CN117096597B - Dual-polarized high-gain patch antenna based on high-order mode - Google Patents

Abstract

The invention discloses a dual-polarization high-gain patch antenna based on a high-order mode, comprising a first and a second dielectric substrate, a first, a second, a third, and a fourth copper-clad layer and a probe; the first dielectric substrate is located above the second dielectric substrate, and an air gap is left between them; the first copper-clad layer is arranged on the upper surface of the first dielectric substrate, and a patch radiation structure is arranged thereon; the second copper-clad layer is arranged on the lower surface of the first dielectric substrate, and a cross-bridge structure is arranged thereon; the third copper-clad layer is arranged on the upper surface of the second dielectric substrate; the fourth copper-clad layer is arranged on the lower surface of the second dielectric substrate, and a first feeding network and a second feeding network are arranged thereon, the first feeding network and the second feeding network are a pair of differential T-type power dividers, and the first feeding network and the second feeding network couple energy to the first copper-clad layer through the probe to radiate electromagnetic waves. The invention realizes a stable and symmetrical radiation excitation effect, can stably work in the range of 3.4GHz-3.6GHz, and has a gain of 11.5-12.7dBi in the passband and an efficiency of 97.4-99%.

Description

Dual-polarization high-gain patch antenna based on high-order modes

Technical Field

The invention relates to the technical field of communication antennas, and in particular to a high-order mode-based dual-polarization high-gain patch antenna.

Background Art

Patch antennas are widely used in wireless communication systems because of their low cost, low profile, and easy processing. In previous designs, scholars have focused their research on the 4G frequency band or the 5G frequency band, especially the application of large-scale MIMO antennas in base station systems. However, with the increasing complexity of communication scenarios and users' further demands for mobile network effects, it is often necessary to meet good communication signal coverage. In order to achieve satisfactory beamforming effects, large-scale MIMO physical antenna units that can generate high-gain dual-polarized electromagnetic waves have been proposed in engineering and academia. In these designs, they often focus on designing higher-gain antenna units or more stable and efficient feeding networks. High-gain antenna units generally occupy a square space frame, which makes it difficult to meet the 1×3 or 1×4 rectangular array profile requirements in base station large-scale MIMO antennas. Exciting the antenna array through a complex power division network will reduce the efficiency of the antenna due to the use of a large number of power dividers. If dual-polarized antennas are used that can achieve high directivity and meet the array configuration requirements in base station large-scale MIMO antenna applications, it can effectively reduce energy loss and heat dissipation in large-scale and even future ultra-large-scale MIMO antenna arrays in base station systems, improve antenna efficiency, and reduce system cost overhead.

Using the high-order mode of the antenna for radiation is a common gain enhancement method to improve efficiency. For a patch antenna that resonates in a high-order mode, the current phase on its surface shows a positive-negative continuous change phenomenon. By suppressing the radiation capability of the part of the antenna where the reverse current is located, reducing its impact on the antenna radiation pattern, and making the antenna approximately regarded as the superposition of several in-phase currents, the antenna gain enhancement effect can be achieved without the need for an additional complex feeding network.

The existing technologies are investigated and understood as follows:

Y.Li et al. proposed a high-gain dual-polarized indoor antenna based on the high-order mode of the patch antenna in 2018. By etching two pairs of rectangular slots in the middle of the cross-shaped patch, the radiation of the reverse current on the high-order mode of the patch antenna is suppressed, making the antenna equivalent to three antenna units resonating in the fundamental mode, thereby greatly improving the directivity of the antenna.

In 2021, Y.He et al. proposed a three-unit patch antenna array fed by a pair of feeding networks. By combining a 1:2 unequal power divider and an equal power divider, three equal power outputs were obtained, thereby designing a physical antenna with higher directivity.

