Antenna-equipped collective entrance unit

Abstract

To provide a collective entrance unit with an antenna that allows a radio base station antenna to be installed inconspicuously in an entrance.SOLUTION: A slot 13a is arranged that constitutes an antenna 13 of a radio base station 12 that performs communication using microwaves or millimeter waves with a mobile terminal T and connects the mobile terminal T to an external communication network T, in part of a metal panel that constitutes a front panel 11 of a collective entrance unit 2 that is installed at an entrance E of a residential complex and has a function for selecting and calling a resident. A closing member 13b is arranged on the back of the front panel 11 having the slot 13a. The antenna 13 has a waveguide structure.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a collective entrance unit that is part of an intercom system for an apartment complex and allows visitors to call residents, and more particularly to a collective entrance unit equipped with a wireless base station antenna that communicates with mobile terminals. [Background technology]

[0002] For example, mobile terminals equipped with 5G functionality that communicate using millimeter waves or microwaves are susceptible to communication interruption with external public communication networks due to significant radio wave attenuation in closed spaces. Therefore, in order to continue communication with external public communication networks, a separate wireless base station is required in the closed space (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-207184 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the common areas of apartment buildings and buildings are closed spaces from the perspective of public communication networks, the installation of wireless base stations is necessary to enable mobile devices to continue communicating with the public communication network even in such spaces. Therefore, a wireless base station must also be installed at the entrance to the building, which serves as the entrance to the building, to enable mobile devices that communicate using millimeter waves or microwaves to continue to be usable. In particular, if a person returning home operates a mobile terminal that uses millimeter waves or microwaves to unlock the entrance door or operate the elevator, a wireless base station is essential at the entrance.

[0005] However, because millimeter-wave and microwave communication antennas are large and unsightly, there is a desire to avoid installing such antennas in conspicuous locations such as apartment building entrances. On the other hand, antennas that transmit and receive radio waves at these frequencies are easily affected by surrounding metal, making it difficult to install them in a metal enclosure and conceal their presence.

[0006] SUMMARY OF THE INVENTION In view of the above problems, the present invention aims to provide an antenna-equipped entrance unit that allows the antenna of a wireless base station to be installed inconspicuously within the entrance. [Means for solving the problem]

[0007] In order to solve the above problem, the invention of claim 1 is characterized in that a metal panel constituting the front panel of a collective entrance unit that is installed at the entrance of an apartment building and has the function of selecting and calling an apartment is provided with a slot formed in part of the metal panel that constitutes the antenna of a wireless base station that connects a mobile terminal that communicates using microwaves or millimeter waves to an external public communication network. With this configuration, the wireless base station antenna is mounted on the front panel of the entrance unit, so the mobile terminal can maintain a connection to the external public communication network without the need to install a separate wireless base station antenna at the entrance. Furthermore, because the front panel only has slots, it can be designed without protrusions, which is aesthetically pleasing. Additionally, using a common panel for the entrance unit and antenna reduces the number of components and makes installation easier.

[0008] The invention of claim 2 is characterized in that, in the configuration described in claim 1, the slots are formed with a length 0.5 times the wavelength of the radio waves to be transmitted and received and a width 0.05 times the wavelength, and the slots are arranged in a straight line with each slot having a predetermined angle, while a box-shaped blocking member is arranged on the back of the front panel in which the slots are formed, surrounding the slots to form a closed space, and the front panel and the blocking member form a waveguide that constitutes the antenna. According to this configuration, although only a slot is formed on the front side of the front panel, the slot is formed on one side of the waveguide, so that an antenna with good characteristics can be formed.

[0009] The invention of claim 3 is characterized in that, in the configuration described in claim 2, the slots arranged in a straight line are arranged in multiple sets of two slots, the slots are inclined at 45 degrees to the arrangement direction, and the two slots in a set are arranged perpendicular to each other in a T-shape, with adjacent sets of slots being spaced apart by a distance of one wavelength of the radio waves being transmitted and received. With this configuration, the two slots in a pair are arranged perpendicular to each other in a T-shape, and the pairs are arranged one wavelength apart, so that the radio waves sent out from the slots can be circularly polarized, reducing fading between the radio base station and the mobile terminal.

