A venue-shaped antenna

Abstract

The solution provided by the present invention is a venue-shaped antenna, which includes a dielectric substrate, a radiator, and a metasurface layer laminated on the upper surface of the dielectric substrate. Among them, an installation groove for accommodating the radiator is formed in the middle of the metasurface layer; dividing slits are etched on the midline along the length direction and the midline along the width direction of the radiator, so that the radiator is divided into four radiation units arranged in a matrix. Among them, a connection bridge is formed between any two adjacent radiation units, so that the four radiation units are correspondingly connected by four connection bridges, thereby realizing the dual-polarization function, improving the frequency band utilization rate, the front-to-back ratio and the antenna gain of the antenna, the slope of the antenna half-power beam width and the -20 dB beam width, reducing the side lobes of the antenna, and meeting the requirements of the venue antenna.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication systems, and particularly to a shaped antenna for a venue. Background Art

[0002] At present, 5G technology has been applied to various scenarios. In application scenarios such as competition or live broadcast venues, the antenna radiation mechanism has an important impact on the competition results or the transmission of live broadcast signals. Among them, in a venue, it is often divided into many sectors. To obtain the same signal at each position in the sector and avoid the situation of "shadow zone", the radiation direction of the antenna needs to have good boundary characteristics, that is, the ratio of the half-power beam width (-3 dB beam width) to the -20 dB beam width of the antenna is greater than a certain fixed value. At the same time, the antenna in the venue still needs to meet the function of low side lobes, otherwise it will affect the radiation of signals in other sectors.

[0003] Currently, most existing shaped antennas for venues are implemented by the following two methods: 1) Using a regular array to implement. When designing the feeding network, each unit is excited with different phases or amplitudes to realize an antenna with a square radiation pattern; 2) Using a sparse array method, by placing antenna elements at different positions to form a pattern with obvious boundary characteristics. Both of these methods can achieve good shaping characteristics, but the first method requires many antenna elements, increasing the manufacturing cost, and its feeding network is very complex, making it difficult to accurately realize the amplitude and phase of the excitation; the disadvantage of the second method is that it is realized by controlling the positions of the antennas, and it is difficult to accurately determine the position of each antenna, which may result in large side lobes.

[0004] Secondly, the ratio of the half-power beam width to the -20 dB beam width of the antenna is an important index of the shaped antenna. Usually, the broadening and narrowing of the half-power beam width and the -20 dB beam width of the antenna change in proportion. Therefore, a method that can greatly broaden the half-power beam width of the antenna but with a very small broadening amplitude of the -20 dB beam width is very important. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a shaped antenna for a venue that can cover the 5G frequency band (3.3 - 3.6 GHz), realize the dual-polarization function, improve the frequency band utilization rate, the front-to-back ratio and the antenna gain of the antenna, the slope of the half-power beam width and the -20 dB beam width of the antenna, reduce the side lobes of the antenna, and meet the requirements of venue antennas.

[0006] To achieve the above object, the solution provided by the present invention is a shaped antenna for a venue, which includes a dielectric substrate, a radiator, and a metasurface layer laminated on the upper surface of the dielectric substrate. Among them, an installation groove for accommodating the radiator is formed in the middle of the metasurface layer; a partition gap is etched on the center line of the radiator along its length direction and the center line of its width direction, so as to divide the radiator into four radiation units arranged in a matrix. Among them, a connection bridge is formed between any two adjacent radiation units, so that the four radiation units are correspondingly connected by four connection bridges.

[0007] Further, it also includes four metal enclosures respectively arranged around the radiator.

[0008] Further, the dielectric substrate includes a first substrate layer and a second substrate layer arranged in a stacked manner up and down. Among them, a first feeding network and a second feeding port are provided on the upper surface of the first substrate layer, a second feeding network and a first feeding port are provided on the upper surface of the second substrate layer, and the second feeding port is connected to the second feeding network after passing through a second differential gap pre-formed in the first substrate layer; the first feeding port is connected to the first feeding network after passing through a first differential gap pre-formed in the first substrate layer.

