Miniaturized low-profile metasurface antenna

Abstract

The invention discloses a miniaturized low-profile metasurface antenna which comprises an upper-layer metal patch array, an upper-layer dielectric substrate, a lower-layer metal patch array, a middle-layer dielectric substrate, a metal ground, a lower-layer dielectric substrate and a metal feeder which are sequentially arranged from top to bottom, the upper-layer metal patch array comprises 21 upper-layer metal patches which are uniformly distributed in 7 rows and 3 columns; the lower-layer metal patch array comprises 14 lower-layer metal patches which are positioned right below the 14 upper-layer column gaps and are uniformly distributed in 7 rows and 2 columns; the center of the metal ground is provided with a radiation gap, and the radiation gap is located on the symmetric plane of the two columns of lower metal patches and is smaller than the column gap of the lower metal patches. The lower layer metal patch array is arranged below the upper layer metal patch array, so that capacitive coupling between the upper layer metal patch and the lower layer metal patch is increased, reduction of the antenna size is equivalently achieved, meanwhile, the good low-profile characteristic is kept, and the problem that a traditional metasurface antenna is large in size is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microwave and antenna technology, and particularly relates to a miniaturized low-profile metasurface antenna. BACKGROUND

[0002] With the rapid development of modern communication technology, especially the urgent demand for miniaturization, light weight and high performance antenna in the field of small satellites, unmanned aerial vehicles and Internet of Things, the limitations of traditional antennas in size, weight, efficiency and multi-functionality are increasingly prominent, and modern antenna design is showing a development trend of miniaturization, low profile, wide bandwidth and high gain. As a new type of antenna technology, metasurface antenna has unique electromagnetic characteristics and broad application prospects, so the research on its miniaturization has important scientific significance and practical value. SUMMARY

[0003] The technical problem to be solved by the present application is to solve the problem of large size of traditional metasurface antennas by providing a miniaturized low-profile metasurface antenna, which increases the capacitive coupling between the upper metal patch and the lower metal patch by arranging the lower metal patch array below the upper metal patch array, thereby achieving the equivalent reduction of antenna size while maintaining good low-profile characteristics.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is: A miniaturized low-profile metasurface antenna, comprising an upper metal patch array, an upper dielectric substrate, a lower metal patch array, a middle dielectric substrate, a metal ground, a lower dielectric substrate and a metal feed line arranged from top to bottom.

[0005] The upper dielectric substrate, the middle dielectric substrate and the lower dielectric substrate are all rectangular plates with the same size, with the long side being x and the wide side being y .

[0006] The upper metal patch array comprises 21 upper metal patches arranged in 7 rows and 3 columns, each upper metal patch is rectangular in shape, and the long side is along x ; the 21 upper metal patches have 14 equal upper column gaps.

[0007] The lower metal patch array comprises 14 lower metal patches arranged in 7 rows and 2 columns directly below the 14 upper column gaps; each lower metal patch is rectangular in shape, and the long side is along x , and the length of each lower metal patch is greater than the upper column gap.

[0008] The metal ground is arranged between the middle dielectric substrate and the lower dielectric substrate, and the center of the metal ground is provided with a radiation slot, the radiation slot is located on the symmetry plane of the two columns of lower metal patches, and is smaller than the column gap of the lower metal patches.

[0009] The column gap of the lower metal patches is greater than the upper column gap.

[0010] The width of each lower metal patch is greater than the width of the upper metal patch, so that the row gap of the lower metal patch array is smaller than the row gap of the upper metal patch array.

[0011] The metal feed line is arranged at the center of the bottom surface of the lower dielectric substrate, and is arranged along x The metal feed line is arranged at the center of the bottom surface of the lower dielectric substrate, and is arranged along

[0012] The metal feed line comprises an oblong metal patch and a fan-shaped metal patch; the oblong metal patch is arranged along x The metal feed line is arranged at the center of the bottom surface of the lower dielectric substrate, and is arranged along

[0013] The total thickness of the antenna is not more than 0.05 air wavelengths.

[0014] The center operating frequency is 7.35 GHz, and the corresponding air wavelength is 40.82 mm.

