage of low cost.

[0013] As a preferred solution of the present invention, the metal via includes a first metal via for feeding the antenna. The first metal via is arranged on both sides of the feeding gap, and the radiating metal sheet is electrically connected to the metal ground through the first metal via.

[0014] As a preferred solution of the present invention, the radiation metal sheet includes two U-shaped metal sheets, and a gap structure is formed between the two U-shaped metal sheets.

[0015] As a preferred solution of the present invention, the U-shaped metal sheet is provided with a cut corner.

[0016] As a preferred solution of the present invention, the metal via further includes a second metal via for participating in radiation and suppressing surface waves, and the second metal via is arranged around the feeding slot and the first metal via.

[0017] As a preferred solution of the present invention, the millimeter wave antenna also includes: two additional metal plates for improving the radiation characteristics of the antenna, the additional metal plates are electrically connected to the metal ground through the second metal vias, and the additional metal plates are arranged on both sides symmetrically of the radiation metal plate.

[0018] As a preferred solution of the present invention, the feeding slot is any one of H-shaped, L-shaped and straight-shaped.

[0019] As a preferred solution of the present invention, the feeding slot can be fed by a microstrip line, a stripline, a coplanar waveguide, or a substrate waveguide.

[0020] As a preferred embodiment of the present invention, the millimeter wave antenna includes several layers of dielectric substrates, and when the dielectric substrates provided with the metal vias are arranged between dielectric substrates not provided with the metal vias, blind holes are formed;

[0021] When the dielectric substrate provided with the metal via is disposed below the dielectric substrate not provided with the metal via, a buried via is formed;

[0022] When the dielectric substrate provided with the metal via is arranged above the dielectric substrate not provided with the metal via, a countersunk hole is formed;

[0023] The dielectric substrates are all provided with the metal vias, thereby forming through holes.

[0024] On the other hand, a millimeter wave antenna array is disclosed, wherein the millimeter wave antenna array is composed of a plurality of millimeter wave antennas described above, wherein the plurality of millimeter wave antennas are divided into feed units and non-feed units, and the non-feed units are symmetrically arranged around the feed units;

[0025] The non-feed unit is used to provide a stable electromagnetic environment for the feed unit.

[0026] The above technical solution creates a symmetrical environment, which can enhance the choke effect without worsening the radiation effect. The radiation is not easily deflected, which can effectively reduce the radiation impact and provide a stable and simple electromagnetic environment for the feed unit. The radiation performance of the feed unit is not easily affected by external interference; the influence of external electromagnetic interference on the feed unit is suppressed.

[0027] On the other hand, an active module is also disclosed, comprising a substrate, a chip, an interface, and a plurality of millimeter wave antennas as described above, wherein the chip, the millimeter wave antenna, and the interface are all disposed on the substrate, and the chip is electrically connected to the millimeter wave antenna and the interface;

[0028] The chip includes a millimeter wave radar processing chip, a processor chip, and a radio frequency chip.

[0029] The above technical solution provides a radio frequency active solution for the system, which can directly integrate the active module of the present invention into the system, saving the research and development time of the system active module. At the same time, the active module of the present invention has the characteristics of low noise and can achieve better system sensitivity.

[0030] As a preferred solution of the present invention, the millimeter wave antenna is arranged on one side or both sides of the substrate. When the millimeter wave antenna is arranged on one side of the substrate, the chip is arranged on the same side or the opposite side of the millimeter wave antenna.

[0031] As a preferred solution of the present invention, the interface is any one of a pad, a ball grid array package, a gold finger package, a stamp package, and a pin interface.

