Car roof antenna based on 5G-R frequency band

Abstract

The utility model discloses a roof antenna based on a 5G-R frequency band, which comprises a substrate and an antenna control board, a plurality of paths of main body antennas are vertically arranged on the substrate, the main body antennas are formed on a copper-clad plate through etching, one path of main body antenna is arranged on one copper-clad plate, the substrate is supported and fixed on the antenna control board through a plurality of glass insulators, and the antenna control board is fixed on the substrate through a plurality of glass insulators. A plurality of coaxial cables penetrate through the antenna control panel to be connected with the main body antennas and grounding lines on the antenna control panel respectively, a plurality of copper-clad plates of the main body antennas are fixed on the substrate in parallel in a staggered mode, the main body antennas are cone copper foils with wide tops and narrow bottoms, and the main body antennas are arranged in the middles of the copper-clad plates. A plurality of vertical copper foil strips are symmetrically etched on the copper-clad plates on the two sides of the main body antenna at intervals, the copper foil strips are called branches, inductors and on-off switches are respectively arranged between the lower ends of the copper foil strips and a grounding circuit on the antenna control panel, and an on-off switch control circuit is arranged on the antenna control panel.

Description

Technical Field

[0001] The utility model relates to a roof antenna based on the 5G-R frequency band. Background Art

[0002] The roof antenna is an important part of the railway communication system, with the function of transmitting and receiving electromagnetic waves. At present, GSM-R, as a railway wireless communication system, is a narrowband communication system, which mainly carries voice services and a small amount of data services, with a low data rate. With the rapid development of 5G communication systems, rail transit has planned the 5G-R frequency band, with an uplink of 1965~1975MHz and a downlink of 2155~2165MHz, each 10MHz, using the FDD standard. The communication system is developed according to the 5G-R frequency band. As a key communication, the performance of the roof antenna is crucial. In addition to hot coverage areas such as railway stations and hubs, there are communication needs for infrastructure along the railway and every place where the railway main line passes. The existing roof antennas are mainly designed as broadband omnidirectional antennas with vertical polarization. Under roof conditions, they have fixed beam width and beam direction. When the train is running, there are two states for the fixed base stations along the line: far away and close to the base stations. Since the beam width, gain and maximum direction of the omnidirectional antenna are fixed, when it is far away from the coverage range of some base stations and does not reach the coverage range of the next base station, there will be a problem of signal transmission interruption and disconnection. Summary of the invention

[0003] In view of the above problems, the purpose of the utility model is to provide a roof antenna based on the 5G-R frequency band. By changing the main structure of the antenna and adding a switch between the branch and the ground plate, the branch can be adjusted to serve as an antenna reflector or antenna director by partially turning the switch on and off, thereby changing the direction of the antenna beam to form a directional antenna. When the switch is completely disconnected, the antenna has omnidirectional performance.

[0004] In order to achieve the above purpose, the solution of the utility model is:

[0005] A roof antenna based on the 5G-R frequency band includes a substrate and an antenna control board, wherein multiple main antennas are vertically arranged on the substrate, the main antennas are formed on a copper-clad board by etching, one copper-clad board is provided with one main antenna, the substrate is supported and fixed on the antenna control board by multiple glass insulators, multiple coaxial cables pass through the antenna control board and are respectively connected to the main antenna and the grounding circuit on the antenna control board, wherein: multiple copper-clad boards of the multiple main antennas are parallel and staggered and fixed on the substrate, the main antenna is in the shape of a conical copper foil which is wide at the top and narrow at the bottom, the main antenna is in the middle of the copper-clad board, multiple vertical copper foil strips are symmetrically etched and arranged on the copper-clad boards on both sides of the main antenna, the copper foil strips are called branches, inductors and on-off switches are respectively arranged between the lower ends of the copper foil strips and the grounding circuit on the antenna control board, and an on-off switch control circuit is arranged on the antenna control board.

[0006] A further solution is that the length of the cone copper foil is one quarter of the wavelength corresponding to the lowest frequency, and the length of the branch is 0.4 times the wavelength corresponding to the lowest frequency.

[0007] A further solution is: there are four main antennas, and the four main antennas are arranged in parallel and staggered from one end to the other end in the length direction of the rectangular substrate.

[0008] The beneficial effects of the utility model are as follows: the width of the top of the antenna body is greater than that of the bottom, forming a single-cone antenna, which is conducive to expanding the bandwidth; the standing wave deviation caused by mutual interference between antennas when different beams are switched is small, the branches are connected to the ground plate through a pin switch, and the inductor is connected in series next to the branches for feeding, and the height of the branches decreases slightly as they are farther away from the main radiation area. When the roof antenna is actually used, the antenna is installed on a 3mx3m metal fixing plate on the top of the train, which is equivalent to installing the antenna on a 3mx3m reflector, causing the reflector to forcibly change the antenna beam to the vertical direction. By introducing multiple branches, the antenna has more energy toward the horizontal direction under directional mode conditions, so that the beam is tilted downward to point in the direction of the base station.

