Antenna device

Abstract

To make multiple and diverse frequency bands available.SOLUTION: An antenna device includes three dipole antennas, six first parasitic elements arranged to surround the three dipole antennas, and three second parasitic elements arranged between the three dipole antennas.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an antenna device. [Background technology]

[0002] Conventionally, technology for broadening the bandwidth of a monopole antenna has been studied (for example, see Patent Document 1). In the antenna device (monopole antenna) described in Patent Document 1, three parasitic elements are arranged to surround the main body of the monopole antenna. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-152595 Summary of the Invention [Problem to be solved by the invention]

[0004] The monopole antenna described in Patent Document 1 mentioned above can be applied to multiple frequency bands available for use by mobile communication systems (for example, a combination of the 760 MHz band and the 870 MHz band, or a combination of the 700 MHz band and the 880 MHz band), but an antenna device that can utilize a wider variety of multiple frequency bands remains an issue.

[0005] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to make it possible to use a variety of frequency bands. [Means for solving the problem]

[0006] One aspect of the present invention is an antenna device comprising three dipole antennas, six first parasitic elements arranged to surround the three dipole antennas, and three second parasitic elements arranged between each of the three dipole antennas. One aspect of the present invention is the antenna device described above, wherein the six first parasitic elements are respectively arranged on the sides of a hexagon, and the center of the hexagon coincides with the centers of the three dipole antennas. One aspect of the present invention is the antenna device described above, wherein the six first parasitic elements are respectively arranged on the sides of a regular hexagon inscribed in a circle of a certain radius from the center of the three dipole antennas. One aspect of the present invention is the antenna device described above, wherein a gap of a certain length is provided between two adjacent first parasitic elements. One aspect of the present invention is the antenna device, wherein the six first parasitic elements are each arranged on the circumference of a circle, and the center of the circle coincides with the center of the three dipole antennas. An aspect of the present invention is the antenna device described above, wherein the six first parasitic elements are arranged at equal intervals on the circumference of the one circle. One aspect of the present invention is the antenna device described above, wherein a gap with a constant gap angle is provided between two adjacent first parasitic elements. Effect of the Invention

[0007] According to the present invention, an effect is obtained in that a variety of frequency bands can be made available. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of an antenna device according to a first embodiment. [Diagram 2] 1 is a diagram illustrating a schematic configuration of an antenna device according to a first embodiment. [Diagram 3] 1 is a diagram illustrating a schematic configuration of an antenna device according to a first embodiment. [Figure 4] 1 is a diagram illustrating a schematic configuration of an antenna device according to a first embodiment. [Diagram 5]FIG. 4 is a dimensional diagram of a second parasitic element according to the first embodiment. [Figure 6] FIG. 2 is a top view of the dipole antenna according to the first embodiment. [Figure 7] 5 is a graph showing simulation results of antenna characteristics of the antenna device according to the first embodiment. FIG. [Figure 8] 11 is a diagram showing a schematic configuration of an antenna device according to a second embodiment. FIG. [Figure 9] 11 is a diagram showing a schematic configuration of an antenna device according to a second embodiment. FIG. [Figure 10] 11 is a diagram showing a schematic configuration of an antenna device according to a second embodiment. FIG. [Figure 11] 13 is a graph showing simulation results of the antenna characteristics of the antenna device according to the second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] [First embodiment] The general configuration of the antenna device 1 according to the first embodiment will be described with reference to Figs. 1 to 4. Figs. 1 to 4 are diagrams showing the general configuration of the antenna device 1 according to the embodiment. Fig. 1 is a top view of the antenna device 1 according to the embodiment. Fig. 2 is an external view of the antenna device 1 according to the embodiment, seen from diagonally above. Fig. 3 is an external view of the antenna device 1 according to the embodiment, seen from the side. Fig. 4 is a dimensional diagram of the antenna device 1 according to the embodiment.

[0011] The antenna device 1 includes three dipole antennas 120 (120-1, 120-2, 120-3), six first parasitic elements 300 (300-1, 300-2, 300-3, 300-4, 300-5, 300-6), and three second parasitic elements 400 (400-1, 400-2, 400-3). The ground plate 30 is a circular flat conductor. The dipole antennas 120 (120-1, 120-2, 120-3) are provided with feeding sections 140 (140-1, 140-2, 140-3). Dipole antennas 120 (120-1, 120-2, 120-3) are fed with power from power feeding units 140 (140-1, 140-2, 140-3). Dipole antennas 120 (120-1, 120-2, 120-3) are horizontally polarized dipole antennas.