In general, there are many studies on high-gain patch antennas in existing work, but in order to meet dual-polarization applications, many works often need to rotate 90° based on the single-polarization high-gain antenna structure and then combine it with the initial structure, so that the spatial profile occupied by the entire structure is similar to a two-dimensional square array, and the area is increased by at least three times compared to the single-polarization antenna structure. However, in actual base station massive MIMO antennas, the antenna subarray is required to meet the one-dimensional rectangular array profile. Therefore, it is of great significance to design a simple and effective high-gain dual-polarization massive MIMO physical antenna.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and proposes a dual-polarization high-gain patch antenna based on high-order modes, which uses a pair of differential T-type power dividers as a feeding network to achieve a stable and symmetrical radiation excitation effect. The antenna can work stably in the range of 3.4GHz-3.6GHz, and has a gain of 11.5-12.7dBi in the passband and an efficiency of 97.4-99%.

To achieve the above-mentioned purpose, the technical solution provided by the present invention is: a dual-polarization high-gain patch antenna based on high-order modes, comprising a first dielectric substrate, a second dielectric substrate, a first copper-clad layer, a second copper-clad layer, a third copper-clad layer, a fourth copper-clad layer and a probe; the first dielectric substrate is located above the second dielectric substrate, and an air gap is left between them; the first copper-clad layer is arranged on the upper surface of the first dielectric substrate, and a patch radiation structure is arranged on the first copper-clad layer, and the patch radiation structure comprises a plurality of square patch units, a short bending microstrip line and a long bending microstrip line, and two adjacent square patch units are electrically connected to each other through the long bending microstrip line to form a whole, and present a current phase distribution of a high-order mode, the current phases on the surfaces of the plurality of square patch units are the same, and the currents with opposite phases to the currents on the surfaces of the square patch units are all bound on the long bending microstrip line, thereby reducing the influence of the reverse phase current in the high-order mode on the radiation pattern, and the corners of each square patch unit are connected to the short bending microstrip line as the The second copper clad layer is arranged on the lower surface of the first dielectric substrate, and a cross bridge structure is provided on the second copper clad layer. The cross bridge structure includes two bent microstrip lines, which realize the same electrical connection and reverse current binding function as the long bent microstrip line in the first copper clad layer, while avoiding electrical contact with the long bent microstrip line in the first copper clad layer; the third copper clad layer is arranged on the upper surface of the second dielectric substrate as the floor of the antenna, ensuring that the radiation direction of the antenna is not only shielded but also the influence of the feeding network located in the fourth copper clad layer on the radiation performance; the fourth copper clad layer is arranged on the lower surface of the second dielectric substrate, and a first feeding network and a second feeding network are provided on the fourth copper clad layer, the first feeding network and the second feeding network are a pair of differential T-type power dividers, and the first feeding network and the second feeding network couple energy to the electromagnetic wave radiated by the first copper clad layer through a probe.

Further, the first feeding network includes a first feeding port, a first impedance input feeder, a first impedance transformation line, a first impedance feeder, a first impedance phase delay feeder, a second impedance transformation line, a third impedance transformation line, a first pad and a second pad, the first feeding port, the first impedance input feeder and the first impedance transformation line are connected in sequence, the first impedance transformation line, the first impedance feeder, the third impedance transformation line and the second pad are connected in sequence, and the first impedance transformation line, the first impedance phase delay feeder, the second impedance transformation line and the first pad are connected in sequence.

Further, the second feeding network includes a second feeding port, a second impedance input feeder, a fourth impedance transformation line, a second impedance feeder, a second impedance phase delay feeder, a fifth impedance transformation line, a sixth impedance transformation line, a third pad and a fourth pad, the second feeding port, the second impedance input feeder and the fourth impedance transformation line are connected in sequence, the fourth impedance transformation line, the second impedance feeder, the fifth impedance transformation line and the third pad are connected in sequence, and the fourth impedance transformation line, the second impedance phase delay feeder, the sixth impedance transformation line and the fourth pad are connected in sequence.

