RU2288539C1 - Phase- and frequency-modulated receiving device - Google Patents

Abstract

FIELD: radio communications; broadband radio stations, enhanced security and noise immunity data transfer systems.

SUBSTANCE: proposed device characterized in extended spectrum of data signals transferred due to tuning their central frequencies obeying linear law and reversing polarity of frequency tuning rate, as well as due to combination of matched filtering including weight processing and time selection of signals and noise being received has synchronizer, switching unit, modulator, mixer, output matching unit, linear frequency-modulated oscillator, and frequency synthesizer on sending end. Modulator has band filters, switches, adder, and inverter. On receiving end device has linear matching unit, second mixer, band filters, intermediate-frequency amplifiers, amplitude detectors, integrators, flip-flops, dispersing compression filters, two switches, AND unit, frequency divider, OR unit, and second frequency synthesizer.

EFFECT: enhanced noise immunity in spot jamming environment.

1 cl, 10 dwg

Description

The invention relates to the field of radio communications and can be used in the development of broadband radio stations and data transmission systems with increased stealth and noise immunity.

Known devices for transmitting and receiving modulated in phase and frequency signals [AS No. 684750, IPC ⁷ : H 04 B 7/165, 1979; Japan application No. 49-25043, IPC N 04 V, 1974], which contain on the transmitting side a synchronizer, the outputs of which are connected to the inputs of the phase and frequency modulators through the corresponding switches, and an output matching unit, while the second inputs of the switches are fed information signals, on the receiving side, a linear matching unit, the output of which is connected to the input of the delay unit and to the inputs of bandpass filters, the outputs of which are connected to the inputs of the maximum signal detector through the corresponding amplitude detectors, rows through integrators which are connected to trigger inputs, and the frequency modulator and the reference signal generating unit, whose output is connected to the first input of the phase detector, the output of the respective integrator is connected to the input of the frequency modulator.

The disadvantage of these devices is low noise immunity.

Of the known devices, the closest in technical essence and the achieved effect is a device for transmitting and receiving modulated in phase and frequency signals [AC No. 684750, IPC ⁷ , N 04 V 7/165, 1979], containing on the transmitting side - connected in series synchronizer, first switch, phase modulator, mixer, to the second input of which is connected the output of the frequency modulator, consisting of two keys, the outputs of which are the output of the frequency modulator, the first inputs of which are connected to the second through the second switch the output of the synchronizer, and the second inputs of the keys of the frequency modulator through the corresponding outputs of the frequency synthesizer are connected to the second input of the phase modulator, and also contains an output matching block, the output of which is the output of the transmitting side, on the receiving side is a linear matching block, the input of which is the input of the receiving side connected in series to a delay unit, a mixer, to the second input of which is connected the output of a frequency modulator consisting of two keys, the outputs of which are the frequency modulator, an intermediate frequency amplifier and a phase detector, the output of which is the first output of the receiving side, the output of the intermediate frequency amplifier is connected to the reference signal generating unit, the first output of which is connected through the frequency synthesizer to the first inputs of the frequency modulator keys, and the second output is connected to the second input of the phase detector, and also contains two bandpass filters, the inputs of which are connected to the input of the delay unit, and the outputs through the corresponding amplitude detectors connected to the corresponding inputs of the maximum signal detector, the outputs of which are connected through the respective integrators to the second inputs of the keys of the frequency modulator and the corresponding inputs of the trigger, the output of which is the second output of the receiving side.

The disadvantage of this device is the low noise immunity in the field of impact interference. In this case, from the output of the integrators to the key inputs of the frequency modulator and the trigger, two logical “1” or “0” can simultaneously arrive, which will lead to a violation of the operation algorithm of both the frequency modulator and the trigger, and this will cause a violation of the reception conditions of the phase-modulated (FM) signal, and, as a result, will reduce the quality of information reproduction.

Thus, the disadvantage of the prototype is the low noise immunity in the field of impact interference.

The technical result of the invention is to increase the noise immunity of a device for transmitting and receiving phase and frequency modulated signals under impact interference by expanding the range of transmitted information signals by linearly adjusting their center frequencies and changing the sign of the frequency tuning speed, as well as combining matched filtering with weight processing and temporal selection of received interference signals.