[0012] In the antenna device 1, three dipole antennas 120 are arranged to surround the center of a circular ground plate 30. The three dipole antennas 120 are arranged at a certain height HB from the ground plate 30 by an insulator 500. In this embodiment, as an example of the centers of the three dipole antennas 120, the centers of the three dipole antennas 120 are the same as the center of the circular ground plate 30.

[0013] The shape of the dipole antenna 120 is configured to follow the circular shape of the base plate 30. As a result, the dipole antenna 120 is disposed so as to fit on the base plate 30.

[0014] Furthermore, in the antenna device 1, six first parasitic elements 300 are arranged to surround three dipole antennas 120. The six first parasitic elements 300 are arranged on the sides of a hexagon. The center of the hexagon is the same as the centers of the three dipole antennas 120. The first parasitic elements 300 are rectangular. Adjacent first parasitic elements 300 of the six first parasitic elements 300 are almost in contact with each other on the sides of the hexagon. A small gap is provided between two adjacent first parasitic elements 300.

[0015] As shown in Fig. 4, the six first parasitic elements 300 are arranged on the sides of a regular hexagon inscribed in a circle of radius RA (circle indicated by a dashed line in Fig. 4) from the center of the three dipole antennas 120. A gap of length GA is provided between two adjacent first parasitic elements 300. The first parasitic elements 300 are rectangular, and the length of one side of the rectangle (the length of the first parasitic elements 300) approximately corresponds to the side of the regular hexagon. The length of the other side of the rectangle (the width of the first parasitic elements 300) is WA.

[0016] The six first parasitic elements 300 are arranged at a fixed height from the ground plate 30. The arrangement height of the six first parasitic elements 300 is equal to or less than the arrangement height HB of the dipole antenna 120. Therefore, the height of the antenna device 1 is substantially within the fixed height HB from the ground plate 30.

[0017] The first parasitic element 300 is made of a conductor. As the conductor, a perfect electric conductor (PEC) or copper may be used.

[0018] Furthermore, in the antenna device 1, three second parasitic elements 400 are arranged between the three dipole antennas 120. The second parasitic element 400-1 is arranged between the dipole antennas 120-1 and 120-2. The second parasitic element 400-2 is arranged between the dipole antennas 120-2 and 120-3. The second parasitic element 400-3 is arranged between the dipole antennas 120-3 and 120-1.

[0019] Further, the second parasitic element 400 is a flat conductor, and is disposed so as to separate two adjacent dipole antennas 120 with the flat conductor.

[0020] 5 is a dimensional diagram of the second parasitic element 400 according to this embodiment. The second parasitic element 400 has a rectangular body. The body has a length HB, a width WB1, and a thickness WB2. The second parasitic element 400 is made of a conductor. PEC or copper may be used as the conductor.

[0021] Fig. 6 is a top view of dipole antenna 120 according to this embodiment. In Fig. 6, dipole antenna 120 includes first dipole antenna element 121 and second dipole antenna element 122. PEC or copper may be used for first dipole antenna element 121 and second dipole antenna element 122. First dipole antenna element 121 and second dipole antenna element 122 are fed with power from power feeding unit 140.

[0022] The first dipole antenna element 121 is a flat conductor arranged on the side farther from the center of the three dipole antennas 120. The first dipole antenna element 121 is arranged so that a surface of the flat conductor faces the ground plate 30. The first dipole antenna element 121 is composed of two flat first sub-conductors 121-1 and 121-2 of the same shape. The first dipole antenna element 121 is fed by the power feeding section 140 from between the first sub-conductor 121-1 and the first sub-conductor 121-2, which is an intermediate portion.

[0023] The second dipole antenna element 122 is a flat conductor arranged closer to the center of the three dipole antennas 120. The second dipole antenna element 122 is arranged so that the surface of the flat conductor faces the ground plate 30. The second dipole antenna element 122 is composed of two flat second sub-conductors 122-1 and 122-2 of the same shape. The second dipole antenna element 122 is fed by the power feeding section 140 from between the second sub-conductor 122-1 and the second sub-conductor 122-2, which is the middle portion.

[0024] The first dipole antenna element 121 has a larger area than the second dipole antenna element 122 .

