JP2001177453A - Supply changeover device, power supply system and broadcast tower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow any antenna to transmit a radio wave without interrupting the radio wave when antennas are switched. SOLUTION: A variable phase shifter 13 changes the phase of one incident wave power among waves sent from a transmitter 20 and distributed by a power distributor 11, a power combiner 12 combines the one incident wave power whose phase is controlled to have a desired phase and the other incident wave power distributed by the power distributor 11, supplies the resultant power to the antenna units 21, 22 of systems A, B with the electric field strength in response to the phase difference of both signals, and a variable phase shifter 16 changes the phase of at least the one incident wave power among the powers combined by the power combiner 12 and supplied to the antenna units and supplies the resulting power to the B system antenna unit 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply system for supplying power to a power supply target, and more particularly to a power supply switching device and a power supply system for supplying power to an omnidirectional transmission antenna suitable for transmitting broadcast waves. And broadcast tower.

[0002]

[Related Background Art] Broadcast waves such as radio and television are radiated from an omnidirectional broadcast antenna installed at the top of a broadcast tower, for example. It is desirable that this type of transmitting antenna be installed at a position as high as possible above the ground in order to secure a radio wave reach. In addition, since it is desirable for the receiver of a plurality of broadcast waves that the arrival directions of the broadcast waves are uniform, the transmitting antennas of the broadcast waves are generally mounted on the same broadcast tower.

[0003] By the way, the broadcast tower 9 is, for example, as shown in FIG.
And a pole portion 2 provided vertically on the upper end thereof. An omnidirectional transmission antenna such as the turn style antenna 3 is exclusively attached to the pole unit 2. However, the number of transmitting antennas attached to the pole part 2 is limited by the length of the pole part 2, and therefore naturally has a limit.

Therefore, it has been attempted to mount a transmitting antenna composed of a multi-plane composite antenna 4 on the peripheral surface of the upper end portion having a relatively small cross section of the skeleton frame 1. This multi-plane composite antenna 4 arranges a plurality of antenna elements (antenna units), such as twin loop antennas, at equal angular intervals around the skeletal frame 1, and combines radio waves radiated from each antenna element in the air. By obtaining an omnidirectional radiation pattern of the radio wave by
Depending on the number of surfaces on which the antenna elements are arranged, they are called a four-plane combined antenna, an eight-plane combined antenna, or the like.

In such a transmitting antenna, two antenna elements are coaxially arranged in the vertical direction in order to improve the reliability of radio wave transmission or to maintain the radio wave transmission. Power is supplied to the antenna element to continue broadcasting tentatively, and during maintenance work, power is supplied to each of the upper and lower sides to prevent the transmission antenna from completely emitting no radio waves.

In a conventional power supply system, for example, FIG.
As shown in an example, in order to mechanically change the transmission route of the radio wave (the power of the incident wave to the transmission antenna) from the transmitter 5, the switch 6 having a switch mechanism is used to switch the B element from the A-system antenna element 7. To the system antenna element 8,
Alternatively, the antenna element 8 of the B system is switched to the antenna element 7 of the A system.

[0007]

However, in the power supply system, the transmission route is mechanically changed.
At the time of switching, there has been a disconnected state in which the switch is not connected to any of the terminals a and b to which the antenna is connected. For this reason, at the time of the switching, there is a problem that a time during which the radio wave is not emitted to any of the antennas of the A system and the B system is generated.

In particular, in the case of digital broadcasting, once the radio wave is interrupted, the receiver takes a long time to perform resynchronization adjustment.
The challenge was how to ensure that radio waves could reach the receiver without interruption. The present invention has been made in view of the above problems, and has as its object to provide a supply switching device, a supply system, and a broadcasting tower that can transmit radio waves with any one of the antennas without interruption of radio waves when switching antennas. I do.