[0015] The length of the upper dielectric substrate, the middle dielectric substrate and the lower dielectric substrate is 30 mm, the width is 22.5 mm, and the thickness is 0.25 mm, 0.75 mm and 0.25 mm respectively; the total thickness of the antenna is 0.03 air wavelengths.

[0016] The length and width of each upper metal patch are 5.8 mm and 1.7 mm respectively, the row spacing of the upper metal patch array is 1 mm, and the column spacing is 0.7 mm.

[0017] The length and width of each lower metal patch are 4.3 mm and 2.4 mm respectively, the row spacing of the lower metal patch array is 0.3 mm, and the column spacing is 2.2 mm.

[0018] The present application has the following beneficial effects: 1. Under the premise of keeping the same performance, the size is reduced to 35% of the traditional metasurface antenna.

[0019] 2、The application can solve the problem of large size of the metasurface, by setting a lower layer of metal patch array below the upper layer of metal patch array, thereby increasing the capacitive characteristics between the upper layer of metal patch and the lower layer of metal patch, lowering the resonant frequency, and realizing the effect of size reduction. The lower layer of metal patch array can significantly enhance the capacitive coupling with the upper layer of metal patch array, and obtain the response of the resonant frequency shifting to low frequency. Compared with the prior art, the scheme provided by the application not only realizes miniaturization design, but also does not increase the thickness of the antenna, and the profile height of the antenna is lower compared with the center working frequency, thereby realizing the design of a miniaturized low-profile metasurface antenna.

[0020] 3、By etching a radiation slot on the metal ground, the energy input from the lowermost metal feed line can be transmitted to the upper two layers of metasurface structure through the radiation slot, to excite the relevant mode of the metasurface structure, and then radiate to the free space.

[0021] 4、The external input energy can be transmitted to the antenna through the metal feed line, and the design of the fan-shaped metal patch in the metal feed line can realize better impedance matching, so that more external energy is transmitted to the antenna. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a side view of the miniaturized low-profile metasurface antenna of the application.

[0023] Figure 2 It is a top view of the miniaturized low-profile metasurface antenna of the application.

[0024] Figure 3 It is a three-dimensional schematic view of the upper layer of metal patch array, the upper layer of dielectric substrate and the lower layer of metal patch array of the miniaturized low-profile metasurface antenna of the application.

[0025] Figure 4 It is a three-dimensional schematic view of the lower layer of metal patch array, the intermediate layer of dielectric substrate and the metal ground of the miniaturized low-profile metasurface antenna of the application.

[0026] Figure 5 It is a three-dimensional schematic view of the metal ground, the lower layer of dielectric substrate and the metal feed line of the miniaturized low-profile metasurface antenna of the application.

[0027] Figure 6 It is a reflection coefficient curve and gain curve diagram of the miniaturized low-profile metasurface antenna of the application.

[0028] Figure 7 It is an E-plane radiation pattern of the miniaturized low-profile metasurface antenna of the application at three different frequencies.

[0029] Figure 8 It is an H-plane radiation pattern of the miniaturized low-profile metasurface antenna of the application at three different frequencies.

[0030] wherein: 10. upper layer metal patch array; 11. upper layer metal patch; 12. upper layer column gap; 20. upper layer dielectric substrate; 30. lower layer metal patch array; 31. lower layer metal patch; 40. middle layer dielectric substrate; 50. metal ground; 51. radiation slot; 60. lower layer dielectric substrate; 70. metal feed line; 71. rectangular metal patch; 72. fan-shaped metal patch. DETAILED DESCRIPTION

[0031] The application will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0032] In the description of the application, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like 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 application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and "first", "second" and the like do not represent the importance of the parts, and therefore cannot be understood as a limitation on the application. The specific dimensions used in the embodiments are only for the purpose of illustrating the technical solutions and do not limit the protection scope of the application.

[0033] For the convenience of description, the present application takes the straight line where the two edges of a right angle of the dielectric substrate are located as x and y , and takes the height direction of the dielectric substrate as z . In this embodiment, the center frequency of the miniaturized low-profile metasurface antenna is taken as 7.35 GHz (corresponding to the air wavelength of 40.82 mm) as an example for detailed description.

