Cross-frequency band dual-frequency dual-polarized multiplexing antenna based on microstrip triangular cavity

Abstract

The application provides a cross-frequency-band dual-frequency dual-polarization multiplexing antenna based on a microstrip triangular cavity, which comprises a second dielectric plate, an adhesive layer, a metal ground plate and a first dielectric plate which are sequentially stacked from bottom to top, and the upper surface of the first dielectric plate is printed with four co-radiator structures, and the lower surface of the second dielectric plate is printed with a plurality of millimeter wave feeding lines and microwave feeding lines; in each co-radiator structure, one end of two rectangular metal patches is connected to the metal ground plate through a plurality of shorting posts, and the other end is connected to the millimeter wave feeding line on the lower surface of the second dielectric plate through a first feeding probe. Through multiplexing of the co-radiator structure, the dual-frequency dual-polarization characteristics of the microwave and millimeter wave bands are realized, the overall size of the antenna is more compact, and the space utilization is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication antennas, in particular to a cross-band dual-band dual-polarized multiplexing antenna based on a microstrip triangular cavity. BACKGROUND

[0002] In the actual engineering application of wireless communication systems, complex and diverse electromagnetic environments are often encountered. During the propagation of communication signals in space, the signals will inevitably be blocked by objects such as plants, buildings, and vehicles, and after multiple reflections and refractions, the signals will produce a multipath effect, resulting in signal fading. In order to improve the anti-fading ability of the communication system, various diversity techniques can be used to reduce the bit error rate, one of the commonly used diversity methods is polarization diversity technology, and simultaneous transmission using polarization orthogonal signals can realize multiple independent channels, thereby reducing the loss caused by the multipath effect, maximizing the recovery of the initial signal, and ensuring the effectiveness of the communication system. With the continuous development of communication technology, dual-polarized antennas often need to work in multiple different frequency bands, and antennas with dual-band dual-polarized characteristics can better adapt to the needs of wireless communication systems.

[0003] To realize the dual-band characteristic, the commonly used method in the prior art is to combine microwave antennas and millimeter wave antennas together through different arrangement methods, for example, placing arrays working in different frequency bands side by side. However, this arrangement method inevitably causes additional space waste between the high-band and low-band arrays, increases the occupied space of the antenna array, and reduces the space utilization.

[0004] In addition, although the above method realizes the dual-band characteristic, the millimeter wave beams of the antenna array are fixed, sacrificing the beam scanning capability of the millimeter wave antenna. In the prior art, dual-band antennas working in the sub-6GHz and millimeter wave bands generally do not have beam scanning capability, and for these two working frequency bands, the edge radiation performance required for wireless applications has not been realized, and improvement and perfection are urgently needed. SUMMARY

[0005] The present application aims to provide a cross-band dual-band dual-polarized multiplexing antenna based on a microstrip triangular cavity, which realizes the dual-band dual-polarized characteristic of the antenna in the microwave and millimeter wave bands through a more compact structure, and simultaneously realizes the beam scanning characteristic in the millimeter wave band and the edge radiation characteristic in the microwave and millimeter wave bands.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] The application discloses a cross-band dual-frequency dual-polarization multiplexing antenna based on a microstrip triangular cavity, which comprises a second dielectric plate, an adhesive layer, a metal ground plate and a first dielectric plate which are sequentially stacked from bottom to top; the upper surface of the first dielectric plate is printed with four co-radiator structures; and the lower surface of the second dielectric plate is printed with a plurality of millimeter wave feeding lines and microwave feeding lines.

[0008] The four co-radiator structures are respectively a first co-radiator structure, a second co-radiator structure, a third co-radiator structure and a fourth co-radiator structure; wherein the first co-radiator structure is arranged in the positive X-axis and positive Y-axis directions of the center of the first dielectric plate; the first co-radiator structure comprises two rectangular metal patches which are arranged in parallel along the Y-axis direction and two connecting microstrip lines which are connected between the two rectangular metal patches along the X-axis direction.