[0010] The invention of claim 4 is characterized in that, in the configuration described in claim 3, the surfaces that block both ends of the blocking member in the direction in which the slots are arranged constitute short-circuit plates for the waveguide, while the blocking member has a feed point on the surface facing the front panel, and the feed point is located at a position 0.25 times the guide wavelength of the radio waves transmitted and received from one of the short-circuit plates and on the center line connecting the two short-circuit plates, and a needle-like conductor with a length 0.25 times the guide wavelength protrudes into the inside of the blocking member. According to this configuration, by locating the feed point at a position 0.25 times the guide wavelength from the short-circuit plate, the waveguide can be used as an antenna with excellent characteristics, enabling good communication with a mobile terminal.

[0011] The invention of claim 5 is characterized in that, in the configuration described in claim 4, the blocking member has a total of three screw holes for screwing in bolts as impedance adjustment means, at a position 0.9375 times the guide wavelength from the feed point and at each position on the center line at a distance of 0.25 times the guide wavelength from the feed point, on the same surface as the placement surface of the feed point, and the three bolts are screwed in from the outside. According to this configuration, the input impedance can be adjusted by changing the height of the bolt that protrudes into the waveguide, making it possible to set the optimum input impedance.

[0012] The invention of claim 6 is characterized in that, in the configuration described in claim 5, the other short-circuit plate is positioned at a position one time the guide wavelength from the center of the set of slots farthest from the feed point. According to this configuration, by positioning the short-circuiting plate at a position that is the guide wavelength from the center of the final set of slots, it is possible to excite traveling waves in multiple sets of slots without using a terminating resistor element.

[0013] The invention of claim 7 is characterized in that in the configuration of any one of claims 1 to 6, a wireless base station is arranged on the back of the front panel adjacent to the slot. According to this configuration, the entrance unit and the wireless base station installed at the entrance are housed within the front panel, so communication-related equipment can be consolidated and maintenance and management are easy. [Effects of the Invention]

[0014] According to the present invention, since the wireless base station antenna is formed on the front panel of the collective entrance unit, it is possible to maintain a connection between the mobile terminal and the external public communication network without installing a separate wireless base station antenna at the entrance. Furthermore, since only a slot is formed on the front panel, it can be designed without protrusions, which is aesthetically pleasing. Additionally, using a common panel for the collective entrance unit and antenna reduces the number of components and makes installation easier. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing an example of an intercom system for an apartment building equipped with an antenna-equipped collective entrance unit according to the present invention; [Figure 2] FIG. 1 is an explanatory diagram of an antenna-equipped collective entrance unit, where (a) is a front view and (b) is a right side view. [Figure 3]1A and 1B are schematic explanatory diagrams of an antenna, in which FIG. 1A is a front view of the antenna formation portion of the front panel, and FIG. 1B is a right side view of the antenna formation portion of the front panel. [Figure 4] FIG. [Figure 5] 10A and 10B are explanatory diagrams of an impedance adjusting means and a power supply point, in which FIG. 10A is an explanatory bottom side view of a part of a closing member, and FIG. 10B is an explanatory front view of a part of the closing member seen through a front panel. DETAILED DESCRIPTION OF THE INVENTION

[0016] Embodiments of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a schematic diagram showing an example of an apartment building intercom system equipped with an antenna-equipped collective entrance unit according to the present invention. The apartment building intercom system 1 includes a collective entrance unit 2 installed at the entrance (common entrance) E and equipped with the functions of selecting a dwelling unit and calling and communicating with the resident, a dwelling unit master unit 3 installed in each dwelling unit and equipped with the function of responding to calls, a control device 4 for controlling communication between devices, a door slave unit 5 installed at the entrance of each dwelling unit and equipped with the function of calling and communicating with the resident, and a management room master unit 6 installed in the management room and equipped with the function of selecting a dwelling unit and communicating with the resident. A front panel 11 equipped with an antenna 13 is arranged around the collective entrance unit 2, forming an antenna-equipped collective entrance unit. In addition, an entrance door 7 equipped with an electric lock 7a is installed at the entrance E.