Furthermore, the end of the short bent microstrip line is connected to a fifth pad, the two ends of the bent microstrip line are respectively connected to sixth pads, four sixth pads are provided on the second copper clad layer, the first copper clad layer is provided with a fifth pad corresponding to the four sixth pads one by one, and the first dielectric substrate is provided with a metallized via connecting the corresponding fifth pad and sixth pad.

Furthermore, there are four probes, one end of each probe is connected to a corresponding pad on the fourth copper clad layer, and the other end thereof passes through the second dielectric substrate, the third copper clad layer, and the first dielectric substrate in sequence upwards and then is connected to the first copper clad layer.

Further, the first impedance input feeder is a 50 ohm characteristic impedance input feeder, the first impedance feeder is a 50 ohm characteristic impedance feeder, and the first impedance phase delay feeder is a 50 ohm characteristic impedance phase delay feeder.

Further, the second impedance input feeder is a 50 ohm characteristic impedance input feeder, the second impedance feeder is a 50 ohm characteristic impedance feeder, and the second impedance phase delay feeder is a 50 ohm characteristic impedance phase delay feeder.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

The present invention uses a patch antenna working in a high-order mode, and replaces the part of the current inversion on the patch antenna by a fine strip line, thereby suppressing the influence of the inversion current on the radiation pattern of the patch antenna working in the high-order mode, and improving the antenna directivity and gain. The square outline of the dual-polarization antenna structure is converted into a rectangular outline by bending the microstrip fine line. The patch antenna is excited by a pair of differential T-type power dividers, which ensures the symmetry of the antenna radiation pattern and achieves a stable radiation excitation effect, so that the antenna has a high-gain working characteristic and a 1×3 antenna array profile. It has a simple structure, a low profile, and a high degree of integration, and has a good application prospect.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an exploded view of a dual-polarized high-gain patch antenna.

FIG. 2 is a side cross-sectional view of a dual-polarized high-gain patch antenna.

FIG. 3 is a schematic structural diagram of the first copper cladding layer.

FIG. 4 is a schematic structural diagram of a first dielectric substrate.

FIG. 5 is a schematic structural diagram of the second copper cladding layer.

FIG. 6 is a schematic diagram of the structure of the third copper cladding layer.

FIG. 7 is a schematic structural diagram of a second dielectric substrate.

FIG. 8 is a schematic structural diagram of the fourth copper cladding layer.

FIG9 is a diagram showing the S-parameter simulation results of the dual-polarization high-gain patch antenna.

FIG10 is a graph showing the simulation results of the gain and efficiency curves of the dual-polarized high-gain patch antenna.

FIG11 is a center frequency simulation pattern of the dual-polarization high-gain patch antenna.