[0009] The second co-radiator structure, the third co-radiator and the fourth co-radiator are respectively obtained by rotating the first co-radiator structure by 90°, 180° and 270° clockwise around the center of the first dielectric plate.

[0010] In each co-radiator structure, one end of the two rectangular metal patches close to the center of the first dielectric plate is connected to the metal ground plate through a plurality of shorting posts, and the other end of the two rectangular metal patches away from the center of the first dielectric plate is connected to the millimeter wave feeding lines on the lower surface of the second dielectric plate through a first feeding probe, so that a triangular cavity subarray is formed on each rectangular metal patch; two smallest electric fields at the edges of each triangular cavity subarray are respectively connected to one of the connecting microstrip lines, and the two ends of each connecting microstrip line are respectively connected to the smallest electric fields at the opposite sides of the two triangular cavity subarrays, and the two connecting microstrip lines are separated by a complete triangular cavity, wherein the middle part of the connecting microstrip line close to the center of the first dielectric plate is connected to the microwave feeding line on the lower surface of the second dielectric plate through a second feeding probe.

[0011] Further, the lower surface of the second dielectric plate is printed with eight millimeter wave feeding lines.

[0012] The eight millimeter wave feeding lines correspond to the eight rectangular metal patches in the four co-radiator structures one by one, and the output end of each millimeter wave feeding line is connected to the corresponding rectangular metal patch through a first feeding probe for feeding the rectangular metal patch in the millimeter wave band; wherein the two millimeter wave feeding lines connected to the same co-radiator structure are fed with a phase difference of 180°.

[0013] Further, the lower surface of the second dielectric plate is printed with two microwave feeding lines for feeding the co-radiator structure in the microwave band.

[0014] Each microwave feed line comprises a main feed line, a one-to-two power divider and a half-wavelength microstrip delay line connected in sequence, wherein the input end of the one-to-two power divider is connected with the main feed line, and one output end of the one-to-two power divider is connected with the microstrip delay line;

[0015] In one of the microwave feed lines, one output end of the one-to-two power divider is connected with the first co-radiator structure through the microstrip delay line and a second feed probe, and the other output end is connected with the third co-radiator structure through a second feed probe; in the other microwave feed line, one output end of the one-to-two power divider is connected with the second co-radiator structure through the microstrip delay line and a second feed probe, and the other output end is connected with the fourth co-radiator structure through a second feed probe.

[0016] Further, each rectangular metal patch is connected with the metal ground plate through three shorting posts penetrating the first dielectric plate, so as to make the rectangular metal patch resonate.

[0017] Further, the first feed probe penetrates the first dielectric plate, the metal ground plate, the adhesive layer and the second dielectric plate in sequence to connect the rectangular metal patch with the millimeter wave feed line; and the second feed probe penetrates the first dielectric plate, the metal ground plate, the adhesive layer and the second dielectric plate in sequence to connect the connecting microstrip line with the microwave feed line.

[0018] The metal ground plate is provided with a circular slot for the first feed probe and the second feed probe to penetrate, and the diameter of the circular slot is greater than the first feed probe and the second feed probe, so that the metal ground plate and the first feed probe and the second feed probe are not in contact with each other.

[0019] Further, each millimeter wave feed line is loaded with a high-pass filter.

[0020] Further, a matching stub is connected to the main feed line of the microwave feed line, so as to improve the matching characteristics of the microwave feed line.

[0021] The co-radiator structure in the application serves as a cavity array in the millimeter wave frequency band and a shorted quarter-wave patch in the microwave frequency band. Through multiplexing of the co-radiator structure, the application realizes dual-frequency and dual-polarization characteristics in the microwave and millimeter wave frequency bands, makes the overall size of the antenna more compact, and improves the space utilization. In addition, the application does not need a complex feed network, and realizes good beam scanning characteristics in the millimeter wave frequency band through a simple structure, and has the same edge radiation characteristics in the microwave frequency band and the millimeter wave frequency band, which can better meet the needs of actual use. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is an exploded view of a cross-frequency dual-frequency dual-polarization multiplexing antenna based on a microstrip triangular cavity provided by an embodiment of the application.