This result is achieved due to the fact that in the known device for transmitting and receiving modulated in phase and frequency signals, containing on the transmitting side are serially connected synchronizer, switch, the second input of which is the information input of the transmitting side, a modulator, a first mixer and an output matching unit , the output of which is the output of the transmitting side, on the receiving side is a linear matching unit, the input of which is the input of the receiving side, the second mixer, two band ph liters, an intermediate frequency amplifier, two amplitude detectors, two integrators and a trigger, the outputs of the first and second integrators being connected to the corresponding inputs of the trigger, the output of which is the output of the receiving side, a linear frequency-modulated generator and a first frequency synthesizer are introduced on the transmitting side, the first the input of the linear frequency-modulated generator is connected to the second output of the first frequency synthesizer, the first output of which is connected to the second input of the first mixer, the second input a linear frequency-modulated generator is connected to the output of the synchronizer, and the output of the linear frequency-modulated generator is connected to the second input of the modulator, while the modulator is made in the form of two bandpass filters, two keys, an adder and an inverter, the inputs of the first and second bandpass filters connected to the second the input of the modulator, and the outputs of the first and second bandpass filters through the corresponding keys are connected to the corresponding inputs of the adder, the output of which is the output of the modulator, while th second switch input coupled to an output of the inverter, the input of which is the first input of the modulator and is connected to the second input of the first key; two dispersion compression filters, two keys, a second intermediate frequency amplifier, a second trigger, a second frequency synthesizer, an OR block, an AND block and a frequency divider are introduced on the receiving side, the output of the linear matching block through the second mixer connected to the inputs of the third and the fourth bandpass filter, the output of the third bandpass filter is connected to the input of the first integrator through a series-connected first dispersion filter, the third key, the first IF amplifier and the first amplitude detector, and the fourth the gloss filter is connected to the second integrator through a second dispersion filter, a fourth key, a second IF amplifier and a second amplitude detector connected in series, the outputs of the first and second integrators being connected respectively to the corresponding inputs of the OR block, the output of which is connected to the first input of the second trigger, the first output which is connected to the second inputs of the third and fourth keys, the second output of the second trigger is connected to the second input of the And block, the first input of which is connected to the second output of the second th frequency synthesizer, a first output of which is connected to the second input of the second mixer and the output of the block "I" through a frequency divider coupled to the second input of the second flip-flop.

The proposed technical solution is new, because from publicly available information, a device for transmitting and receiving phase and frequency modulated signals is not known, which provides increased noise immunity in impact interference by expanding the spectrum of transmitted information signals by tuning their center frequencies linearly and by changing the sign of the tuning speed frequency, as well as a combination of matched filtering with weight processing and temporary selection of received signals.

In the proposed device, the expansion of the spectrum of transmitted information signals (logical "1" and "0" binary information) is achieved by linear frequency-modulated radio pulses with positive and negative values of the frequency tuning frequency [Kochemasov VN, Belov LA, Okoneshnikov BC Signal generation with linear frequency modulation. -M.: Radio and Communications, 1983, pp. 124-127]. For this purpose, a linear frequency-modulated oscillator (LFMG), two bandpass filters, two keys, an adder and an inverter are introduced on the transmitting side.

To implement coordinated filtering of LFM radio pulses with positive and negative values of the frequency tuning rate, a mixer, a frequency synthesizer, two dispersion compression filters, and an intermediate-frequency amplifier are introduced at the receiving side.

раз [Ч.Кук, М.Бернфельд. Радиолокационные сигналы, Теория и применение. Перевод с английского под редакцией B.C.Кельзона. М., "Сов. радио", 1971, рис.1.8, стр.24], где τ_И, ΔF - длительность и девиация частоты ЛЧМ радиоимпульса.The use of dispersion compression filters increases the amplitude of compressed informational radio pulses by at least

times [C. Cook, M. Bernfeld. Radar signals, Theory and application. Translation from English edited by BC Kelson. M., "Sov. Radio", 1971, Fig. 1.8, p. 24], where τ _И , ΔF are the duration and frequency deviation of the LFM radio pulse.

