RU2635272C1 - Digital-to-analog synthesizer of complex frequency-modulated signals - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: digital-to-analog synthesizer of complex frequency-modulated signals comprises of a digital computing synthesizer, a voltage controlled oscillator (VCO) with two control elements, a first divider with a variable division coefficient (DVDC), a second divider with a variable division coefficient, a first phase discriminator, a low pass filter (LPF), a third divider with a variable division coefficient, a modulator, a second phase discriminator.

EFFECT: providing frequency tuning by introducing a second control loop and increasing the speed of acting.

1 dwg

Description

The invention relates to electronic computing and radio engineering, is intended for the formation of frequency-modulated signals and can be used in telecommunication systems and modern adaptive communication systems.

Known frequency synthesizers incorporating a voltage controlled oscillator (VCO) having two control elements [1].

The closest technical solution (prototype) is a synthesizer with a V-shaped law of frequency modulation, containing a clock pulse generator, a reverse counter, a digital-to-analog converter, a VCO, a code comparison circuit, a constant memory unit, a first frequency divider, a phase discriminator, a second frequency divider, and a digital computational synthesizer [2].

However, the well-known frequency synthesizers have a relatively low speed and narrow functionality.

A positive technical result - expanding the functionality of the synthesizer and increasing its speed - is achieved due to the fact that the digital-analog synthesizer of complex frequency-modulated signals containing a series-connected digital computer synthesizer, a second divider with a variable division ratio, the first phase discriminator; a voltage-controlled oscillator (VCO) connected in series with two control elements and a first divider with a variable division ratio, and the new one is that a second control loop is introduced, consisting of a modulator, a second phase discriminator, a third divider with a variable division ratio, and the output of the VCO connected to the input of the third divider with a variable division ratio, the output of the latter is connected to the first input of the second phase discriminator, the second input of which receives a signal from odulyatora; the output of the second phase discriminator is connected to the second VCO control element; the output of the first frequency divider with a variable division coefficient is connected to the second input of the first phase discriminator, the output of which is connected through the low-pass filter to the first control element of the VCO; the VCO output is the analog output of a digital-to-analog synthesizer.

The digital-analog synthesizer of complex frequency-modulated signals contains a digital computational synthesizer 1, a voltage-controlled oscillator (VCO) 2 with two control elements, a first divider with a variable division ratio (DPKD) 3, a second divider with a variable division coefficient 4, the first phase discriminator 5, low-pass filter (LPF) 6, a third divider with a variable division ratio 7, a modulator 8, a second phase discriminator 9. The output of the VCO 2 is the analog output of a digital-to-analog synthesizer.

The digital-analog synthesizer of complex frequency-modulated signals contains a digital computational synthesizer 1 connected in series, a second divider with a variable division ratio (DPKD) 4, the first input of the first phase discriminator, a low-pass filter (LPF) 6, the first control element of the VCO 2; VCO 2 is connected to the input of the first divider with a variable division ratio (DPKD) 3, the output of which is connected to the second input of the first phase discriminator; connected in series modulator 8, the first input of the second phase discriminator 9, the second control element of the VCO 2; the output of the VCO 2 is connected to the input of the third divider with a variable division ratio (DPKD) 7, the output of the latter is connected to the second input of the second phase discriminator 9; VCO 2 output is an analog output of a digital-analog synthesizer.

The digital-analog synthesizer of complex frequency-modulated signals works as follows.

Digital computational synthesizer 1 generates a signal with the desired frequency modulation, which is fed to the second frequency divider 4, where it is divided N times and then fed to the first input of the first phase discriminator 5; VCO 2 generates a sinusoidal signal, which is M times divided in the first frequency divider and fed to the second input of the phase discriminator 5, the output of the latter through the low-pass filter 6 is connected to the first control element of the VCO 2.

Thus, the frequency at the output of the VCO 2 can be described by the formula

To transmit the information message, a modulator 8 is used, the output signal of which goes to the first input of the second phase discriminator; the output frequency of the VCO 2 is divided K times in the third frequency divider 7 and is fed to the second input of the phase discriminator 9, the output of which is connected to the second control element of the VCO 2.

Thus, the output of the VCO 2 will be the following combination of frequencies:

The signal at the output of the VCO 2 can be described by the formula

Thus, at the output of the digital-analog synthesizer, a complex frequency-modulated signal is obtained, which can be used in modern adaptive communication systems with software tuning of the operating frequency.

Literature

1. V. Manassevich. Frequency synthesizers. M .: Radio and communications, 1979.

2. RF patent No. 2407144. IPC H03L 7/18. A synthesizer with a V-shaped law of frequency modulation / Ryabov I.V., Dedov A.N., Yuryev P.M. Claim 06/22/2009. Publ. 12/20/2010. Bull. Number 35. - 8 p.

Claims (1)

Digital-to-analog synthesizer of complex frequency-modulated signals, comprising a series-connected digital computational synthesizer, a second divider with a variable division ratio, a first phase discriminator; a voltage-controlled oscillator (VCO) connected in series with two control elements and a first divider with a variable division ratio, characterized in that a second control circuit is introduced, consisting of a modulator, a second phase discriminator, a third divider with a variable division ratio, the output of the VCO connected to the input of the third divider with a variable division coefficient, the output of the latter is connected to the first input of the second phase discriminator, the second input of which receives a signal from the modulate pa; the output of the second phase discriminator is connected to the second VCO control element; the output of the first frequency divider with a variable division coefficient is connected to the second input of the first phase discriminator, the output of which is connected through the low-pass filter to the first control element of the VCO; the VCO output is the analog output of a digital-to-analog synthesizer.

Images