JP2020150470A - Apparatus having both of base station function and illumination function, base station, illumination device, and road lamp - Google Patents

Abstract

To provide an apparatus having both of a base station function and an illumination function, the base station function including a function for controlling a directional radio wave, the apparatus enabling space saving and easy securing of an installation space.SOLUTION: An apparatus 10 having both of a base station function and an illumination function comprises a board 3A having a plurality of light emitting elements 1 and a plurality of antenna elements 2 arranged on at least one surface of the board, the plurality of antenna elements 2 forming an array type antenna capable of controlling directivity of a radio wave. A light emitting surface and an antenna surface are formed on the same board surface, which implements space saving of the apparatus. Also, a radio wave having directivity is radiated from the antenna surface and a direction of the directivity is variable. In the case where a large number of small-sized base stations having a function for controlling a directive radio wave required for high speed communication/large-capacity communication between the small-sized base stations and a mobile terminal are required, a method of replacing an existing illumination facility with the apparatus 10 can be adopted.SELECTED DRAWING: Figure 1

Description

The present invention relates to a road light having both a base station function and a lighting function. It also relates to various devices that exhibit base station functions and lighting functions. Furthermore, it relates to a base station and a lighting device having both functions.

Currently, the technological development and standardization of the 5th generation mobile communication (5G) is being rapidly promoted worldwide. Conventional 3G and 4G have almost the same frequency band used only by the difference in communication speed, so technologies such as semiconductors and wireless are almost common. On the other hand, as a frequency band for 5G, in addition to the conventional band of 3.6 GHz or less, a band of less than 6 GHz such as 3.7 GHz or 4.5 GHz, or a high frequency band that can be put into practical use is a candidate. A plurality of high frequency bands such as 28 GHz, 39 GHz, 73 GHz and the like have been proposed within the range of 20 to 90 GHz.

As described above, in 5G, the frequency band used is increased by an order of magnitude, which requires a large technological leap. Further, in 5G, since high-speed communication and large-capacity communication at the same level as optical fibers are realized for each mobile terminal, a large technological leap is required for this as well.

In order to realize 5G, it is necessary to arrange a large number of small base stations called small cells (communicable areas with a radius of about 200 meters) and to provide each base station at a position of about 10 meters in height.

In response to the problem of where to install a large number of small base stations, there is a plan to install them on existing utility poles, but in urban areas, electric wires are disappearing from the ground due to undergrounding of electric wires, so small base stations are installed. Not suitable for medium- to long-term use. On the other hand, the idea of installing a small base station on a road light is suitable for medium- to long-term use and is likely to be adopted. Patent Document 1 provides an example in which an antenna for communication is provided on a street light.

Further, in mobile communication, especially land mobile communication, it is important to take measures against obstacles such as buildings existing in the radio wave propagation path. Radio waves from the transmitting side travel through multiple propagation paths due to reflection, diffraction, and scattering at obstacles, and reach the receiving side as multiple waves. On the receiving side, multipath fading occurs due to the interference between the multiple waves. Multipath fading means "fluctuation of received radio waves due to multiple propagation paths".

As a countermeasure, beamforming (directional radio wave formation) technology using an adaptive array antenna (also simply called an array type antenna) is effective. With this technology, radio waves can be concentrated only in a specific direction, and the direction in which radio waves are transmitted can be changed or narrowed down. As a result, a single propagation path is formed with the mobile terminal, and fluctuations in the received radio wave due to the multiple propagation path can be avoided. An example thereof is described in Patent Document 2.

Specifically, the amplitude and phase of the radio waves emitted from each element of the multi-element antenna constituting the array type antenna are adaptively controlled (applied control), and the radio waves emitted from each element of the multi-element antenna strengthen or weaken each other. By matching, a radio wave having a directional pattern such as being strong in a specific direction and weak in another direction is formed, and the radio wave transmission direction can be electrically changed. That is, the antenna gain in a particular direction increases or decreases.

Further, the array type antenna of Patent Document 2 is configured to multiplex directional radio waves in the directions of a plurality of mobile terminals in a time-division manner. By forming directional radio waves for each mobile terminal, it is possible to communicate with a plurality of mobile terminals at the same time while avoiding fluctuations in received radio waves due to multiple propagation paths.

