Base station and radio wave radiation method

Abstract

A base station (10) comprises an antenna board (13) for radiating radio waves, a case (11), and a gasket (16). The antenna board (13) has an antenna (12) formed on a front surface thereof. The case (11) has a window (15). The antenna (12) is exposed outside the case (11) through the window (15). The gasket (16) surrounds the window (15). The front surface of the antenna board (13) and an inner surface of the case (11) sandwich the gasket (16). The base station (10) additionally comprises a stiffener (18) on a rear surface of the antenna board (13). The stiffener (18) extends along the gasket (16).

Description

Technical Field

[0001] The present disclosure relates to an antenna device, particularly to a base station and its use.

Background Art

[0002] Patent Documents 1 to 2 disclose antennas with waterproof measures in consideration of outdoor use. Patent Document 1 discloses a manhole cover with an antenna. Patent Document 2 discloses an integrated antenna device that is not exposed to rain as long as sealing is maintained.

[0003] Patent Document 3 discloses a millimeter-wave planar antenna. In such a millimeter-wave planar antenna, a gasket is sandwiched between a dielectric substrate used as an antenna dome and a ground conductor plate integrated with a support plate. The gasket surrounds the radiation circuit on the ground conductor plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0005] In the antenna devices described in Patent Documents 1 to 3, waterproofing or sealing of the antenna is considered, but cooling of the antenna is not considered. An object of the present disclosure is to provide an antenna device, particularly a base station, in which waterproofing and cooling are considered in view of the above-described problems.

[0006] The base station includes an antenna substrate that radiates radio waves, a case, and a gasket. The antenna substrate has an antenna formed on its front surface. The case has a window. The antenna is exposed outside the case through the window. The gasket surrounds the window. The front surface of the antenna substrate and the inner surface of the case sandwich and crush the gasket. The antenna substrate further includes a stiffener on its back surface. The stiffener extends along the gasket.

[0007] When radiating radio waves using the base station, the radio waves are radiated to the antenna while allowing the surface of the antenna to be in contact with the outside air. Heat generated during the radiation of the radio waves is released from the surface of the antenna to the outside air.

[0008] According to the present disclosure, an antenna device that takes waterproofing and cooling into consideration, particularly a base station, can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0010] FIG. 1 shows a cross-section of the base station 10. The base station 10 includes a case 11, an antenna substrate 13, and a gasket 16. The case 11 houses the antenna substrate 13 and the gasket 16. The case 11 further houses components other than the antenna substrate 13 that constitute the base station 10. The illustration of the components is omitted. The base station 10 has communication wiring and power wiring that connect from the inside of the case 11 to the outside of the case 11, or terminals thereof. The illustration of these wirings and terminals is omitted.

[0011] The antenna substrate 13 shown in FIG. 1 has its front side on the lower side in the figure and its back side on the upper side in the figure. The antenna substrate 13 has an antenna 12 formed on its front surface. The antenna 12 is a planar antenna, preferably a planar antenna. The front surface of the antenna substrate 13 including the antenna 12 is waterproofed.

[0012] As one embodiment of the waterproofing treatment of the antenna substrate 13 shown in FIG. 1, the antenna substrate 13 further has a coating 19 covering the surface of the antenna 12. The coating 19 waterproofs the antenna 12. In one embodiment, the coating 19 is a paint film. Examples of the material of the coating 19 are fluororesin and silicone.

[0013] The case 11 shown in FIG. 1 has a window 15. The window 15 is a through-hole provided in the case 11. The antenna 12 is exposed outside the case 11 through the window 15. The case 11 includes a box-shaped housing 17 and a cover 14 that serves as a lid for the housing 17. The window 15 is provided in the center of the cover 14. A gasket 16 surrounds the window 15. In one embodiment, the gasket 16 is annular.

[0014] In the base station 10 shown in FIG. 1, the antenna substrate 13 and the cover 14 are clamped with the gasket 16 in between. The front surface of the antenna substrate 13 and the inner surface of the case 11 crush the gasket 16. In one embodiment, the gasket 16 is made of an elastomer, such as fluororubber or silicone rubber. The crushed gasket 16 rebounds and pushes back the front surface of the antenna substrate 13 and the inner surface of the case 11. For this reason, the gap between the front surface of the antenna substrate 13 and the inner surface of the case 11 is filled. The gasket 16 prevents water and dust from entering the case 11 through this gap.

