JP2626258B2 - Wireless transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio transmitting apparatus, and more particularly to a radio transmitting apparatus having a redundant configuration provided with a backup transmitter in addition to an active transmitter.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional radio transmitter of this type has a plurality of (three) active transmitters 1, one standby transmitter 1A, and three channel filters 31. Combiner 3 and three active transmitters 1 are connected to backup transmitters 1A
A switching circuit 2 having a changeover switch 21 for switching to
A transmission antenna 4 for transmitting the output of the combiner 3 is provided. In this wireless transmission device, signals output from the active transmitters 1 having different transmission frequencies are combined by the combiner 3 via the switching circuit 2 and transmitted from one antenna 4. The combiner 3 corresponds to each of the active transmitters 1 to ensure isolation between input signals.
It has two channel filters 31, and these channel filters 31 are configured by band-pass filters tuned in advance to different frequencies so as to pass only the transmission frequency of the connected working transmitter.

In this radio transmitting apparatus, when any one of the active transmitters 1 fails, the circuit is switched by the changeover switch 21 of the switching circuit 2 so that the failed active transmitter is replaced with the backup transmitter 1A. Can be switched,
Transmission can be secured. At this time, since the output frequency of the transmitter can be easily set by the synthesizer method, the transmission frequency of the switched spare transmitter 1A is set to the transmission frequency of the failed working transmitter.

[0004]

In this conventional radio transmitting apparatus, since the frequency of each channel filter 31 is set in advance, the spare transmitter is composed of a plurality of active transmitters 1.
The switching circuit 2 is provided so that switching can be performed for any of the above. For this reason, the switching circuit 2 requires, for example, the number of high frequency changeover switches 21 composed of coaxial relays, the same as the number of channel filters 31, that is, the number of active transmitters 1.

However, this type of changeover switch 21
However, there is a problem that the high frequency signal is turned on and off mechanically, so that the reliability is easily lowered, and the number of wirings and the number of connection points are large, so that a mismatch easily occurs and the high frequency characteristics are easily degraded. In addition, there is also a problem that the cost increases because a large number of expensive coaxial relays are required. An object of the present invention is to provide a wireless transmission device which does not require a switching circuit in order to solve such a problem.

[0006]

SUMMARY OF THE INVENTION A wireless transmission apparatus according to the present invention is adapted to transmit a plurality of active transmitters respectively corresponding to a plurality of active transmitters.
A combiner having a channel filter which is set to a frequency capable of outputting a signal signal, the filter frequency or external
And a channel filter having a frequency remote tuning function that can be changed by remote control of the transmitter.
Remote control when transmission of some data is disabled
The frequency of the channel filter
Set to the frequency of the active transmitter, and
Output the transmission signal at the same frequency as the transceiver.
It is configured as described above.

[0007]

According to the present invention, switching is performed by setting the frequency of the channel filter with the frequency remote tuning function to the frequency of the failed working transmitter and causing the standby transmitter to transmit at the frequency of the failed working transmitter. Switching between the active system and the standby system can be realized without using a circuit.

[0008]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a wireless transmission apparatus according to the present invention, and shows an example composed of three active transmitters 1 and one backup transmitter 1A. Each of the working transmitter 1 and the backup transmitter 1A is connected to a combiner 3 and connected to a transmission antenna 4. The combiner 3 is connected to a channel filter 31 set to a required frequency band corresponding to each working transmitter 1. The combiner 3 is provided with a channel filter 32 having a frequency remote tuning function corresponding to the backup transmitter 1A.

The channel filter 32 is automatically tuned to a designated frequency by an external remote operation.
1 so that it can be set to any of the frequency bands. This frequency variable function can be realized by a method using a variable capacitance element such as a varactor or a method of moving a resonance frequency adjusting rod provided in the resonator of the channel filter by a motor or the like. The output of the channel filter 32 is
1 and is connected to the antenna 4.

According to this configuration, if any of the working transmitters 1 fails and transmission becomes impossible, the channel filter 32
Is specified for the transmission frequency of the failed working transmitter and automatically tuned to that frequency. The backup transmitter 1A outputs a transmission signal at the frequency of the working transmitter that has failed. In this manner, switching from the active system to the standby system can be performed without using a conventional switching circuit.

When two or more backup transmitters are provided,
As shown in FIG. 3, the auxiliary transmitter 1B and the channel filter 33 are connected in parallel with the auxiliary transmitter 1A and the channel filter 32.
May be connected in parallel, and the degree of redundancy against device failure can be further improved.

[0012]

As described above, according to the present invention, a channel filter having a frequency remote tuning function whose filter frequency can be changed is provided in the combiner, and this channel filter is connected to the output of the standby transmitter. By tuning the frequency of this channel filter and performing transmission at that frequency from the standby transmitter, switching from the active system to the standby system can be realized, and a mechanically ON / OFF switching switch such as a coaxial relay is provided. Since the switching circuit used is not required, the reliability is improved, and the number of wirings and connection points is reduced, so that the high-frequency characteristics are also improved. In addition, since an expensive changeover switch and complicated wiring are not required, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a wireless transmission device according to the present invention.

FIG. 2 is a block diagram of a conventional wireless transmission device.

FIG. 3 is a block diagram of another embodiment of the wireless transmission device of the present invention.

[Description of Signs] 1 Working transmitter 1A, 1B Spare transmitter 3 Combiner 31 Channel filter 32, 33 Channel filter with frequency remote tuning function

Claims (1)

(57) [Claims] 1. A transmission signal having a unique frequency is output.
A plurality of working transmitters, at least one spare transmitter, and a transmitter for each working transmitter corresponding to each working transmitter.
And a combiner having a channel filter set to a frequency capable of outputting a communication signal , wherein the combiner has a filter frequency of external.
And a channel filter provided with a frequency remote tuning function that can be changed by remote control . The channel filter is connected to the output of the standby transmitter ,
When some of the transmitters are disabled,
The frequency of the channel filter by remote control
Set to the frequency of the unreliable working transmitter, and
Outputs the transmission signal at the same frequency as the working transmitter
Radio transmission apparatus characterized by being configured to the.