JP-A-2017-139230 Japanese Unexamined Patent Publication No. 2015-12568

In Patent Document 1, an antenna (reference numeral ANT) and a lighting fixture are independently installed on the top of a pillar (reference numeral P) of a street lamp. Further, the antenna is nothing more than a conventional antenna having a function of receiving radio waves from the base station BC of the information transmission source and a function of transferring the received signal to another road light. Since the antenna and the lighting fixture are installed independently, the required installation space becomes large, and there is a problem of space saving.

Further, Patent Document 2 discloses an array type antenna having a directional radio wave control function, but when a large number of small base stations composed of such antennas are installed in the future, there is a problem of securing an installation place thereof. There is.

An object of the present invention is to relate a device having both a base station function and a lighting function, the base station function includes a control function of a directional radio wave, so that space can be saved and an installation location can be easily secured. Providing equipment.

The inventors of the present invention have focused on the fact that by arranging a plurality of light emitting elements and a plurality of antenna elements on the same surface of the substrate, a compact substrate capable of achieving both a directional radio wave control function and a lighting function can be constructed. Has been completed.

That is, the device having both the base station function and the lighting function according to the present invention is
A substrate having a plurality of antenna elements and a plurality of light emitting elements arranged on at least one surface is provided.
The plurality of antenna elements are characterized in that they form an array-type antenna capable of controlling the directivity of radio waves.

In a device having this configuration, the surface on which a plurality of light emitting elements are arranged (referred to as a light emitting surface) and the surface on which a plurality of antenna elements are arranged (referred to as an antenna surface) are on the same substrate surface. Since it is formed, it is possible to easily manufacture a device having both a base station function and a lighting function, and it is possible to realize space saving of the device in that it can be formed on the same substrate.

Further, from the antenna surface of the array type antenna formed on the same surface as the light emitting surface for lighting, a sharp beam-shaped radio wave is formed by the control function of the directional radio wave, and the direction of the beam-shaped radio wave is changed. Can be made to.

Therefore, if you want to install a large number of small base stations with directional radio wave control functions in order to realize high-speed communication and large-capacity communication between small base stations and mobile terminals, you can save space. A device having both a base station function and a lighting function of the present invention that can be realized is most suitable in terms of securing an installation place thereof. For example, it becomes easy to adopt a method of replacing existing lighting equipment with a device having both a base station function and a lighting function of the present invention.

Further, in a device having both a base station function and a lighting function of the present invention, a reflector or a lens is arranged for each of the light emitting elements or for each of a plurality of the light emitting elements, and the reflector or the lens is the above-mentioned. It is preferable that the light emitting element is formed so as to change the irradiation direction.

In the above configuration, since the light emitting element and the antenna element are arranged on the same substrate surface, the irradiation direction of the light emitting element is the same as the normal direction of the antenna surface. However, in the configuration of the present invention, since the reflector is further provided for each light emitting element or for each of a plurality of light emitting elements, the irradiation direction of the light emitting element is different from the normal direction of the antenna surface. Can be set in the direction. A lens may be used instead of the reflector. As a result, even if the light emitting element and the antenna element are arranged on the same substrate surface, the irradiation direction of the light emitting element is not fixed, and irradiation in a direction according to the purpose of irradiation becomes possible, expanding the use of lighting. ..

Further, in the device having both the base station function and the lighting function of the present invention,
An optical reflection / condensing element is arranged for each of the light emitting elements or for each of the plurality of light emitting elements.
The reflection condensing element is
The incident surface of the irradiation light from the light emitting element and
An internal reflection surface that totally reflects the incident irradiation light,
It has an exit surface that emits the irradiation light after total reflection toward the irradiation target.
It is preferable that a Fresnel lens structure is formed on the exit surface.

With the device having the above configuration, not only the same effect as when the above-mentioned reflector or lens is arranged can be obtained, but also the direction of the irradiation light from the light emitting element can be efficiently directed by the total reflection on the internal reflection surface. A compact optical element can be formed by the exit surface which can be changed and has a Fresnel lens structure, and the irradiation light can be irradiated without waste.