[0009] Further, the first feeding network is divided into two to form two first output ends, and the two first output ends are connected to two first feeding points provided on the radiator; the second feeding network is divided into two to form two second output ends, and the two second output ends are connected to two second feeding points provided on the radiator.

[0010] Further, the two first feeding points are respectively arranged adjacent to two connection bridges on the center line of the radiator along its length direction; the two second feeding points are respectively arranged adjacent to two connection bridges on the center line of the radiator along its width direction.

[0011] Further, the upper surface of the metasurface layer has a periodic square metasurface structure.

[0012] The beneficial effects of the present invention are as follows: 1) By differential feeding and etching partition gaps to correct the current flow direction, good directivity is obtained, the dual-polarization function is realized, and the isolation of the antenna is improved; 2) By setting the metasurface layer as the ground, the backward radiation of the antenna energy is effectively reduced, the gain of the antenna is increased, and the front-to-back ratio of the antenna is increased; 3) By setting the metal enclosures, the half-power beam width of the antenna can be greatly widened, and the -20 dB beam width can be slightly widened, improving the boundary of the antenna radiation pattern. Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram of the shaped antenna.

[0014] Figure 2Schematic diagram of the metasurface layer.

[0015] Figure 3 Schematic diagram of the radiator.

[0016] Figure 4 Top view of the radiator.

[0017] Figure 5 Schematic diagram of the first substrate layer.

[0018] Figure 6 Schematic diagram of the second substrate layer.

[0019] Figure 7 Front and rear current distribution diagrams and radiation patterns.

[0020] Figure 8 Schematic diagram of the front-to-back ratio of the antenna.

[0021] Figure 9 Schematic diagram of radiation pattern comparison.

[0022] Figure 10 Schematic diagram of the electric field distribution of the differential feeding network.

[0023] Figure 11 Simulation diagram of the S-parameters of the feeding network.

[0024] Figure 12 Phase difference diagram.

[0025] Figure 13 S-parameter diagram of the antenna.

[0026] Figure 14 Antenna gain curve diagram

[0027] Figure 15 2D and 3D radiation patterns of the antenna.

[0028] Wherein, 1 - dielectric substrate, 11 - first substrate layer, 12 - second substrate layer, 2 - radiator, 21 - separation gap, 22 - connection bridge, 3 - metasurface layer, 31 - mounting groove, 4 - metal enclosure, 51 - first feeding network, 52 - first feeding port, 53 - second feeding network, 54 - second feeding port, 55 - first differential gap, 56 - second differential gap. Detailed implementation manner

[0029] For ease of understanding the present invention, the present invention will be described more comprehensively below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the disclosure of the present invention more thorough and comprehensive. It should be noted that the "first" and "second" in the present invention do not represent specific quantities and sequences, but are only used for name distinction.

[0030] See the attached Figures 1-6 As shown, in this embodiment, a venue-shaped antenna includes a dielectric substrate 1, a radiator 2, and a metasurface layer 3. Among them, the dielectric substrate 1 includes a first substrate layer 11 and a second substrate layer 12 arranged in a stacked manner up and down. The metasurface layer 3 is stacked on the first substrate layer 11 to realize that the metasurface layer 3 is stacked on the dielectric substrate 1. The above-mentioned first substrate layer 11, second substrate layer 12, and metasurface layer 3 are all FR4 dielectric plates with the same size (dielectric constant is 4.4, tangent loss is 0.02). In addition, the upper surface of the metasurface layer 3 has a periodic square metasurface structure, which can effectively reduce the energy radiated backward by the antenna and improve the front-to-back ratio of the antenna. The front-to-back ratio of the antenna is increased from 23 dB to 29 dB.

[0031] In this embodiment, an installation groove 31 for accommodating the radiator 2 is formed in the middle of the metasurface layer 3, so that the radiator 2 is embedded in the installation groove 31. The radiator 2 has a square patch structure. Partition slits 21 are etched on the midlines of the length direction and the width direction of the radiator 2. Among them, connection bridges 22 are formed between any two adjacent radiation units, so that the four radiation units are correspondingly connected by the four connection bridges 22. The four connection bridges 22 are divided into two groups. One group is located on the midline of the length direction of the radiator 2; the other group is located on the midline of the width direction of the radiator 2. The above-mentioned radiation units are symmetrically arranged to facilitate the realization of the dual-polarization function.