To reduce the level of the side lobes of the compressed signal in the device, it is proposed to use dispersion compression filters with Hamming weighted processing [C. Cook, M. Bernfeld. Radar signals, Theory and application. Translated from English by B.C. Kelson. M., "Sov. Radio", 1971, Fig. 7.14, p. 218]. The duration of the compressed signal when measured at a level of 4 dB below the peak amplitude is close to the calculated one [Ch. Cook, M. Bernfeld. Radar signals, Theory and application. Translated from English by B.C. Kelson. M., "Sov. Radio", 1971, p. 215]

So, for example, for the frequency deviation ΔF = 1.0 MHz, the calculated duration of the compressed signal from expression (1) is 1.3 μs, and obtained experimentally (see Fig. 5) is 1.65 μs.

The use of dispersive compression filters with Hamming-weighted processing makes it possible to isolate the compressed signal against the background of impact interference when the interference exceeds the signal by more than 33 dB (see Fig. 6) or by an interference-masked uncompressed signal (see Fig. 7). The selection of the compressed signal against the background of interference (see Fig. 8) is explained by the fact that the components of the harmonics of the noise have random phase values and at the output of the dispersion compression filter, all noise harmonics are added randomly, partially canceling each other [V. Svistov. Radar signals and their processing. M., "Sov. Radio", 1977, 448 pp. see page 178].

The duration of the interference τ _P at the output of the dispersion compression filter does not change and practically coincides with the repetition period of information chirp pulses

Temporary selection of information signals from impact interference is ensured by introducing two keys on the receiving side, an “OR” block, a second trigger, an “I” block, and a frequency divider.

The second trigger forms a strobe (logical signal "0"), which is fed to the second inputs of the third and fourth keys and reduces the level of impact interference at the output of the first and second integrators (see Fig. 8).

The duration of the strobe is selected from the condition

Then, the duration of the interference _jam τ _pp on the output of the third and fourth keys can be found from expression (3)

From the ratio of expressions (2) and (4) we find the suppression coefficient of impact interference

So, for example, for the repetition period of information LFM pulses T = 32 μs and frequency deviation ΔF = 1.0 MHz, the noise immunity of the transmission and reception device for signals phase and frequency modulated under impact interference only due to temporal selection will be more than 12 times .

Figure 1 shows the structural diagram of the transmitting side of the proposed device, figure 2 is a structural diagram of the receiving side of the device, figure 3 is a structural diagram of a linear frequency-modulated generator, figure 4 is the amplitude-frequency spectrum of the signal at the output of the linear frequency -modulated generator, in Fig.5 - amplitude-frequency characteristics of the first and second bandpass filters, respectively, Fig.6 is a view of the compressed information signal at the output of the dispersion compression filter in the absence of impact interference, on f g.7 - amplitude-frequency spectra of the information LFM signal and impact interference (for example, at the input of the first dispersion compression filter), Fig. 8 is a view of the information LFM signal and impact interference, for example, at the input of the first dispersion compression filter, in Fig. 9 - view of the information signal and interference (for example, at the output of the first dispersion compression filter), figure 10 is a view of the information signal (for example, at the output of the first integrator).

In figure 1, the following notation:

1 - synchronizer;

2 - switch;

3 - modulator;

4.1-4.2 - mixers:

5 - output matching unit;

6.1-6.2 - synthesizers;

7 - LFM - generators;

8.1-8.4 - bandpass filters;

9.1-9.4 - keys;

10 - adder;

11 - inverter.

In figure 2, the following notation:

12 is a linear matching unit;

13.1-13.2 - dispersion filters;

14.1-14.2 - IF amplifiers;

15.1-15.2 - amplitude detector;

16.1-16.2 - integrator;

17.1-17.2 - triggers;

18 - block "OR";

19 - frequency divider;

20 - block "And."

In figure 3, the following notation:

21 - Schmitt trigger;

22 - block "And";

23.1-23.2 - triggers;

24 - address counter;

25 - register;

26 - read-only memory (ROM);

27 - selector-multiplexer;

28 - digital-to-analog converter (DAC).