[0025] The first dipole antenna element 121 (121-1, 121-2) and the second dipole antenna element 122 (122-1, 122-2) are fixed by an insulator 123 (123-1, 123-2).

[0026] The three dipole antennas 120 (120-1, 120-2, 120-3) are excited together with the six first parasitic elements 300 (300-1, 300-2, 300-3, 300-4, 300-5, 300-6) and the three second parasitic elements 400 (400-1, 400-2, 400-3).

[0027] Fig. 7 is a graph diagram showing a simulation result of the antenna characteristics of the antenna device 1 according to the first embodiment. The antenna device 1 used in the simulation shown in Fig. 7 has a dipole antenna 120 configured to target both the 700 MHz band (718 MHz to 783 MHz) and the 800 MHz band (815 MHz to 875 MHz) as the usable frequency bands. For example, based on the results of a simulation, an experiment, or the like, the dipole antenna 120 may be designed to target both the 700 MHz band and the 800 MHz band as the usable frequency bands.

[0028] 7, the first parasitic element 300 has a width WA of 10 millimeters (mm) and a thickness of 2 mm. The second parasitic element 400 has a length HB of 38.5 mm, a width WB1 of 16 mm, and a thickness WB2 of 0.835 mm. The radius RA is 130 mm, and the gap length GA is 5.2 mm.

[0029] In the graph of FIG. 7, the horizontal axis is frequency (unit: gigahertz (GHz)), and the vertical axis is return loss (unit: decibels (dB)). As shown in the graph of FIG. 7, in both of the 700 MHz and 800 MHz frequency bands, the return loss is −10 dB or less, which is a good result. The return loss shown in the graph of FIG. 7 is a good result applicable to a mobile communication system using either or both of the 700 MHz and 800 MHz frequency bands. As a result, the antenna device 1 can be shared with a mobile communication system using either or both of the 700 MHz and 800 MHz frequency bands. In this way, according to this embodiment, an effect is obtained in which a variety of multiple frequency bands can be used. Furthermore, from the simulation results of the antenna characteristics of the antenna device 1 according to the first embodiment, it was confirmed that the horizontal plane directivity was also good.

[0030] [Second embodiment] The general configuration of the antenna device 1a according to the second embodiment will be described with reference to Figs. 8 to 10. Figs. 8 to 10 are diagrams showing the general configuration of the antenna device 1a according to the present embodiment. Fig. 8 is an external view of the antenna device 1a according to the present embodiment, seen from diagonally above. Fig. 9 is a top view of the antenna device 1a according to the present embodiment. Fig. 10 is an external view of the antenna device 1a according to the present embodiment, seen from the side. In Figs. 8 to 10, parts corresponding to the respective parts of the antenna device 1 according to the first embodiment are given the same reference numerals, and their description will be omitted.

[0031] The antenna device 1a according to the second embodiment is different from the antenna device 1 according to the first embodiment in the method of configuring the six first parasitic elements 300. Specifically, in the antenna device 1a according to the second embodiment, the six first parasitic elements 300 (300-1, 300-2, 300-3, 300-4, 300-5, 300-6) are arranged to surround the three dipole antennas 120 in the same manner as the antenna device 1 according to the first embodiment, but are arranged on the circumference of a circle by being installed on the inner surface of an insulator 600 in the form of a cylindrical side surface. The center of the circle is the same as the centers of the three dipole antennas 120. The first parasitic elements 300 are rectangular. The six first parasitic elements 300 are arranged at equal intervals on the circumference of the circle. In this embodiment, as an example of the centers of the three dipole antennas 120, the centers of the three dipole antennas 120 are the same as the center of a circular ground plate 30.

[0032] The circle on which the six first parasitic elements 300 are arranged has a radius RB from the center of the three dipole antennas 120. A gap of gap angle θB is provided between two adjacent first parasitic elements 300. The first parasitic elements 300 are rectangular, and the length of one side of the rectangle (the length of the first parasitic elements 300) is 1 / 6 of the length obtained by subtracting the total length of the gaps of gap angle θB from the circumference of the circle. The length of the other side of the rectangle (the width of the first parasitic elements 300) is WD.

[0033] The six first parasitic elements 300 are arranged at a fixed height from the ground plate 30. The arrangement height of the six first parasitic elements 300 is equal to or less than the arrangement height HB of the dipole antenna 120. Therefore, the height of the antenna device 1a is substantially within the fixed height HB from the ground plate 30.

