JPH11346182A - Radio rebroadcasting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide radio rebroadcasting equipment which is small-sized and inexpensive and does not cause an oscillation phenomenon by infiltrating of a rebroadcast radio wave into a reception antenna. SOLUTION: A repeater amplifier 8 is provided at a connection part between a power feeding line 5 and a transmission antenna 6 in a tunnel, outputs of transmission pats 3a to 3n can be made small by the gain of the repeater amplifier 8 and the transmission parts 3a to 3n and a mixing part 4 can be made inexpensive and small. Also, by making the output levels of the transmission parts 3a to 3n small, the rebroadcast radio wave outputted by the transmission parts 3a to 3n is prevented from directly infiltrating the reception antennas 1a to 1n, rebroadcast radio wave leaked from the power feeding line 5 is prevented from sneaking the reception antenna 1a to 1n, and the oscillation phenomenon is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio rebroadcasting apparatus for retransmitting radio waves in a tunnel.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a conventional radio rebroadcasting apparatus. In the drawing, reference numerals 1a to 1n denote receiving antennas for receiving radio waves from a plurality of radio broadcasting stations, and 2a.
To 2n are receiving sections for receiving and processing the received radio waves, 3a to 3n
n is a transmitting unit that reconverts and amplifies the frequency of the broadcasting station and amplifies. 4 is a mixing unit that mixes and outputs the outputs of the transmitting units 3a to 3n. 5 transmits a rebroadcast signal mixed by the mixing unit 4 to the tunnel. The feed line 6 is a transmission antenna which is constituted by a leaky coaxial cable or a guide line and emits a rebroadcast radio wave in the tunnel.

Next, the operation will be described. The radio waves emitted from the broadcast stations receive the antennas 1a to 1n for each broadcast frequency.
And input to the receiving units 2a to 2n. Receiver 2a
2 to 2n, the input received signal is converted into an audio signal or an intermediate frequency signal by a receiving method and output to the transmitting units 3a to 3n. The transmitting units 3a to 3n convert the signals into the original broadcast frequency, amplify the signals, and output the amplified signals to the mixing unit 4. The mixing unit 4 mixes the rebroadcast signal converted into the original broadcast frequency and transmits the mixed signal to the tunnel via the power supply line 5. The transmission antenna 6 laid inside the tunnel emits the rebroadcast signal transmitted by the feed line 5 into the tunnel as a rebroadcast radio wave.

[0004]

Since the conventional radio rebroadcasting apparatus is configured as described above, all necessary power is required to enable good rebroadcast wave reception even at the end of the tunnel. It must be amplified by the transmitting units 3a to 3n, and the rebroadcast radio wave amplified by the transmitting units 3a to 3n goes directly to the receiving antennas 1a to 1n. 6, the re-broadcast radio wave leaked from the feeder line 5 and the transmitting antenna 6 at the tunnel entrance becomes the receiving antenna 1a.
１1n, which causes an oscillation phenomenon. In addition, all of the power required in this way is transmitted by the transmission units 3a to 3a.
3n, the transmission units 3a to 3n
In addition, there is a problem that the mixing section 4 is large and expensive. Furthermore, if the required signal level cannot be obtained up to the end of the tunnel due to attenuation of the rebroadcast signal at the transmitting antenna 6 when the tunnel is long, a similar device must be installed on the opposite side of the tunnel. There is a problem that the installation becomes difficult and expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a small and inexpensive radio rebroadcasting apparatus which does not cause an oscillation phenomenon due to rebroadcast radio waves wrapping around a receiving antenna. Aim.

Another object of the present invention is to provide an inexpensive radio rebroadcasting apparatus which can perform good rebroadcasting even in a long tunnel, can be easily installed, and is inexpensive.

[0007]

A radio rebroadcasting apparatus according to the present invention is provided in a tunnel or at an entrance of the tunnel, and amplifies a rebroadcast signal transmitted by a feeder line, and an illumination for lighting in the tunnel. A power supply processing unit for rectifying and stabilizing the power supply and supplying the stabilized DC power to the amplifier, and a rebroadcast signal laid in the tunnel by a leaky coaxial cable or a guide wire and amplified by the amplifier. And a transmitting antenna for emitting a broadcast wave into the tunnel.

[0008] A radio rebroadcasting apparatus according to the present invention includes a power supply unit for supplying a DC power supply, and a DC power supply supplied from the power supply unit superimposed on a rebroadcast signal output from the radio retransmission apparatus to reach a tunnel. A power supply line for transmission, an amplifier provided in the tunnel or at the entrance of the tunnel, for amplifying the rebroadcast signal transmitted by the power supply line, and a DC power source transmitted by the power supply line is stabilized, and the amplifier is stabilized. And a transmission antenna laid by a leaky coaxial cable or induction wire in the tunnel and emitting a rebroadcast signal amplified by an amplifier into the tunnel as a rebroadcast radio wave. is there.