The device contains on the transmitting side (Fig. 1) a synchronizer 1, a switch 2, a modulator 3, a first mixer 4.1, an output matching unit 5, a first frequency synthesizer 6.1 and a linear frequency-modulated oscillator 7, and the modulator 3 consists of a first and second band filters 8.1 and 8.2, the first and second keys 9.1 and 9.2, the adder 10 and the inverter 11, on the receiving side (figure 2) is a linear matching unit 12, the second mixer 4.2, the third and fourth band-pass filters 8.3 and 8.4, the first and second dispersion compression filters 13.1 and 13.2, the third and fourth key 9.3 and 9.4, the first and second intermediate frequency amplifiers 14.1 and 14.2, the first and second amplitude detectors 15.1 and 15.2, the first and second integrators 16.1 and 16.2, the first and second triggers 17.1 and 17.2, the OR block 18, the frequency divider 19, the second frequency synthesizer 6.2 and block "And" 20.

Moreover, on the transmitting side, the synchronizer 1 is connected to the second input of the linear frequency-modulated generator 7 and to the first input of the switch 2, the second input of which is the information input of the transmitting side, and the output of the switch 2 through series-connected modulator 3, the first mixer 4.1, and the output matching unit 5, which is the output of the transmitting side, while the second input of the first mixer 4.1 is connected to the first output of the first frequency synthesizer 6.1, the second output of which is connected linearly to the first input about the frequency-modulated generator 7, the output of which is connected to the second input of the modulator 3, which contains the first and second bandpass filters 8.1 and 8.2, the inputs of which are connected to the second input of the modulator 3, and the outputs of the corresponding bandpass filters through the first and second keys 9.1 and 9.2 are connected to the corresponding inputs of the adder 10, the output of which is the output of the modulator 3, while the second input of the second key 9.2 is connected to the output of the inverter 11, the input of which is connected to the second input of the first key 9.1 and the first input of modulator 3, at on my side - a linear matching block 12, the input of which is connected to the input of the receiving side, and the second mixer 4.2, the output of which is connected to the inputs of the third and fourth bandpass filters 8.3 and 8.4, the outputs of which are connected through the first and second dispersion filters 13.1 and 13.2 in series compression, the third and fourth switches 9.3 and 9.4, the first and second intermediate frequency amplifiers 14.1 and 14.2, the first and second amplitude detectors 15.1 and 15.2, the first and second integrators 16.1 and 16.2 are connected to the first and second inputs of block 18 "OR" and the first trigger 17.1, the output of which is the output of the receiving side, and the output of the block 18 "OR" is connected to the first input of the second trigger 17.2, the first output of which is connected to the second inputs of the third and fourth keys 9.3 and 9.4, the second output of the second trigger 17.2 connected to the second input of the And block 20, the output of which through a frequency divider 19 is connected to the second input of the second trigger 17.2, while the first and second outputs of the synthesizer 6.2 are connected respectively to the second input of the second mixer 4.2 and the first input of the And block 20.

Bandpass filters 8.1 ... 8.4 can be implemented, for example, according to the filter scheme of concentrated selection [Svistov V.M. Radar signals and their processing. M .: "Sov. Radio", 1977. - 448 p., Ill., P. 130, fig. 3.13].

The first and second mixers 4.1 and 4.2 are, for example, a diode frequency converter, made, for example, according to a balanced circuit [M.S. Shumilin, V. B. Kozyrev, V. A. Vlasov. Design of transistor cascades of transmitters. Textbook for technical schools. - M.: Radio and Communications, 1987. - 320 p., Ill., P. 178, Fig. 2.77].

The first and second frequency synthesizers 6.1 and 6.2 consist, for example, of a reference oscillator made, for example, on a chip of the KR1533LN2 series according to the scheme (V.N. Veniaminov, O.N. Lebedev, A.I. Miroshnichenko. Microcircuits and their application: Handbook - 3rd ed., Revised and revised - M .: Radio and communications, 1989, 240 s, p. 210, fig. 7.10, d], the output of which is the second output of the first (second) synthesizer 6.1 (6.2), and also connected to the input of the phase detector, which is part of the PLL with multiplication by N (M) times [MV Halperin Practical circuitry in industrial automation. - M .: 1987. - 320 s., Ill., See page 183, Fig. 4. 18, b], where N, M = N + 1 is the multiplication factor of the reference signal when generating the local oscillator voltage for the transmitting and receiving sides, respectively , and the PLL output is the first output of the first (second) synthesizer 6.1 (6.2) frequencies.

