A broadband dual-linear polarization base station antenna based on parasitic patches

Abstract

The present invention discloses a broadband dual-linear polarization base station antenna based on a parasitic patch, and belongs to the field of antenna technology. The parasitic patch structure of the antenna increases the antenna aperture, thereby widening the antenna bandwidth. By placing a 45° polarized radiation patch adjacent to a ‑45° polarized floor, a high degree of isolation between the two linear polarizations is achieved, and the patch is fed by a rigid cable. The metal floor and the parasitic patch of the present invention are respectively located at the bottom and top of the antenna, thereby achieving directional radiation while improving the antenna gain.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, and in particular to a broadband dual-linear polarization base station antenna based on a parasitic patch. Background Art

[0002] MIMO antenna technology is a key element of future 5G wireless systems. MIMO technology significantly improves spectrum efficiency and capacity. 5G systems utilize both low-band and high-band frequencies to efficiently utilize spectrum, however, low-band frequencies below 6GHz are primarily used for MIMO base stations. According to 5G standards, the available sub-6GHz frequency bands are 3.3-3.8GHz and 4.4-5GHz. The following are the difficulties faced when designing MIMO base station antennas.

[0003] 1 Bandwidth: In some cases, MIMO antennas need to cover two low-frequency bands of 3.3-5 GHz at the same time. Considering the processing error, it is very challenging to design an antenna with 51% impedance bandwidth.

[0004] 2 Isolation: The spacing between antenna array elements significantly affects mutual coupling. By increasing the spacing between antenna elements to >λ / 2 at 5GHz, mutual coupling can be reduced, but relatively speaking, the grating lobes appear earlier, reducing the overall scanning range of the phased array. On the other hand, by allowing an array spacing of λ / 2 at 5GHz, mutual coupling in the low frequency band can be greatly reduced, but a wider scanning range cannot be obtained. Therefore, a compromise needs to be made between isolation range and scanning range.

[0005] 3. Gain: It is very challenging to obtain stable gain over a large bandwidth, and the antenna should be accurately modeled and optimized. The total phased array gain is usually less than the theoretical value, which can be compensated by increasing the gain of a single antenna element.

[0006] From the above analysis, it can be seen that it is very difficult for base station antennas to achieve a VSWR less than 1.5 in the 4.4GHz-5GHz frequency band. Summary of the invention

[0007] In view of this, the present invention provides a broadband dual-linear polarization base station antenna based on a parasitic patch. The antenna has the advantages of ultra-wideband and dual slant polarization.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A broadband dual-linear polarization base station antenna based on a parasitic patch, comprising a parasitic patch layer and a radiation layer stacked sequentially from top to bottom;

[0010] The parasitic patch layer includes a first dielectric substrate 5, and a first parasitic patch 7 and a second parasitic patch 6 are provided on the upper surface of the first dielectric substrate;

[0011] The radiation layer includes a second dielectric substrate 8; the upper surface of the second dielectric substrate is provided with a first radiation patch 10 and a second radiation patch 9, and the lower surface is provided with a third radiation patch 14 and a fourth radiation patch 15; the shape of the first radiation patch is the projection of the first parasitic patch on the upper surface of the second dielectric substrate; the shape of the third radiation patch is the projection of the second parasitic patch on the lower surface of the second dielectric substrate;

[0012] The first parasitic patch, the first radiation patch and the fourth radiation patch are all the first patch group, the first patch group includes a trapezoidal patch 4 and a first semicircular patch 3, and the diameter side of the first semicircular patch is in close contact with the lower bottom of the trapezoidal patch; the second parasitic patch, the second radiation patch and the third radiation patch are all the second patch group, the second patch group includes a triangular patch 2 and a second semicircular patch 1, and the diameter side of the second semicircular patch is in close contact with one side of the triangular patch;

[0013] The first semicircular patch of the first parasitic patch and the second semicircular patch of the second parasitic patch are centrally symmetrical, and the diameter sides of the two are parallel; the diameter side of the second semicircular patch of the second radiation patch is perpendicular to the diameter side of the first semicircular patch of the first radiation patch; the diameter side of the second semicircular patch of the third radiation patch is perpendicular to the diameter side of the first semicircular patch of the fourth radiation patch;

[0014] A metal floor 18 is provided at a position of one quarter wavelength below the radiation layer; the triangular patch of the second radiation patch is connected to the inner conductor 12 of the first coaxial feed line, and the trapezoidal patch of the fourth radiation patch is connected to the outer conductor 17 of the first coaxial feed line; the trapezoidal patch of the first radiation patch is connected to the inner conductor 13 of the second coaxial feed line, and the triangular patch of the third radiation patch is connected to the outer conductor 11 of the second coaxial feed line.