DETAILED DESCRIPTION

The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

As shown in Figures 1 to 8, this embodiment discloses a dual-polarized high-gain patch antenna based on high-order modes. For the continuous phase reversal current that appears in the patch antenna under the high-order mode, the radiation capability of the reverse current on the antenna is suppressed by replacing the part of the patch antenna where the reverse current is located with a microstrip thin line, thereby improving the gain of the antenna. The square outline of the dual-polarized antenna structure is converted into a rectangular outline by bending the microstrip thin line; the patch antenna includes a first dielectric substrate 2, a second dielectric substrate 4, a first copper clad layer 1, a second copper clad layer 3, a third copper clad layer 5, a fourth copper clad layer 6 and a probe 8; the first dielectric substrate 2 and the second dielectric substrate 4 have a thickness of 1 mm, a length of 200 mm, a width of 100 mm, a dielectric constant of 2.65, and a loss tangent of 0.00. 29; the first dielectric substrate 2 is located above the second dielectric substrate 4, with an air gap 7 between them; the first copper clad layer 1 is arranged on the upper surface of the first dielectric substrate 2, and a patch radiation structure is arranged on the first copper clad layer 1, the patch radiation structure comprises three square patch units 11, a short bent microstrip line 12 and a long bent microstrip line 14, the three square patch units 11 are arranged in a row at intervals, and two adjacent square patch units 11 are connected by a long bent microstrip line 14, and the long bent microstrip line 14 ensures the electrical connection of adjacent square patch units 11, so that the three square patch units 11 and the long bent microstrip line 14 can together constitute an antenna as a whole, and the antenna presents a traditional high-order mode current phase distribution. At this time, the three square patch units 11 are arranged in a row, and the three square patch units 11 are connected to each other by a long bent microstrip line 14. The long bent microstrip line 14 ensures the electrical connection of adjacent square patch units 11, so that the three square patch units 11 and the long bent microstrip line 14 can jointly constitute an antenna as a whole, and the antenna presents a traditional high-order mode current phase distribution. The currents on the surface of the sheet unit 11 are in phase with each other, while the currents with opposite phases to the currents on the surface of the square patch unit 11 are just bounded on the long bent microstrip wire 14, thereby reducing the influence of the reverse phase current on the antenna radiation pattern in the traditional high-order mode antenna; the corners of each square patch unit 11 are connected to the short bent microstrip wire 12 as an extension of the corners, and the overall profile of the antenna structure can be adjusted through the short bent microstrip wire 12, thereby meeting the rectangular profile requirements of the antenna array, and solving the inevitable square profile feature problem in the existing high-order mode antenna technology; the second copper clad layer 3 is arranged on the lower surface of the first dielectric substrate 2, and a cross bridge structure is provided on the second copper clad layer 3, and the cross bridge structure includes two bent microstrip wires 31, which are connected to the first copper clad layer 1 has the same electrical connection and reverse current binding function as the long meander microstrip thin line 14 in the first copper clad layer 1, while also avoiding electrical contact with the long meander microstrip thin line 14 in the first copper clad layer 1; the third copper clad layer 5 is arranged on the upper surface of the second dielectric substrate 4, and the third copper clad layer 5 serves as the floor of the antenna, which ensures the radiation direction of the antenna while shielding the influence of the feeding network located in the fourth copper clad layer 6 on the radiation performance; the fourth copper clad layer 6 is arranged on the lower surface of the second dielectric substrate 4, and the first feeding network 61 and the second feeding network 62 are provided on the fourth copper clad layer 6, and the first feeding network 61 and the second feeding network 62 are a pair of differential T-type power dividers, and the first feeding network 61 and the second feeding network 62 couple energy to the first copper clad layer 1 through the probe 8 to radiate electromagnetic waves.

Specifically, the first feeding network 61 includes a first feeding port 611, a first impedance input feeder 612, a first impedance transformation line 613, a first impedance feeder 614, a first impedance phase delay feeder 615, a second impedance transformation line 616, a third impedance transformation line 617, a first pad 618 and a second pad 619, the first feeding port 611, the first impedance input feeder 612 and the first impedance transformation line 613 are connected in sequence, the first impedance transformation line 613, the first impedance feeder 614, the third impedance transformation line 617 and the second pad 619 are connected in sequence, the first impedance transformation line 613, the first impedance phase delay feeder 615, the second impedance transformation line 616 and the first pad 618 are connected in sequence.

Specifically, the second feeding network 62 includes a second feeding port 621, a second impedance input feeder 622, a fourth impedance transformation line 623, a second impedance feeder 624, a second impedance phase delay feeder 625, a fifth impedance transformation line 626, a sixth impedance transformation line 627, a third pad 628 and a fourth pad 629, the second feeding port 621, the second impedance input feeder 622 and the fourth impedance transformation line 623 are connected in sequence, the fourth impedance transformation line 623, the second impedance feeder 624, the fifth impedance transformation line 626 and the third pad 628 are connected in sequence, and the fourth impedance transformation line 623, the second impedance phase delay feeder 625, the sixth impedance transformation line 627 and the fourth pad 629 are connected in sequence.