The Schmitt trigger input 21 is connected to the second input of the LFM generator 7, the output of which is through a series-connected block 22 AND, the address counter 24, the register 25 is connected to the first input of the read-only memory 26, the corresponding outputs of which are connected to the first input through a selector-multiplexer 27 digital-to-analog Converter 28, the output of which is the output of the LFM generator 7, the second output of the block 22 "And" through a series-connected first trigger 23.1, the second input of which is connected to the first inputs of the digital-analog of the new converter 28 and the chirp generator 7, the second trigger 23.2 is connected to the third input of the read-only memory 26, the second input of which is connected to the second inputs of the counter 24 of the address register 25 and the first output of the first trigger 23.1, the second output of which is connected to the fourth input of the read-only memory 26 and the third input of the selector-multiplexer 27.

Triggers 17.1, 17.2, 23.1 and 23.2 can be implemented, for example, on 1533TM2 series microcircuits [B. Perelman, V. I. Shevelev Domestic microcircuits and foreign analogues. Handbook, "Scientific and Technical Center Mikrotekh", 2000 - 375 pp., Ill., P. 35, 86].

The keys 9.1 ... 9.4 can be implemented, for example, on a chip of the 286KT2 series [Perelman B.L., Shevelev V.I. Domestic microcircuits and foreign analogues. Handbook, "Scientific and Technical Center Mikrotekh", 2000 - 375 pp., Ill., P. 193, 222].

The adder 10 can be implemented, for example, on passive elements [Design of radar receiving devices. Edited by M. A. Sokolov, M., "Higher School" 1984, 335 pp., Ill., P. 126, Fig. 5.3].

Inverter 11, blocks 20 and 22 "AND" and 18 "OR" can be implemented, for example, on microcircuits of the series 1533LN1, 1533LI1 and 1530LL1 [Perelman B.L., Shevelev V.I. Domestic microcircuits and foreign analogues. Handbook, "Scientific and Technical Center Mikrotekh", 2000 - 375 pp., Ill., Pp. 14, 12, 13, 75 and 74].

The first and second dispersion compression filters 13.1 and 13.2 are, for example, an ultrasonic device of the diffraction grating type [C. Cook, M. Bernfeld. Radar signals. Theory and application. Translated from English by B.C. Kelson. M., "Sov. Radio", 1971, fig. 13.23 p. 498.].

The frequency divider 19 and counter 24 addresses can be performed, for example, on a series of chips KS193IE7A and KR1533IE7 [Perelman BL, Shevelev V.I. Domestic microcircuits and foreign analogues. Reference, "Scientific and Technical Center Mikrotekh", 2000 - 375 pp., Ill., P. 26, 80], respectively.

Register 25 is a register on D-type triggers, made, for example, on a chip series KR1533IR23 [Perelman B.L., Shevelev V.I. Domestic microcircuits and foreign analogues. Handbook, "Scientific and Technical Center Mikrotekh", 2000 - 375 pp., Ill., Pp. 33, 85].

Permanent storage device (ROM) 26 is a one-time programmable read-only memory device, made, for example, on two chips series KR556RT17 [Perelman BL, Shevelev V.I. Domestic microcircuits and foreign analogues. Reference, "Scientific and Technical Center Mikrotekh", 2000 - 375 pp., Ill., Pp. 111, 124].

The multiplexer 27 is a selector-multiplexer, made, for example, on two chips of the series KR1533KP11A [Perelman B.L., Shevelev V.I. Domestic microcircuits and foreign analogues. Reference, "Scientific and Technical Center Mikrotekh", 2000 - 375 pp., Ill., Pp. 44, 88].

The digital-to-analog converter (DAC) 28 is, for example, a high-speed ten-digit DAC, made, for example, on a chip of the KR1118PA2A series [Perelman B.L., Shevelev V.I. Domestic microcircuits and foreign analogues. Handbook, "Scientific and Technical Center Mikrotekh", 2000 - 375 pp., Ill., P. 70, 102].

The device operates as follows.

On the transmitting side (see figure 1), the first frequency synthesizer 6.1 generates:

a local oscillator voltage with a constant frequency for frequency conversion of the output LFM signal of the modulator 3;

reference signal of the clock frequency f _t to ensure the operation of the chirp generator 7.