[0032] Compared with the prior art, the beneficial effects of the present invention are: the millimeter wave antenna provided in this application adopts a surface wave choke structure, which can effectively solve the problem of deflection of the digital array antenna pattern due to environmental factors and surface wave interference, and the surface wave choke structure is arranged inside the antenna, which reduces the space occupied by the substrate (such as PCB, chip package) and has the advantage of low cost; the millimeter wave antenna array creates a symmetrical environment, which can enhance the effect of choke without deteriorating the radiation effect. The radiation is not easy to deflect, and the radiation impact can be effectively reduced, providing a stable and simple electromagnetic environment for the feeding unit, so that the radiation performance of the feeding unit is not easily affected by external environment interference; and suppressing the influence of external electromagnetic interference on the feeding unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a top view of a millimeter wave antenna according to Example 1 of the present application;

[0034] FIG2 is a schematic structural diagram of a millimeter wave antenna according to Example 1 of the present application;

[0035] FIG3 is a schematic diagram of a feeding slot of a millimeter wave antenna according to Example 1 of the present application;

[0036] FIG4 is a schematic diagram of a surface wave choke structure and a radiation metal sheet of a millimeter wave antenna according to Example 1 of the present application;

[0037] FIG5 is a structural model diagram of a millimeter wave antenna using microstrip line feeding according to Example 1 of the present application;

[0038] FIG6 is a schematic diagram of a 1*2 array of a millimeter wave antenna array according to Example 2 of the present application;

[0039] FIG7 is a directional diagram of a feed unit of a 1*2 array of a millimeter wave antenna array according to Example 2 of the present application;

[0040] FIG8 is a schematic diagram of a 2*2 array of a millimeter wave antenna array according to Example 2 of the present application;

[0041] FIG9 is a structural block diagram of an active module according to Example 3 of the present application;

[0042] Markings in the figure: 1-extra metal sheet, 2-radiating metal sheet, 3-metal ground, 4-feeding gap, 5-metal via, 6-second metal via, 7-dielectric substrate. DETAILED DESCRIPTION

[0043] The present application is further described in detail below in conjunction with experimental examples and specific implementation methods. However, this should not be understood as limiting the scope of the above-mentioned subject matter of the present application to the following embodiments. All technologies implemented based on the content of the present application fall within the scope of the present application.

[0044] Example 1

[0045] A millimeter wave antenna, as shown in Figures 1 and 2, includes: a surface choke structure, a radiating metal sheet 2, and a metal ground 3 provided with a feed slot 4. The surface choke structure is a plurality of metal vias provided on a dielectric substrate 7, the dielectric substrate 7 is provided on the metal ground 3, and the radiating metal sheet 2 is electrically connected to the metal ground 3 through the metal vias.

[0046] The surface choke structure is used to suppress the interference of surface waves on the radiation performance of the antenna.

[0047] Metal vias are mechanically drilled on a dielectric board, and then the hole walls are metallized by electroplating to enable electrical conduction. Specific metallized vias can be hollow or solid. Solid metallized vias are resin-plugged, with resin added inside.

[0048] The surface wave choke structure can effectively solve the problem of deflection of the digital array antenna pattern due to environmental factors and surface wave interference. The surface wave choke structure is arranged inside the millimeter wave antenna, which reduces the space occupied by the substrate (such as PCB, chip package) and has the advantage of low cost.

[0049] The metal vias include first metal vias 5 for feeding the antenna. The first metal vias 5 are arranged on both sides of the feeding slot 4 . The radiation metal sheet 2 is electrically connected to the metal ground 3 through the first metal vias 5 .

[0050] The radiation metal sheet 2 includes two U-shaped metal sheets, and a gap structure is formed between the two U-shaped metal sheets. The function of the gap structure is to guide electromagnetic waves and enable the antenna to perform impedance matching.

[0051] The U-shaped metal sheet is provided with a cut corner, which can improve the impedance matching of the antenna.

[0052] The metal via further includes a second metal via 6 for participating in radiation and suppressing surface waves. The second metal via 6 is arranged around the feeding slot 4 and the first metal via 5 .

[0053] The millimeter wave antenna also includes: two additional metal sheets 1 for improving the radiation characteristics of the antenna, such as the radiation pattern and gain. The additional metal sheets 1 are electrically connected to the metal ground 3 through the second metal via 6. The additional metal sheets 1 are arranged on both sides symmetrically of the radiation metal sheet 2.

