JPS61171203A - Antenna device - Google Patents

Abstract

PURPOSE:To prevent service interruption of a radio line by constituting an array antenna with plural circular conductor discs in parallel with a ground conductor board and changing over a switch of a feeding system at abnormality so as to shape a specific beam. CONSTITUTION:The circular conductor discs provided within a plane in parallel with the ground conductor board 1 are used as element antennas 2-7 and constitute the array antenna. Coaxial cables with different length are used as fixed phase shifters 23-29 of the feeding system, and when arranging intervals d1, d2 of the antennas 2-7, the exciting phase amount to be given to the antennas 2-7 is decided in order to form each radiation beam irradiated from the antennas (forward/backward/left/right direction beams used normally and a four-leaf beam directed in forward/backward/left/right directions used in abnormality). Then switches 11-22 are thrown to the position A at the abnormality of a power supply to obtain the four-leaf beam directed four (forward/backward/left/right) directions depending on the operation of the antennas 2, 5, 6, the resulting beam is close nearly to the nondirectivity and the communication with each base station is attained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an antenna device used for train radio communication, etc., and particularly relates to an antenna device that can secure a wireless line even during abnormal times such as power outages. .

[Conventional technology]

FIG. 3 is a schematic configuration diagram of a conventional train roof antenna device used for train radio communication, and in the figure, 3'0, 31, 32, and 33 are Haho antennas whose element antennas are monoball antennas. It is a unit antenna with a configuration, and although some reflector elements are shared, there are four independent antennas. 34, 35. 36.3
7 is an input/output terminal of each unit antenna, and 38 is an antenna device constituted by each unit antenna 2 antennas.

In the antenna device configured in this way, the input/output terminal 3 is
4-37. Therefore, the directions of the radiation beams radiated from the unit antennas 30 to 33 are forward, backward, left, and right, respectively, as indicated by arrows in FIG. 3.

In other words, by switching the above-mentioned switch, the unit antennas 30 to 33 to be excited are switched, and the radiation beam of the energizing device 38 is switched in the forward, backward, and left/right directions. However, in the left and right directions, since it is necessary to simultaneously emit radiation beams from both the left and right sides, the input/output terminals 36 and 37 are excited at the same time by the above-mentioned switch. As a result, the radiation beam from the antenna device 38 can be viewed in three directions: □, forward, backward, and left/right.

Problems to be Solved by Invention C] However, in the above-described conventional antenna device, the unit antennas 30 to 30 are
By switching 33, the direction of the radiation beam from the antenna device is changed, so if the drive current of the switch is cut off in the event of an abnormality such as a power outage, it will not operate correctly. This causes the problem that the wireless line, which is backed up by a standby power source, becomes disconnected.

The present invention has been made in order to solve these problems, and it is an object of the present invention to provide an antenna device that can perform communication in the same manner as in normal times without causing the wireless line to be disconnected even in abnormal situations such as power outages. This is the purpose.

[Means for solving problems]

- Therefore, in the antenna device according to the present invention, a plurality of element antennas are constituted by a ground conductor plate and a circular conductor plate provided in parallel to the ground conductor plate, and a plurality of element antennas are connected to a feeding circuit that feeds power to each element antenna. A fixed phase shifter, switch, and distributor are installed, and instead of fixing each switch in a specific direction in the event of an abnormality such as a power outage, only some of the element antennas are operated so as to be omnidirectional. .

[For production]

In the antenna device configured in this way, the beam becomes a quatrefoil beam that is oriented in four mutually orthogonal directions within a plane parallel to the ground conductor plate, so it becomes nearly omnidirectional and can be used at train radio base stations. Wireless communication can be performed regardless of direction.

〔Example〕

FIG. 1 is a configuration diagram showing an embodiment of an antenna device according to the present invention, and numeral 1 denotes a ground conductor plate that also serves as a base of the antenna device. 2, 3, 4.5, 6°T are element antennas made of circular conductor plates provided in a plane parallel to the ground conductor plate 1 and arranged in 3 rows and 2 columns. This constitutes an array antenna. d1s'2 is the arrangement interval of the element antennas, and is determined from the antenna gain, beam width, and front-to-back ratio of the radiation pattern required for each normal radiation beam from the antenna device; in this example, the wavelength λ to d to λ/21 d2 two λ/
3. is set to .

FIG. 2 is a schematic configuration diagram of a feeder circuit connected to the antenna device shown in FIG. 1, where 81 to 8C are two-way dividers, 9 is a three-way divider, and 10 is an input/output terminal to the feeder circuit. . 11
22 are single-pole, double-throw switches, which are on the A side when the power is off.

In the on state, it is located on the B side. 23-2
9 is a fixed phase shifter, and coaxial cables of different lengths are used. Moreover, when the array spacing dl+d2 of the element antennas 2 to 7 in the antenna device shown in FIG.

The amount of excitation phase to be given to each element antenna 2 to T is determined in order to form a beam oriented in the rear and left and right directions, and a quatrefoil beam oriented in the front, rear, left and right directions used in abnormal situations. Then, from this required excitation phase amount,
The amount of phase change required by each of the fixed phase shifters 23 to 29 is determined.

That is, the length of the coaxial cable of each fixed phase shifter 23 to 29 is determined. In the embodiment, fixed phase shifters 23, 2
4, 25, and 27 are set to have a phase change amount of 180', fixed phase shifters 26 and 29 are set to have a phase change amount of -120', and fixed phase shifter 2B is set to have a phase change amount of +120@.