[0017] The dwelling unit master unit 3 is connected to the control device 4 via a trunk line L1, and the collective entrance unit 2 and the management room master unit 6 are connected to the control device 4 via transmission lines L2 and L3, respectively. The electric lock 7a is connected to the collective entrance unit 2 via an electric lock control panel 8. The control device 4 is also connected to an external communication network N such as the Internet. Note that T represents a mobile terminal that communicates with the wireless base station 12.

[0018] Figure 2 is an explanatory diagram of the antenna-equipped collective entrance unit 2, with (a) being a front view and (b) being a right side view. As shown in Figure 2, the collective entrance unit 2 is located at the top of the front panel 11, and the antenna 13 is located at the bottom. The front panel 11 is made of an aluminum panel. The collective entrance device 2 is equipped with an operation unit 21 for selecting an apartment to call a resident, a call button 22 for performing the call operation, a display unit 23 for displaying the operation content, and a call unit (not shown) for communicating between visitors and residents.

[0019] Antenna 13 is composed of slot 13a formed in the shape of a slit in front panel 11 and a blocking member 13b disposed on the back of front panel 11. Antenna 13 has a waveguide structure by blocking the space behind slot 13a with blocking member 13b.

[0020] Specifically, a plurality of slots 13a are formed in the left-right direction on front panel 11 and are arranged in a straight line. Antenna 13 is formed by closely adhering box-shaped aluminum blocking member 13b with one open side to the back of front panel 11 where slots 13a are formed. Blocking member 13b has a rectangular prism shape that is elongated in the horizontal direction and is arranged so as to surround all of slots 13a. Wireless base station 12 is arranged on the back of front panel 11 adjacent to slots 13a, i.e., in the area adjacent to blocking member 13b. Here, the wireless base station 12 is formed as a privately operated wireless base station managed by the apartment complex, and the antenna 13 is attached as a privately operated wireless antenna.

[0021] In this way, the collective entrance unit 2 and the wireless base station 12 installed at the entrance E are housed within the front panel 11, so that communication-related equipment can be consolidated and maintenance and management are easy. Furthermore, because the antenna 13 of the wireless base station 12 is formed on the front panel 11 of the collective entrance device 2, it is possible to maintain a connection between the mobile terminal T and the external communication network N without having to install a separate wireless base station antenna at the entrance E. And because only slot 13a is formed on the front panel 11, it can be shaped without protrusions, which is aesthetically pleasing. In addition, using a common panel for the collective entrance device 2 and the antenna 13 reduces the number of components and makes installation easier. Furthermore, even if the only exposed portion of the antenna 13 is the slot 13a, the antenna has a waveguide structure with the blocking member 13b at the rear of the slot 13a, so that the antenna 13 can have good characteristics.

[0022] 3 is an explanatory diagram of the antenna 13, where (a) is a front view of the portion of the front panel 11 where the antenna 13 is formed, and (b) is a right side view. As shown in Fig. 3, the slots 13a are formed at an angle of 45 degrees with respect to the direction in which they are arranged, and five sets of slots 13a, each set consisting of two slots 13a, are arranged in a straight line. The slots 13a in each pair are arranged so as to intersect at right angles with each other, forming a T shape.

[0023] 4 shows the shape (dimensions) of the slots 13a. If the wavelength of the signal transmitted and received by the radio base station 12 is λ, then each slot 13a has a width Q1 that is 0.05 times the wavelength λ (0.05λ) and a length Q2 that is 0.5 times the wavelength λ (0.5λ). Furthermore, if the guide wavelength of the transmitted and received signal is λg, then the distance P2 between the slots 13a constituting a pair is one-fourth the guide wavelength λg (0.25λg). Furthermore, the distance P3 between adjacent pairs of slots 13a is one time the guide wavelength λg.