[0054] Specifically, as shown in Figure 4, it includes two first metal vias 5, and the two first metal vias 5 are symmetrically arranged on both sides of the H-shaped feeding slot 4 as shown in Figure 3, connecting the radiating metal sheet 2 and the metal ground 3, and includes 14 second metal vias 6, and the 14 second metal holes 6 surround and are symmetrically arranged around the feeding slot 4 and the first metal via 5, connecting the additional metal sheet 1 and the metal ground 3. The first metal via 5 and the second metal via 6 are symmetrically arranged to optimize the performance of the millimeter wave antenna.

[0055] The feeding slot 4 can be any one of an H-shape, an L-shape and a straight-line shape.

[0056] The feeding slot 4 can be fed by a microstrip line, a stripline, a coplanar waveguide, or a substrate waveguide.

[0057] The millimeter wave antenna includes several layers of dielectric substrates 7, and when the dielectric substrates 7 provided with the metal vias are arranged between dielectric substrates 7 not provided with the metal vias, blind holes are formed;

[0058] When the dielectric substrate 7 provided with the metal via is disposed below the dielectric substrate 7 not provided with the metal via, a buried via is formed;

[0059] When the dielectric substrate 7 provided with the metal via is placed above the dielectric substrate 7 not provided with the metal via, a countersunk hole is formed;

[0060] The dielectric substrates 7 are all provided with the metal vias, thereby forming through holes.

[0061] Specifically, as shown in FIG5 , a structural model diagram of a millimeter antenna using microstrip line feeding is shown.

[0062] Example 2

[0063] A millimeter wave antenna array is composed of several millimeter wave antennas described in Example 1, wherein the several millimeter wave antennas are divided into feeding units and non-feeding units, and the non-feeding units are symmetrically arranged around the feeding units, thereby creating a symmetrical environment, which can enhance the choking effect without deteriorating the radiation effect, and the radiation is not easily deflected.

[0064] Specifically, as shown in Figure 6, a 1*2 array includes two feeding units and ten non-feeding units. The non-feeding units are symmetrically arranged around the feeding unit. The directional pattern shown in Figure 7, the solid line and the dotted line are the simulation results of the directional patterns of the two feeding units, respectively. It can be seen that the directional pattern of the millimeter wave antenna array is not affected by external interference.

[0065] Figure 8 shows a millimeter-wave antenna array consisting of 2x2 millimeter-wave antenna elements and its surrounding structure. The feed element is an active radiating element, while the peripheral non-feed elements have a similar antenna structure to the feed element, but are not fed and are non-active radiating elements. The non-feed elements effectively reduce the impact of radiation, provide a stable and simple electromagnetic environment for the feed element, and make the radiation performance of the feed element less susceptible to external interference. They also suppress the impact of external electromagnetic interference on the feed element.

[0066] Example 3

[0067] An active module, comprising a substrate, a chip, an interface, and a plurality of any of the above-mentioned millimeter-wave antennas, wherein the chip, the millimeter-wave antennas, and the interface are all disposed on the substrate, and the chip is electrically connected to the millimeter-wave antennas and the interface;

[0068] The chips include millimeter wave radar processing chips, processor chips, radio frequency chips, etc.

[0069] An RF active solution is provided for the system, which can directly integrate the active module of the present application into the system, saving the research and development time of the system active module. At the same time, the active module of the present application has the characteristics of low noise and can achieve better system sensitivity.

[0070] The millimeter wave antenna is arranged on one side or both sides of the substrate. When the millimeter wave antenna is arranged on one side of the substrate, the chip is arranged on the same side or the opposite side of the millimeter wave antenna.

[0071] The interface is any one of a solder pad, a ball grid array package, a gold finger package, a stamp package, and a pin interface.

[0072] Specifically, as shown in Figure 9, the millimeter wave antenna, chip and interface are placed on the substrate, and are welded or in surface contact with the substrate. The antenna can be placed on one side or both sides of the substrate. The chip, antenna and interface are electrically connected. When the antenna is placed on one side of the substrate, the chip can be located on the same side or opposite side of the substrate as the antenna. The substrate is electrically connected to the next-level electronic system through the interface. This arrangement can enable the antenna to flexibly cover different areas according to different usage scenarios. At the same time, the arrangement of the antennas on the same substrate ensures the system's integration and low cost.

