Low profile multi-mode broadband high isolation microstrip dual antenna pair

Abstract

The application discloses a low-profile multi-mode broadband high-isolation microstrip double-antenna pair, which comprises a metal floor and two antenna units; the metal floor is located at the lowermost part of the overall structure; the two antenna units are located above the metal floor and are centrally symmetrically distributed about the center point of the metal floor; the two antenna units are of the same structure and each comprises a radiation patch, a metal column, a lumped capacitor and a feeding port; the metal column is below the radiation patch, the metal floor is below the metal column, the lumped capacitor is located on one side of the long side of the radiation patch, and the feeding port is located on one side of the short side of the radiation patch. The double-antenna pair generates a multi-mode resonance effect by adding the metal column and the capacitor element, realizes the low-profile broadband characteristics, provides support for the radiation patch and increases the mechanical stability; the two antenna units are still of the high-isolation characteristic without introducing an additional decoupling structure; the double-antenna pair has the characteristics of extremely low profile height, simple structure and easy integration.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microstrip antennas, and particularly relates to a low-profile multi-mode wideband high-isolation microstrip double-antenna pair. BACKGROUND

[0002] In recent years, with the continuous development and popularization of the fifth generation mobile communication technology (5G), the demand for antennas in mobile communication devices is increasing, and higher requirements are put forward for antenna design.

[0003] Traditional mobile phones usually arrange antennas in the frame area, but as the number of antenna requirements increases, the frame area becomes more crowded. If these antennas on the frame are integrated into real devices, the performance of the antennas will be affected. The antennas in the frame area usually need sufficient ground clearance to meet the bandwidth requirements.

[0004] Nowadays, the development trend of antennas in mobile phones is smaller ground clearance and larger screen-to-body ratio. Therefore, antenna designers turn their attention to the rear cover area of the mobile phone, which does not occupy internal space and ground clearance. In order to be integrated with the rear cover of the mobile phone, the antenna needs to have a complete ground layer with low profile to avoid damaging the mainboard of the mobile phone, and the microstrip antenna is a suitable choice. However, the known conventional microstrip antenna has low profile, high quality factor, which limits the actual use of the microstrip antenna due to its inherent properties of low gain, low efficiency and most importantly low bandwidth. Therefore, how to expand the bandwidth while maintaining low profile and efficiency has always been a challenge in antenna design. SUMMARY

[0005] The technical problem to be solved by the application is to solve the shortcomings of the prior art, and to provide a low-profile multi-mode wideband high-isolation microstrip double-antenna pair. Under the premise of strictly limiting the height of the antenna profile, the wide working frequency band and high antenna efficiency characteristics are realized, and the two antenna units are very close without introducing additional decoupling structure, and still have good isolation between the two antenna units. The double-antenna pair of the application has the characteristics of wide working frequency band, high total efficiency, high isolation between units, high working efficiency, simple overall structure, easy integration, easy processing, low manufacturing cost, etc. Therefore, it has good development prospects in the future mobile communication field.

[0006] To achieve the above technical purpose, the technical solution adopted by the application is as follows:

[0007] A low-profile multi-mode wideband high-isolation microstrip double-antenna pair, comprising a metal ground plate, a first antenna unit and a second antenna unit.

[0008] The metal ground plate is located at the bottom of the overall structure of the double-antenna pair.

[0009] The first antenna unit and the second antenna unit are located above the metal floor and are centrally symmetrically distributed about a center point of the metal floor;

[0010] The first antenna unit and the second antenna unit are structurally identical, the first antenna unit comprises a first radiating patch, a first metal column with an arc edge, a first lumped capacitor and a first feeding port, and correspondingly, the second antenna unit comprises a second radiating patch, a second metal column with an arc edge, a second lumped capacitor and a second feeding port.

[0011] To optimize the above technical solution, the specific measures taken also include:

[0012] The first radiating patch is located at the top layer of the first antenna unit, the first metal column is located below the first radiating patch, and the lower side of the first metal column is the metal floor;

[0013] The first lumped capacitor is located on one side of the long side of the first radiating patch and connects the first radiating patch and the metal floor;

[0014] The first feeding port is located on one side of the short side of the first radiating patch;

[0015] The second radiating patch is located at the top layer of the second antenna unit, the second metal column is located below the second radiating patch, and the lower side of the second metal column is the metal floor;

[0016] The second lumped capacitor is located on one side of the long side of the second radiating patch and connects the second radiating patch and the metal floor;

[0017] The second feeding port is located on one side of the short side of the second radiating patch.