Further, the device having both the base station function and the lighting function of the present invention is further described.
A DC power supply circuit that converts and generates AC power from the outside into DC power for lighting to the plurality of light emitting elements,
A base station circuit that generates and supplies drive voltages to the plurality of antenna elements is provided.
It is preferable that the DC power supply circuit and the base station circuit are connected so that a part of the DC power for illumination generated by the DC power supply circuit is supplied to the base station circuit.

Usually, a DC power supply circuit for lighting is configured to convert power from an external AC power supply, for example, to generate low-noise DC power that does not cause flicker in the light emitting element. Therefore, in the case of the device having the above configuration, the base station circuit as a control means for the base station function receives a high-quality DC power supply with low noise from the DC power supply circuit for lighting, so that a good communication state can be obtained. It will be easier.

Further, in the device having both the base station function and the lighting function of the present invention, it is preferable that the antenna surface of the array type antenna is provided vertically. The directivity control of the array antenna can change the direction of emission of sharp beam-like radio waves in various ways, but as a base station function, the direction of directivity is usually controlled to be mainly horizontal. .. Therefore, in the case of the device having the above configuration, the gain of the antenna under the directivity control can be increased by making the antenna surface of the array type antenna vertical.

Further, in the case of a device provided with a reflector, a lens, etc. for changing the irradiation direction of the light emitting element, the direction of directivity by the array type antenna is mainly horizontal, and the irradiation direction is set to the target direction of irradiation. It can be used such as pointing.

Further, in the device having both the base station function and the lighting function of the present invention, the antenna surface of the array type antenna forms an oblique downward inclined surface at an angle larger than 0 ° and 20 ° or less with respect to the vertical surface. Is preferable.

If the inclination of the antenna surface is in the range of an angle greater than 0 ° and 20 ° or less with respect to the vertical surface, the gain of the antenna under directivity control can be maintained to some extent. Further, when a reflector, a lens, etc. are provided and the irradiation direction of the light emitting element is to be directed downward or diagonally downward of the device, the antenna surface (irradiation surface) is larger than 0 ° and 20 ° or less with respect to the vertical surface. It is convenient if the angle is diagonally downward. Therefore, by tilting the antenna surface diagonally downward at an angle greater than 0 ° and 20 ° or less with respect to the vertical surface, it is possible to obtain the effect of irradiating the lower side or diagonally lower side of the device while maintaining the gain of the antenna to some extent. Be done.

Further, in the device having both the base station function and the lighting function of the present invention, it is preferable that the light emitting element and the antenna element are arranged at intervals of at least one wavelength of the radio wave used. According to the device having this configuration, since the distance between the light emitting element and the antenna element is appropriate, it is possible to prevent an influence between the two when transmitting or receiving radio waves. For example, it is possible to suppress the induced current from flowing to the light emitting element.

The base station according to the present invention is characterized by including a device having both the above-mentioned base station function and the lighting function. Further, the lighting device according to the present invention is characterized by including a device having both the above-mentioned base station function and the lighting function. Further, the road light according to the present invention is characterized by including a device having both the above-mentioned base station function and the lighting function.

Further, in the road light of the present invention, an antenna surface having a plurality of the antenna elements is formed in the upper area of the surface of the substrate, and a light emitting surface having the plurality of the light emitting elements is formed in the lower area of the surface of the substrate. It is preferable that it is.

According to the road light having this configuration, the area of the array type antenna and the area of the light emitting element are separated vertically on the substrate surface, so that the directional radio wave mainly in the horizontal direction is emitted from the upper antenna surface. Irradiation light is mainly emitted downward or diagonally downward from the lower light emitting surface. Therefore, the road light of the present invention can deliver radio waves as far as possible from the antenna surface, and it becomes easy to guide the irradiation light from the light emitting surface to the lower side of the device or diagonally downward.

Further, the road light of the present invention includes the plurality of the substrates, and the plurality of the substrates are arranged around the central axis of the structure supporting the road light in a posture in which each element arrangement surface faces outward. It is preferable that it is.