A radio rebroadcasting apparatus according to the present invention is a relay amplifier in which an amplifier and a power supply processing unit are unitized,
A plurality of such relay amplifiers are provided in the middle of the transmitting antenna in the tunnel.

A radio rebroadcasting apparatus according to the present invention has an amplifier and a power supply processing unit or a relay amplifier built in a microphone box for interrupt broadcasting.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a radio rebroadcasting apparatus according to Embodiment 1 of the present invention. In the drawing, reference numerals 1a to 1n denote reception antennas for receiving radio waves from a plurality of radio broadcast stations, and 2a to 2n receive radio waves. Receiving sections for receiving and processing radio waves, 3a to 3n are transmitting sections for re-converting and amplifying the frequency of the broadcasting station and amplifying, and 4 are mixing sections for mixing and outputting the outputs of the transmitting sections 3a to 3n. ~
2n, transmitting sections 3a to 3n and mixing section 4 constitute radio retransmitting apparatus 7. Reference numeral 5 denotes a power supply line for transmitting the rebroadcast signal mixed by the mixing unit 4 to the tunnel, and reference numeral 6 denotes a transmission antenna formed of a leaky coaxial cable or a guide line and emitting rebroadcast radio waves in the tunnel. Reference numeral 8 denotes a relay amplifier. In the relay amplifier 8, 9 is provided in the tunnel or at the entrance of the tunnel, and amplifies the rebroadcast signal transmitted by the feeder line 5. Is a power processing unit that rectifies and stabilizes the DC power and supplies the stabilized DC power to the amplifier 9.

Next, the operation will be described. The radio waves emitted from the broadcast stations receive the antennas 1a to 1n for each broadcast frequency.
And input to the receiving units 2a to 2n. Receiver 2a
2 to 2n, the input received signal is converted into an audio signal or an intermediate frequency signal by a receiving method and output to the transmitting units 3a to 3n. The transmitting units 3a to 3n convert the signals into the original broadcast frequency, amplify the signals, and output the amplified signals to the mixing unit 4. The mixing unit 4 mixes the rebroadcast signal converted into the original broadcast frequency and transmits the mixed signal to the tunnel via the power supply line 5. Here, the power of the rebroadcast signal output from the transmitting units 3a to 3n is set to such an extent that an oscillation phenomenon does not occur due to the rebroadcast radio wave wrapping around the receiving antennas 1a to 1n. An amplifier 9 is provided in the tunnel or at the entrance of the tunnel, and the amplifier 9 amplifies the rebroadcast signal transmitted by the power supply line 5. Further, the power supply processing unit 10 rectifies and stabilizes an AC power supply used as a lighting power supply in the tunnel in advance, and uses the AC power supply as a power supply for the amplifier 9.
Further, the transmission antenna 6 installed inside the tunnel emits the rebroadcast signal amplified by the amplifier 9 into the tunnel as a rebroadcast radio wave.

As described above, according to the first embodiment, the relay amplifier 8 is provided at the connection portion between the feeder line 5 and the transmission antenna 6 in the tunnel. The outputs of 3a to 3n can be reduced, and the transmitting units 3a to 3n and the mixing unit 4 can be reduced in size at low cost. Further, since the output levels of the transmitting units 3a to 3n can be reduced, the rebroadcast radio waves output from the transmitting units 3a to 3n can be directly transmitted to the receiving antennas 1a to 1n.
And the rebroadcast radio wave leaked from the feeder line 5 is prevented from sneaking into the receiving antennas 1a to 1n, thereby preventing the occurrence of an oscillation phenomenon. further,
Since the power supply of the amplifier 9 can be supplied by the power supply unit 10 using the power supply for lighting in the tunnel, installation can be facilitated without laying a dedicated power cable.

Embodiment 2 FIG. FIG. 2 is a block diagram showing a radio rebroadcasting apparatus according to a second embodiment of the present invention. In the drawing, reference numeral 11 denotes a power supply unit provided in the radio retransmission apparatus 7 for supplying DC power to the power supply line 5 , 12 are DC cut capacitors. Further, in the relay amplifier 8, 13 is a power supply processing unit for stabilizing the DC power transmitted through the power supply line 5 and supplying the stabilized DC power to the amplifier 9, 14a and 14b are DC cut capacitors,
15a and 15b are AC cut inductors. The other configuration is the same as that of FIG.