[0009]

In order to achieve the above object, according to the present invention, there are provided first and second power supply targets.
A supply switching device for switching the power-supplied target to the first or second power-supplied target for the power supply, the power-distribution means for distributing the power, First phase shift means for changing the phase of one of the power signals; first phase shift control means for controlling the first phase shift means to change the one power signal to a desired phase; One power signal controlled to a desired phase is synthesized with the other power signal distributed by the distribution means, and the first and second power-supplied objects are supplied with an electric field strength corresponding to a phase difference between the two signals. Synthesizing means for supplying power to an object, second phase shifting means for changing a phase of at least one of the powers synthesized and supplied to the power-supplied object, and the second phase shift Means for changing said one power signal to a desired phase. Supply switching device is provided with a second phase shift control means.

[0010] In a preferred aspect of the present invention, the power-supplied object comprises first and second antennas having different systems, and the distributing means includes an incident light from a radio wave transmitting means. Wave power is distributed. That is, the phase of one incident wave power distributed by the distribution unit is changed, and one incident wave power controlled to a desired phase and the other incident wave power distributed by the distribution unit are combined, First and second electric field strengths corresponding to the phase difference between the two signals
Power is supplied to the antenna, and at least one of the combined powers supplied to the antenna is supplied to the antenna by changing the phase of the incident wave power.

According to a third aspect of the present invention, the power supply apparatus includes a plurality of power-supplied objects to be supplied with power, which are connected in multiple stages, and the power-supplied object is set to one of the power-supplied objects to supply the power. In the power supply system described above, each of the power-supplied objects is connected in multiple stages via a plurality of supply switching devices according to claim 1 to distribute and supply power.

In a preferred aspect of the present invention, the object to be supplied includes a plurality of antennas having different systems, and the distributing means sequentially supplies incident wave power from the radio wave transmitting means. Distribute. According to a fifth aspect of the present invention, there is provided a broadcast tower including the supply switching device or the power supply system according to the second or fourth aspect and the antenna provided at a predetermined ground height.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a supply switching device, a supply system and a broadcasting tower according to the present invention will be described with reference to the drawings of FIGS. FIG. 1 is a configuration diagram showing a configuration of a first embodiment of a supply switching device according to the present invention. In this embodiment, a case where power is supplied to two antenna units as a representative will be described.

In the figure, a supply switching device 10 is connected to a transmitter 20 and comprises a hybrid power distributor 11 constituting distribution means according to the present invention, a power distributor 11 and two A-system antenna units 21. A hybrid-type power combiner 12 connected to the B-system antenna unit 22 and constituting the combining means according to the present invention; a first phase shift means according to the present invention connected between the power distributor 11 and the power combiner 12 , A phase shifter control plate 14 which constitutes the first phase shift control means according to the present invention and controls the phase shift of the variable phase shifter 13, and a power combiner 12 And a continuous variable phase shifter 15 which is connected between the B-system antenna unit 22 and constitutes the second phase shift means according to the present invention, and comprises a variable phase shifter which constitutes the second phase shift control means according to the present invention. Phase shift for phase shift control of phaser 15 A control plate 16, is connected to the power divider 11 is configured to power return and a non-reflective terminator 17 that terminates.

The hybrid power divider 11 and the combiner 12 are of a so-called short-slot type or a magic T type. When distributing and combining, the phase of the incident wave power output from the port is changed at the time of input. Changes depending on the phase. Therefore, the distributor 11 and the synthesizer 12
It is necessary to select an appropriate combination with the continuous variable phase shifter 13.

The continuous variable phase shifter 13 is a phase shifter capable of continuously or manually changing the passing phase manually or automatically.
It is possible to use what is called a trombone type phase shifter. In the supply switching device 10 having such a configuration, a radio wave (broadcast wave) having a predetermined frequency band output from the transmitter 20 is input to the power distributor 11, where the power absolute value is distributed to 3 dB, In the case of the short slot type, the phases are distributed to two incident waves whose phases are shifted by π / 2 (in the case of Magic T, the phase is distributed to π). One of the incident waves is transmitted to the variable phase shifter 13.
After the passing phase is adjusted to a desired phase by the phase control of the phase shifter control plate 14, the signal is input to the power combiner 12. The other incident wave is directly input to the power combiner 12.