Specifically, the end of the short bent microstrip line 12 is connected to a fifth pad 13, the two ends of the bent microstrip line 31 are respectively connected to sixth pads 32, four sixth pads 32 are provided on the second copper clad layer 3, the first copper clad layer 1 is provided with a fifth pad 13 corresponding to the four sixth pads 32, four vias 21 and four metallized vias 22 for connecting the corresponding fifth pad 13 and the sixth pad 32 are provided on the first dielectric substrate 2, four vias 41 are provided in the second dielectric substrate 4, and four circular holes 51 are provided on the third copper clad layer 5.

Specifically, there are four probes 8, one end of each probe 8 is connected to the corresponding pad on the fourth copper clad layer 6, and the other end thereof passes through the second dielectric substrate 4, the third copper clad layer 5, and the first dielectric substrate 2 in sequence upward and then is connected to the first copper clad layer 1.

Specifically, the first impedance input feeder 612 is a 50 ohm characteristic impedance input feeder, the first impedance feeder 614 is a 50 ohm characteristic impedance feeder, the first impedance phase delay feeder 615 is a 50 ohm characteristic impedance phase delay feeder, the second impedance input feeder 622 is a 50 ohm characteristic impedance input feeder, the second impedance feeder 624 is a 50 ohm characteristic impedance feeder, and the second impedance phase delay feeder 625 is a 50 ohm characteristic impedance phase delay feeder.

See Figure 9, which shows the S parameter simulation results of the dual-polarized high-gain patch antenna of this embodiment. As can be seen from the figure, the frequency range of the reflection coefficient of the present invention being less than -10dB is 3.4GHz-3.6GHz, and the isolation between ports is greater than 20dB.

See Figure 10, which shows the gain curve and efficiency simulation results of the dual-polarized high-gain patch antenna of this embodiment. As can be seen from the figure, the gain of the present invention is flat and stable in the frequency range of 3.4GHz-3.6GHz, the gain is 11.5-12.7dBi, and the efficiency is 97.4-99%, with high gain and high efficiency.

See Figure 11, which is the simulation result of the center frequency direction of the dual-polarized high-gain patch antenna of this embodiment. It can be seen from the figure that the directional diagram of the present invention at the center frequency is unidirectional radiation, and the cross-polarization level of the two main planes is better than -18dB, and the side lobe level is lower than -10dB, with low cross-polarization level and side lobe level.

The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims (7)

1. The dual-polarized high-gain patch antenna based on the high-order mode is characterized by comprising a first dielectric substrate (2), a second dielectric substrate (4), a first copper-clad layer (1), a second copper-clad layer (3), a third copper-clad layer (5), a fourth copper-clad layer (6) and a probe (8); the first dielectric substrate (2) is positioned above the second dielectric substrate (4), and an air gap (7) is reserved between the first dielectric substrate and the second dielectric substrate; the antenna comprises a first dielectric substrate (2), a first copper-clad layer (1) and a second copper-clad layer (1), wherein the first copper-clad layer (1) is provided with a patch radiation structure, the patch radiation structure comprises a plurality of square patch units (11), short bending microstrip thin lines (12) and long bending microstrip thin lines (14), every two adjacent square patch units (11) are electrically connected through the long bending microstrip thin lines (14) to form a whole, and current phase distribution of a higher order mode is shown, the current phases on the surfaces of the square patch units (11) are the same, currents with opposite current phases on the surfaces of the square patch units (11) are bound on the long bending microstrip thin lines (14), so that influence of reverse current in the higher order mode on a radiation pattern is reduced, corners of each square patch unit (11) are connected with the short bending microstrip thin lines (12) to extend as the corners, and the whole outline of the antenna structure is adjusted through the short bending microstrip thin lines (12), and therefore the rectangular outline requirement of the antenna array is met; the second copper-clad layer (3) is arranged on the lower surface of the first dielectric substrate (2), a cross bridge structure is arranged on the second copper-clad layer (3), the cross bridge structure comprises two bending micro-strip thin lines (31), and the electric contact with the long bending micro-strip thin lines (14) in the first copper-clad layer (1) is avoided while the electric connection and the reverse current binding functions same as those of the long bending micro-strip thin lines (14) in the first copper-clad layer (1) are realized; the third copper-clad layer (5) is arranged on the upper surface of the second dielectric substrate (4) and is used as a floor of the antenna, so that the influence of a feed network in the fourth copper-clad layer (6) on radiation performance is shielded besides the radiation direction of the antenna; the fourth copper-clad layer (6) is arranged on the lower surface of the second dielectric substrate (4), a first feed network (61) and a second feed network (62) are arranged on the fourth copper-clad layer (6), the first feed network (61) and the second feed network (62) are a pair of differential T-shaped power dividers, and the first feed network (61) and the second feed network (62) couple energy to the first copper-clad layer (1) through a probe (8) to radiate electromagnetic waves.