Next, the operation will be described. In the first embodiment, the power of the amplifier 9 is processed by the power processing unit 10 to supply the power for illumination in the tunnel, but in the second embodiment, the power is provided in the radio retransmission device 7. The power is supplied from the power supply unit 11. In the radio retransmission device 7, DC power is supplied from the power supply unit 11 to the power supply line 5. At this time, the feeder line 5 superimposes the DC power supplied from the power supply unit 11 on the rebroadcast signal output from the mixing unit 4 and transmits the signal to the tunnel. The DC cut capacitor 12 prevents the DC power supply from flowing into the mixing section 4. Further, the rebroadcast signal on which the DC power is superimposed by the feeder line 5
The DC cut capacitors 14a and 14b and the AC cut inductors 15a and 15b separate the DC power supply from the rebroadcast signal and output the rebroadcast signal to the amplifier 9. Further, the DC power is supplied to the power processing unit 13, which stabilizes the DC power and supplies the stabilized DC power to the amplifier 9.

As described above, according to the second embodiment, the power supply unit 11 provided in the radio retransmission device 7
Thus, the rebroadcast signal and the DC power supply are superimposed on the power supply line 5, the DC power supply and the rebroadcast signal are separated in the relay amplifier 8, the DC power supply is stabilized by the power supply processing unit 13, and the Since the power is supplied, installation can be facilitated without laying a dedicated power cable.

Embodiment 3 FIG. 3 is a block diagram showing a radio rebroadcasting apparatus according to Embodiment 3 of the present invention. In the figure, reference numerals 6a and 6b denote transmitting antennas, and 8a and 8
b is a relay amplifier, 9a and 9b are amplifiers, 10a and 10b
Denotes a power processing unit. The other configuration is the same as that of FIG.

Next, the operation will be described. In the first and second embodiments, the relay amplifier 8 is connected to the feed line 5.
In the third embodiment, only one unit is provided at the connection between the antenna and the transmitting antenna 6, but in the case where the tunnel is long,
The transmitting antenna 6 in the tunnel is connected to the transmitting antenna 6a,
6b, and relay amplifiers 8a and 8b are provided in the middle of the transmitting antennas 6a and 6b. FIG.
In, the relay amplifier 8a and the transmitting antenna 6a operate in the same manner as described in Embodiment 1, but the rebroadcast signal is attenuated at the end of the transmitting antenna 6a. Therefore, re-amplification is performed by the relay amplifier 8b so as to correct the attenuation of the rebroadcast signal. Here, the transmitting antennas 6a,
When the transmission antenna 6a is a leaky coaxial cable, it is desirable to provide the relay amplifiers 8a, 8b about every 1 km, and when the transmission antennas 6a, 6b are guide wires, it is desirable to provide the relay amplifiers 8a, 8b every about 3km.
In FIG. 3, the relay amplifier 8 shown in the first embodiment is used.
Is shown, but the relay amplifier 8 described in the second embodiment may be adopted. In this case, the power supply processing unit 13 transmits the rebroadcast signal to the lower transmitting antenna 6 by direct current. The power supply may be superimposed and transmitted, and the DC power supply superimposed on the lower relay amplifier 8 may be used.

As described above, according to the third embodiment, the transmitting antennas 6a, 6b
A plurality of relay amplifiers 8a and 8b are provided on the way to correct the attenuation of the rebroadcast signal. Therefore, in a conventional technique, in the case of a long tunnel, the same device must be installed from the opposite side of the tunnel. However, the installation of the device becomes difficult and the device becomes expensive. However, in the third embodiment, only one set of the receiving antennas 1a to 1n and the radio retransmitting device 7 are required, and the installation of the device can be facilitated. , Can be inexpensive. Further, as compared with the first and second embodiments, it is not necessary to increase the degree of amplification by the amplifier 9a at the tunnel entrance, so that it is not necessary to increase the signal level of the transmitting antenna 6a at the tunnel entrance. It is possible to prevent the rebroadcast radio wave leaked from the transmission antenna 6a from wrapping around to the reception antennas 1a to 1n, thereby preventing an oscillation phenomenon from occurring.

Embodiment 4 In the configuration of the radio rebroadcasting apparatus according to the fourth embodiment, the relay amplifier 8 according to the first to third embodiments is built in a microphone box for interrupt broadcasting.

Next, the operation will be described. In the first to third embodiments, the relay amplifier 8 is installed alone in the tunnel. However, in the fourth embodiment, in the case of a system having a microphone box for interrupt broadcasting, the relay amplifier 8 It is built into the microphone box. Here, the interrupt broadcasting system is provided with a microphone box provided with a microphone, a control switch, a power supply unit, and an amplifier in a tunnel. When the control switch is switched and a speaker speaks with the microphone, the audio signal is transmitted to the amplifier 9. And transmitted to the radio retransmitting device 7 via the transmitting antenna 6 and the feeder line 5, and transmitted by the transmitting units 3a to 3n.
Of the rebroadcast signal by the
3n, the voice signal is combined with a carrier wave of a predetermined frequency and transmitted to the feeder line 5, so that the receiving device in the tunnel can receive the voice of the speaker.