[0015] Furthermore, the first patch group and the second patch group are both axisymmetric shapes; the diameter of the second semicircular patch is smaller than the side length of the triangle closely attached to it, and the diameter of the first semicircular patch is smaller than the lower base of the trapezoid closely attached to it.

[0016] Furthermore, the trapezoidal patch of the first parasitic patch and the triangular patch of the second parasitic patch are both located inside their corresponding semicircular patches.

[0017] The beneficial effects of the above technical solution of the present invention are:

[0018] 1. In order to increase the gain of the antenna, the present invention adds a layer of parasitic patch on the top of the radiation patch, optimizes the position of the parasitic patch and the distance between it and the corresponding radiation patch, and improves the antenna gain.

[0019] 2. The metal floor of the present invention is located at a quarter wavelength away from the radiation layer, thereby achieving directional radiation.

[0020] 3. The present invention achieves high isolation between the two linear polarizations by placing a 45° polarized radiation patch adjacent to a -45° polarized floor, and feeds the patch through a rigid cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 4 is a schematic diagram of the structure of the second patch group in an embodiment of the present invention.

[0022] Figure 2 It is a schematic diagram of the structure of the first patch group in an embodiment of the present invention.

[0023] Figure 3 It is a schematic structural diagram of the upper surface of the first dielectric substrate in an embodiment of the present invention.

[0024] Figure 4 Schematic diagram of the structure of the upper surface of the second dielectric substrate in an embodiment of the present invention.

[0025] Figure 5 Schematic diagram of the structure of the lower surface of the second dielectric substrate in an embodiment of the present invention.

[0026] Figure 6 Schematic diagram of the array structure of an embodiment of the present invention.

[0027] Figure 7 Schematic diagram of S parameter simulation of an embodiment of the present invention.

[0028] In the figure: 1. second semicircular patch, 2. triangular patch, 3. first semicircular patch, 4. trapezoidal patch, 5. first dielectric substrate, 6. second parasitic patch, 7. first parasitic patch, 8. second dielectric substrate, 9. second radiation patch, 10. first radiation patch, 11. outer conductor of second coaxial feed line, 12. inner conductor of first coaxial feed line, 13. inner conductor of second coaxial feed line, 14. third radiation patch, 15. fourth radiation patch, 16. via, 17. outer conductor of first coaxial feed line, 18. metal floor. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Reference Figures 1 to 6 , This embodiment provides a broadband dual-linear polarization base station antenna based on a parasitic patch, comprising a parasitic patch layer and a radiation layer stacked sequentially from top to bottom;

[0032] The parasitic patch layer includes a first dielectric substrate 5, and a first parasitic patch 7 and a second parasitic patch 6 are provided on the upper surface of the first dielectric substrate;

[0033] The radiation layer includes a second dielectric substrate 8; the upper surface of the second dielectric substrate is provided with a first radiation patch 10 and a second radiation patch 9, and the lower surface is provided with a third radiation patch 14 and a fourth radiation patch 15; the shape of the first radiation patch is the projection of the first parasitic patch on the upper surface of the second dielectric substrate; the shape of the third radiation patch is the projection of the second parasitic patch on the lower surface of the second dielectric substrate;

[0034] The first parasitic patch, the first radiation patch and the fourth radiation patch are all the first patch group, the first patch group includes a trapezoidal patch 4 and a first semicircular patch 3, and the diameter side of the first semicircular patch is in close contact with the lower bottom of the trapezoidal patch; the second parasitic patch, the second radiation patch and the third radiation patch are all the second patch group, the second patch group includes a triangular patch 2 and a second semicircular patch 1, and the diameter side of the second semicircular patch is in close contact with one side of the triangular patch;

[0035] The first semicircular patch of the first parasitic patch and the second semicircular patch of the second parasitic patch are centrally symmetrical, and the diameter sides of the two are parallel; the diameter side of the second semicircular patch of the second radiation patch is perpendicular to the diameter side of the first semicircular patch of the first radiation patch; the diameter side of the second semicircular patch of the third radiation patch is perpendicular to the diameter side of the first semicircular patch of the fourth radiation patch;

[0036] A metal floor 18 is provided at a position of one quarter wavelength below the radiation layer; the triangular patch of the second radiation patch is connected to the inner conductor 12 of the first coaxial feed line, and the trapezoidal patch of the fourth radiation patch is connected to the outer conductor 17 of the first coaxial feed line; the trapezoidal patch of the first radiation patch is connected to the inner conductor 13 of the second coaxial feed line, and the triangular patch of the third radiation patch is connected to the outer conductor 11 of the second coaxial feed line.

[0037] Furthermore, the first patch group and the second patch group are both axisymmetric shapes; the diameter of the second semicircular patch is smaller than the side length of the triangle closely attached to it, and the diameter of the first semicircular patch is smaller than the lower base of the trapezoid closely attached to it.