[0024] The frequency of the radio waves transmitted and received by the antenna 13 is in the 4 GHz to 6 GHz band, or the 28 GHz band. Also, each dimension based on the wavelength λ or the guide wavelength λg allows for an error, for example, an error of about 10%. Here, the relationship between the wavelength λ of the radio wave to be transmitted and received and the wavelength within the waveguide is expressed by the following equation 1. In equation 1, a is the width W of the waveguide.

[0025]

number

[0026] To give an example based on the above formula (1), when transmitting and receiving 6 GHz radio waves, the wavelength λ = 50 mm, and when the width W of the waveguide is 48 mm, the in-guide wavelength λg is 58.6 mm. Also, the blocking member 13b is formed with a width W of 8 to 48 mm, a depth D that is half the width W, and a length that covers the entire row of slots 13a, which will be described later. For example, if the width W of the blocking member 13b is 48 mm, the depth D is 24 mm.

[0027] 5 is an explanatory diagram of the impedance adjusting means and the feeding point S, where (a) is an explanatory bottom side view of a portion of the blocking member 13b, and (b) is an explanatory front view of a portion of the blocking member 13b seen through the front panel 11. As shown in FIG. 5, the blocking member 13b is provided with three bolts 15 as impedance adjusting means and the feeding point S. As a result, the side surfaces at both ends of the blocking member 13b are configured to function as short-circuit plates 14 for the waveguide.

[0028] The feed point S is formed by the connected coaxial cable 16, and is formed by protruding the core wire 16a of the coaxial cable 16 connected to the coaxial connector 17 as a needle-shaped conductor. The coaxial connector 17 is disposed on the center line M at a distance of 0.25 times the guide wavelength λg from one short-circuiting plate 14, and the amount of protrusion of the core wire 16a of the coaxial cable 16 into the blocking member 13b is 0.25 times the wavelength λ of the radio waves to be transmitted and received. Three bolts 15 are attached at equal intervals along the longitudinal center line M connecting both short-circuit plates 14 of the blocking member 13b. The bolts are spaced apart at an interval of 0.25 times the guide wavelength λg. The central bolt 15 (15a) is positioned at a fixed distance B from the feed point S, and this distance B is 0.9375 times the guide wavelength λg. The input impedance can be changed by changing the amount of protrusion of each of the bolts 15 thus arranged into the blocking member 13b.

[0029] Of the left and right short-circuiting plates 14, the short-circuiting plate 14 farthest from the feed point S is provided at a position where the distance P1 (shown in Figure 3) from the center of the set of slots 13a farthest from the feed point S to the short-circuiting plate 14 is 1 time the guide wavelength λg.

[0030] In this way, two slots 13a forming a pair are arranged perpendicular to each other in a T-shape, and the pairs are arranged one wavelength apart, so that the radio waves transmitted from the slots 13a can be made circularly polarized, thereby reducing fading between the radio base station 12 and the mobile terminal T. Furthermore, since the feed point S is located at a distance of 0.25 times the guide wavelength from one of the short-circuiting plates 14, the antenna 13 can have excellent characteristics, and good communication with the mobile terminal T can be achieved. Furthermore, by changing the height of the bolt 15, it is possible to set the optimum input impedance. In addition, by positioning the other short-circuiting plate 14 at a position that is the guide wavelength from the center of the final set of slots 13a, it is possible to excite traveling waves in multiple sets of slots 13a without using a terminating resistor element.