The synchronizer 1 generates rectangular video pulses of positive polarity with a repetition period equal to the duration of the chirp signal.

The reference clock signal ƒ _T from the first input of the chirp generator 7 (see figure 3) is supplied to the counting (second) inputs of the first trigger 23.1 and DAC 28.

The input of the Schmitt trigger 21 from the second input of the LFM generator 7 receives a sequence of video pulses of positive polarity. Schmitt trigger 21 is designed to increase the steepness of the fronts of the input pulses. At the output of the Schmitt trigger 21, a form is formed equal to the duration of the LFM radio pulse. The form from the output of the Schmitt trigger 21 through the block 22 "And" is supplied to the first inputs of the counter 24 addresses and the first trigger 23.1. At the output of the first trigger 23.1, a sequence of clock pulses is formed for the duration of the blank.

Clock pulses from the direct output of the first trigger 23.1 arrive at the counting inputs of the second trigger 23.2, counter 24 addresses, register 25 and ROM 26.

Clock pulses from the inverse output of the first trigger 23.1 arrive at the fourth input of the ROM 26 and the third input of the multiplexer 27.

The second trigger 23.2 increases the duration and the repetition period of clock pulses twice, which from the inverse output are fed to the third input of the ROM 26.

The counter 24 addresses starts the calculation of the current values of the addresses of the codes of the amplitudes of the samples of the synthesized LFM signal. The calculation of the codes of the samples of the amplitude of the synthesized chirp signal Ku (At), for example, with a positive frequency tuning frequency is performed according to the expression

where i = 0 ... 2 ^L -1 is the cycle variable, where 2 ^L is the capacity, and L is the number of ROM bits 26;

t is the current time;

ent (x) is the operator of rounding the number "x" to the nearest integer;

Na = 2 ^m -1 is the number of amplitude quantization levels;

F ₀ is the central frequency of the synthesized LFM signal;

t _H = 1 / f _H is the additional time interval at the beginning of the signal, where f _H is the initial frequency of the synthesized oscillation.

The calculated values of the address code are recorded in the register 25 and are used to address the ROM 26. The values of the sinusoidal samples K _u (Δt) are recorded in the ROM 26 in accordance with expression (6).

The width of the input words of the ROM 26 in the General case is less than or equal to the width of the counter 24 addresses. The amplitude code K _u (Δt) from the two outputs of the ROM 26 is supplied to the corresponding inputs of the multiplexer 27.

Depending on the polarity of the control voltage at the third input of the multiplexer 27, the first or second outputs of the ROM 26 are connected to the first input of the DAC 28. Using the DAC 28, the transition to analog values Un (t), where n - 1, 2, 3 ... number sub-spectrum of the chirp signal.

The amplitude-frequency spectrum of the synthesized oscillations at the output of the DAC 28 has the form shown in figure 4. When constructing this graph, it was accepted, firstly, that the DAC 28 is equipped with a zero order interpolator, that is, the samples at its input have a constant value over time t _T = l / f _T , and secondly, the initial spectrum of continuous oscillation is uniform.

The main subspectrum of the discrete oscillation generated by the DAC 28 occupies the band from the lower frequency f _H to the upper f _B (see figure 4). In addition, the spectrum at the output of the DAC 28 has a periodic (with a period equal to f _T ) structure.

что приводит к их паразитной модуляции.Spectrum envelope is a function

which leads to their parasitic modulation.

The distance between the end of the main and the beginning of the second subspectra Δf, as well as the distance between any neighboring subspectra located within each of the envelope lobes, is selected from the condition

where m _MIN. - the minimum number of samples in the elementary period of the synthesized oscillation. In accordance with the Kotelnikov theorem, the number of samples cannot be less than two.

The relative distance between the subspectra is defined as the ratio Δf / ΔF and is equal to

- коэффициент, характеризующий степень узкополосности формируемого сигнала.Where

- coefficient characterizing the degree of narrowband of the generated signal.

The LFM signals from the output of the LFM generator 7 are fed to the inputs of the first and second band-pass filters 8.1 and 8.2, respectively.