By changing the phase of one of the incident waves to a desired phase by the variable phase shifter 13, the power combiner 12 distributes the power of the one of the phase-adjusted incident waves to the power splitter 11. Combining the other incident wave power
Electric power is supplied to the A-system and B-system antenna units 21 and 22 with an electric field strength corresponding to the phase difference between the two power signals.
Therefore, the power combiner 12 can change the antenna that emits radio waves from, for example, the A-system antenna unit 21 to the B-system antenna unit 22. In the supply switching device 10 of the present embodiment, (A system antenna unit output) + (B system antenna unit output) = (transmitter output) − (transmission loss of all systems).

The incident wave output from the power combiner 12 to the B-system antenna unit 22 is input to the variable phase shifter 15, and the passing phase is adjusted to a desired phase by the phase control of the phase shifter control plate 16. Later, the B-system antenna unit 22
It is output and radiated. As described above, in the present embodiment, in the supply switching device connected to the two transmission antennas, the phase shifter adjusts the phase of one of the divided incident wave powers, and adjusts the adjusted incident wave power and power. Since power is supplied to the transmitting antenna with an electric field intensity corresponding to the phase difference from the power of the incident wave from the distributor, the transmitting antenna that radiates radio waves without instantaneous interruption can be switched. In this way, in the event of a failure, power can be supplied to the transmission antenna of a system that does not have a failure and the broadcasting can be continued tentatively. It is possible to prevent a state in which radiation is not completely emitted.

For this reason, the present embodiment can be applied to digital broadcasting that requires resynchronization adjustment in the receiver once the radio wave is interrupted. Radio waves can reach the receiver without interruption. In the above-described embodiment, the supply switching device that switches between the A-system antenna and the B-system antenna has been described.
It can also be used for switching the transmission antenna of the system. In other words, when the incident wave power is constantly distributed to two transmission antennas at a predetermined distribution ratio and used, the distribution ratio is continuously adjusted by adjusting the phase of the incident wave power in the same manner as in the above embodiment. By making a configuration that can be changed dynamically,
The switching of the transmission antenna is enabled. Again, in this case,
The same effect as the above embodiment can be obtained.

FIG. 2 shows a second embodiment of the supply switching device according to the present invention.
FIG. 1 is a configuration diagram illustrating a configuration of an embodiment. In the figure, the same components as those of the first embodiment are described.
For convenience of explanation, the same reference numerals are added. In the figure, the configuration of the present embodiment differs from the first embodiment in that the power supplied to the A-system and B-system antenna units 21 and 22 is monitored by the monitor device 18 in order to automatically perform power distribution. An instruction signal is output to the phase shifter control boards 14 and 16 so that a personal computer (hereinafter, referred to as “PC”) 19 performs appropriate power distribution in accordance with the power value, and the variable phase shifters 13 and 15 is to automatically perform the phase adjustment of the incident wave power by the feedback control.

As described above, in the present embodiment, since the power is distributed by performing the phase adjustment according to the power supplied to the transmitting antenna, the same effects as those of the first embodiment can be obtained.
Since the power distribution is performed by feedback control of a personal computer, antenna switching can be performed automatically without manual intervention, and the reliability of power supply can be further improved.

