JP2005124084A - Air monitor antenna system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air monitor antenna system capable of shortening a wave transmission stoppage time during faults. <P>SOLUTION: The air monitor antenna system comprises a directional antenna 9. The directional antenna 9 is provided with a function for receiving waves transmitted from a transmission antenna 5 and a function for transmitting waves in place of the transmission antenna 5. Both functions can be switched over. The directional antenna 9 monitors the transmission antenna 5 usually, but it transmits waves in place of the transmission antenna 5 during wave transmission stoppage in the transmission antenna 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air monitor antenna system for monitoring transmission radio waves of a broadcast, and more particularly to an air monitor antenna system capable of shortening a stop time at the time of abnormality.

  An air monitor antenna system is provided to monitor a transmission radio wave radiated from a transmission antenna at a transmitting station for television broadcasting or FM broadcasting. Abnormalities in the transmission system can be found by monitoring the transmission radio waves. For example, in recent years, an abnormality has occurred due to damage to a main feed line that transmits a broadcast signal to a transmitting antenna due to small animals such as flying squirrels and mommoths.

  An antenna for an air monitor antenna system (hereinafter referred to as an air monitor antenna) transmits a radio wave whose electric field intensity has been reduced to an appropriate electric field intensity due to directivity attenuation and spatial attenuation due to distance. In order to be able to be monitored, the transmission antenna is installed away from the directivity direction and separated from the transmission antenna by an appropriate space. For example, as shown in FIG. 3, an air monitor antenna 33 is attached to a tower leg 32b of a tower 32 where a transmission antenna 31 mainly directed to a service area in the horizontal direction is attached on a tower top 32a. The air monitor antenna 33 is attached toward the transmission antenna 31 so that the transmission radio wave can be received with high sensitivity. The reception output of the air monitor antenna 33 is connected to a transmission radio wave monitoring device 35 installed in a transmission station station 34 near the steel tower. A transmitter 36 is installed in the station building 34, and a main feed line 37 from the transmitter 36 to the transmitting antenna 31 is wired along the tower 2. The transmitter 36, the main feeder 37, and the transmission antenna 31 are collectively referred to as a transmission system.

  When an abnormality occurs in the transmission system and the wave is stopped, an alarm is issued by the monitoring device, and the alarm is reported to the broadcasting station head office via a public line. Upon receiving this notification, the worker moves to the station building equipped with the transmitting antenna for confirmation and recovery of the abnormality. As part of the restoration work, a temporary alternative antenna is installed in place of the transmitting antenna in which an abnormality has occurred, and a feeder line from the transmitter is connected to the alternative antenna.

  In addition, replacement of the transmitting antenna in which an abnormality has occurred and routine maintenance work are performed during the broadcast suspension time, but if the work is not completed within that time period or if emergency broadcasting is necessary, In order to start broadcasting immediately, the above replacement work and maintenance work are performed after a spare antenna is temporarily installed.

  As a technique for monitoring the failure of the transmitting antenna, an abnormality in the transmitting antenna is detected by measuring the signal reflected from the transmitting antenna to the transmitter. Patent Document 1 discloses a technique for transmitting the detected information to a remote monitoring device via a public line.

JP-A-8-254556

  The conventional air monitor antenna is installed toward the transmitting antenna as described above. The direction in which the air monitor antenna faces the transmitting antenna is different from the direction in which the transmitting antenna faces the service area. That is, the air monitor antenna is not directed to the service area. Therefore, it is impossible to use the air monitor antenna as a transmitting antenna (an antenna that radiates broadcast radio waves).

  In addition, since the reception opening of the air monitor antenna faces upward, if the reception level of the air monitor antenna decreases due to snow accumulation during snowfall, it may be mistaken for an abnormality in the transmission antenna.

  In addition, when an abnormality occurs in the transmission system and the wave is stopped, an alarm issued by the monitoring device is received, the worker goes from the broadcasting station headquarters to the transmitting station, temporarily installs an alternative antenna, and completes the restoration work. In the meantime, the wave stop state will continue. At this time, even if an emergency broadcast is required, the broadcast cannot be started immediately.

  In addition, when exchanging transmission antennas and carrying out routine maintenance work, it is necessary to temporarily install a spare antenna and lay a feeder to feed the spare antenna. It takes a lot of personnel and time, and also requires extensive preparations.

  It is desired to eliminate the above-mentioned problems and eliminate the need for various operations and to eliminate the need for a spare antenna, and to reduce (or eliminate) the stop time during abnormal conditions.

  Accordingly, an object of the present invention is to provide an air monitor antenna system capable of solving the above-described problems and shortening the wave stop time at the time of abnormality.

  In order to achieve the above object, the present invention has a directional antenna, a function of receiving a transmission radio wave from a transmission antenna by this antenna, and a function of transmitting a radio wave by the antenna instead of the transmission antenna And can be switched.

  You may provide the direction switching mechanism which switches the direction of the said antenna to the direction which faced the said antenna for transmission, and the direction which faced the service area of the said antenna for transmission.