[0023] Figure 2 is a top surface structure diagram of a cross-band dual-frequency dual-polarization multiplexing antenna based on a microstrip triangular cavity provided by the embodiment of the present application.

[0024] Figure 3 is a bottom surface structure diagram of a cross-band dual-frequency dual-polarization multiplexing antenna based on a microstrip triangular cavity provided by the embodiment of the present application.

[0025] Figure 4 is a top surface and bottom surface structure projection comparison diagram of a cross-band dual-frequency dual-polarization multiplexing antenna based on a microstrip triangular cavity provided by the embodiment of the present application.

[0026] Figure 5 is an electric field distribution decomposition principle diagram of a co-radiator structure in the embodiment of the present application.

[0027] Figure 6 is an S parameter diagram of the embodiment of the present application in a microwave band.

[0028] Figure 7 is an S parameter diagram of the embodiment of the present application in a millimeter wave band.

[0029] Figure 8 is a beam scanning characteristic diagram simulated and calculated by the embodiment of the present application at 27 GHz. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described in detail below in combination with the drawings and specific embodiments.

[0031] As shown in Figure 1 , the cross-band dual-frequency dual-polarization multiplexing antenna based on a microstrip triangular cavity provided by the embodiment of the present application comprises a second dielectric plate 22, an adhesive layer 4, a metal ground plate 3 and a first dielectric plate 21 which are sequentially stacked from bottom to top, the upper surface of the first dielectric plate 21 is printed with four co-radiator structures 1, and the lower surface of the second dielectric plate 22 is printed with a plurality of millimeter wave feeding lines 5 and microwave feeding lines 6.

[0032] Specifically, as shown in Figure 2As shown, the four co-radiator structures 1 are respectively a first co-radiator structure 11, a second co-radiator structure 12, a third co-radiator structure 13 and a fourth co-radiator structure 14. The first co-radiator structure 11 is arranged in the positive X-axis and positive Y-axis directions of the center of the first dielectric plate 21. The first co-radiator structure 11 includes two rectangular metal patches arranged in parallel along the Y-axis direction and two connecting microstrip lines connected between the two rectangular metal patches along the X-axis direction. The second co-radiator structure 12, the third co-radiator structure 13 and the fourth co-radiator structure 14 are respectively obtained by rotating the first co-radiator structure 11 by 90°, 180° and 270° clockwise around the center of the first dielectric plate 21.

[0033] In combination Figures 1 to 4 As shown, in each co-radiator structure 1, one end of the two rectangular metal patches close to the center of the first dielectric plate 21 is connected to the metal ground plate 3 through a plurality of shorting posts 101, and the other end of the two rectangular metal patches away from the center of the first dielectric plate 21 is connected to the millimeter wave feeding line 5 on the lower surface of the second dielectric plate 22 through a first feeding probe 102, so that a triangular cavity subarray is formed on each rectangular metal patch. Two smallest electric field positions at the edge of each triangular cavity subarray are respectively connected to a connecting microstrip line, and the two ends of each connecting microstrip line are respectively connected to the smallest electric field positions on the opposite sides of the two triangular cavity subarrays, and the two connecting microstrip lines are separated by a complete triangular cavity. The middle part of the connecting microstrip line close to the center of the first dielectric plate 21 is connected to the microwave feeding line 6 on the lower surface of the second dielectric plate 22 through a second feeding probe 103.

[0034] In this embodiment, each rectangular metal patch is connected to the metal ground plate 3 through three shorting posts 101 penetrating the first dielectric plate 21, for making the rectangular metal patch resonate. The three shorting posts 101 are uniformly distributed at the ends of the rectangular metal patch.

[0035] In combination Figure 3 and Figure 4 As shown, the lower surface of the second dielectric plate 22 is printed with eight millimeter wave feeding lines 5. The eight millimeter wave feeding lines 5 correspond one-to-one to the eight rectangular metal patches in the four co-radiator structures 1, and the output end of each millimeter wave feeding line 5 is connected to the corresponding rectangular metal patch through a first feeding probe 102 for feeding the rectangular metal patch in the millimeter wave band. The two millimeter wave feeding lines 5 connected to the same co-radiator structure 1 are fed with a phase difference of 180°.