View of the amplitude-frequency characteristics of the first and second band-pass filters 8.1 and 8.2 are shown in Fig.5.

The first and second bandpass filters 8.1 and 8.2 are tuned to the third and second subspectra, respectively (see Fig. 4 and Fig. 5). From the output of the first and second bandpass filters 8.1 and 8.2, the LFM signals with positive and negative rate of frequency tuning go to the first inputs of the first and second keys 9.1 and 9.2.

The information signal in the form of logical "1" and "0" from the input of the transmitting side through the switch 2 is fed to the first input of the modulator 3.

Logic signal "1" from the first input of modulator 3 is fed to the second input of the first key 9.1 and allows the LFM to pass through a positive frequency tuning frequency to the first input of adder 10. The duration of the logical "1" signal at the second input of the first key 9.1 is equal to the duration of the LFM pulse with positive speed tuning frequency.

The logical 0 information signal from the first input of the modulator 3 through the inverter 11 is fed to the second input of the second switch 9.2 and allows the LFM to pass through a negative frequency tuning rate from the output of the second band-pass filter 8.2 to the second input of the adder 10. The duration of the logical "1" signal is the second input of the second key 9.2 is equal to the duration of the LFM radio pulse with a negative frequency tuning speed.

The LFM radio pulses arriving at the first and second inputs of the adder 10 differ not only in the sign of frequency modulation, but also in the central frequency f _0j , where j = 1, 2 is the input number of the adder 10.

The value of the central frequency of the LFM radio pulse at the j-th input of the adder 10 is found from the condition

where f ₀₁ is the central frequency of the LFM of the radio pulse received at the first input of the adder 10;

f ₀₂ is the central frequency of the LFM of the radio pulse received at the second input of the adder 10.

The LFM radio pulses from the output of the adder 10 are fed to the output of the modulator 3.

Thus, the modulator 3 generates an information LFM-FM signal at an intermediate frequency.

The LFM-FM signal from the output of the modulator 3 is fed to the first input of the first mixer 4.1. The signal converted to the frequency of the LFM-FM signal through the output matching unit 5 is fed to the output of the transmitting side.

On the receiving side (see Fig. 2), in the initial state, the logical 1 signal from the first output of the second trigger 17.2 is supplied to the second inputs of the third and fourth keys 9.3 and 9.4, respectively, and connects the outputs of the first and second dispersion compression filters 13.1 and 13.2 to the inputs first and second intermediate frequency amplifiers 14.1 and 14.2.

The logical signal "0" from the second output of the second trigger 17.2 is fed to the second input of the block "20" and prevents the passage of the reference signal to the input of the frequency divider 19.

The LFM-FM signal from the output of the linear matching unit 12 is supplied to the first input of the second mixer 4.2. The local oscillator voltage is supplied to the second input of the second mixer 4.2 from the output of the second frequency synthesizer 6.2. The signal converted to the intermediate frequency LFM-FM is fed to the inputs of the third and fourth band-pass filters 8.3 and 8.4.

The third band-pass filter 8.3 is consistent with the central frequency and spectral width of the LFM radio pulse with a positive frequency tuning frequency (9), and the fourth band-pass filter 8.4 is matched with the central frequency and spectral width of the LFM radio pulse with a negative frequency tuning frequency (10).

LFM-FM signals with a positive (negative) frequency tuning rate after passing through the third and fourth filters 8.3 and 8.4 are fed to the inputs of the first and second dispersion compression filters 13.1 and 13.2.

At the output of the first and second dispersion compression filters 13.1 and 13.2, radio pulses with a duration (1) and central frequencies are formed

Radio pulses from the output of the first and second compression dispersion filters 13.1 and 13.2 through the third and fourth switches 9.3 and 9.4 are fed to the inputs of the first and second intermediate frequency amplifiers 14.1 and 14.2, which are tuned to the frequencies f _{IF 1} and f _{IF 2} (11), respectively . The bandwidth of the first and second amplifiers 14.1 and 14.2 is consistent with the width of the spectrum of the compressed radio pulses received at the input. From the output of the first and second amplifiers 14.1 and 14.2, the radio pulses arrive at the inputs of the first and second amplitude detectors 15.1 and 15.2.

