JPS5869104A - Parallel operating system for fm modulator - Google Patents

Abstract

PURPOSE:To prevent the transmission output from being interrupted even momentarily, in switching two modulators, by giving an output of the 1st FM modulator to the 2nd FM modulator, taking the synchronism and picking up the output. CONSTITUTION:At normal operation, an output of the 1st FM modulator 2 is given to the 2nd FM modulator 3 via circulator 7 in the signal flow as shown in broken lines 10. An output of the modulator 2 is given to a modulator 3 so as to be synchronized. The output synchronized with that of the modulator 2 is outputted to the circulator 7 in the flow as shown in broken lines 11. Even if the modulator 2 is failed and the output is interrupted, the transmission output of the modulator 3 is uninterruptible and starts its operation as an independent modulator. Further, if the output of the modulator 3 is interrupted, since an input signal from the modulator 2 is almost fully reflected at an output terminal of the modulator 3, the output of the modulator 2 can be picked up from an output terminal 6, almost without power loss.

Description

DETAILED DESCRIPTION OF THE INVENTION (81 Technical Field of the Invention)
tion) relates to a parallel operation method of modulators.

(Background of BL technology The FM modulation section that constitutes a part of the radio equipment is usually required to have high reliability. Therefore, as a means to obtain high reliability of the FM inflection section, There have been proposed methods for increasing the reliability of the modulator itself, and (2) a method for operating two FM modulators in parallel, one for active use and one for backup.

However, since there is a limit to improving the reliability of the FM modulator itself, the above-mentioned method (2) of operating the FM modulators in parallel is more effective. In addition, such parallel operation is attracting attention because it is expected that the reliability of the modulation section as a whole will be dramatically improved. The parallel operation method of modulators will be explained.

In the figure, l is a hybrid circuit, 2 is a first FM modulator, and 3 is a hybrid circuit.
4 indicates a second FM modulator, and 4 indicates a changeover switch.

The baseband signal input from the input terminal is divided into two parts by the hybrid 1, and one part is sent to the first FM modulator 2 and the other part to the second FM converter tJN unit 3.

During normal operation when the two transformers are operating normally, the changeover switch 4 takes out only the output of the first modulator 4. In addition, FM51i, which constitutes the so-called working transformer 11,
When a failure occurs in the modulator 2, the changeover switch 4 is switched to connect the output terminal 6 to the output terminal of the so-called standby modulator 3.

In the above-mentioned conventional FM transformer, since the connection between the two modulators is switched by the switching switch, the transmission output is forced to be cut off during the above-mentioned switching between working and standby.

id1 Purpose of the Invention The present invention solves the above-mentioned problems in the conventional transmitting device, and provides a simple structure that does not cause instantaneous interruption of the transmitting output when switching between two transformers operating in parallel. The purpose is to provide a parallel operation method.

(el) Structure of the Invention In order to achieve the above object, the present invention is characterized in that the output of the $IFM modulator is injected into the second FM transformer, synchronized, and the output is taken out. FM strange F
This provides a parallel operation method for EAR.

An embodiment of the present invention will be described below with reference to FIG.

゛In the figure, parts indicated by the same drawing numbers as in Fig. 1 indicate the same parts, and 7 indicates the first FM transformer 2 and the second
A circulator is shown that connects the output end of the FM modulator 3 and the output end 6 from the modulation section to first to third ports, respectively.

During normal operation when the two modulators are operating normally, the output of the first FM modulator 2 is injected into the second FM modulator 3 via the circulator 7 with the signal flow shown in UA10. . The rotational characteristics of the circulator 7 are arranged so that the output of the first FM modulator 2 is injected into the second FM modulator 3 as shown in the figure, so that the first FM modulation B2
The output itself does not appear at the output terminal 6.

The second FM modulator 3 is injected with the output of the first FM modulator 2 and is synchronized. Therefore,! The output synchronized with the output of the IFM transformer 2 is shown by the broken line 11, and the signal flow is as follows.
- Output via curator 7.

Kokote, even if a failure occurs in the 1st FM unit 2 (around Wakashiku Hasono) and its output is cut off, the 2nd FM
Modulator 3 generates substantially the same output as when operating as injection-locked modulator 3. In other words, the 12 FM modulator 3 can
Operation as an independent variable ts'm is started without momentarily interrupting the transmission output.

On the other hand, if a failure occurs in the second FM modulator 3 (or its surroundings) and its output is cut off, the second FM modulator 3
Since the input signal from the first FM modulator 2 is substantially totally reflected at the output end of the first FM modulator 2, the output of the first FM transformer can be taken out from the output end 6 with almost no power loss.

As described above, according to the present invention, the second FM variable Di
Parallel synchronous operation is performed in which the second FM modulator is operated as an injected signal source and the second FM modulator is operated as an injected synchronous modulator. Also,
On the other hand, FM Hen 1! If the output of FM is cut off, the other FM tuner continues its operation without interrupting its transmission.

(g) Effects of the Invention According to the present invention, the failure rate of a single modulator can be reduced by P(<
1), & makes it possible to operate with extremely high reliability because the failure occurrence rate during parallel operation is approximately P2.

Therefore, compared to the conventional parallel operation method, the reliability of the entire modulation section can be greatly improved, and the complicated switch control process can be omitted, and the transmission output can be interrupted when switching the modulator. None.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional parallel operation system of 11 FM transformers, and FIG. 2 is a block diagram showing a parallel operation system according to the present invention. In the figure, ■ is a hybrid, 2 is a first FM modulator, 3 is a second FM modulator, 4 is a changeover switch, and 7 is a circulator.

Claims (1)

[Claims] The input base punt signal is divided into two, one is input to a first FM modulator, and the other is input to a second FM modulator having substantially the same operating characteristics as the first FM modulator, thereby operating the FM modulators in parallel. A parallel operation system for FM modulators, characterized in that the output of the first F'M modulator is injected into the second FM modulator, synchronized, and the output thereof is taken out.