[0015] In the base station 10 shown in FIG. 1, the cross-sectional shape and the overall shape of the gasket 16 before being crushed are appropriately designed. At least one of the front surface of the antenna substrate 13 and the inner surface of the case 11 may have a groove for fitting the gasket 16.

[0016] The film 19 shown in FIG. 1 covers at least the portion of the front surface of the antenna substrate 13 surrounded by the gasket 16. Such gasket 16 and film 19 waterproof the front surface of the antenna substrate 13. In a preferred embodiment, the film 19 covers at least the portion of the front surface of the antenna substrate 13 surrounded by the gasket 16. In a preferred embodiment, the gasket 16 is in contact with the film 19.

[0017] The base station 10 shown in FIG. 1 further includes a stiffener 18 on the back surface of the antenna substrate 13. In one embodiment shown in the figure, the stiffener 18 is separate from the antenna substrate 13. In other embodiments, the stiffener 18 is integrally formed with the antenna substrate 13. In one embodiment, the stiffener 18 has a rail shape or other shape. Such stiffener 18 extends along the gasket 16. In one embodiment, the stiffener 18 is annular. In one embodiment, the stiffener 18 is made of an insulator.

[0018] The gasket 16 shown in FIG. 1 waterproofs the inside of the case 11. Here, the antenna substrate 13 is deflected by the repulsion of the gasket 16. For this reason, the antenna substrate 13 warps. The warp of the antenna substrate 13 impairs waterproofing. This is because there are portions where the antenna substrate 13 cannot sufficiently crush the gasket 16.

[0019] The stiffener 18 shown in FIG. 1 suppresses the warp of the antenna substrate 13 by reinforcing the back surface of the antenna substrate 13. The stiffener 18 helps the front surface of the antenna substrate 13 to uniformly and sufficiently crush the gasket 16. The stiffener 18 prevents water from entering from any location on the gasket 16.

[0020] From another perspective, the deflection of the antenna substrate 13 shown in FIG. 1 may lead to damage to the components mounted on the antenna substrate 13. The stiffener 18 also helps to prevent damage to these components by suppressing the deflection of the antenna substrate 13.

[0021] In Case 11 shown in FIG. 1, it is waterproof between the cover 14 and the housing 17. In one embodiment, the case 11 is opened by separating the cover 14 and the housing 17. By opening the case 11, the back surface of the antenna substrate 13 inside it can be maintained. Also, parts other than the antenna substrate 13 can be maintained. When the cover 14 and the housing 17 are joined again, the space between the cover 14 and the housing 17 is waterproofed again. Waterproofing may be performed by installing a gasket between the cover 14 and the housing 17.

[0022] The base station 10 shown in FIG. 1 is used as follows. While allowing the surface of the antenna 12 to be in contact with the outside air, radio waves are transmitted from the antenna 12. The heat generated accordingly is released from the surface of the antenna 12 to the outside air. In a preferred embodiment, the antenna 12 radiates its heat to the outside through the coating 19 outside the case 11.

[0023] The base station 10 shown in FIG. 1 is attached to a structure that is fixed to the ground. Examples of structures are buildings, poles, towers, tunnels, and basements. In other embodiments, the base station 10 is attached to an object that moves on land, on water, or in the air. The moving object is manned or unmanned. Examples of moving objects are automobiles, airships, and ships.

[0024] The base station 10 shown in FIG. 1 is installed outdoors where it may rain or snow. In other embodiments, the base station 10 is installed indoors in a place where water splashes or water droplets may occur. In these cases, water enters from between the antenna substrate 13 and the cover 14. The gasket 16 prevents water from entering the inside of the housing 17 as described above.

[0025] FIG. 2 shows a three - view of a base station 20 which is an embodiment of the base station 10 shown in FIG. 1. The lower left is the front view, the top of the front view is the plan view, and the right of the front view is the left - side view. The base station 20 is different from the base station 10 shown in FIG. 1 in that it includes a radome 21. The radome 21 is fixed to the front of the cover 14. The radome 21 covers the window 15. The radome 21 is made of an insulator, for example, resin. The radome 21 has a duct 22 and a top 23.