[0018] The first radiating patch and the second radiating patch are both rectangular, with a length L1 of 42 mm, a width W1 of 24.5 mm and a thickness of 0.1 mm.

[0019] The first metal column and the second metal column are symmetrically placed about the center point of the metal floor, with a width Lz of 7.5 mm, an arc edge radius of 8.5 mm and a height h of 0.5 mm.

[0020] The distance L2 between the first feeding port and the edge on one side of the first lumped capacitor is 13.75 mm, and the distance L2 between the second feeding port and the edge on one side of the second lumped capacitor is 13.75 mm;

[0021] The distance L3 between the first lumped capacitor and the edge on one side of the first feeding port is 20.5 mm, and the distance L3 between the second lumped capacitor and the edge on one side of the second feeding port is 20.5 mm.

[0022] The capacitance values of the first lumped capacitor and the second lumped capacitor are consistent.

[0023] The aforementioned metal floor, first metal column, second metal column, first radiating patch, and second radiating patch are all made of copper.

[0024] The first and second radiant patches mentioned above are separated from the metal floor by air.

[0025] The aforementioned metal floor is rectangular, 1mm thick, 145mm long, and 76mm wide.

[0026] The total projected area of ​​the aforementioned dual antenna pair is 1.345λ0×0.368λ0, and the profile height is 0.009λ0, where λ0 is the wavelength corresponding to the center frequency in free space.

[0027] The present invention has the following beneficial effects:

[0028] 1. Compared with other traditional microstrip antennas, this invention generates multimode resonance by adding a metal pillar element with an arc edge and a capacitor element to the original microstrip patch antenna. The profile height is extremely low. While maintaining the extremely low profile characteristics (the profile height is 0.5mm, i.e., 0.009λ0, where λ0 is the wavelength corresponding to the center frequency), broadband characteristics are achieved. At the same time, it provides support for the radiating patch and increases mechanical stability.

[0029] 2. Compared with traditional microstrip antennas, this invention achieves low profile height and wide frequency band characteristics while ensuring antenna efficiency. Ultimately, the total efficiency of the antenna reaches 43%-78% within the operating frequency band.

[0030] 3. Compared with traditional microstrip antenna pairs, the present invention can still achieve high isolation characteristics for closely spaced dual antenna pairs without introducing additional decoupling structures, with a value greater than 15dB in the operating frequency band. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the dual antenna pair according to an embodiment of the present invention;

[0032] Figure 2 This is a top view of a dual-antenna pair according to an embodiment of the present invention;

[0033] Figure 3 This is a structural diagram of an antenna unit in an embodiment of the present invention, wherein (a) is a front view of the antenna unit and (b) is a side view of the antenna unit;

[0034] Figure 4 The S-parameter curves of the dual antenna pairs in this embodiment of the invention are shown.

[0035] Figure 5 This is the overall efficiency curve of the dual antenna pair in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The embodiments of the present application will be further described in detail with reference to the drawings.

[0037] As Figures 1-3 shown, the low profile multi-mode wideband high isolation microstrip dual antenna pair of the present application includes a metal ground plate and two antenna units, the two antenna units are placed at the center point of the ground plate 11, a single antenna unit includes a rectangular radiation patch, a metal column, a lumped capacitor and a feed port, the lower side of the rectangular radiation patch is a rectangular metal column element with arc edges, the lower side of the metal column is the metal ground plate 11, in addition, the lumped capacitor is designed to be placed on one side of the long side of the radiation patch, and the feed port is located on one side of the short side of the radiation patch. Specifically, the metal ground plate 11 is located at the lowermost part of the overall structure, the two antenna units are located above the metal ground plate 11, and the two antenna units are placed in central symmetry about the center point of the metal ground plate 11. The two antenna units include a first antenna unit 1 and a second antenna unit 2.

[0038] Further, for the two antenna units as a whole, it further includes: a first radiation patch 3, a second radiation patch 4, a first metal column 5, a second metal column 6, a first lumped capacitor 7, a second lumped capacitor 8, a first feed port 9 and a second feed port 10.