[0032] In this embodiment, a first feeding network 51 and a second feeding port 54 are provided on the upper surface of the first substrate layer 11, a second feeding network 53 and a first feeding port 52 are provided on the upper surface of the second substrate layer 12, and the second feeding port 54 passes through a second differential slit 56 pre-formed in the first substrate layer 11 and is connected to the second feeding network 53; the first feeding port 52 passes through a first differential slit 55 pre-formed in the first substrate layer 11 and is connected to the first feeding network 51. Secondly, the first feeding network 51 is divided into two to form two first output ends, and the two first output ends are connected to two first feeding points provided on the radiator 2; the second feeding network 53 is divided into two to form two second output ends, and the two second output ends are connected to two second feeding points provided on the radiator 2. Thus, feeding is realized at the front, rear, left, and right positions of the radiation plate.

[0033] By using the differential feeding method and setting the separation gap 21, the currents in the middle of the radiation plate cancel each other out, and the currents of the two adjacent parts flow in the same direction at the same time, obtaining a directional radiation pattern.

[0034] Furthermore, the two first feeding points are respectively arranged adjacent to two connection bridges 22 on the center line in the length direction of the radiator 2; the two second feeding points are respectively arranged adjacent to two connection bridges 22 on the center line in the width direction of the radiator 2.

[0035] The above double-layer structure using the first substrate layer 11 and the second substrate layer 12 realizes a relatively perfect 180° phase difference in the required frequency band through the structure of the feeding port - differential gap - feeding network, and the phase fluctuates between ±1°. Compared with the traditional method of realizing the phase difference by increasing the length, it has smaller phase fluctuations.

[0036] In this embodiment, it further includes four metal enclosures 4 respectively arranged around the radiator 2. The four metal enclosures 4 are of the same size, and any two adjacent metal enclosures 4 are arranged perpendicular to each other. By setting the metal enclosures 4, the half-power beam width and sidelobes of the antenna are controlled, so that the half-power beam of the antenna becomes wider, the sidelobes are reduced, and at the same time, the slope of the beam from -3dB to -20 dB is increased, realizing the function of square shaping and improving the boundary of the antenna radiation pattern.

[0037] To facilitate the understanding of the above antenna, the parameter performance of the antenna will be further explained below with reference to specific drawings.

[0038] See Figure 7 In the front and rear current distribution diagrams and radiation pattern diagrams shown, taking the radiation plate without loading differential feeding as a reference example, it can be obtained that: the three parts of currents generated by the antenna reference example without loading differential feeding flow in different directions at the same time, resulting in two main lobes in the radiation pattern; while for the antenna of this embodiment, the currents in the middle part cancel each other out, and the currents of the two adjacent parts flow in the same direction at the same time, showing a directional radiation pattern.

[0039] See Figure 8 In the front-to-back ratio schematic diagram shown, taking the antenna with an ordinary ground as a reference example, it can be obtained that: the antenna of this embodiment with the metasurface layer 3 can effectively reduce the energy radiated backward by the antenna, and the front-to-back ratio of the antenna is increased from 23 dB to 29 dB.

[0040] See Figure 9In the schematic diagram of the pattern comparison shown, taking the antenna without the metal enclosure 4 as the reference example, it can be obtained that for the antenna with the metal enclosure 4 in this embodiment, the half-power beamwidth is broadened (from 34° to 40°), and the side lobe is reduced from -15 dB to -22.5 dB. Based on the slope calculation formula of the beamwidth, the slope of the antenna without the metal enclosure 4 is K1 = 34° / 88° = 0.386; the slope of the antenna in this embodiment is K2 = 40° / 90° = 0.444. The slope has been significantly improved, and the function of square shaping can be better realized.

[0041] Referring to Figure 10 the schematic diagram of the electric field distribution of the differential feeding network shown, it can be obtained that when excited at one port, the energy is transmitted to the slot through the microstrip line. After passing through the slot, the electric field directions on the left and right are opposite. Therefore, the energy amplitudes reaching the second port and the third port are equal, and the phase difference is 180°. Thus, the requirements for the differential feeding phase and amplitude are realized.