[0026] In the radome 21 shown in FIG. 2, the duct 22 is provided around the top 23, in other words, at the skirt portion of the radome 21. The duct 22 is open to such an extent that raindrops can pass through. The diameter of raindrops is generally said to be about 0.2 to 6 mm. The radome 21 has at least one duct 22. Outside air enters through the duct 22 and the window 15 to the front of the antenna substrate 13. The antenna on the antenna substrate 13 is in direct contact with the outside air through the duct 22 of the radome 21. It is preferable to provide two or more ducts 22. The outside air circulates in the radome 21 by passing through from one duct 22 to the other duct 22.

[0027] In the radome 21 shown in FIG. 2, the top 23 faces the front of the antenna substrate 13 through the window 15. The top 23 protects the antenna on the antenna substrate 13 from, for example, flying objects. The radome 21 may be removed from the base station 20 as necessary. When it is not necessary to protect the antenna substrate from the outside world, the base station 10 without a radome as shown in FIG. 1 is also useful.

[0028] The radome 21 shown in FIG. 2 may be integrally formed with the cover 14. The shape of the radome 21, the shape of the cover 14, and the shape of the housing 17 are variously designed according to the performance required for the base station and the location where the base station is placed.

[0029] FIG. 3 shows an exploded view of the base station 20. The left hand in the figure is the front side. The antenna substrate 13 is fixed around the window 15 from the inside of the cover 14. When fixing the antenna substrate 13 to the cover 14, the gasket 16 is sandwiched between them. The antenna substrate 13 is fixed to the inside of the cover 14 by pressing the stiffener 18 against the back surface of the antenna substrate 13. As described with reference to FIG. 1, the stiffener 18 extends along the gasket 16. The antenna substrate 13 with the stiffener 18 attached in advance may be pressed against the gasket 16. Finally, the cover 14 is attached to the housing 17 to seal the inside of the housing 17. Further, the radome 21 is attached to the cover 14.

[0030] FIG. 4 shows a cross section of the base station 30 according to the comparative example. The base station 30 includes a case 31 and an antenna substrate 33. An antenna 12 is formed on the front surface of the antenna substrate 33. The case 31 includes a housing 37 and a radome 34 that covers the housing 37. The housing 37 has a natural air cooling device 32. The radome 34 is made of resin and serves as a radio wave radiation surface. The radome 34 protects the antenna substrate 33 and waterproofs the housing 37. The resin of the radome 34 has a low thermal conductivity. Therefore, the radome 34 does not radiate the heat generated by the antenna 12 outside the case 31.

[0031] The base station 10 shown in FIG. 1 has an antenna 12 exposed through the window 15. Therefore, the base station 10 shown in FIG. 1 has higher antenna cooling efficiency than the base station 30 shown in FIG. 4. Thus, the base station 10 shown in FIG. 1 is advantageous in providing a smaller and lighter base station compared to the base station 30 shown in FIG. 4.

[0032] In the base station 30 shown in FIG. 4, it is conceivable to dissipate the heat generated by the antenna 12 from the radome 34. In this case, the material of the radome 34 may be changed to a material with good thermal conductivity, that is, a conductor. However, the conductor interferes with the radio wave radiation of the antenna 12. On the other hand, the base station 10 shown in FIG. 1 does not have a radome. Therefore, the radio wave radiation of the antenna 12 is not impaired. The base station 20 shown in FIG. 2 has an insulating radome 21. Therefore, the radome 21 does not interfere with the radio wave radiation of the antenna 12.

[0033] In the base station 30 shown in FIG. 4, the natural air cooling device 32 or other waste heat removal devices are essential for removing the heat generated by the antenna 12. In contrast, in the base station 10 shown in FIG. 1, the outside air removes the heat generated by the antenna 12 through the window 15. Therefore, it is not essential to provide a special waste heat removal device for the base station 10. It can be said that the base station 10 has a simpler structure than the base station 30 shown in FIG. 4. On the other hand, by further attaching a natural air cooling device or other waste heat removal devices to the base station 10, the heat generated by the antenna 12 may be removed more efficiently.