  You may provide the signal switcher which switches the connecting point of the said antenna to the monitoring apparatus of a transmission radio wave, and the transmitter of a transmission radio wave.

  The antenna may be attached to a steel tower to which the transmitting antenna is attached.

  You may provide the communication means which acquires the instruction | command which switches the said some function from a public line.

  The present invention exhibits the following excellent effects.

  (1) It is possible to shorten the wave stop time at the time of abnormality.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a tower 2 and a station building 3 are installed in a transmitting station 1 using an air monitor antenna system according to the present invention.

  A mounting column 4 is provided upright on the tower top 2 a of the steel tower 2, and one or more transmitting antennas 5 are mounted on the side surface of the mounting column 4. The transmitting antenna 5 is installed mainly toward the service area in the horizontal direction. A main feeding line 6 is connected to the transmitting antenna 5, and the main feeding line 6 is wired to the ground in the tower 2 and is connected to the transmitter 8 through the signal switch 7 in the station 3.

  An directional antenna 9 (hereinafter referred to as an air monitor antenna) 9 for the air monitor antenna system is attached to the tower top 2 a of the tower 2. In this embodiment, the air monitor antenna 9 is installed toward the service area in the same manner as the transmission antenna 5, but as another embodiment, when the direction of the air monitor antenna 9 is switched, the air monitor antenna 9 is It is directed to the transmitting antenna 5.

  The air monitor antenna 9 is connected to an air monitor power supply line 10 made of a coaxial cable. The air monitor power supply line 10 is wired to the ground in the tower 2 and connected to the monitoring device 11 in the station 3 via the signal switch 7. Has been.

  The monitoring device 11 can capture the reception level (power value) of broadcast radio waves as data, and can calculate evaluation data such as VSWR, BER (Bit Error Rate) indicating radio wave quality, and MER (Modulation Error Ratio).

  The signal switcher 7 connects the main power supply line 6 to the transmitter 8 and connects the air monitor power supply line 10 to the monitoring device 11 at normal times, and connects the air monitor power supply line 10 to the transmitter 8 at times other than normal. A terminator 12 is connected to the monitoring device 11.

  A warning / control signal transmission / reception facility 14 for controlling the direction switching mechanism 13 shown in FIG. 2 is connected to the monitoring device 11. The alarm / control signal transmission / reception facility 14 can communicate with a remote broadcasting station head office 16 via a public line 15. Evaluation data and reception level in the monitoring device 11 can be known from the broadcasting station head office 16. In addition, the direction switching mechanism 13 and the signal switch 7 can be remotely operated via the alarm / control signal transmission / reception facility 14 and the monitoring device 11. In addition, the direction switching mechanism 13 and the signal switch 7 can be manually operated in the station 3.

  The public line 15 is preferably a mobile communication line such as a mobile phone if the transmitting station 1 is within communication range. By using the public line 15, it is possible to communicate with the alarm / control signal transmission / reception facility 14 of the transmitting station 1 from any place at any time zone.

  When acquiring information on the transmitting station 1 from a mobile terminal such as a mobile phone or a personal computer, the transmitting station 1 can be accessed after a command is transmitted from the mobile terminal to the broadcasting station head office 16. Access requires a security code for security, and there is a restriction that only a person who knows the security code can obtain information. The direction switching mechanism 13 and the signal switch 7 can be switched by transmitting a command from the mobile terminal.

  As shown in FIG. 2, the air monitor antenna 9 attached to the tower top 2 a is configured to be able to tilt and stand up in an upward direction that faces the transmitting antenna 5 and a horizontal direction that faces the service area. The direction can be changed by the direction switching mechanism 13. In this figure, the air monitor antenna 9 is directed to the transmitting antenna 5. A power line and a control signal line (not shown) for operating the direction switching mechanism 13 are routed through the tower 2 to the ground and drawn into the station 3.

  Next, the operation of the air monitor antenna system according to the present invention will be described.

  During normal broadcasting, the air monitor antenna 9 is directed to the service area in the same manner as the transmission antenna 5 as shown in FIG. Alternatively, as shown in FIG. 2, when the direction of the air monitor antenna 9 is switched, the air monitor antenna 9 is made to face the transmitting antenna 5. The air monitor antenna 9 functions to receive transmission radio waves from the transmission antenna 5.

  A broadcast signal from the transmitter 8 is supplied from the main feeder 6 to the transmitting antenna 5. A part of the radio wave radiated from the transmitting antenna 5 is received by the air monitor antenna 9 with the electric field strength lowered to an appropriate electric field strength due to directivity attenuation and spatial attenuation. This received output is input to the monitoring device 11. The reception level and the evaluation data are monitored by the monitoring device 11 or the remote broadcasting station head office 16 or an operator at an arbitrary place (not shown).

  Since the air monitor antenna 9 is installed on the tower top 2a and the reception signal is transmitted to the ground by the air monitor feeder 10, the reception signal is attenuated when input to the monitoring device 11, but on the other hand, the transmission antenna 5 Since the distance from the air monitor antenna 9 to the air monitor antenna 9 is short (in the vicinity), the spatial attenuation is small. Therefore, the monitoring device 11 can obtain a reception level necessary and sufficient for monitoring.