[0036] Furthermore, two microwave feed lines 6 are printed on the lower surface of the second dielectric substrate 22 for feeding power to the co-radiator structure 1 in the microwave band. Each microwave feed line 6 includes a main feed line 61, a 1-to-2 power divider 62, and a half-wavelength (half-wavelength of the microwave band) microstrip delay line 63 connected in sequence. The input terminal of the 1-to-2 power divider 62 is connected to the main feed line 61, and one output terminal of the 1-to-2 power divider 62 is connected to the microstrip delay line 63. Matching stubs 64 are connected to the main feed line 61 to improve the matching characteristics of the microwave feed line 6.

[0037] In one microwave feed line 6, one output terminal of the 1-to-2 power divider 62 feeds to the first common radiator structure 11 through a microstrip delay line 63 and a second feed probe 103, and the other output terminal feeds to the third common radiator structure 13 through a second feed probe 103; in the other microwave feed line 6, one output terminal of the 1-to-2 power divider 62 feeds to the second common radiator structure 12 through a microstrip delay line 63 and a second feed probe 103, and the other output terminal feeds to the fourth common radiator structure 14 through a second feed probe 103.

[0038] Furthermore, the first feed probe 102 sequentially penetrates the first dielectric substrate 21, the metal ground plane 3, the adhesive layer 4, and the second dielectric substrate 22 to connect the rectangular metal patch to the millimeter-wave feed line 5; the second feed probe 103 sequentially penetrates the first dielectric substrate 21, the metal ground plane 3, the adhesive layer 4, and the second dielectric substrate 22 to connect the microstrip line and the microwave feed line 6.

[0039] The metal floor 3 is provided with a circular groove for the first power supply probe 102 and the second power supply probe 103 to pass through. The diameter of the circular groove is larger than that of the first power supply probe 102 and the second power supply probe 103, so that the metal floor 3 does not contact the first power supply probe 102 and the second power supply probe 103.

[0040] Furthermore, each millimeter-wave feed line 5 is equipped with a high-pass filter 50 to enhance the high-pass characteristics of the millimeter-wave feed line and improve its isolation characteristics.

[0041] The following will combine Figure 5 The working principle of the embodiments of the present invention will be explained in detail. For example... Figure 5 As shown in (a), in each rectangular metal patch, one end is connected to the metal ground plane 3 via a short-circuit post 101 to make the rectangular metal patch resonate; the other end is connected to the millimeter-wave feed line 5 via a first feed probe 102 to achieve millimeter-wave feeding; the electric field distribution between the short-circuit post 101 and the first feed probe 102 forms a triangular cavity subarray on the rectangular metal patch; Figure 5In the middle, the area with the minimum electric field (the darkest wavy band in the figure) is separated by each triangle on the rectangular metal patch, that is, a triangular cavity. Figure 5 As shown in (b) in the middle, in each co-radiator structure 1, due to the 180° phase difference between the two millimeter wave feed lines 5 connected to the two rectangular metal patches, the triangular cavity sub-array on the two rectangular metal patches is symmetrically distributed; the two connecting microstrip lines are connected at the minimum electric field of the inner side of the two triangular cavity sub-arrays, so that the co-radiator structure is equivalent to a quarter wavelength (a quarter wavelength in the microwave band) patch in the microwave band. As shown in (c) in the middle, after rotating the co-radiator structure 1 by 180° around the Z axis, the two co-radiator structures 1 are differentially fed by one microwave feed line 6 to excite the overall radiation of the two co-radiator structures 1 in the microwave band, thereby obtaining a single-polarized microwave millimeter wave dual-band antenna. Figure 5