[0038] Furthermore, the trapezoidal patch of the first parasitic patch and the triangular patch of the second parasitic patch are both located inside their corresponding semicircular patches. A via hole is provided on the fourth radiation patch, and the inner conductor of the first coaxial feed line passes through the via hole. The second radiation patch and the third radiation patch are both provided with an extension for connecting the coaxial feed line.

[0039] The patches of the first patch group and the second patch group increase the antenna aperture, thus widening the antenna bandwidth and making the overall structure of the antenna more compact; in order to increase the gain of the antenna, a parasitic patch is added on top of the radiating patch, and the size and shape of the parasitic patch are the same as those of the radiating patch. By optimizing the position of the parasitic patch and its distance from the radiating patch, the antenna gain is improved.

[0040] The two parasitic patches are placed diagonally with respect to the radiating patch, with the tops of the parasitic and radiating patches aligned. High isolation between the two linear polarizations is achieved by placing the 45° polarized radiating patch adjacent to the -45° polarized floor, and the patches are fed by rigid cables.

[0041] The antenna is compact with an overall size of 21mm x 21mm. The antenna's radiating patches are placed crosswise and printed on the top and bottom of the substrate. The parasitic patch is located on top of the radiating patch to increase the overall antenna gain and compensate for the loss. The antenna S parameter curve simulation results are shown in Figure 1. Figure 7 As shown, it can be seen that the antenna has achieved broadband impedance matching characteristics. The antenna operates in the frequency range of 3.5GHz-6GHz, and the VSWR is less than 1.5 in the 4.1GHz-5.9GHz band. Similarly, in the 4.5-5GHz band, the isolation between polarizations is also better than -25dB.

[0042] Although the present invention has been shown and described with reference to certain embodiments of the present invention, it will be appreciated by those skilled in the art that various changes may be made in form and detail without departing from the scope of the present invention. Therefore, the scope of the present disclosure should not be limited to the aforementioned embodiments, but should be limited by the appended claims and their equivalents.

Claims

1. A broadband dual-linear polarization base station antenna based on a parasitic patch, comprising a parasitic patch layer and a radiation layer stacked in sequence from top to bottom; characterized in that: The parasitic patch layers each comprise a first dielectric substrate (5), the upper surface of the first dielectric substrate being provided with a first parasitic patch (7) and a second parasitic patch (6) which are opposite to each other; The radiation layer comprises a second dielectric substrate (8); the upper surface of the second dielectric substrate is provided with a first radiation patch (10) and a second radiation patch (9), and the lower surface is provided with a third radiation patch (14) and a fourth radiation patch (15); the shape of the first radiation patch is the projection of the first parasitic patch on the upper surface of the second dielectric substrate; the shape of the third radiation patch is the projection of the second parasitic patch on the lower surface of the second dielectric substrate; The first parasitic patch, the first radiation patch and the fourth radiation patch are all a first patch group, the first patch group comprises a trapezoidal patch (4) and a first semicircular patch (3), the diameter side of the first semicircular patch is in close contact with the bottom of the trapezoidal patch; the second parasitic patch, the second radiation patch and the third radiation patch are all a second patch group, the second patch group comprises a triangular patch (2) and a second semicircular patch (1), the diameter side of the second semicircular patch is in close contact with one side of the triangular patch; The first semicircular patch of the first parasitic patch and the second semicircular patch of the second parasitic patch are centrally symmetrical, and the diameter sides of the two are parallel; the diameter side of the second semicircular patch of the second radiation patch is perpendicular to the diameter side of the first semicircular patch of the first radiation patch; the diameter side of the second semicircular patch of the third radiation patch is perpendicular to the diameter side of the first semicircular patch of the fourth radiation patch; A metal floor (18) is provided at a position of one quarter wavelength below the radiation layer; the triangular patch of the second radiation patch is connected to the inner conductor (12) of the first coaxial feeder, and the trapezoidal patch of the fourth radiation patch is connected to the outer conductor (17) of the first coaxial feeder; the trapezoidal patch of the first radiation patch is connected to the inner conductor (13) of the second coaxial feeder, and the triangular patch of the third radiation patch is connected to the outer conductor (11) of the second coaxial feeder; The fourth radiation patch is provided with a via hole, and the inner conductor of the first coaxial feed line passes through the via hole; the second radiation patch and the third radiation patch are both provided with an extension for connecting the coaxial feed line.

2. The broadband dual-linear polarization base station antenna based on a parasitic patch according to claim 1, characterized in that: The first patch group and the second patch group are both axisymmetric shapes; the diameter of the second semicircular patch is smaller than the side length of the triangle closely attached to it, and the diameter of the first semicircular patch is smaller than the lower base of the trapezoid closely attached to it.

3. The broadband dual-linear polarization base station antenna based on a parasitic patch according to claim 2, characterized in that: The trapezoidal patch of the first parasitic patch and the triangular patch of the second parasitic patch are both located inside their corresponding semicircular patches.

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