SU1483588A1 - Frequency-modulated signal shaper - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to increase the frequency stability. The goal is achieved by introducing the synchronizer 7, and the phase tracking unit 4 contains two subtractors, two keys, two memory units, an integration unit and an inverter. During the modulation time, the second subtractor and the integration unit determine the total phase shift at the output of the target detector 3 due to the modulation. During the transition to a pause, the full phase shift is remembered in the second storage unit, frequency divider 2 is preset (to output the phase detector 3 to the operating point) and the oscillator 1 is tuned to the automatic oscillator frequency mode. At the same time, no phase transition occurs. The output of the first subtractor will be equal to the voltage at the output of the first memory unit, thereby increasing the frequency stability. 1 hp f-ly, 2 ill.

Description

Output

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FIG. one

The invention relates to radio engineering and can be used for frequency modulation of oscillators in radio engineering systems for generating frequency modulated signals.

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

FIG. Figure 1 shows a structural electrical circuit for the formation of a frequency-modulated signal; in fig. 2 shows an example of the execution of a phase tracking unit.

The shaper of frequency-modulated signals contains an auto-oscillator 1, a divider 2 frequencies, a phase detector 3, a phase tracking unit 4, a control element 5, an amplitude selector 6, a synchronizer 7, a frequency modulator 8, and a reference generator 9. The phase tracking unit 4 contains the first subtractor 10, the first key 11, the first storage unit 12, the second subtractor 13, the integration unit 14, the second key 15, the second storage unit 16 and the inverter 1 7.

Shaper frequency-modulated signals as follows.

When the power is turned on and in the pause in the modulating signal (for example, when the clock signal is in the television signal), the output of the amplitude selector 6 is a high potential that allows the synchronizer 7 to pass one pulse from the reference generator 9 to the divider 2 frequencies and thereby realize it preset. At the same time, a low potential from the synchronizer 7 is applied to the control input of the phase tracking unit 4. This voltage closes the key 15 of the unit 4 (therefore, the memory unit 16 remembers O and opens the key 11 (the control voltage is supplied to it through the inverter 17). The frequency and phase of the signal from the output of the auto generator 1, divided by divider 2, are compared in phase detector 3 with the frequency and phase of oscillation of the reference generator 9. The error signal from the output of phase detector 3 through subtractor 10, key 11 and block 12 is given to the control element 5, with which the frequency of the oscillator 1 is changed and adjusted to the value of GLG) Nf0, where N is the division factor of the splitter 2 frequency; f0 is the oscillation frequency of the reference generator 9.

At the end of the pause: at the output of the amplitude selector 6, the potential is low, which will cause a high potential at the output of the synchronizer 7, which, in turn, will close the key 11 of block 4, memorize in block 12 the memory of the tuning of the autogenerator 1 and open the key 15. Block 4

5 will go into phase shift tracking mode by varying the frequency of the oscillator 1 during frequency modulation. During the modulation time using the subtractor 13 and block 14

0, the integration determines the total phase shift at the output of the phase detector 3 due to modulation. When going back to the pause, the full phase shift is remembered in the memory block 16,

5, a divider 2 frequency is preset (in order to output the phase detector 3 to the operating point) and transition to the auto-tuning mode of the oscillator 1. At the same time, there will be no transient in phase, since the voltage at the output of the subtractor 10 will be equal to the output voltage a storing unit 12, thereby increasing frequency stability.

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Claims (2)

1. A shaper of frequency-modulated signals, containing a series-connected oscillator, to the first and second control inputs of which are connected respectively the outputs of the control element and the frequency modulator, and the divider frequencies connected in series with a reference oscillator and a phase detector, as well as an amplitude selector, the frequency modulator input being a modulating signal input, and the oscillator output being an output of a frequency modulated signal former, in order to increase frequency stability, A synchronizer is inputted to it, the signal input of which is connected to the output of the reference generator, the control input to the output of the amplitude selector, and the first output to the setting input of the divider frequency, and a phase tracking unit, whose information input is connected to the output of the phase detector, the control input to the second output of the synchronizer, and the output to the input of the control element, while the input of the amplitude selector is connected to the input of the frequency modulator, and the output of the divider frequency is connected to the second input of the phase detector. 2. The former according to claim 1, characterized in that the phase tracking unit comprises, in series, a first reader, a first key, a lion, a memory unit, the second subtractor, the integration unit, the second key and the second block of minning, the output of which is connected to the first input of the first subtractor, as well as the inverter, the input of which is connected to the control input of the second key, and the output In this way, the output of the first subtractor is connected to the second input of the second subtractor, the second input of the second subtractor is an information input, the control input of the second key is a control input, and the output of the first storage unit is the output of the phase tracking unit. Output FIG. Z