[0073] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A millimeter wave antenna, characterized in that: include: A surface choke structure, a radiating metal sheet (2), and a metal ground (3) provided with a feeding slot (4), wherein the surface choke structure is a plurality of metal vias provided on a dielectric substrate (7), the dielectric substrate (7) is provided on the metal ground (3), and the radiating metal sheet (2) is electrically connected to the metal ground (3) through the metal vias; The surface choke structure is used to suppress the interference of surface waves on the radiation performance of the antenna.

2. A millimeter wave antenna according to claim 1, characterized in that: The metal vias include a first metal via (5) for feeding the antenna, the first metal via (5) being arranged on both sides of the feeding slot (4), and the radiating metal sheet (2) being electrically connected to the metal ground (3) via the first metal via (5).

3. A millimeter wave antenna according to claim 2, characterized in that: The radiation metal sheet (2) comprises two U-shaped metal sheets, and a gap structure is formed between the two U-shaped metal sheets.

4. A millimeter wave antenna according to claim 3, characterized in that: The U-shaped metal sheet is provided with a cut corner.

5. The millimeter wave antenna according to claim 2, characterized in that: The metal via further comprises a second metal via (6) for participating in radiation and suppressing surface waves, and the second metal via (6) is arranged around the feeding slot (4) and the first metal via (5).

6. A millimeter wave antenna according to claim 5, characterized in that: The millimeter wave antenna further comprises: two additional metal sheets (1) for improving the radiation characteristics of the antenna, the additional metal sheets (1) being electrically connected to the metal ground (3) through the second metal vias (6), and the additional metal sheets (1) being arranged on two symmetrical sides of the radiation metal sheet (2).

7. The millimeter wave antenna according to claim 1, characterized in that: The feeding slot (4) is any one of an H-shape, an L-shape and a straight-line shape.

8. The millimeter wave antenna according to claim 7, characterized in that: The feeding slot (4) can be fed by means of a microstrip line, a stripline, a coplanar waveguide or a substrate waveguide.

9. The millimeter wave antenna according to claim 1, characterized in that: The millimeter wave antenna comprises a plurality of layers of dielectric substrates (7), and when the dielectric substrates (7) provided with the metal vias are arranged between dielectric substrates (7) not provided with the metal vias, blind holes are formed; When the dielectric substrate (7) provided with the metal via hole is arranged below the dielectric substrate (7) not provided with the metal via hole, a buried hole is formed; When the dielectric substrate (7) provided with the metal via hole is arranged above the dielectric substrate (7) not provided with the metal via hole, a countersunk hole is formed; The dielectric substrate (7) is provided with the metal via hole, thereby forming a through hole.

10. A millimeter wave antenna array, characterized in that: The millimeter wave antenna array is composed of a plurality of millimeter wave antennas according to any one of claims 1 to 9, wherein the plurality of millimeter wave antennas are divided into a feed unit and a non-feed unit, and the non-feed unit is symmetrically arranged around the feed unit; The non-feed unit is used to provide a stable electromagnetic environment for the feed unit.

11. An active module, characterized in that: The active module is composed of a substrate, a chip, an interface, and a plurality of millimeter wave antennas according to any one of claims 1 to 9, wherein the chip, the millimeter wave antenna, and the interface are all arranged on the substrate, and the chip is electrically connected to the millimeter wave antenna and the interface; The chip includes a millimeter wave radar processing chip, a processor chip, and a radio frequency chip.

12. An active module according to claim 11, characterized in that: The millimeter wave antenna is arranged on one side or both sides of the substrate. When the millimeter wave antenna is arranged on one side of the substrate, the chip is arranged on the same side or the opposite side of the millimeter wave antenna.

13. An active module according to claim 11, characterized in that: The interface is any one of a solder pad, a ball pin grid array package, a gold finger package, a stamp package, and a pin interface.

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