[0009] The utility model is described in detail below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure decomposition of the utility model;

[0011] Figure 2 It is a schematic diagram of the utility model after the structure is assembled. DETAILED DESCRIPTION

[0012] A roof antenna based on the 5G-R band, such as Figure 1 and Figure 2As shown, the roof antenna includes a substrate 1 and an antenna control board 2, a multi-channel main antenna 3 is vertically arranged on the substrate 1, an antenna cover 4 is buckled on the mounting plate 8 to cover the substrate 1 and the antenna control board 2 with the multi-channel main antenna 3, the main antenna 3 is formed on the copper clad plate 5 by etching, and one copper clad plate 5 is provided with one main antenna 3, the substrate 1 is supported and fixed on the control board 2 by multiple glass insulators 6 to connect the microstrip line on the antenna control board 2 and the antenna microstrip line, an aluminum lining plate 7, a mounting plate 8 and a support seat 9 are sequentially arranged under the antenna control board 2, the roof antenna is fixedly installed on the roof of the car through the support seat 9, and multiple coaxial cables 10 pass through the antenna control board 2 to connect the main antenna 3 and the antenna control board 2 respectively. The grounding circuit is parallel to the coaxial cable 10 to form a bundle, and the power supply and control signal cable 11 is connected to the antenna control board 2, wherein: multiple copper clad plates 5 of the multi-channel main antenna 3 are fixed on the substrate in parallel and staggered, the main antenna 3 is in the shape of a conical copper foil that is wide at the top and narrow at the bottom, the main antenna is in the middle of the copper clad plate, and multiple vertical copper foil strips 301 are symmetrically etched on the copper clad plates on both sides of the main antenna. The copper foil strips 301 are called branches, and an inductor 12 and an on-off switch 13 are respectively arranged between the lower end of the copper foil strip 301 and the grounding circuit on the antenna control board 2, and an on-off switch control circuit is arranged on the antenna control board 2, and the on-off switch 13 is an electronic switch.

[0013] Wherein: the length of the cone copper foil is one quarter of the wavelength corresponding to the lowest frequency, and the length of the branch is 0.4 times of the wavelength corresponding to the lowest frequency.

[0014] In the embodiment: the main antenna 3 has four paths, and the four-path main antenna 3 is arranged in parallel and staggered from one end to the other end in the length direction of the rectangular substrate; the four copper-clad plates 5 of the four-path main antenna 3 in this embodiment are arranged in parallel and staggered from one end to the other end in the length direction of the rectangular substrate in parallel to the length direction of the substrate. Of course, they can also be arranged horizontally, but it is necessary to ensure that the front and back of the main antennas are not opposite.

[0015] The above-mentioned roof antenna embodiment based on the 5G-R frequency band: the top width of the antenna body is larger than the bottom, forming a single cone antenna, which is conducive to expanding the bandwidth; so that the standing wave deviation caused by mutual interference between antennas when different beams are switched is small, and the total height of the cone is about one-fourth of the wavelength corresponding to the lowest frequency. The branch is connected to the ground plate through a pin switch, and the inductor is connected in series next to the branch for feeding. The initial size of the branch height is about 0.4 times the wavelength corresponding to the lowest frequency, and the branch height decreases slightly as it is farther away from the main radiation area. When the roof antenna is actually used, the antenna is installed on a 3mx3m metal fixing plate on the top of the train, which is equivalent to installing the antenna on a 3mx3m reflector, causing the reflector to forcibly change the antenna beam to the vertical direction. By introducing multiple branches, the antenna has more energy in the horizontal direction under the directional mode condition, so that the beam is tilted downward and points to the base station direction.

Claims

1. A roof antenna based on the 5G-R frequency band, comprising a substrate and an antenna control board, wherein a plurality of main antennas are vertically arranged on the substrate, the main antennas are formed on a copper-clad board by etching, one copper-clad board is provided with one main antenna, the substrate is supported and fixed on the antenna control board by a plurality of glass insulators, a plurality of coaxial cables pass through the antenna control board and are respectively connected to the main antenna and the grounding line on the antenna control board, wherein: Multiple copper-clad plates of the multi-channel main antenna are fixed on the substrate in parallel and staggered manner. The main antenna is in the shape of a conical copper foil that is wide at the top and narrow at the bottom. The main antenna is located in the middle of the copper-clad plate. Multiple vertical copper foil strips are symmetrically etched and arranged on the copper-clad plates on both sides of the main antenna. The copper foil strips are called branches. An inductor and an on-off switch are respectively arranged between the lower end of the copper foil strip and the grounding circuit on the antenna control board. An on-off switch control circuit is arranged on the antenna control board.

2. The roof antenna according to claim 1, characterized in that: The length of the cone copper foil is one quarter of the wavelength corresponding to the lowest frequency, and the length of the branch is 0.4 times of the wavelength corresponding to the lowest frequency.

3. The roof antenna according to claim 1, characterized in that: The main body antennas include four paths, and the four paths are arranged in parallel and staggered from one end to the other end in the length direction of the rectangular substrate.

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