RU1774496C - Automatic phase-locking unit - Google Patents

Abstract

Usage: radio engineering, receivers of phase-shift keyed signals. SUMMARY OF THE INVENTION: The device comprises 2 phase detectors 1.9. 1 comparator 2, 1 multiplier 3, 1 loop filter 4, comprising an integrating part 5 and a proportionally differentiating part 6, 1 tunable oscillator 7 and 1 phase shifter 90 ° deg; 8, bx-1-2-3-5-7-8, -1, bx-9-6-3, 7-9. The reduction of sharp changes in the frequency of the tunable generator 7, which impedes the device from entering synchronism, thereby leads to an increase in speed. 1 ill.

Description

The invention relates to radio engineering and can be used in phase-shift (FM) signal receivers.

A device is known that contains an in-phase and a quadrature channel (a tunable generator, the frequency control input of which is connected through a low-pass filter to the output of the phase detector of the in-phase channel, and the output of the phase detector of the quadrature channel is connected to a control input of a key that controls the electronic switch of the low-pass filter, moreover, the first output of the electronic switch is connected directly to the integrating block of the low-pass filter, and the second output of the electronic switch is connected to egriruyuschim unit through an inverter.

A disadvantage of this device is that. that at relatively high speed it is sensitive to a 180 ° change in the phase of the input signal.

A device is known comprising a tunable oscillator connected in a ring, a 90 ° phase shifter, a first phage detector, a comparator, a multiplier and a loop filter, as well as a second phase detector, the first input of the second phase detector being connected to the output of the tunable generator, the second inputs of the first and second phase detectors are the input of the device, and the output of the second phase detector is connected to another input of the multiplier.

The disadvantage of this device is its insufficiently high speed.

An object of the invention is to increase speed.

This goal is achieved by the fact that in the device for phase locked loop, comprising a tunable oscillator, a 90 ° phase shifter, a first phase detector, a comparator and a multiplier, as well as a proportional-integrating loop filter, a second phase detector, the first input of the second phase the detector is connected to the output by adjusting

with

Xi vj

I

CN

generator, and the second inputs of the first and second phase detectors are the input of the device, the proportionally differentiating part of the loop filter is connected between the output of the second phase detector and the other input of the multiplier, and the integrating part is between the output of the multiplier and the control input of the adjustable generator.

The drawing shows a functional diagram of the device.

The device for phase-locked loop includes a first phase detector 1, a comparator 2, a multiplier 3, a loop filter 4, consisting of an integrating part 5 and a proportionally differentiating part 6, an adjustable oscillator 7, a phase shifter 8 by 90 °, and a second phase detector 9. When the first phase detector 1, the comparator 2, the multiplier 3, the integrating part 5 of the loop filter 4, the adjustable oscillator 7 and the phase shifter 8 90 ° are connected in a ring, the first input of the second phase detector 9 is connected to the output of the tunable nerator 7, the second inputs of the first and second phase detectors 1 and 9 are combined and are the input of the device, the output of the second phase detector 9 is connected to the input of the proportional-differentiating part 6 of the loop filter 4, the output of which is connected to another input of the multiplier 3.

The device operates as follows,

In the process of entering the synchronous mode at the output of the multiplier 3, a beat signal is generated, the frequency of which in

two times the difference between the frequencies of the input signal and the signal of the tunable generator 7, Unlike the Costas system, this signal is not subject to this device

differentiation, since the proportionally differentiating part b of the loop filter 4 is located up to the multiplier 3. Due to this, the device does not differentiate signals having sharp changes. As a result, the level of the constant component, providing the transition to synchronous mode, in the signal at the input of the integrating part 5 of the loop filter

4 is higher than the Kosts system. This determines the increased performance of the device. Formula A phase locked loop containing a tunable oscillator, a 90 ° phase shifter, a first phase detector, a comparator and multiplier, and a proportional-integrating loop filter

type and a second phase detector, wherein the first input of the second phase detector is connected to the output of the adjustable oscillator, and the second inputs of the first and second phase detectors are the input of the device, characterized in that, in order to increase the speed, a proportionally differentiating part of the loop filter is connected between the output of the second phase detector and another input of the multiplier, and the integrating part is between the output of the multiplier and the control input of the adjustable oscillator.