  When the air monitor antenna 9 is directed to the transmitting antenna 5, directivity attenuation on the air monitor antenna 9 side can be eliminated.

  When exchanging the transmitting antenna or performing routine maintenance work, the signal switch 7 and the direction switching mechanism 13 are switched in conjunction with each other. That is, the air switch feeder 10 is connected to the transmitter 8 by the signal switcher 7 and the terminator 12 is connected to the monitoring device 11, and the air monitor antenna 9 is directed to the service area in the direction switching mechanism 13 as shown in FIG.

  In this state, a broadcast signal from the transmitter 8 is supplied to the air monitor antenna 9 via the air monitor power supply line 10. Accordingly, broadcast radio waves are radiated from the air monitor antenna 9 instead of the transmission antenna 5 being stopped. At this time, since the terminator 12 is connected to the monitoring device 11, no unnecessary signal is input.

  In this way, since broadcast radio waves are radiated from the air monitor antenna 9 toward the service area, it is not necessary to temporarily install a temporary substitute antenna or a spare antenna, and it is not necessary to perform temporary work or wiring work. Switching from the transmitting antenna 5 to the air monitor antenna 9 is performed electrically and mechanically, so that manual operation is unnecessary and can be performed instantaneously.

  Broadcasting can be started immediately even if emergency broadcasting / emergency broadcasting is required when working during the broadcast suspension time.

  Even when the main power supply line 6 is abnormal, the air monitor antenna 9 is supplied with power by the air monitor power supply line 10. Therefore, it is not necessary to wire a new power supply line, and the wave stopping time can be shortened.

  Since data can be collected from the transmission station 1 and the transmission station 1 can be controlled via the public line 15, it is possible to shorten the time during which the abnormality continues and the stop time for recovery work.

  In the embodiment in which the direction of the air monitor antenna 9 is fixed to the service area, there is no need to configure the air monitor antenna 9 so that the air monitor antenna 9 can be tilted and raised or to provide the direction switching mechanism 13. Further, when the air monitor antenna 9 has a horn or a flat surface, it tends to be covered with snow if it is installed upward, but it can be avoided if it is directed toward the service area. On the other hand, in the embodiment in which the direction of the air monitor antenna 9 is switched, since the air monitor antenna 9 faces the transmitting antenna 5 at the normal time, the transmission radio wave can be received without being buried in other noise.

  In the air monitor antenna system described above, the type of antenna used for the air monitor antenna 9 is not limited, and any antenna that can receive transmission radio waves from the transmitting antenna 5 and sufficiently radiate broadcast radio waves to the service area can be used. Any type of antenna may be used. The illustrated antenna is a corner antenna, but may be a double loop antenna or a dipole antenna.

  The installation location of the air monitor antenna 9 is not limited to the tower top portion 2a, and any location can be used as long as it can receive transmission radio waves from the transmission antenna 5 and sufficiently radiate broadcast radio waves to the service area. , Anywhere.

  This air monitor antenna system can be applied not only to the transmission station 1 having a transmission antenna for the service area, but also to a relay station arranged in the middle from the master station to the transmission station. In this case, for example, the installation location of the air monitor antenna 9 is determined so that the radio wave transmitted from the upstream station to the relay station and the radio wave transmitted from the relay station to the downstream station can be distinguished by the difference in arrival time. Decide. In this case, not only the radio wave transmitted from the relay station to the downstream station is monitored by the air monitor antenna 9, but also the radio wave transmitted from the upstream station to the relay station can be monitored by the air monitor antenna 9. .

It is a schematic diagram of the transmitting station which shows one Embodiment of this invention. It is an installation view of an air monitor antenna showing an embodiment of the present invention. It is a schematic diagram of the conventional transmitting station.

Explanation of symbols

2 Steel Tower 5 Transmitting Antenna 6 Main Feeding Line 7 Signal Switcher 8 Transmitter 9 Air Monitor Antenna 10 Air Monitor Feeding Line 11 Monitoring Device 13 Direction Switching Mechanism 14 Alarm / Control Signal Transmission / Reception Facility 15 Public Line

Claims (5)

  A directional antenna is provided, and a function of receiving a transmission radio wave from a transmission antenna by the antenna and a function of transmitting a radio wave by the antenna instead of the transmission antenna are switchable. Air monitor antenna system.   The air monitor antenna system according to claim 1, further comprising a direction switching mechanism that switches a direction of the antenna to a direction facing the transmitting antenna and a direction facing the service area of the transmitting antenna.   The air monitor antenna system according to claim 1, further comprising a signal switching unit that switches a connection destination of the antenna to a transmission radio wave monitoring device and a transmission radio wave transmitter.   The air monitor antenna system according to claim 1, wherein the antenna is attached to a steel tower to which the transmitting antenna is attached. The air monitor antenna system according to any one of claims 1 to 4, further comprising communication means for acquiring a command for switching the plurality of functions from a public line.

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