SU879792A1 - Device for checking frequency-modulated signals - Google Patents

Description

(54) DEVICE FOR CONTROL OF FREQUENCY MODULATED SIGNALS

I

The invention relates to radio engineering .;

A device for controlling frequency-modulated multichannel lines of a satellite communication is known, containing a series-connected antenna, input amplifier, mixer, intermediate frequency amplifier and receiver of frequency-modulated signals, a local oscillator whose output is connected to another mixer input, a switch whose output is connected to an indicator input and calibrator Ij.

However, in the known device a significant time control.

The purpose of the invention is to reduce the control time.

To do this, into a device controlling frequency-modulated signals of multichannel communication lines containing a serially connected antenna, input amplifier, mixer, intermediate frequency amplifier and receiver of frequency-modulated signals, a local oscillator whose output is connected to another mixer input, a switch which output is connected to indicator and calibrator, a splitter, a carrier separation unit and a modulator are inserted, while another output of the intermediate frequency amplifier is connected to the input of the splitter of the first th output of which through the block separating the carrier is connected to the first input of the modulator, a second input of which the output soedinens calibrator output modulation podklk torus) chen to a first input of the switch 5, the second input of which soediien the second output of the splitter.

The drawing shows a structural electrical circuit of the device. The device contains an antenna 1, an input

10 amplifier 2, mixer 3, local oscillator 4, intermediate frequency amplifier 5, receiver 6 of frequency-modulated signals splitter 7, switch 8, indicator 9, carrier separation 10, modulator 11 15 and calibrator 12..

The device works as follows.

The frequency modulated signals of a multichannel communication line are fed to antenna 1, amplified by input amplifier 2, and fed to mixer 3.

With the help of a local oscillator 4

20 signal conversion to intermediate frequency. Intermediate-frequency signals are amplified by amplification of 5 and fed to

standard receiver 6. The bandwidth of amplifier 5 is chosen equal to the width of the portion of the range in which all trunks of the monitored multi-channel communication link are located. Standard receiver 6 demodulates signals and gives the ability to monitor the group spectrum and the capacity of each barrel.

From the BTopoR output of the amplifier 5, the signals of the intermediate frequency through the splitter 7 and the electronic switch 8 are fed to the indicator 9. From the second output of the splitter 7, signals are sent to the block 10 ' which carries out the selection of the carriers of each trunk. All carriers are fed to the modulator 11, in which they are modulated by the auxiliary signal of the calibrator 12. The parameters of the auxiliary signal can vary within wide limits.

Through the electronic switch 8, carriers, modulated by the auxiliary signal, are applied to the indicator 9. Thus, the indicator 9 induces both real signals from the output of amplifier 5 and calibrated auxiliary signals with a certain periodicity.

Since the auxiliary signals coincide in the center frequency with the signals of the multilateral link, it is obvious that during the control it is not necessary to make both the tuning and the possible re-adjustment while adjusting the calibrator 12,

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thereby reducing the average signal monitoring time.

Claims (1)

1. US patent No. 3930200, CL. H 04 H 17/00, published 1977 (prototype). / / 7