JPH04314215A - Totally solid-state transmitter - Google Patents

Abstract

PURPOSE:To always keep an output level of a transmitter to a 100% level even when one or over of plural solid-state power amplifiers operated in parallel stops its operation. CONSTITUTION:When an output of one set of active solid-state power amplifiers 7-10 is stopped due to a fault, a changeover device connecting to the failed active solid-state power amplifier among the changeover devices 12-15 is operated and output of a standby solid-state power amplifier 11 is fed to a synthesizer 17. Thus, even when one of the active solid-state power amplifiers 7-10 is failed, an output of a transmitter is kept to 100%. Moreover, the relation of the phase of the signal fed to the synthesizer 17 is always kept constant.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an all-solid-state transmitter used for broadcasting, for example.

0002

2. Description of the Related Art As an example of a conventional all-solid-state transmitter, a system diagram of an all-solid-state FM transmitter is shown in FIG. In this figure, this all-solid-state transmitter uses two FM exciters and four solid-state power amplifiers so that even one transmitter has redundancy to improve reliability. The carrier waves generated by the first and second FM exciters 23 and 24 are FM-modulated by the audio signals applied to the audio signal input terminals 21 and 22. The outputs of these two FM exciters 23 and 24 are switched by a switch 25 and applied to a distributor 26. The signals divided into four by the divider 26 are applied to the first to fourth solid-state power amplifiers 27 to 30, respectively, and amplified. These four solid-state power amplifiers 27
The four signal outputs of 30 to 30 are combined by a combiner 37,
After harmonic components are removed by the harmonic filter 38, the signal is taken out from the output terminal 39 as the output of the transmitter.

In this conventional all-solid-state transmitter, redundancy is provided by using two FM exciters 23 and 24 as active backup systems in the excitation stage, and four solid-state power amplifiers in the power amplification stage. 27 to 30 are operated in parallel to provide redundancy.

0004

[Problem to be Solved by the Invention] By the way, in a transmitter that normally operates n power amplifiers in parallel, when one of the plurality of power amplifiers stops outputting, the output level of the transmitter becomes (n-1)2/n2. Therefore, when four solid-state power amplifiers are operated in parallel as in the conventional all-solid-state transmitter mentioned above, even if one solid-state power amplifier stops operating, the transmitter's Although the output does not stop, the output level drops to about 56%. Such a reduction in the transmission output level has a particularly large effect on viewers located at the edge of the service area, and is not desirable from the viewpoint of securing the service area.

The present invention was proposed in order to solve the problems of the conventional technology, and even if one or more of a plurality of solid-state power amplifiers stops operating,
The purpose of the present invention is to provide an all-solid-state transmitter that can maintain the output level of the transmitter at 100% level.

[0006]

[Means for Solving the Problems] In order to achieve this object, the present invention provides an all-solid-state transmitter configured to operate a plurality of solid-state power amplifiers in parallel to provide redundancy. The configuration includes a power amplifier and a switch that can switch the current solid-state power amplifier to this standby solid-state power amplifier for use.

[0007]

[Operation] According to this configuration, even if one or more of the plurality of active solid-state power amplifiers operating in parallel fails, the failed solid-state power amplifier can be switched to the backup solid-state power amplifier. Therefore, the transmission output is not reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the all-solid-state transmitter according to the present invention will be described in detail below with reference to the drawings. In Figure 1, F.M.
An example of this all-solid-state transmitter applied to a transmitter will be shown. In this figure, carrier waves oscillated by first and second FM exciters 3 and 4 are FM-modulated by audio signals applied to audio signal input terminals 1 and 2, and these FM exciters 3,
The output of 5 is switched by a switch 5 and supplied to a distributor 6. The signal distributed into five by this distributor 6 is the first
to a fourth four current solid-state power amplifiers 7 to 10;
The signals are respectively added to one standby solid-state power amplifier 11 and amplified. The four outputs of these four currently used solid-state power amplifiers 7 to 10 pass through switchers 12 to 15, are combined in a combiner 17, and after harmonic components are removed by a harmonic filter 18, the output is It is taken out from terminal 19 as the output of the transmitter.

The output terminal of the standby solid-state power amplifier 11 is
They are connected to switchers 12 to 15, respectively, and can switch between one of the four active solid-state power amplifiers 7 to 10 and the standby solid-state power amplifier 11 by these switchers 12 to 15. Note that 16 is a dummy load.

In the all-solid-state transmitter having such a configuration, when one of the currently used solid-state power amplifiers 7 to 10 stops outputting due to a failure, the currently used solid-state power amplifier of the failed solid-state power amplifiers 12 to 15 The switch connected to the solid-state power amplifier is operated to supply the output of the standby solid-state power amplifier 11 to the combiner 17. As a result, even if one of the currently used solid-state power amplifiers 7 to 10 breaks down,
Transmitter output can be maintained at 100%. Note that the phase relationship of the signals supplied to the combiner 17 is always kept constant.

[0011] In the above-mentioned embodiment, an example was explained in which four solid-state power amplifiers are currently used, but the present invention is not limited to four, and the present invention is applicable to a transmitter that uses a plurality of currently-used solid-state power amplifiers. also applies. It can also be applied to a transmitter that uses only one FM exciter. When using a large number of solid-state power amplifiers, or when trying to increase safety by maintaining 100% output level even if one or more amplifiers fail at the same time, use a spare solid-state power amplifier. Two or more power amplifiers may be provided.

[0012]Although the embodiment shows the case of an FM transmitter, the present invention can also be applied to a television transmitter. In the case of a television transmitter as well, it is necessary to separately provide standby solid-state power amplifiers and switching devices for video and audio.

[0013]

As explained above, according to the present invention, when one or more of the plurality of active solid-state power amplifiers fails, it is possible to switch to the standby solid-state power amplifier. The conventional problem of a drop in transmitter output is eliminated, and 100% output level can be maintained at all times.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an all-solid-state transmitter according to the present invention.

FIG. 2 is a block diagram of a conventional all-solid-state transmitter.

[Explanation of symbols]

1, 2 Audio signal input terminal 3,4 FM exciter 5　Switcher 6. Distributor 7 to 10 Current solid state power amplifier 11 Spare solid-state power amplifier 12 to 15 Switcher 16 Dermi Road 17 Synthesizer 18 Harmonic filter 19 Transmitter output terminal

Claims (2)

[Claims] [Claim 1] In an all-solid-state transmitter configured to operate multiple solid-state power amplifiers in parallel to provide redundancy,
1. An all-solid-state transmitter comprising a spare solid-state power amplifier and a switch for switching a current solid-state power amplifier to the spare solid-state power amplifier. 2. The all-solid-state transmitter according to claim 1, further comprising a plurality of standby solid-state power amplifiers.