[0034] In the base station 30 shown in FIG. 4, the natural air cooling device 32 removes heat generated inside the base station 30 other than the heat generated by the antenna 12. Similarly, by further attaching a natural air cooling device or other exhaust heat device to the base station 10 shown in FIG. 1, heat generated inside the base station 10 other than the heat generated by the antenna 12 is removed. However, the exhaust heat device required for the base station 10 shown in FIG. 1 may be smaller and have a lower exhaust heat capacity than the natural air cooling device 32 of the base station 30 shown in FIG. 4. This is because in the base station 10 shown in FIG. 1, the window 15 bears the burden of removing the heat generated by the antenna 12.

[0035] In the base station 10 shown in FIG. 1, the front surface of the antenna substrate 13 is exposed on the window 15 side. Therefore, more space can be secured inside the case 11. The components and wiring arranged inside the case 11 can be arranged more freely.

[0036] Some or all of the above embodiments can also be described as follows in the appended claims, but are not limited thereto. [Appended Claim 1] A base station comprising an antenna substrate that radiates radio waves, a case, and a gasket, The antenna substrate has an antenna formed on its front surface, The case has a window, The antenna is exposed outside the case through the window, The gasket surrounds the window, The front surface of the antenna substrate and the inner surface of the case sandwich and crush the gasket, The antenna substrate further includes a stiffener on its back surface, The stiffener extends along the gasket, Base station. [Appended Claim 2] The antenna substrate has a coating formed on its front surface, The coating waterproofs the front surface of the antenna substrate including the surface of the antenna, The base station according to Appended Claim 1. [Appendix 3] Further comprising a dome of an insulator covering the window, The dome has a duct at its skirt, The top of the dome faces the front of the antenna substrate, The base station according to Appendix 1 or 2. [Appendix 4] The stiffener is integrally formed with the antenna substrate or is separate from the antenna substrate, The base station according to any one of Appendices 1 to 3. [Appendix 5] The case includes a box-shaped housing and a cover that serves as the lid of the housing, The cover has the window, The base station according to any one of Appendices 1 to 4. [Appendix 6] Use of the base station according to any one of Appendices 1 to 5, By radiating radio waves to the antenna while allowing the surface of the antenna to be exposed to the outside air, heat generated during the radiation of radio waves is released from the surface of the antenna to the outside air, Use of the base station. [Appendix 7] An antenna device including an antenna substrate, a case, and a gasket, The antenna substrate has an antenna formed on its front surface, The case has a window, The antenna is exposed outside the case through the window, The gasket surrounds the window, The front surface of the antenna substrate and the inner surface of the case sandwich and crush the gasket, The antenna substrate further includes a stiffener on its back surface, The stiffener extends along the gasket, Antenna device.

[0037] The present invention has been described above with reference to the embodiments, but the present invention is not limited thereto. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

Explanation of Signs

[0038] 10 Base station, 11 Case, 12 Antenna, 13 Antenna substrate, 14 Cover, 15 Window, 16 Gasket, 17 Housing, 18 Stiffener, 19 Coating, 20 Base station, 21 Radome, 22 Duct, 23 Top, 30 Base station, 31 Case, 32 Natural air cooling device, 33 Antenna substrate, 34 Radome, 37 Housing

Claims

1. A base station comprising an antenna substrate that radiates radio waves, a case, and a gasket, wherein the antenna substrate has an antenna formed on its front surface, the case has a window and a radome of an insulator that covers the window, the radome has a duct at its skirt portion, the top of the radome faces the front surface of the antenna substrate, the antenna is exposed outside the case through the window, the gasket surrounds the window, the front surface of the antenna substrate and the inner surface of the case sandwich and crush the gasket, the antenna substrate further includes a stiffener on its back surface, the stiffener extends along the gasket, A base station.

2. The antenna substrate has a coating formed on its front surface, the coating waterproofs the front surface of the antenna substrate including the surface of the antenna, The base station according to Claim 1.

3. The stiffener is integrally formed with the antenna substrate or is separate from the antenna substrate, The base station according to Claim 1 or 2.

4. The case includes a box-shaped housing and a cover that serves as a lid for the housing, the cover has the window, The base station according to any one of Claims 1 to 3.

5. A method of radiating radio waves performed using the base station according to any one of Claims 1 to 4, wherein heat generated during radio wave radiation is released from the surface of the antenna to the outside air by radiating radio waves to the antenna while allowing the surface of the antenna to be in contact with the outside air, A method of radiating radio waves.

Images