The central axis of the structure supporting the road light represents, for example, the central axis of the support column for the road light. According to the road light of this configuration, a plurality of substrates arranged around the central axis of the structure supporting the road light can perform directivity control of the array type antenna, so that the directivity of the array type antenna can be controlled by 360 degrees in the almost horizontal direction. Directive radio waves can be emitted at an azimuth angle. Further, as for the illumination light, it is possible to irradiate the road light downward and diagonally downward around the central axis of the structure supporting the road light over the entire circumference.

As described above, according to the configuration of the present invention, with respect to a device having both a base station function and a lighting function, the base station function includes a directional radio wave control function, which saves space and allows an installation location. It is possible to provide a device that can easily secure the above. Further, the same effect can be obtained for a base station, a lighting facility, or a road light having a device having such a base station function and a lighting function.

The schematic block diagram of the apparatus which has both the base station function and the lighting function which concerns on 1st Embodiment. The schematic block diagram of the road light and 5G small base station which concerns on 2nd Embodiment. The schematic block diagram of the road light and 5G small base station which concerns on 3rd Embodiment. The elevation view which shows the installation state of the road light and 5G small base station of the 2nd Embodiment. The elevation view which shows the installation state of the road light and 5G small base station of the 3rd Embodiment. The figure which shows another installation state of the road light and 5G small base station of the 2nd Embodiment. The vertical sectional view which shows the said 5G small base station provided with a reflector. The vertical sectional view which shows the said 5G small base station provided with a lens. The block diagram which shows the circuit structure of the 5G small base station. The operating principle diagram of the adaptive array antenna. The conceptual diagram which shows the high density of the network by the road light and 5G small base station of this embodiment.

Hereinafter, embodiments of a device having both a base station function and a lighting function of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of the device 10 according to the first embodiment. The device 10 includes a plurality of LED elements (light emitting elements) 1, a plurality of antenna elements 2, a substrate 3A in which these two types of elements are arranged in a plane, and a housing 4A in which the substrate 3A is housed. .. The substrate 3A also serves as a heat radiating plate for the LED element 1. The arrangement of the LED element 1 and the antenna element 2 in the figure is only an example, and the arrangement pattern and the number of each element may be set according to the application of the device 10. The distance between the LED element 1 and the antenna element 2 is at least one wavelength of the radio wave used so that the influence of each other is suppressed, for example, the induced current flowing through the LED element 1 is suppressed.

In FIG. 1, the XY plane indicated by the XY axes is a horizontal plane, and the Z axis is a vertical axis. That is, the antenna surface and the light emitting surface of the device 10 in FIG. 1 are vertical. Regarding the antenna element 2, it is preferable that at least 5 elements or more, preferably 10 elements or more, and at most about 50 elements of the antenna elements 2 are arranged so as to be arranged in the horizontal direction. These minute antenna elements are shared for transmission and reception, and transmission and reception can be switched in a short time. The distance between the antenna elements 2 may be half the wavelength (λ / 2) of the radio wave used.

The individual antenna elements 2 may be fixed on the substrate 3A in a direction in which the direction of the antenna length (usually, the length of a half wavelength) of the antenna element 2 is horizontal. The plane of polarization of the electric field component of the radio wave (electromagnetic wave) radiated from the antenna element 2 becomes horizontal as in the direction of the antenna length. When the electric field component of the radio wave (electromagnetic wave) is horizontally polarized, it is easily affected by a conductor such as a metal in the horizontal direction such as a building, and it is more easily attenuated than when the electric field component is vertically polarized. In the present embodiment, when the direction of the antenna length of the antenna element 2 is horizontal, the radio wave (electromagnetic wave) from the device 10 provided with the antenna element 2 goes to the small cell area formed by another adjacent device. It is less likely to have an impact and contributes to the stabilization of the communication network by the small cell.

Specifically, a group of 10 antenna elements 2 arranged in the horizontal direction is formed in a total of 8 stages in the vertical direction, and the antenna elements 2 are a total of 80 elements. Regarding the arrangement of the antenna elements 2, a large interval is provided for each of the two stages, and the three LED elements 1 are arranged side by side in the horizontal direction at the large interval. Regarding the LED element 1, there are three groups of three elements in the vertical direction, for a total of nine elements.