[0039] The two antenna unit structures are completely symmetrical and consistent, so the first antenna unit 1 is selected to introduce the specific structure.

[0040] The first radiation patch 3 is located at the top layer of the first antenna unit 1, the lower side of the first radiation patch 3 is a first metal column 5 with arc edges, and the lower side of the first metal column 5 is the metal ground plate 11.

[0041] The first lumped capacitor 7 is located on one side of the long side of the first radiation patch 3, connecting the first radiation patch 3 and the metal ground plate 11.

[0042] The first feed port 9 is located on one side of the short side of the first radiation patch 3.

[0043] The second radiation patch 4 is located at the top layer of the second antenna unit 2, the second metal column 6 is located below the second radiation patch 4, and the lower side of the second metal column 6 is the metal ground plate 11.

[0044] The second lumped capacitor 8 is located on one side of the long side of the second radiation patch 4, connecting the second radiation patch 4 and the metal ground plate 11.

[0045] The second feed port 10 is located on one side of the short side of the second radiation patch 4.

[0046] Further, the first radiation patch 3 and the second radiation patch 4 are both rectangular, with a length L1 of 42 mm, a width W1 of 24.5 mm, and a thickness of 0.1 mm.

[0047] Further, the first metal column 5 with an arc edge and the second metal column 6 with an arc edge are symmetrically arranged about the center point of the metal floor 11, with a width Lz of 7.5 mm, an arc edge radius of 8.5 mm, and a height h of 0.5 mm.

[0048] Further, the first feeding port 9 and the second feeding port 10 are respectively arranged on the short side of the first radiation patch 3 and the second radiation patch 4, and the distance L2 between the first feeding port 9 and the second feeding port 10 and the edge on one side of the first lumped capacitor 7 and the second lumped capacitor 8 of the same unit is 13.75 mm.

[0049] The distance L3 between the first lumped capacitor 7 and the second lumped capacitor 8 and the edge on one side of the first feeding port 9 and the second feeding port 10 of the same unit is 20.5 mm.

[0050] Further, the first lumped capacitor 7 and the second lumped capacitor 8 of the antenna pair are respectively arranged on the long side of the first radiation patch 3 and the second radiation patch 4, and the capacitance values of the first lumped capacitor 7 and the second lumped capacitor 8 are set to be consistent.

[0051] Further, the first antenna unit 1 and the second antenna unit 2 are completely identical in structure and do not introduce additional decoupling structures therebetween, and the structure is simple.

[0052] Further, the metal floor 11, the first metal column 5, the second metal column 6, the rectangular first radiation patch 3, and the rectangular second radiation patch 4 are all made of copper material, and the rectangular first radiation patch 3 and the rectangular second radiation patch 4 are in air medium with the metal floor 11.

[0053] Further, the metal floor 11 has a thickness of 1 mm, a length of 145 mm, and a width of 76 mm.

[0054] The total projected area of the double antenna pair is 89.7 mm x 24.5 mm (1.345 λ0 x 0.368 λ0), and the cross-sectional height is 0.5 mm (0.009 λ0), where λ0 is the wavelength corresponding to the center frequency in free space. The overall volume of the antenna is small, and the structure is compact and simple.

[0055] Figure 4For the S parameter curve of the dual antenna of the embodiment of the present application, the S11 and S22 curve charts show the impedance matching condition of the two antenna units of the antenna pair. It can be seen from the figure that the metal column structure with arc edge and the capacitive loading technology in the present application produce multi-mode resonance, and realize the wideband characteristics. The impedance matching bandwidth of the final antenna is 950MHz (4.05-5GHz), and the relative bandwidth is 21.3%, so it can be seen that the antenna is well matched in the working frequency band. At the same time, it can also be seen from S21 that the isolation between the two ports in the working frequency band range is greater than 15dB, and the antenna pair can still maintain good isolation without introducing additional decoupling structure.

[0056] Figure 5 For the total efficiency curve of the dual antenna of the embodiment of the present application, it can be seen that the total efficiency is better than 40% in the working frequency range, the highest efficiency reaches 78%, the average efficiency is greater than 50%, which shows that the antenna has good radiation performance.