[0034] As shown in Figure 1 and Figure 2 , a miniaturized low-profile metasurface antenna includes, from top to bottom, an upper layer metal patch array 10, an upper layer dielectric substrate 20, a lower layer metal patch array 30, a middle layer dielectric substrate 40, a metal ground 50, a lower layer dielectric substrate 60 and a metal feed line 70.

[0035] The upper layer dielectric substrate, the middle layer dielectric substrate and the lower layer dielectric substrate are all rectangular plates with the same size, and the dielectric constant is preferably 2.2. In this embodiment, the long side is taken as x and the wide side is taken as y . The long and wide dimensions are both preferably 30 mm and 22.5 mm respectively; the thickness zThe thicknesses of the upper dielectric substrate, the middle dielectric substrate, and the lower dielectric substrate are preferably 0.25 mm, 0.75 mm, and 0.25 mm, respectively.

[0036] The total thickness of the metasurface antenna does not exceed 0.05 air wavelengths. In this embodiment, it is preferably 0.03 air wavelengths. The antenna has a low profile, achieving a low profile design.

[0037] like Figures 1 to 3 As shown, the upper metal patch array includes 21 upper metal patches 11 evenly arranged in 7 rows and 3 columns. Each upper metal patch is rectangular in shape, and its long side is along... x Towards; 21 upper metal patches have 14 equal upper column gaps 12.

[0038] In this embodiment, the dimensions of the upper metal patch in the x and y directions are preferably 5.8 mm and 1.7 mm, respectively, the column gap of the upper layer is preferably 0.7 mm, and the row spacing (i.e., the y-direction spacing) of the upper metal patch is preferably 1 mm.

[0039] like Figure 2 and Figure 4 As shown, the lower metal patch array includes 14 lower metal patches 31 located directly below the gaps between the 14 upper columns and evenly arranged in 7 rows and 2 columns; each lower metal patch is rectangular in shape, and its long side is along... x The length of each lower metal patch is greater than the gap between the upper columns, and both ends of each lower metal patch extend to the bottom of the two upper metal patches on either side of the gap between the upper columns directly above.

[0040] Furthermore, the column spacing of the lower metal patch is greater than the column spacing of the upper metal patch; the width of each lower metal patch is preferably greater than the width of the upper metal patch, so that the row spacing of the lower metal patch array is smaller than the row spacing of the upper metal patch array.

[0041] In this embodiment, the dimensions of the lower metal patch in the x and y directions are preferably 4.3 mm and 2.4 mm, respectively. The column spacing (i.e., x-axis spacing) of the lower metal patch is preferably 2.2 mm, and the row spacing (i.e., y-axis spacing) of the lower metal patch is preferably 0.3 mm.

[0042] A metal ground is disposed between the middle dielectric substrate and the lower dielectric substrate, and its dimensions in the x and y directions are consistent with those of the dielectric substrate, preferably 30 mm in the x direction and 22.5 mm in the y direction.

[0043] The center of the metal ground is provided with a rectangular radiation gap 51, which is located on the symmetry plane of the two columns of lower metal patches and is smaller than the column gap of the lower metal patches. The radiation gap can facilitate the energy passing and coupling into the upper metasurface structure, thereby effectively radiating. In this embodiment, the dimensions of the radiation gap in the x direction and the y direction are preferably 0.2 mm and 9.4 mm, respectively.

[0044] The metal feed line is arranged at the center of the bottom surface of the lower dielectric substrate and extends in the x direction to feed the upper metasurface structure.

[0045] As shown in Figure 5 , the metal feed line includes a rectangular metal patch 71 and a fan-shaped metal patch 72; the rectangular metal patch extends in the x direction. In this embodiment, the dimensions of the rectangular metal patch in the x direction and the y direction are preferably 18 mm and 3 mm, respectively; the center point of the arc in the fan-shaped metal patch is preferably 4 mm away from the rectangular metal patch in the x direction, and the edge point of the arc is preferably 3 mm and 2 mm away from the rectangular metal patch in the x direction and the y direction, respectively.

[0046] Figure 6 The reflection coefficient curve and the gain curve of the miniaturized low-profile metasurface antenna of the present application are shown. It can be seen that in the range of 6.96-7.75 GHz, the reflection coefficient is less than -10 dB, and the gain in this frequency range is 6.43-7.89 dBi, which meets the 3 dB gain requirement. Therefore, the operating bandwidth of the antenna is 6.96-7.75 GHz, and the relative bandwidth is 10.7%.

