SU526997A1 - Device for automatic frequency control, changing according to a given law - Google Patents

Description

one

The invention relates to radio engineering and can be used, for example, in radiolocation, in communication technology.

A device for automatic frequency control is variable, varying by a given law, containing a controllable generator connected in a ring, a phase detector, a second input connected to a reference: a generator, a key, a low-pass filter and an adder, the second INPUT of which is connected to the modulator, and the third through the correction unit a pulse-phase detector with a synchronizer connected to the control inputs of the modulator and the key. However, in the known device, the allowable deviations from a given law of frequency variation, at which synchronization is possible, are small.

The purpose of the invention is to increase synchronization fleece with respect to a given frequency variation law. For this, between the second input of the pulse-phase detector and the second output of the key, an oscillator with a variable frequency is connected to a sequence of pulses of SO With a constant frequency, the second input of which is connected to the output of the synchronizer.

The drawing shows a block diagram of the device.

A device for automatic frequency regulation, changing according to a given law, contains connected in 1 ring controlled generator 1, phase detector 2, a second input connected to a reference generator 3, a key 4, a low pass filter (LPF) 5 and an adder 6, the second input of which is connected with the modulator 7, and the third through the correction unit 8 and the pulse-phase detector 9 with the synchronizer 10 connected to the control inputs of the modulator 7 and the key 4, moreover, between the second input of the pulse-phase detector 9 and the second output of the key 4 oscillations with a variable frequency in the sequence of pulses with a constant frequency of the Following, the second input of which is connected to the output of the synchronizer 10.

The device works as follows.

Prior to modulation, the phase locked loop, consisting of controlled oscillator 1, phase detector 2, switch 4, low pass filter 5, and adder -6, nullifies both the frequency difference and the phase difference of the controlled and reference oscillators 1 and 3. With the start of modulation using key 4, the first ring is opened and the modulator 7 is turned on. In this case, the voltage at the output of phase detector 2 varies according to the law:

and - sin 0,5 Zg%

2r.W

where p

treoyema frequency variation rate;

co-frequency deviation;

T is the duration of the signal; t is the time counted from the beginning of the modulation.

The change in phase "and the integer number of periods / (0, 1, 2, 3, correspond to the following times:

, / - 4.Y

four

Have

In converter 11, only O, 1, 4, 9, etc., pulses are generated from IMPulsoe, which are formed at times th, which, if the given modulation law is strictly followed, follow the same intervals

Ktvremeni equal

When the frequency of auto-oscillations deviates from the given one, the position of the pulses changes. Comparing this sequence of pulses from the converter 11 with the reference pulse from the synchronizer 10, the error signal of the processing unit in the Pulse Phase Detector 9 is selected 8 adjusts the frequency of the controlled oscillator 1 in accordance with the required law of its change.

Claims (1)

Invention Formula A device for auto-tuning the frequency, varying according to a given law, containing a controllable oscillator connected in a ring, a phase detector, a second input connected to a reference oscillator, a key, a low-pass filter and an adder, the second input of which is connected to the modulator, and the third through a correction unit and a pulse-phase detector — with a synchronizer connected to the control inputs of the modulator and key, characterized in that, in order to increase the synchronization band relative to a given frequency variation law, between the second input of the pulse phase detector and The second output of the key is a variable frequency oscillation transducer in the sequence of pulses with a constant tracking frequency, the second input of which is connected to the synchronizer output. I „I