Such a supply switching device can be used in a power supply system for transmission antennas connected in multiple stages. FIG. 3 is a system configuration diagram of an example of a typical power supply system. In the present embodiment, a configuration of a power supply system of a two-element 4L dual-loop antenna, which is a multi-stage composite antenna having four stages and nine planes, will be described. The two-element 4L dual-loop antenna includes first to fourth antenna groups 23, 24, 25, and 26 arranged coaxially in the vertical direction. The first antenna group 23 in the upper first stage and the second antenna group 24 in the second stage and the third antenna group 25 in the lower third stage and the fourth antenna group 26 in the fourth stage are shown in FIG. 1 or FIG. The supply switching devices 30 and 31 having the same configuration as the supply switching device shown are connected in multi-stages in sets of two groups, respectively.
31 is connected to the transmitter 20 via the supply switching device 10 shown in FIG. 1 or FIG.

The supply switching device 10 includes an upper antenna group 2
The incident wave power from the transmitter 20 is distributed and supplied to the antenna groups 3 and 24 and the lower antenna groups 25 and 26 at a predetermined distribution ratio. The supply switching device 30 distributes one of the incident wave powers distributed by the supply switching device 10 to the first antenna group 23 in the upper first stage and the second antenna group 24 in the second stage at a predetermined distribution ratio. Supply. Further, the supply switching device 31
The other incident wave power distributed by the supply switching device 10 is distributed and supplied to the third antenna group 25 at the lower third stage and the fourth antenna group 26 at the fourth stage at a predetermined distribution ratio. In other words, the supply switching device 10 always uses the incident wave power from the transmitter 20 at a predetermined distribution ratio to the upper and lower transmission antenna groups at a predetermined distribution ratio.

In this state, for example, if a failure occurs in any of the systems, the antenna group is divided into upper and lower stages, and the broadcast is tentatively continued in the system without the failure. That is, the phases of the incident waves of the variable phase shifters 13 and 16 of the supply switching device 10 are changed to desired phases, and one of the incident waves and the other incident wave are combined by the power combiner 12 to obtain the two power signals. Antenna group 2 in the upper stage with the electric field strength according to the phase difference of
3, 24 and the lower antenna groups 25, 26 are supplied with power. As a result, power is supplied to the antenna group at the stage where no failure occurs, and radio waves are radiated. Power supply to the antenna group at the stage where the failure occurs is stopped to stop the wave. Can be.

In the supply switching device 30 or 31 connected to the two antenna groups in the stage where no failure occurs, the power distributed at the predetermined distribution ratio is supplied to each of the antenna groups to temporarily Broadcast can be continued. When it is desired to change the power distribution ratio, the phases of the incident waves of the variable phase shifters 13 and 16 are changed to a desired phase, and the power combiner 12 combines one of the incident waves with the other. Then, by supplying power to each antenna group with an electric field strength corresponding to the phase difference between the two power signals, the distribution ratio can be changed and the broadcast can be tentatively continued.

As described above, according to the present invention, in a power supply system in which a supply switching device is connected to a set of two antenna groups and a plurality of such components are connected in multiple stages, Since power is supplied to the antenna groups at each stage with an electric field intensity corresponding to the phase difference of the power signal, the antenna groups that emit radio waves without instantaneous interruption can be switched.
As a result, it is possible to prevent the broadcast service from being significantly deteriorated, and the reliability of the broadcast is improved.

In the above-described power supply system, even when a failure occurs in any one of the antenna groups in the same stage, the supply switching device directly connected to the electric power supply system has an electric field corresponding to the phase difference of the distributed power signal. By supplying power to each antenna group with strength, it is possible to switch to one of the antenna groups without any interruption. A broadcast tower in which the above-described supply switching device and the power supply system are provided will be described with reference to the above-described schematic configuration of FIG. In this example, a case of a power supply system using the two-element 4L dual-loop antenna 4 shown in FIG. 3 will be described.

The two-element 4L double-loop antenna 4 prepares four antenna groups consisting of nine antenna units arranged at equal angular intervals around the skeletal frame 1 of the broadcast tower 9. 26 is coaxial in the vertical direction.
The antennas are arranged in a row, and a set of two antennas, an upper antenna group 23, 24 and a lower antenna group 25, 26, is configured to emit radio waves. Each supply switching device has an upper antenna group 2
The incident wave power from the transmitter 20 of the radio wave transmitting station (not shown) is distributed and supplied to the antenna groups 3 and 24 and the lower antenna groups 25 and 26 at a predetermined distribution ratio. The two-element 4L double-loop antenna 4 is provided at a high position above the ground in the broadcast tower 9, and compensates for a reduction in the radio wave reach depending on the radio frequency.

