SU767999A1 - Device for transmitting signals with frequency modulation - Google Patents

Description

(54) DEVICE FOR TRANSFERING SIGNALS WITH FREQUENCY MODULATION

The invention relates to radio engineering and can be used in time-division information transmission systems.

A device for transmitting signals with frequency modulation is known, comprising a serially connected sync., A switch, a first switching unit, a correction unit, a modulator, a signal generator and a tunable band-pass filter, the synchronization input of which is connected to the output of the synchronizer and the synchronization input of the first switching unit. the second output of which is connected to the input of the modulator 1.

However, the known device does not provide high frequency stability of the transmitted signals.

The purpose of the invention is to increase the frequency stability of transmitted signals.

To do this, a device for transmitting signals with frequency modulation, containing a series-connected synchronizer, switch, first switching unit, correction unit, modulator, signal generator, and tunable band-pass fl, whose synchronization input is connected with a synchronizer input and the synchronization input of the first a switching unit, the second output of which is connected to the modulator input, a driver of the control signal, a key, a frequency divider, a driver of the pulses and a sequence are entered Flax-connected reference signal generator, phase modulator, phase detector, low-pass filter, second switching unit and amplifier whose output is connected to the second input of the signal generator, the output of which is connected to the input of a frequency divider whose output is connected to the first input of the key, the second input of which connected to the output of the pulse generator, the synchronization input of which is connected to the output of the synchronizer syn15 and the synchronization inputs of the second switching unit and the driver of the control signal, which input is connected to the second input of the phase modulator, and the OUTPUT key is connected

2Q with the second input of the phase detector.

FIG. 1 shows a structural electrical circuit of the proposed device; in fig. 2, al - voltage diagrams.

A device for transmitting signals with frequency modulation contains synchronizer 1, switch 2, tunable band-pass filter 3, first switching unit 4, correction unit 5, modulator 6, signal generator 7, reference signal generator 8, phase detector 9, low-pass filter 10 , amplifier P, frequency divider 12, phase modulator 13, control signal shaper 14, switch 15, pulse shaper 16, and second switching unit 17.

Fig. 2 shows the following voltage patterns:

a - signal at the output of switch 2;

b - clock pulses at the output of synchronizer 1;

in - the signal from the first output of the first switching unit 4;

g is the signal from the second output of the first switching unit 4;

d - signal from the output of the driver 14 of the control signal;

e is the frequency change at the first input of the phase detector 9;

W - signal from the output of the imager 16 pulses;

. 3 - change the frequency at the second input of the phase detector 9;

and - the signal at the output of the low-pass filter 10;

K - signal at the output of the second switching unit 17;

l - change the frequency at the output of the generator 7 signals.

The device works as follows.

The modulation of the useful information of the generator-7 is carried out by a signal from the switch 2 (Fig. 2, a) through the first switching unit 4, the correcting unit 5 and the modulator 6. In this case, the correcting unit 5 is adjusted so that the frequency or phase deviation from the main The frequency of the oscillator 7 was equal to the frequency or phase deviation at the shifted frequency of the oscillator 7. The frequency stability of the oscillator 7 is determined by the PLL circuit consisting of the oscillator 8 reference signals, the phase detector 9, the low-pass filter 10, the second switching unit 17, the amplifier 11, frequency divider 12, key 15. The PLL circuit auto-tunes the frequency of the generator 7 only during the action of the frame OBbix pulses that arrive at the key 15 from the driver 16 (Fig. 2, g), where OHM would be divided from the sync pulses supplied from synchronizer 1 (Fig. 2.6). Key 15. Closes and opens the PLL. the frequency of the oscillator 7 is adjusted at the fundamental frequency during the action of the tiepBOro personnel pulse, and at the shifted frequency - during the action of the second personnel pulse (Fig. 2, and).

The frequency shift is performed by changing the phase and frequency of the signal from the generator 8 reference signals using a phase modulator 13 due to a signal of a special form (for example, sawtooth) received in the driver 14 of the control signal (Fig. 2, e) from the clock pulses to it from the synchronizer 1. The phase detector 9 receives, therefore, a signal from the generator 8 reference signals with a frequency shift (Fig. 2, e) and a signal from the frequency divider 12 with a similar frequency shift (Fig. 2, h) . After

0 comparison in the phase detector 9, a step signal is obtained at its output, which is proportional to the departure of the fundamental and shifted frequencies and equal in duration to the duration of the action of the frame pulses. Passing through the lowpass filter 10, this signal (Fig. 2, i) is fed to the first input of the second switching unit 17, to the second input of which clock pulses are supplied from synchronizer 1 controlling the memory. As a result, a step signal is removed from the output of the second switching unit 17 (FIG. 2, k), stored at levels proportional to the fundamental and frequency shifted, during the period of the channel pulses until the next frame pulses arrive from the imager 16. Pass through the amplifier 11, this signal adjusts the frequency of oscillator 7. Tunable band-pass filter 3 per clock with clock pulses performs the necessary filtering of the output signal spectrum at the fundamental and shifted frequencies. The technical and economic effect of the application of the proposed device lies in the possibility of transmitting a highly informative signal over several radio channels with a high frequency stability of each

5 radio channels without phase failure and widening of the occupied frequency band.

Such a decision in several orders increases the stability of the carrier frequencies of the emitted signal, significantly increases the reliability of communication over the radio channel, allows for the use of bespodstroynoe connection in connection, improves the operational capabilities of the device, facilitates the maintenance of operating systems.

Since the device mainly contains

j are relatively low-frequency elements, the possibility of reducing its dimensions, weight, increasing efficiency, and increasing the device as a whole with the help of integrated technology increases.

® The proposed device was tested on a laboratory model, which confirmed the possibility of transmitting a highly informative signal over several radio channels with a high frequency stability of each radio channel without breaking the phase and extending the occupied frequency band. This made it possible to effectively apply multi-point coding, to achieve an increase in the speed of information transmission in half without

expansion of the allocated frequency band and showed the promise of using the device in the systems for transmitting analog-digital information with time division channels.

Claims (1)

Invention Formula A device for transmitting signals with frequency modulation, comprising a synchronizer connected in series, a switch, a first switching unit, a correction unit, a modulator, a signal generator and a tunable band-pass filter, whose synchronous input is connected to the synchronizer output and the synchronization input of the first switching unit, the second the output of which is connected to the modulator input, characterized by the fact that, in order to increase the frequency stability of the transmitted signals, a driver o signal key a frequency divider, a pulse shaper and a series-connected generator of reference signals, a phase modulator, a phase detector, a low-pass filter, a second switching unit and an amplifier, the output of which is connected to the second input of the signal generator, the output of which is connected to the input of the frequency divider, the output of which is connected to the first input of the key, the second input of which is connected to the output of the pulse shaper, synchronization the input of which is connected to the output of the synchronizer and the synchronization inputs of the second switching unit and the driver of the control signal, the output of which is connected to the second input of the phase modulator, and the output of the key is connected to the second input of the phase detector. Sources of information taken into account in the examination 1. USSR author's certificate 20 No. 542351, cl. H 04 J 4/00, 1975 (prototype). 2 frame, and fin. frame.inp F F / well m IT Srig. 2