An adaptive array antenna (hereinafter, referred to as an array type antenna 2A) capable of controlling the directivity of radio waves is formed on the substrate 3A by arranging a plurality of antenna elements 2, and exhibits a base station function. Further, a light emitting surface 1A including a plurality of LED elements 1 is also formed on the substrate 3A, and the illumination function is exhibited. These elements are arranged on one side or both sides of the substrate 3A depending on the application of the device 10.

For example, the size of the antenna element for the 28 GHz band becomes very small, and the radio waves emitted from the individual minute antenna elements 2 arranged in an array are plane waves traveling in a predetermined direction from a macroscopic point of view. Become.

In the case of transmission, the phase of the high-frequency drive voltage supplied to each antenna element 2 is gradually changed along the arrangement direction (a phase difference is given according to the target direction), so that the array type antenna 2A is used. Plane waves can be radiated in any desired direction.

In the case of reception, by synthesizing the received signals of each antenna element 2 with a phase difference according to the target direction, it is possible to narrow down the reception to the radio waves radiated from an arbitrary target direction.

The device 10 is used not only for road lights and base stations, which will be described later, but also for various devices having a flat light emitting surface, such as wall-mounted / self-standing illuminated signboards, illuminated advertising towers, and illuminated bulletin boards. The device 10 of the present embodiment is suitable when it is desired to impart a function. It can be applied not only for lighting but also for various purposes such as advertising and traffic information display.

According to the device 10 of the present embodiment, the light emitting surface 1A by the plurality of LED elements 1 and the array type antenna 2A by the plurality of antenna elements 2 may be formed on the surface of the same substrate 3A, so that the base station function and illumination The device 10 having both functions can be easily manufactured. Further, the space of the device 10 can be saved in that it can be formed on the same substrate 3A. Further, by using the directivity control function of the array type antenna 2A, a sharp beam-shaped radio wave can be formed from the antenna surface, and the direction of the beam-shaped radio wave can be changed.

Therefore, in order to realize high-speed communication and large-capacity communication between the small base station and the mobile terminal, it is desired to install a large number of small base stations for directional radio waves in the frequency band used within the range of 20 to 90 GHz. In this case, the existing lighting equipment (road lights, etc.), road information display, advertising tower, etc. can be replaced with the device 10 of the present embodiment, which has the effect of facilitating the securing of the installation location of the small base station. is there. Further, if the antenna surface of the device 10 is used vertically, the gain of the antenna under the directivity control is increased, and the performance as a base station can be easily maintained. Further, the design of the road light or the like can be enhanced when these functions are integrally formed as compared with the case where the base station and the lighting device are independent.

FIG. 2 is a schematic configuration diagram of a road light and 5G small base station according to the second embodiment. Similar to the above-described embodiment, in the road light and 5G small base station (hereinafter, simply referred to as a small base station) 20, the substrate 3B is provided in the housing 4B, and the LED element 1 and the antenna are provided on the surface of the substrate 3B. An arrangement pattern of the elements 2 is formed. Hereinafter, only the differences will be described.

In the small base station 20 of the present embodiment, an array type antenna 2B having an antenna element 2 having a total of 110 elements in 11 rows × 10 columns is formed in the upper area of the substrate 3B, and 3 rows are formed in the lower area of the substrate 3B. A light emitting surface 1B including a total of 9 LED elements 1 in 3 rows is formed. For example, since the array type antenna 2B for the high frequency band of the 28 GHz band described above has a half wavelength of about 5 mm, when 10 elements are arranged vertically and horizontally at a pitch of half wavelength (λ / 2), the antenna element 2 Even if the area of the LED element 1 which is far smaller than the number is included, the size of the small base station 20 is within the size of about 10 cm in length and width and about several cm in depth. Therefore, the size is sufficiently large so that it can be placed on a pole or the like as a road light at a height of about 10 m.

The small base station of the present embodiment includes a large number of antenna elements 2 of about several tens to several hundreds, whereas the number of LED elements 1 is about several to several tens, and the antennas. Obviously less than the number of elements.