[0031] Here, we will explain an example of the operation of the apartment building intercom system 1 equipped with the antenna-equipped collective entrance unit 2 configured as described above. Note that we will omit explanations of the basic operations of the call operation from the collective entrance unit 2 and the response operation from the dwelling unit base unit 3 that receives the call, and instead explain the operation performed when the mobile terminal T of a resident who has returned home from inside the entrance E communicates with the wireless base station 12 installed integrally with the collective entrance unit 2. However, a server (not shown) is placed on the cloud that stores information relating to the mobile terminal ID and the apartment number of the apartment building, control information for the entrance door 7, and control information for the elevator (not shown) of the apartment building, and communication is possible between this server and the control device 4.

[0032] With this configuration, when a person returning home enters entrance E, communication begins between the mobile terminal T carried by the person and wireless base station 12, and ID information of the mobile terminal T is sent from wireless base station 12 to the server. The server, having obtained the information of the mobile terminal T, automatically unlocks the electric lock 7a of the entrance door 7 by sending a control signal to the control device 4. It also controls to automatically call an elevator to the entrance floor. In this way, control can be implemented to enable the person returning home to proceed smoothly thereafter.

[0033] In the above embodiment, the antenna 13 and the wireless base station 12 are placed below the collective entrance unit 2, but the wireless base station 12 may be placed elsewhere. Also, the antenna 13 may be placed above the collective entrance unit 2. [Explanation of symbols]

[0034] 1··Apartment building intercom system, 2··Apartment entrance unit, 3··Apartment base unit, 11··Front panel, 12··Radio base station, 13··Antenna, 13a··Slot, 13b··Blocking member, 14··Short-circuiting plate, 15··Volt (impedance adjustment means), 16a··Core wire (needle-shaped conductor), M··Center wire, S··Power supply point, T··Mobile terminal.

Claims

1. This is a collective entrance unit with an antenna, which is installed at the entrance of an apartment building and has the function of selecting and calling an apartment, and which has a metal panel constituting the front panel, in part of which a slot is formed to constitute the antenna of a wireless base station that connects a mobile terminal that communicates by microwave or millimeter wave to an external public communication network.

2. The slots are formed with a length of 0.5 times the wavelength of the radio wave to be transmitted and received, and a width of 0.05 times the wavelength, and the slots are arranged in a line with a predetermined angle between them. The antenna-equipped collective entrance unit described in claim 1, characterized in that a box-shaped blocking member is placed on the back of the front panel in which the slot is formed, surrounding the slot to form a closed space, and the front panel and the blocking member form a waveguide that constitutes the antenna.

3. The slots arranged in a straight line are arranged in a plurality of sets, each set consisting of two slots; The slots are inclined at 45 degrees with respect to the arrangement direction, and two of the slots forming a pair are arranged perpendicular to each other in a T-shape, 3. The antenna-equipped entrance unit according to claim 2, wherein adjacent pairs of said slots are spaced apart by an interval of one wavelength of the radio waves to be transmitted and received.

4. The surfaces of the blocking member that block both ends in the direction in which the slots are arranged constitute short-circuit plates for the waveguide, a power supply point on a surface of the closing member facing the front panel; The antenna-equipped collective entrance unit of claim 3, characterized in that the power supply point is located at a position 0.25 times the guide wavelength of the radio waves transmitted and received from one of the short-circuiting plates and on the center line connecting the two short-circuiting plates, and a needle-shaped conductor having a length 0.25 times the guide wavelength protrudes inside the blocking member.

5. The antenna-equipped entrance unit according to claim 4, characterized in that it has a total of three screw holes for screwing in bolts as impedance adjustment means, at a position 0.9375 times the duct wavelength from the feed point and at respective positions on the center line at a distance of 0.25 times the duct wavelength from the feed point, on the same surface as the placement surface of the blocking member, and the three bolts are screwed in from the outside.

6. 6. The antenna-equipped entrance unit according to claim 5, wherein the other short-circuiting plate is arranged at a position one time the wavelength within the guide from the center of the set of slots farthest from the feed point.

7. 7. The antenna-equipped entrance unit according to claim 1, wherein the wireless base station is disposed on the rear of the front panel adjacent to the slot.

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