In the antenna device configured as described above, all the element antennas 2 to 7 of the antenna device are normally operated by selecting the connection switching terminals A and B of the switches 11 to 22 shown in FIG. At the same time, the direction of the radiation beam can be switched forward, backward, or left and right in FIG. That is, the switches 11, 13,
15°17.18 to A@ and the switches 12.14, 16, 19, 20, 21.22 to the B side, the radiation beam is emitted in the forward direction and the switches 11.13, 15. When 2'1 and 22 are connected to the A side, and switches 12, 14, and 16°1T~20 are connected to the B side, radiation is emitted only in the rear direction, and furthermore, switch 1
If 2, 14, 16, 17 to 22 are connected to the A side, and one switch 11° 13.15 is connected to the B side, the radiation will be switched to the left and right. In addition, in the event of an abnormality such as a power outage,
That is, when all the switches are powered off, all the switches 11 to 22 are connected to the A side, so the element antennas 2, 5, and 6 are operated to produce a four-leaf beam directed in four directions: front, back, left, and right. Obtainable. However, the radio equipment that supplies radio frequency signals to the input/output terminal 10 is driven by a separate standby power source.

Therefore, in an antenna device configured in this way, when all switches are turned off in an abnormality such as a power outage, the antenna device becomes almost omnidirectional and cannot communicate with base stations in any direction. can be done.

In the above embodiment, the switches 11 to 22 are coaxial switches that operate mechanically through voltage control. However, electronic switches that operate electrically such as diode switches may also be used. Also, 2
As the distributor 8 and the three-way distributor 9, it is also possible to use a hybrid circuit formed by an IJ tube line formed by etching on a printed circuit board. Further, instead of the hybrid circuit, an active type distributor such as a tee branch may be used.

Furthermore, although a case has been described in which so-called capacitor antennas in which circular conductor plates are used as element antennas are used as the element antennas 2 to T, an antenna that is non-directional in a horizontal plane such as a monoball antenna may also be used. Further, radomes may be provided on the upper surfaces of the element antennas 2 to T at appropriate intervals to protect the element antennas.

Further, as the fixed phase shifters 23 to 2g, strip lines of different lengths fabricated by etching on a printed circuit board can be used instead of coaxial cables of different lengths.

Furthermore, in the above explanation, the case where element antennas 2 to 1 are arranged in 3 rows and 2 columns and a 96-element array antenna is used is described, but the required antenna gain, beam width, 9 beam direction in normal times, and the beam direction in abnormal conditions It goes without saying that the number of element antennas and the arrangement of the element antennas may be changed in order to satisfy conditions such as the shape of the radiation beam.

〔Effect of the invention〕

As explained above, 1 the antenna device according to the present invention is
A plurality of element antennas that are almost omnidirectional in a plane parallel to the ground conductor plate are arranged on the same plane, and a feeding circuit that feeds each element antenna is equipped with a plurality of fixed phase shifters and switches. By providing a distributor, the radiation beam is normally switched in multiple directions within a plane parallel to the ground conductor plate, and in the event of an abnormality, some element antennas are operated to create a near-omnidirectional beam within the above plane, i.e. Since this method obtains quatrefoil beams oriented in four mutually orthogonal directions, it has an excellent effect of preventing wireless line interruptions.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the antenna device according to the present invention, Fig. 2 is a schematic block diagram of a power feeding circuit connected to the antenna device of Fig. 1, and Fig. 3 is a conventional train roof antenna. FIG. 2 is a schematic configuration diagram of the device. 1 is a ground conductor plate, 2, 3, 4, 5, 6.7 are element antennas, 8 is a 2-way divider, 9 is a 3-way divider, 1o is an input/output terminal, 1
1 to 22 are switches, and 23 to 29 are fixed phase shifters. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1. 2nd meter 10 ・ Innovative sword version Te 11-22: Switch 23-29;

Claims (6)

[Claims] (1) In an antenna device formed by arranging a plurality of element antennas, the element antenna is configured by a ground conductor plate and a circular conductor plate provided parallel to the ground conductor plate, so that the ground conductor In addition to using an antenna that is almost omnidirectional in a plane parallel to the plate, a plurality of the circular conductor plates are arranged on the same plane, and a plurality of fixed phase shifters are used in a feeding circuit that feeds power to each element antenna. A switch, a switch, and a distributor are installed to switch the direction of the radiation beam in multiple directions within a plane parallel to the ground conductor plate by operating all the element antennas during normal times, and in the event of an abnormality when the drive current of the switch is cut off. An antenna device characterized in that a quatrefoil beam directed in four mutually orthogonal directions within the plane is obtained by operating only some of the element antennas. (2) The antenna device according to claim 1, wherein a single-pole double-throw coaxial switch is used as the switch. (3) The antenna device according to claim 1, wherein a diode switch is used as the switch. (4) The antenna device according to claim 1, wherein coaxial cables of different lengths are used as the fixed phase shifter. (5) The antenna device according to claim 1, wherein the distributor is a hybrid circuit made up of a strip line formed by etching on a printed circuit board. (6) The antenna according to claim 1, characterized in that a reactive distribution circuit constituted by a strip line formed by etching on a printed circuit board is used as the distributor. Device.