Further, a reflecting mirror 5 is provided in front of the LED element 1 for each LED element 1, and the irradiation direction is changed by the reflecting mirror 5. The reflector 5 is supported by the housing 4B at a certain distance from the LED element 1. A reflecting mirror 5 may be provided for each group of several LED elements 1, or a lens having the same function may be provided instead of the reflecting mirror 5. With such a reflecting mirror 5, the irradiation direction of the LED element 1 can be changed to a direction different from the normal direction of the antenna surface. For example, it becomes possible to use the array type antenna 2B so that the direction of directivity is mainly horizontal and the direction of irradiation is directed to the target direction of irradiation, and the use of the small base station 20 is expanded.

FIG. 3 is a schematic configuration diagram of a road light and 5G small base station according to the third embodiment. The small base station 30 has almost the same configuration as the small base station of the second embodiment, but is characterized in that a roadside light 6 is provided on the bottom surface of the housing 4C. Since the small base station 30 is installed as a road light at a height of about 10 m from the ground, the irradiation target is the road and the side of the road. The roadside lamp 6 is a dedicated lamp for irradiating a range (such as a roadside) where the irradiation light from the light emitting surface 1B formed on the substrate 3B does not reach.

Next, a state in which the above-mentioned small base stations 20 and 30 are installed on a pole as road lights will be described with reference to FIGS. 4 to 6. According to the elevation view of FIG. 4, the small base station 20 is fixed to the top of a pole 40 erected on the side of the road in a posture in which the antenna surface and the light emitting surface are vertical. In FIG. 4, the antenna surface and the light emitting surface are orthogonal to the paper surface. Reference numeral 60 is an image of a luminous flux emitted from a light emitting surface in the housing of the small base station 20 and irradiating the road surface by changing the direction diagonally downward by a reflecting mirror provided in front of the LED element. Reference numeral 70 is an image of a directional radio wave emitted substantially horizontally (in the horizontal direction slightly downward) from the antenna surface of the small base station 20.

According to the small base station 20 of FIG. 4, since the area of the array type antenna and the area of the light emitting element are vertically separated from each other on the substrate, the directional radio wave mainly in the horizontal direction (image 70) is transmitted from the upper antenna surface. ) Is emitted, and the irradiation light (image 60) diagonally downward is emitted from the lower light emitting surface. Therefore, the radio wave can be expected to reach farther from the small base station 20, and the irradiation light can be easily guided diagonally downward of the small base station 20.

In the elevation of FIG. 5, the small base station 30 is similarly fixed to the top of the pole 40. Since the small base station 30 is provided with the roadside light 6 on the bottom surface of the housing, the roadside light, which is the lower part of the road light, is surely illuminated as shown in the image of the luminous flux of reference numeral 80.

In the elevation view of FIG. 6, the small base station 20 is fixed to the pole 40 so that the antenna surface faces diagonally downward by about 10 ° with respect to the vertical surface. By inclining the antenna surface in this way, it is possible to apply the luminous flux to the side of the road without relying on the roadside light 6 while maintaining the gain of the antenna under directivity control to some extent. It is also convenient when you want to make the irradiation direction as downward as possible by using a reflector.

The effects when the small base stations 20 and 30 of each embodiment shown in FIGS. 4 to 6 are used as road lights will be described. For array-type antennas, in order to maximize the antenna gain (maximize the base station function), it is better to install the antenna surface vertically. This is because the gain of the antenna becomes smaller when the radio wave transmitting direction deviates from the main direction of the antenna (that is, the normal direction with respect to the antenna surface). In order to emit a sharp beam-shaped directional radio wave in any direction, it is most effective to install the antenna surface vertically.

On the other hand, in the conventional road light, since the irradiation direction is usually downward, the light emitting surface of the LED element is often horizontal. This becomes an obstacle when the array type antenna and the light emitting surface of the LED element are combined. According to the configurations of the small base stations 20 and 30 of the present embodiment, the irradiation direction of the LED element 1 can be arbitrarily set by using the reflecting mirror 5 and the lens 8, so that the antenna surface and the antenna surface, which are preferably set vertically, are horizontal. It has become possible to combine it with the light emitting surface of an LED element whose setting is preferable.