[0047] Figure 7 The E-plane radiation pattern of the miniaturized low-profile metasurface antenna of the present application is shown, which shows the two-dimensional radiation pattern at the center operating frequency point 7.35 GHz and the two edge operating frequency points 6.96 GHz and 7.75 GHz, respectively. It can be seen from the pattern that the sidelobe is low, and the radiation characteristics are good.

[0048] Figure 8 The H-plane radiation pattern of the miniaturized low-profile metasurface antenna of the present application is shown, which shows the two-dimensional radiation pattern at the center operating frequency point 7.35 GHz and the two edge operating frequency points 6.96 GHz and 7.75 GHz, respectively. It can be seen from the pattern that the sidelobe is low, and the radiation characteristics are good.

[0049] The above describes the preferred embodiments of the present application, but the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, various equivalent transformations of the technical solutions of the present application can be made, and these equivalent transformations all belong to the protection scope of the present application.

Claims

1. A miniaturized low-profile metasurface antenna, characterized in that: The antenna comprises, from top to bottom, an upper metal patch array, an upper dielectric substrate, a lower metal patch array, a middle dielectric substrate, a metal ground, a lower dielectric substrate and a metal feed line; The upper, middle and lower dielectric substrates are all rectangular plates with the same size, and the long side is x towards, and the wide side is y towards; The upper layer metal patch array includes 21 upper layer metal patches arranged in 7 rows and 3 columns uniformly, each upper layer metal patch is in a rectangular shape, and the long side is along x The 21 upper layer metal patches have 14 equal upper layer column gaps. The lower metal patch array includes 14 lower metal patches which are arranged in 7 rows and 2 columns uniformly and located directly below the 14 upper layer column gaps; the shape of each lower metal patch is rectangular, and the long side is along x The length of each lower metal patch is greater than the upper layer column gap. The metal ground is arranged between the middle dielectric substrate and the lower dielectric substrate, and a center of the metal ground is provided with a radiation slot, the radiation slot is located on a symmetry plane of 2 columns of lower metal patches, and is smaller than a column gap of the lower metal patches.

2. The miniaturized low-profile metasurface antenna of claim 1, wherein: The column gap of the lower metal patches is greater than the upper column gap.

3. The miniaturized low-profile metasurface antenna of claim 1, wherein: The width of each lower metal patch is greater than the width of the upper metal patch, so that the row gap of the lower metal patch array is smaller than the row gap of the upper metal patch array.

4. The miniaturized low-profile metasurface antenna of claim 1, wherein: The metal feed line is disposed at the center of the bottom surface of the lower dielectric substrate and extends in the direction of the arrow A. x to the disposition.

5. The miniaturized low-profile metasurface antenna of claim 4, wherein: The metal feed line comprises a rectangular metal patch and a sector metal patch; the rectangular metal patch is arranged along x to the layout.

6. The miniaturized low-profile metasurface antenna of claim 1, wherein: The total thickness of the antenna is not more than 0.05 air wavelengths.

7. The miniaturized low-profile metasurface antenna of claim 6, wherein: The center operating frequency is 7.35 GHz, and the corresponding air wavelength is 40.82 mm.

8. The miniaturized low-profile metasurface antenna of claim 7, wherein: The length and width of the upper dielectric substrate, the middle dielectric substrate and the lower dielectric substrate are 30 mm and 22.5 mm respectively, and the thicknesses are 0.25 mm, 0.75 mm and 0.25 mm respectively; the total thickness of the antenna is 0.03 air wavelengths.

9. The miniaturized low-profile metasurface antenna of claim 8, wherein: The length and width of each upper metal patch are 5.8 mm and 1.7 mm respectively, the row spacing of the upper metal patch array is 1 mm, and the column spacing is 0.7 mm.

10. The miniaturized low-profile metasurface antenna of claim 8, wherein: The length and width of each lower metal patch are 4.3 mm and 2.4 mm respectively, the row spacing of the lower metal patch array is 0.3 mm, and the column spacing is 2.2 mm.

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