[0042] Referring to Figure 11 the simulated S-parameter diagram of the feeding network and Figure 12 the phase difference diagram shown, it can be obtained that through the double-layer structure of the dielectric substrate 1 and the structure of the feeding port - differential slot - feeding network, a perfect 180° differential of the phase difference is realized. Secondly, for the antenna using the differential feeding method, |S11| ≤ -20 dB in the frequency band of 3.3 - 3.6 GHz, |S12| & |S13| ≥ -3.8 dB, and the phase difference fluctuates within 180° ± 1°. This shows good power division effect and good differential performance.

[0043] Referring to Figure 13 the S-parameter diagram of the antenna shown, it can be obtained that |S11| & |S22| are both less than -11 dB in the frequency band, having good matching; due to the use of differential feeding, |S21| is less than -27 dB in the frequency band, having good isolation.

[0044] Referring to Figure 14 the antenna gain curve diagram shown, it can be obtained that in the frequency band of 3.3 - 3.6 GHz, the gain of the antenna is greater than 12.5 dBi, and due to the symmetric structure, the two gain curves almost coincide.

[0045] Referring to Figure 15 In the 2D and 3D patterns of the antenna shown, it can be obtained that the half-power beamwidth range is [40°, 45°], the -20 dB beamwidth range is [86°, 95°], and the slope of its beamwidth is greater than 0.4. The front-to-back ratio is greater than 29 dB, and the side lobe is less than -18 dB. It can be seen from the 3D pattern that its radiation characteristics have the characteristics of a square, meeting the requirements of the venue shaping antenna.

[0046] The embodiments described above are only the preferred embodiments of the present invention, and do not impose any formal limitations on the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, may make more possible changes, refinements or modifications to the technical solution of the present invention by using the technical content disclosed above, which are all equivalent embodiments of the present invention. Therefore, all equivalent changes made according to the idea of the present invention without departing from the content of the technical solution of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A venue-shaped antenna, characterized in that: It includes a dielectric substrate (1), a radiator (2), and a metasurface layer (3) laminated on the upper surface of the dielectric substrate (1). Among them, an installation groove (31) for accommodating the radiator (2) is formed in the middle of the metasurface layer (3); dividing slits (21) are etched on the center line of the radiator (2) along its length direction and the center line of its width direction, so as to divide the radiator (2) into four radiation units arranged in a matrix. Among them, a connection bridge (22) is formed between any two adjacent radiation units, so that the four radiation units are correspondingly connected by four connection bridges (22); the dielectric substrate (1) includes a first substrate layer (11) and a second substrate layer (12) laminated up and down. Among them, a first feeding network (51) and a second feeding port (54) are provided on the upper surface of the first substrate layer (11), a second feeding network (53) and a first feeding port (52) are provided on the upper surface of the second substrate layer (12), and the second feeding port (54) passes through a second differential slit (56) pre-formed in the first substrate layer (11) and is connected to the second feeding network (53); the first feeding port (52) passes through a first differential slit (55) pre-formed in the first substrate layer (11) and is connected to the first feeding network (51); the first feeding network (51) is divided into two to form two first output ends, and the two first output ends are connected to two first feeding points provided on the radiator (2); the second feeding network (53) is divided into two to form two second output ends, and the two second output ends are connected to two second feeding points provided on the radiator (2); by using the differential feeding method and setting the dividing slits (21), the currents in the middle of the radiation plate are mutually cancelled and the currents on the two sides flow in the same direction at the same time.

2. The venue-shaped antenna according to claim 1, characterized in that: It further includes four metal enclosures (4) respectively arranged around the radiator (2).

3. The venue-shaped antenna according to claim 1, characterized in that: The two first feeding points are respectively arranged adjacent to two connection bridges (22) on the center line of the length direction of the radiator (2); the two second feeding points are respectively arranged adjacent to two connection bridges (22) on the center line of the width direction of the radiator (2).

4. The venue-shaped antenna according to claim 1, characterized in that: The upper surface of the metasurface layer (3) has a periodic square metasurface structure.

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