[0042] Further, as shown in (c) in the middle, the single-polarized microwave millimeter wave dual-band antenna is rotated by 90° around the Z axis, and another feeding network composed of another microwave feed line 6 and four millimeter wave feed lines 5 is introduced for feeding, thereby finally realizing a dual-band dual-polarized antenna across the microwave and millimeter wave frequency bands. Figure 5

[0043] The feeding network of the embodiment of the present application is composed of two microwave feed lines and eight millimeter wave feed lines. In the millimeter wave band, each co-radiator structure realizes millimeter wave band radiation through two millimeter wave feed lines, so that the co-radiator structure works as a triangular cavity array in the millimeter wave band, realizing the edge radiation characteristic in the millimeter wave band. In the sub-6GHz microwave band, the two microwave feed lines are differentially fed to the diagonally located two co-radiator structures in a one-to-two differential feeding manner, so that the co-radiator structure works as a shorted quarter wavelength patch in the microwave band, realizing the edge radiation characteristic in the microwave band.

[0044] The size of the co-radiator structure 1 and the frequency ratio of the overall antenna in the embodiment of the present application have the following relationship: when the overall size of the co-radiator structure 1 increases, the frequency ratio of the overall antenna also increases; and the working frequency of the co-radiator structure 1 in the microwave band is mainly determined by the side length of the triangular cavity in the triangular cavity sub-array, and the bandwidth in the millimeter wave band is jointly determined by the side length, height of the triangular cavity and the high-pass filter 50 loaded on the millimeter wave feed line 5.

[0045] ​​Compared with the prior art design, the embodiment of the application has two polarization modes of 0° and 90° in two working frequency bands of microwave and millimeter wave bands, and the isolation between the respective ports is kept higher than 14dB, which is more suitable for polarization diversity technology to reduce signal error rate. Meanwhile, the application also overcomes the problem of structural asymmetry often existing in single-polarization dual-frequency antennas, and the directivity pattern maintains sufficient symmetry and the cross-polarization level is also low. Figure 6 and Figure 7 are respectively the S parameter diagrams of the embodiment of the application in the microwave band and the millimeter wave band, Figure 6 and Figure 7 The results shown in the figures indicate that the working frequency bands of the embodiment of the application can simultaneously meet the 5G wireless communication system of sub-6GHz (microwave band) and millimeter wave band.

[0046] As shown in Figure 8 , the beam scanning characteristic diagram simulated and calculated by the embodiment of the application at 27GHz, from the figure, it can be seen that the embodiment of the application realizes good beam scanning characteristics under the two polarization modes of the millimeter wave band.

[0047] The common radiator structure in the application is used as a cavity array in the millimeter wave band, and is multiplexed as a short-circuit quarter-wave patch in the microwave band. By multiplexing the common radiator structure, the application realizes the dual-frequency dual-polarization characteristics of the microwave and millimeter wave bands, and makes the overall size of the antenna more compact, improving the space utilization. In addition, the application does not need a complex feed network, and through a simple structure, it realizes good beam scanning characteristics in the millimeter wave band, and has the same edge radiation characteristics in the microwave band and the millimeter wave band, which can better meet the needs of actual use.

[0048] The above-described embodiments only express several embodiments of the application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent of the application. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which all belong to the protection scope of the application. Therefore, the protection scope of the patent of the application should be subject to the appended claims.