2. The high order mode based dual polarized high gain patch antenna of claim 1, wherein: the first feeding network (61) comprises a first feeding port (611), a first impedance input feeder (612), a first impedance transformation line (613), a first impedance feeder (614), a first impedance phase delay feeder (615), a second impedance transformation line (616), a third impedance transformation line (617), a first bonding pad (618) and a second bonding pad (619), the first feeding port (611), the first impedance input feeder (612) and the first impedance transformation line (613) are sequentially connected, the first impedance transformation line (613), the first impedance feeder (614), the third impedance transformation line (617) and the second bonding pad (619) are sequentially connected, and the first impedance transformation line (613), the first impedance phase delay feeder (615), the second impedance transformation line (616) and the first bonding pad (618) are sequentially connected.

3. The high order mode based dual polarized high gain patch antenna of claim 2, wherein: the second feeding network (62) comprises a second feeding port (621), a second impedance input feeder (622), a fourth impedance transformation line (623), a second impedance feeder (624), a second impedance phase delay feeder (625), a fifth impedance transformation line (626), a sixth impedance transformation line (627), a third bonding pad (628) and a fourth bonding pad (629), the second feeding port (621), the second impedance input feeder (622) and the fourth impedance transformation line (623) are sequentially connected, the fourth impedance transformation line (623), the second impedance feeder (624), the fifth impedance transformation line (626) and the third bonding pad (628) are sequentially connected, and the fourth impedance transformation line (623), the second impedance phase delay feeder (625), the sixth impedance transformation line (627) and the fourth bonding pad (629) are sequentially connected.

4. A dual polarized high gain patch antenna based on higher order modes as claimed in claim 3 wherein: the end of the short bending microstrip thin line (12) is connected with a fifth bonding pad (13), the two ends of the bending microstrip thin line (31) are respectively connected with a sixth bonding pad (32), four sixth bonding pads (32) are arranged on the second copper-clad layer (3), fifth bonding pads (13) which are in one-to-one correspondence with the four sixth bonding pads (32) are arranged on the first copper-clad layer (1), and metallized through holes (22) for connecting the corresponding fifth bonding pads (13) and the sixth bonding pads (32) are arranged on the first dielectric substrate (2).

5. The high order mode based dual polarized high gain patch antenna of claim 4, wherein: the number of the probes (8) is four, one end of each probe (8) is connected with a corresponding bonding pad on the fourth copper-clad layer (6), and the other end of each probe is connected with the first copper-clad layer (1) after penetrating through the second dielectric substrate (4), the third copper-clad layer (5) and the first dielectric substrate (2) in sequence.

6. The high order mode based dual polarized high gain patch antenna of claim 5, wherein: the first impedance input feed (612) is a 50 ohm characteristic impedance input feed, the first impedance feed (614) is a 50 ohm characteristic impedance feed, and the first impedance phase delay feed (615) is a 50 ohm characteristic impedance phase delay feed.

7. The high order mode based dual polarized high gain patch antenna of claim 6, wherein: the second impedance input feed (622) is a 50 ohm characteristic impedance input feed, the second impedance feed (624) is a 50 ohm characteristic impedance feed, and the second impedance phase delay feed (625) is a 50 ohm characteristic impedance phase delay feed.