A modified example of the installation state of the base stations 20 and 30 shown in FIGS. 4 to 6 is shown. That is, a plurality of base stations 20 such as three or four may be combined and installed as a road light on the upper part of the pole 40. The plurality of base stations 20 are arranged around the central axis of the pole 40 in a posture in which each element arrangement surface faces outward. Since the plurality of base stations 20 can each execute the directivity control of the array type antenna, the directivity radio waves can be emitted at an azimuth angle of 360 degrees in the substantially horizontal direction. Further, as for the illumination light, it is possible to irradiate the entire circumference of the pole 40 including the side of the road toward the lower side and the diagonally lower side of the road light.

The configuration of the reflector 5 provided in the small base station 20 will be specifically described with reference to FIG. 7. FIG. 7 is a cross-sectional view of the small base station 20 cut along a vertical plane. The reflecting mirror 5 is arranged in front of the LED element 1 and has a reflecting surface that reflects the light flux from the LED element 1 obliquely downward. The reflecting mirror 5 is provided for each LED element 1 and is fixed to the upper edge of the opening formed in the support plate 9 (which may also be used as the housing 4B). The shape of the reflective surface is a curved surface as a whole, and it is almost horizontal in the vicinity of the mounting portion to the support plate 9, but it is shaped so as to gradually incline diagonally downward as the distance from the mounting portion increases. ..

Further, a space is provided between the substrate 3B and the support plate 9, and a parabolic mirror 7 is fixed around the LED element 1 on the substrate 3B. The parabolic mirror 7 efficiently guides the light flux from the LED element 1 to the reflector 5.

The vertical sectional view of FIG. 8 shows the configuration of the lens (reflection and condensing element) 8 provided in the small base station 20. The lens 8 is an optical element that changes the traveling direction of the light flux from the LED element 1 instead of the reflecting mirror 5. The lens 8 is arranged in front of each LED element 1 and is fixed to the support plate 9 so as to cover the opening of the support plate 9. The lens 8 directs the incident surface 8A of the irradiation light from the LED element 1, the internal reflection surface 8B that totally reflects the incident irradiation light diagonally downward, and the irradiation light after total internal reflection traveling diagonally downward toward the irradiation target. It has an exit surface 8C, and a Fresnel lens structure is formed on the exit surface 8C. That is, the side surface of the lens 8 is an incident surface 8A, an internal reflecting surface 8B is formed on the upper side of the lens, and an exit surface 8C having a Fresnel lens structure is formed on the lower side.

By using the lens 8 of FIG. 8, it is possible to efficiently change the direction of the irradiation light from the LED element 1 by total reflection on the internal reflection surface 8B, and compact optics by the emission surface 8C having a Fresnel lens structure. The element can be formed, and the irradiation light can be irradiated toward the target without waste.

FIG. 9 shows a block diagram of a circuit configuration common to the small base stations of each embodiment. As shown in FIG. 9, the small base station further includes an LED power supply circuit (DC power supply circuit) 21 and a base station circuit 22. The LED power supply circuit 21 uses an external AC power supply to improve the power factor, converts it into low-voltage DC based on a dimming signal command, and outputs DC power for lighting to each LED element 1.

Further, the LED power supply circuit 21 also supplies the low voltage DC power after the conversion as a power supply voltage to the base station circuit 22. Then, the base station circuit 22 generates and supplies a drive voltage to each antenna element 2 by using the power supplied from the LED power supply circuit 21.

The base station circuit 22 is electrically connected to each antenna element 2. The base station circuit 22 receives a command from the upper level through an optical fiber, controls a phase shifter 23 and an amplitude adjuster 24 provided for each antenna element 2, emits a plane wave in an arbitrary direction at the time of transmission, and receives the command. Time receives a plane wave from any direction. Here, the phase shifter 23 adjusts the phase of the signal of each antenna, and the amplitude adjuster 24 adjusts the amplitude.

According to the circuit configuration of such a small base station, since the base station circuit 22 receives a high-quality DC power supply with low noise from the LED power supply circuit 21, it is possible to provide a stable communication state with low noise. ..

FIG. 10 is an operating principle diagram of an adaptive array antenna (array type antenna). Depending on the distance dn from the reference point of the antenna to each antenna element 2-n (n is a natural number of 1 to N) and the incident angle θ of the received radio wave, the phase shifter 23-n and the amplitude adjuster 24-n are each. The phase and amplitude of the received signal of the antenna 2-n are adjusted. For example, the phase of the received signal is delayed by the phase corresponding to the distance cτn. When it is desired to advance the phase, a process is performed in which the entire phase is uniformly delayed and then advanced by the phase corresponding to the distance cτn. As a result, the gain of the signal from a desired direction can be increased. Note that c is the propagation speed of the received radio wave.