The present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. In the present invention, since power is supplied to the transmitting antenna with the electric field strength according to the distributed phase difference, it is also possible to adjust the vertical directivity pattern of the transmitting antenna with respect to the relative electric field strength.

[0030]

As described above, according to the present invention, the phase of one incident wave power distributed by the distribution means is changed,
One incident wave power controlled to a desired phase and the other incident wave power distributed by the distribution means are combined and applied to the first and second antennas with an electric field strength corresponding to a phase difference between both signals. While supplying power, the combined power supplied to the antenna is supplied to the antenna by changing the phase of at least one incident wave power, so that the radio wave is not interrupted when the antenna is switched, Radio waves can be transmitted with the antenna.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a first embodiment of a supply switching device according to the present invention.

FIG. 2 is a configuration diagram showing a configuration of a supply switching device according to a second embodiment of the present invention.

FIG. 3 is a system configuration diagram showing an example of a power supply system using a supply switching device according to the present invention.

FIG. 4 is a diagram illustrating an example of a broadcasting tower on which a broadcasting transmitting antenna is installed.

FIG. 5 is a configuration diagram illustrating an example of a conventional power supply system.

[Explanation of symbols]

 4 Polyhedral synthesis antenna (2 element 4L double loop antenna) 9 Broadcast tower 10, 30, 31 Supply switching device 11 Power distributor 12 Power combiner 13, 15 Variable phase shifter 14, 16 Phase shifter control plate 21, 22 Antenna Unit 18 Monitoring device 19 Personal computer 23-26 Antenna group

Continued on the front page (72) Inventor Reiji Fukuhara 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Inventor Katsuyuki Naka 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Inside Electric Industry Co., Ltd. (72) Inventor Kazuo Kogure 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. F-term (reference) 5J021 AA02 AA05 AA11 AB04 CA00 DB05 FA06 FA34 HA05 5K059 CC02 CC04

Claims (5)

[Claims] 1. A power supply comprising first and second power-supplied objects to be supplied with power, wherein the power-supplied object is switched to the first or second power-supplied object for the power supply. In the switching device, a distribution unit that distributes the power, a first unit that changes a phase of the one of the divided power signals.
A first phase shift control means for controlling the first phase shift means to change the one power signal to a desired phase; and one power signal controlled to the desired phase Synthesizing means for synthesizing the other power signal distributed by the distributing means and supplying power to the first and second power-supplied objects with an electric field strength according to a phase difference between the two signals; Of the power that is combined and supplied to the power-supplied object,
A second phase shifter for changing a phase of at least one power signal; and a second phase shifter for controlling the second phase shifter and changing the one power signal to a desired phase. A supply switching device, comprising: 2. The power-supplied object is a first power-supply object having a different system.
2. The supply switching device according to claim 1, further comprising a second antenna, and wherein the distribution unit distributes incident wave power from the radio wave transmission unit. 3. 3. An electric power supply comprising: a plurality of power-supplied objects to be supplied with power in a multi-stage connection, wherein the power-supplied objects are set to any of the power-supplied objects and the power is supplied. A power supply system, wherein each of the power-supplied objects is connected in multiple stages via the plurality of supply switching devices according to claim 1 to distribute and supply power. 4. The power supply according to claim 3, wherein the power supply target object includes a plurality of antennas having different systems, and the distribution unit sequentially distributes incident wave power from the radio wave transmission unit. Feeding system. 5. A broadcasting tower comprising the supply switching device or the power supply system according to claim 2 or 4, and the antenna provided at a predetermined ground height.