As described above, according to the fourth embodiment, in the case of a system having a microphone box for interrupt broadcasting, the relay amplifier 8 is built in the microphone box. And the like can be shared, and the installation can be made cheaper than when the relay amplifier 8 is installed alone.

[0023]

As described above, according to the present invention, the output of the radio retransmission device can be reduced by the gain of the amplifier, and the radio retransmission device can be reduced in cost and size. . In addition, since the output level of the radio retransmitter can be reduced, the rebroadcast radio wave output from the radio retransmitter goes directly to the receiving antenna, or the rebroadcast radio leaked from the feed line goes to the receiving antenna. And the occurrence of an oscillation phenomenon can be prevented. Furthermore, since the power of the amplifier can be supplied by the power supply unit using the power supply for lighting in the tunnel, without laying a dedicated power cable,
There is an effect that installation can be facilitated.

According to the present invention, the rebroadcast signal and the DC power supply are superimposed on the power supply line by the power supply unit, and the DC power transmitted from the power supply line is stabilized by the power supply processing unit, and the amplifier is stabilized. Since DC power is supplied, there is an effect that installation can be facilitated without laying a dedicated power cable.

According to the present invention, a plurality of relay amplifiers can be provided on the way of the transmitting antenna in accordance with the length of the tunnel to correct the attenuation of the rebroadcast signal. The device can be used, the installation of the device can be facilitated, and the cost can be reduced. Furthermore, since it is not necessary to increase the amplification by the amplifier at the entrance of the tunnel, it is not necessary to increase the signal level of the transmitting antenna at the entrance of the tunnel, and it is possible to prevent rebroadcast radio waves leaking from the transmitting antenna at the entrance of the tunnel from entering the receiving antenna. This has the effect of preventing the occurrence of an oscillation phenomenon.

According to the present invention, an amplifier and a power supply processing unit or a relay amplifier are built in a microphone box for interrupt broadcasting, so that the housing, the amplifier and the power supply processing unit can be shared, and the installation is inexpensive. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a radio rebroadcasting apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a radio rebroadcasting apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a block diagram showing a radio rebroadcasting apparatus according to Embodiment 3 of the present invention.

FIG. 4 is a block diagram showing a conventional radio rebroadcasting apparatus.

[Explanation of symbols]

1a to 1n receiving antenna, 5 feeder line, 6, 6a, 6
b transmitting antenna, 7 radio retransmitter, 8, 8a, 8
b Relay amplifier, 9, 9a, 9b Amplifier, 10, 10
a, 10b, 13 Power supply processing unit, 11 Power supply unit.

Claims (4)

[Claims] 1. A receiving antenna for receiving a radio wave from a radio broadcasting station, receiving a radio wave received from the receiving antenna, amplifying the received signal at an original broadcast frequency, and outputting the signal as a rebroadcast signal. A radio retransmitter,
A feed line for transmitting a rebroadcast signal output from the radio retransmitting device to a tunnel; an amplifier provided in the tunnel or at an entrance of the tunnel, for amplifying the rebroadcast signal transmitted by the feed line; A power processing unit for rectifying and stabilizing the power supply for lighting in the power supply unit and supplying the stabilized DC power to the amplifier, and laid by a leaky coaxial cable or an induction wire in the tunnel;
A radio rebroadcasting apparatus comprising: a transmission antenna for emitting the rebroadcast signal amplified by the amplifier as rebroadcast radio waves into the tunnel. 2. A receiving antenna for receiving a radio wave from a radio broadcasting station, receiving a radio wave received from the receiving antenna, amplifying the received signal at an original broadcast frequency, and outputting the signal as a rebroadcast signal. A radio retransmitter,
A power supply unit for supplying DC power, a power supply line for superimposing DC power supplied from the power supply unit on a rebroadcast signal output from the radio retransmission device and transmitting the signal to a tunnel, and in or in the tunnel. An amplifier provided at the entrance of the tunnel for amplifying the rebroadcast signal transmitted by the power supply line; and a power supply for stabilizing the DC power transmitted by the power supply line and supplying the stabilized DC power to the amplifier. A radio rebroadcasting apparatus comprising: a processing unit; and a transmission antenna laid in the tunnel with a leaky coaxial cable or a guide wire and emitting a rebroadcast signal amplified by the amplifier as a rebroadcast radio wave into the tunnel. 3. The radio rebroadcast according to claim 1, wherein the amplifier and the power supply processing unit are unitized relay amplifiers, and a plurality of relay amplifiers are provided in the middle of the transmitting antenna in the tunnel. apparatus. 4. The radio rebroadcasting apparatus according to claim 1, wherein the amplifier and the power supply processing unit or the relay amplifier are incorporated in a microphone box for interrupt broadcasting.