[0057] The dual antenna pair designed in the present application has the characteristics of wide working frequency band, high total efficiency, high isolation between units, high working efficiency, simple structure, easy processing, low manufacturing cost and the like on the basis of maintaining low profile characteristics, so it has good development prospect in the future mobile communication field.

[0058] The above is only the preferred embodiment of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiment. Any technical scheme falling within the idea of the present application belongs to the protection scope of the present application. It should be noted that for ordinary skilled in the art, some improvements and decorations without departing from the principle of the present application should be considered as the protection scope of the present application.

Claims

1. A low profile multi-mode wideband high isolation microstrip dual antenna pair, characterized in that, The metal floor, the first antenna unit (1) and the second antenna unit (2) are included. The metal floor (11) is located at the bottom of the whole structure of the double antenna pair. The first antenna unit (1) and the second antenna unit (2) are located above the metal floor (11) and are centrally symmetrically distributed about the center point of the metal floor (11). The first antenna unit (1) and the second antenna unit (2) are completely the same in structure, the first antenna unit (1) includes a first radiation patch (3), a first metal column (5) with an arc edge, a first lumped capacitor (7) and a first feeding port (9), and correspondingly, the second antenna unit (2) includes a second radiation patch (4), a second metal column (6) with an arc edge, a second lumped capacitor (8) and a second feeding port (10). The first radiation patch (3) is located at the top layer of the first antenna unit (1), the first metal column (5) is located below the first radiation patch (3), and the lower side of the first metal column (5) is the metal floor (11). The first lumped capacitor (7) is located on one side of the long side of the first radiation patch (3) and connects the first radiation patch (3) and the metal floor (11). The first feeding port (9) is located on one side of the short side of the first radiation patch (3). The second radiation patch (4) is located at the top layer of the second antenna unit (2), the second metal column (6) is located below the second radiation patch (4), and the lower side of the second metal column (6) is the metal floor (11). The second lumped capacitor (8) is located on one side of the long side of the second radiation patch (4) and connects the second radiation patch (4) and the metal floor (11). The second feeding port (10) is located on one side of the short side of the second radiation patch (4).

2. A low profile multi-mode wideband high isolation microstrip dual antenna pair according to claim 1, wherein, The first radiation patch (3) and the second radiation patch (4) are both rectangular, the length L1 is 42mm, the width W1 is 24.5mm, and the thickness is 0.1mm.

3. A low profile multi-mode wideband high isolation microstrip dual antenna pair according to claim 1, wherein, The first metal column (5) and the second metal column (6) are symmetrically placed about the center point of the metal floor (11), the width Lz is 7.5mm, the arc edge radius is 8.5mm, and the height h is 0.5mm.

4. The low profile multi-mode wideband high isolation microstrip dual antenna pair of claim 1, wherein, The distance L2 between the first feeding port (9) and the edge on one side of the first lumped capacitor (7) is 13.75mm, and the distance L2 between the second feeding port (10) and the edge on one side of the second lumped capacitor (8) is 13.75mm. The distance L3 between the first lumped capacitor (7) and the edge on one side of the first feeding port (9) is 20.5mm, and the distance L3 between the second lumped capacitor (8) and the edge on one side of the second feeding port (10) is 20.5mm.

5. The low profile multi-mode wideband high isolation microstrip dual antenna pair of claim 1, wherein, The capacitance values of the first lumped capacitor (7) and the second lumped capacitor (8) are consistent.

6. A low profile multi-mode wideband high isolation microstrip dual antenna pair according to claim 1, wherein, The metal floor (11), the first metal column (5), the second metal column (6), the first radiation patch (3) and the second radiation patch (4) all adopt copper material.

7. The low profile multi-mode wideband high isolation microstrip dual antenna pair of claim 1, wherein, The first radiation patch (3), the second radiation patch (4) and the metal floor (11) are in air medium.

8. The low profile multi-mode wideband high isolation microstrip dual antenna pair of claim 1, wherein, The metal floor (11) is rectangular, the thickness is 1mm, the length is 145mm, and the width is 76mm.

9. The low profile multi-mode wideband high isolation microstrip dual antenna pair of claim 1, wherein, The total projected area of the dual antenna pair is 1.345λ0×0.368λ0, and the profile height is 0.009λ0, λ0 being the wavelength corresponding to the center frequency in free space.

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