Claims

1. A microstrip triangular cavity based cross-band dual-frequency dual-polarized multiplexing antenna, characterized in that, The second dielectric plate, the adhesive layer, the metal ground plate and the first dielectric plate are sequentially stacked from bottom to top, the upper surface of the first dielectric plate is printed with four common radiator structures, and the lower surface of the second dielectric plate is printed with a plurality of millimeter wave feeding lines and microwave feeding lines; The four common radiator structures are respectively a first common radiator structure, a second common radiator structure, a third common radiator structure and a fourth common radiator structure; wherein the first common radiator structure is arranged in the positive X-axis and positive Y-axis directions of the center of the first dielectric plate; the first common radiator structure comprises two rectangular metal patches arranged in parallel along the Y-axis direction and two connecting microstrip lines connected between the two rectangular metal patches along the X-axis direction; The second common radiator structure, the third common radiator and the fourth common radiator are respectively obtained by rotating the first common radiator structure by 90°, 180° and 270° clockwise around the center of the first dielectric plate; In each common radiator structure, one end of the two rectangular metal patches close to the center of the first dielectric plate is connected to the metal ground plate through a plurality of shorting posts, and the other end of the two rectangular metal patches away from the center of the first dielectric plate is connected to the millimeter wave feeding line on the lower surface of the second dielectric plate through a first feeding probe, so that a triangular cavity subarray is formed on each rectangular metal patch; two smallest electric field positions at the edge of each triangular cavity subarray are respectively connected to one of the connecting microstrip lines, and the two ends of each connecting microstrip line are respectively connected to the smallest electric field positions on the opposite sides of the two triangular cavity subarrays, and the two connecting microstrip lines are separated by a complete triangular cavity, wherein the middle part of the connecting microstrip line close to the center of the first dielectric plate is connected to the microwave feeding line on the lower surface of the second dielectric plate through a second feeding probe.

2. The microstrip triangular cavity based cross-band dual-frequency dual-polarized multiplexed antenna according to claim 1, wherein, The lower surface of the second dielectric plate is printed with eight millimeter wave feeding lines; The eight millimeter wave feeding lines correspond one-to-one to the eight rectangular metal patches in the four common radiator structures, and the output end of each millimeter wave feeding line is connected to the corresponding rectangular metal patch through a first feeding probe for feeding the rectangular metal patch in the millimeter wave band; wherein the two millimeter wave feeding lines connected to the same common radiator structure are fed with a phase difference of 180°.

3. The microstrip triangular cavity based cross-band dual-frequency dual-polarized multiplexed antenna according to claim 2, wherein, The lower surface of the second dielectric plate is printed with two microwave feeding lines for feeding the common radiator structure in the microwave band; Each microwave feeding line comprises a main feeding line, a one-to-two power divider and a half-wavelength microstrip delay line connected in sequence, the input end of the one-to-two power divider is connected to the main feeding line, and one output end of the one-to-two power divider is connected to the microstrip delay line; In one of the microwave feeding lines, one output end of the one-to-two power divider is connected to the first common radiator structure through the microstrip delay line and a second feeding probe, and the other output end is connected to the third common radiator structure through a second feeding probe; In the other microwave feeding line, one output end of the one-to-two power divider is connected to the second common radiator structure through the microstrip delay line and a second feeding probe, and the other output end is connected to the fourth common radiator structure through a second feeding probe.

4. The microstrip triangular cavity based cross-band dual-frequency dual-polarized multiplexed antenna according to claim 1, wherein, Each rectangular metal patch is connected with the metal floor through three shorting posts penetrating the first dielectric plate, for making the rectangular metal patch resonate.

5. The microstrip triangular cavity based cross-band dual-frequency dual-polarized multiplexed antenna according to claim 1, wherein, The first feeding probe penetrates the first dielectric plate, the metal floor, the adhesive layer and the second dielectric plate in sequence, and connects the rectangular metal patch with the millimeter wave feeding line; the second feeding probe penetrates the first dielectric plate, the metal floor, the adhesive layer and the second dielectric plate in sequence, and connects the connecting microstrip line with the millimeter wave feeding line; The metal floor is provided with a circular slot for the first feeding probe and the second feeding probe to pass through, and the diameter of the circular slot is greater than the first feeding probe and the second feeding probe, so that the metal floor and the first feeding probe and the second feeding probe are not in contact with each other.

6. The microstrip triangular cavity based cross-band dual-frequency dual-polarized multiplexed antenna according to claim 2, wherein, Each millimeter wave feeding line is loaded with a high-pass filter.

7. The microstrip triangular cavity based cross-band dual-frequency dual-polarized multiplexed antenna according to claim 3, wherein, A matching branch is connected to the main feeding line of the microwave feeding line, for improving the matching characteristics of the microwave feeding line.

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