The video signals from the output of the first and second amplitude detectors 15.1 and 15.2 through the first and second integrators 16.1 and 16.2 are fed to the corresponding inputs of the first trigger 17.1 to restore the information signal at the output of the receiving side, as well as to the first and second inputs of the OR block 18 for generating pulses start of the second trigger 17.2. The second trigger 17.2 changes its state to the opposite.

Logical signal "1" from the second output of the second trigger 17.2 is fed to the second input of the second block 20 "And" and allows the reference signal to pass to the input of the frequency divider 19, and the logic signal "0" from the first output of the second trigger 17.2 goes to the second inputs of the third and fourth keys 9.3 and 9.4 and prohibits the passage of noise to the inputs of the first and second amplifiers 14.1 and 14.2. After a time equal to the duration of the logical “0”, expression (3), a transfer pulse will appear at the output of the frequency divider 19, which is fed to the second input of the second trigger 17.2 and changes its state to the original one.

The logical signal "0" from the second output of the second trigger 17.2 is fed to the second input of the second block 20 "And" and prohibits the passage of the reference signal to the input of the frequency divider 19.

Logical signal "1" from the first output of the second trigger 17.2 is fed to the second inputs of the third and fourth keys 9.3 and 9.4 and allows the passage of time-compressed information signals to the inputs of the first and second amplifiers 14.1 and 14.2 of intermediate frequency. The duration of the logical “1” signal (see expression (4)) is selected taking into account transients in the third and fourth keys 9.3 and 9.4, as well as the duration of the compressed information signals (1).

Thus, the introduction of a device for transmitting and receiving phase and frequency modulated signals of new blocks and links provides for the expansion of the spectrum of transmitted information signals by rearranging their central frequencies according to the linear law and changing the sign of the frequency tuning speed, coordinated filtering with weight processing and temporal selection received signals from impact interference, which increases the noise immunity of the proposed device up to 12 times.

Claims (1)

A device for transmitting and receiving phase and frequency modulated signals, comprising, on the transmitting side, a synchronizer, a switch, the second input of which is the information input of the transmitting side, a modulator, a first mixer and an output matching unit, the output of which is the output of the transmitting side, to the receiving side side - a linear matching unit, the input of which is the input of the receiving side, a second mixer, two bandpass filters, an intermediate frequency amplifier, two amplitude detectors a torus, two integrators, and a trigger, the outputs of the first and second integrators being connected to the corresponding inputs of the trigger, the output of which is the output of the receiving side, characterized in that a linear frequency-modulated oscillator and a first frequency synthesizer are introduced on the transmitting side, the first input of a linear frequency -modulated generator connected to the second output of the first frequency synthesizer, the first output of which is connected to the second input of the first mixer, the second input of a linear frequency-modulated gene the herator is connected to the output of the synchronizer, and the output of the linear frequency-modulated generator is connected to the second input of the modulator, while the modulator is made in the form of two band filters, two keys, an adder and an inverter, the inputs of the first and second band filters are connected to the second input of the modulator, and the outputs of the first and second bandpass filters are connected through the corresponding keys to the corresponding inputs of the adder, the output of which is the output of the modulator, while the second input of the second key is connected to the output an inverter whose input is the first input of the modulator and is connected to the second input of the first key; on the receiving side, two dispersion compression filters, two keys, a second intermediate frequency amplifier, a second trigger, a second frequency synthesizer, an OR block, an I block and a frequency divider are introduced, the output of the linear matching block through the second mixer connected to the inputs of the third and a fourth band-pass filter, wherein the output of the third band-pass filter is connected to the input of the first integrator through a series-connected first dispersion filter, a third key, a first IF amplifier and a first amplitude detector, and the output of the fourth the olos filter is connected to the second integrator, through the second dispersion filter, the fourth key, the second amplifier and the second amplitude detector, connected in series, the outputs of the first and second integrators being connected respectively to the corresponding inputs of the OR block, the output of which is connected to the first input of the second trigger, the first the output of which is connected to the second inputs of the third and fourth keys, the second output of the second trigger is connected to the second input of the AND block, the first input of which is connected to the second output of the second A second frequency synthesizer, the first output of which is connected to the second input of the second mixer, and the output of the “I” block is connected through the frequency divider to the second input of the second trigger.

Images