FIG. 11 is a conceptual diagram showing the realization of high density of the network by the road lights and 5G small base stations 20 and 30. It is shown in comparison with the conventional macro base station. Adopting a method of installing a 5G small base station on a pole of a road light that also serves as lighting has the effect of facilitating securing installation locations for a large number of small base stations. Further, since the array type antenna capable of emitting a sharp beam-shaped millimeter wave or the like in an arbitrary horizontal direction can be vertically installed, there is an effect that the gain of the antenna is increased. Further, there is no problem that the emission from the beam-shaped millimeter wave from the array type antenna and the irradiation from the road light interfere with each other.

1: LED element (light emitting element)
1A: Light emitting surface 2: Antenna element 2A: Adaptive array antenna (array type antenna)
3A: Substrate 4A: Housing 5: Reflector 6: Roadside light 7: Parabolic mirror 8: Lens (reflection condensing element)
8A: Incident surface 8B: Total internal reflection surface 8C: Fresnel lens surface 9: Support plate 10: Equipment 20, 30: Road light and 5G small base station (base station)
21: LED power supply circuit 22: 5G base station circuit 23: Phase shifter 24: Amplitude adjuster 40: Pole (post)
60: Image of luminous flux emitted from road light 70: Image of directional radio wave emitted from small base station 80: Image of luminous flux emitted from roadside light

Claims (12)

A substrate having a plurality of antenna elements and a plurality of light emitting elements arranged on at least one surface is provided.
The plurality of antenna elements are devices having both a base station function and a lighting function, characterized in that they form an array-type antenna capable of controlling the directivity of radio waves. In the device according to claim 1,
A reflector or a lens is arranged for each of the light emitting elements or for each of the plurality of the light emitting elements, and the reflecting mirror or the lens is formed so as to change the irradiation direction of the light emitting element. A device that has both a base station function and a lighting function. In the device according to claim 1,
An optical reflection / condensing element is arranged for each of the light emitting elements or for each of the plurality of light emitting elements.
The reflection condensing element is
The incident surface of the irradiation light from the light emitting element and
An internal reflection surface that totally reflects the incident irradiation light,
It has an exit surface that emits the irradiation light after total reflection toward the irradiation target.
A device having both a base station function and a lighting function, characterized in that a Fresnel lens structure is formed on the exit surface. The device according to any one of claims 1 to 3 further comprises.
A DC power supply circuit that converts and generates AC power from the outside into DC power for lighting to the plurality of light emitting elements,
A base station circuit that generates and supplies drive voltages to the plurality of antenna elements is provided.
The base station function and lighting are characterized in that the DC power supply circuit and the base station circuit are connected so that a part of the DC power for illumination generated by the DC power supply circuit is supplied to the base station circuit. A device that also has functions. The device according to any one of claims 1 to 4, wherein the device has both a base station function and a lighting function, characterized in that the antenna surface of the array type antenna is provided vertically. In the device according to any one of claims 2 to 4, the antenna surface of the array type antenna forms an inclined surface obliquely downward at an angle of 20 ° or less, which is larger than 0 ° with respect to the vertical surface. A device that has both a base station function and a lighting function. In the device according to any one of claims 1 to 6,
A device having both a base station function and a lighting function, wherein the light emitting element and the antenna element are arranged at intervals of at least one wavelength of radio waves used. A base station including the device according to any one of claims 1 to 7. A lighting device comprising the device according to any one of claims 1 to 7. A road light comprising the device according to any one of claims 2 to 7. In the road light according to claim 10,
An antenna surface having a plurality of the antenna elements is formed in the upper area of the surface of the substrate.
A road light characterized in that a light emitting surface including a plurality of the light emitting elements is formed in an area below the surface of the substrate. In the road light according to claim 10 or 11.
The road light includes a plurality of the substrates.
A road light characterized in that the plurality of substrates are arranged around a central axis of a structure supporting the road light in a posture in which each element arrangement surface faces outward.

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