[0034] The three dipole antennas 120 (120-1, 120-2, 120-3) are excited together with the six first parasitic elements 300 (300-1, 300-2, 300-3, 300-4, 300-5, 300-6) and the three second parasitic elements 400 (400-1, 400-2, 400-3).

[0035] Fig. 11 is a graph diagram of a simulation result of the antenna characteristics of the antenna device 1a according to the second embodiment. The antenna device 1a used in the simulation shown in Fig. 11 has a dipole antenna 120 configured to target both the 700 MHz band (718 MHz to 783 MHz) and the 800 MHz band (815 MHz to 875 MHz) as the usable frequency bands. For example, based on the results of a simulation, an experiment, or the like, the dipole antenna 120 may be designed to target both the 700 MHz band and the 800 MHz band as the usable frequency bands.

[0036] In the antenna device 1a used in the simulation shown in FIG. 11, the width WD of the first parasitic element 300 is 10 mm and the thickness is 2 mm. The width WE of the insulator 600 in the shape of a side surface of a cylinder is 15 mm. The second parasitic element 400 has a length HB of 38.5 mm, a width WB1 of 16 mm, and a thickness WB2 of 0.835 mm. In addition, the radius RA is 120 mm, and the gap angle θB is 8 degrees.

[0037] In the graph of FIG. 11, the horizontal axis is frequency (unit: GHz), and the vertical axis is return loss (unit: dB). As shown in the graph of FIG. 11, in both of the 700 MHz and 800 MHz frequency bands, the return loss is −10 dB or less, which is a good result. The return loss shown in the graph of FIG. 11 is a good result applicable to a mobile communication system using either or both of the 700 MHz and 800 MHz frequency bands. As a result, the antenna device 1a can be shared with a mobile communication system using either or both of the 700 MHz and 800 MHz frequency bands. In this way, according to this embodiment, an effect is obtained in which a variety of multiple frequency bands can be used. Furthermore, from the simulation results of the antenna characteristics of the antenna device 1a according to the second embodiment, it was confirmed that the horizontal plane directivity was also good.

[0038] This will, for example, make it possible to improve the overall service quality of mobile communications systems, thereby contributing to Goal 9 of the United Nations' Sustainable Development Goals (SDGs), which is to "build resilient infrastructure, promote sustainable industrialization and foster innovation."

[0039] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not deviate from the gist of the present invention are also included.

[0040] For example, in the above-described embodiment, the centers of the three dipole antennas 120 are the same as the center of the circular ground plate 30, but this is not limited thereto. For example, the centers of the three dipole antennas 120 may be offset from the center of the circular ground plate 30. For example, when the shape of the ground plate 30 is not circular or the size of the ground plate 30 is very large, the centers of the three dipole antennas 120 may be set independently of the ground plate 30.

[0041] For example, the dipole antenna is not limited to the above-described dipole antenna 120, and may be a dipole antenna of any shape. For example, a single rod-shaped dipole antenna may be used.

[0042] In addition, an antenna targeting various frequency bands (e.g., a dipole antenna, a monopole antenna, etc.) may be added to the above-mentioned antenna device 1, 1a so as to fit on the base plate 30, thereby forming a further multiband antenna. [Explanation of symbols]

[0043] Reference Signs List 1, 1a...antenna device, 120...dipole antenna, 300...first parasitic element, 400...second parasitic element, 500...insulator, 30...ground plate, 140...power supply section

Claims

1. Three dipole antennas, Six first parasitic elements are arranged to surround the three dipole antennas; three second parasitic elements arranged between the three dipole antennas, respectively; An antenna device comprising:

2. The six first parasitic elements are arranged on sides of a hexagon, The center of the hexagon is the same as the center of the three dipole antennas.

2. The antenna device according to claim 1.

3. The six first parasitic elements are arranged on sides of a regular hexagon inscribed in a circle of a certain radius from the center of the three dipole antennas, 3. The antenna device according to claim 2.

4. A gap of a certain length is provided between two adjacent first parasitic elements.

4. The antenna device according to claim 3.

5. the six first parasitic elements are arranged on a circumference of a circle, The center of the one circle is the same as the centers of the three dipole antennas.

2. The antenna device according to claim 1.

6. The six first parasitic elements are arranged at equal intervals on the circumference of the circle.

6. The antenna device according to claim 5.

7. A gap having a constant gap angle is provided between two adjacent first parasitic elements.

7. The antenna device according to claim 6.

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