SU1679645A1 - Unit to receive the broadband signals with linear frequency modulation - Google Patents

Description

The invention relates to communication technology and can be used in the construction of radio communication systems and radio telemetry with wideband signals with linear frequency modulation. The purpose of the invention, the expansion of the volume of information received 2

mation of the radiation source schet.pelengatsii _to Nia in two planes. A device for receiving broadband signals with linear frequency modulation contains the first receiver 1 with an antenna, the first 6 and second 17 mixers, a frequency detector 12, a differentiating unit 13, a pulse shaper 14, a decisive block 15, a compression filter 11, the first 4 and second 16 local oscillators.

The goal is achieved by the introduction of two receivers 2,3 with antennas, the third 5 and fourth 7 mixers, the first 9, second 8 and third 10 intermediate frequency amplifiers, second intermediate frequency amplifier 18, first 19 and second 20 multipliers, first 21 and second 22 narrowband _Λ filters, the first 23 and second 24'phase 5 detectors. 1 il. to

The invention relates to communication technology and can be used in the construction of radio communication sibtem and radio telemetry with wideband signals with linear frequency modulation (chirp).

The aim of the invention is to expand the amount of received information due to the direction finding of the radiation source in two planes.

The drawing shows a structural electrical circuit of the proposed device '.

The device contains three receivers with antennas 1-3, the first local oscillator 4, the third 5, the first 6 and the fourth 7 mixers, the second amplifier 8 of the first intermediate frequency, the first amplifier 9 of the first intermediate frequency, the third amplifier 10 of the first intermediate frequency, compressive filter 11, frequency detector 12, differentiating unit 13, pulse shaper 14, decider 15, second local oscillator 16, second mixer 17, second intermediate frequency amplifier 18, first 19 and second 20 multipliers, first 21 and second 22 narrowband filters, first 23 and second 24 f Azov detectors.

The device works as follows.

Received chirp signals

1H (x) = Y _s cos (bESH + lt? + ^ 1);

ΙΙ ₂ (ί) = Us cos (O) with ί + l g ί ² + (p3);

J (ϊ) = Us soz (bout ΐ + l g ί ² + φ ₃ );

0 <ι <T _s

where is us. Fe. T _с , <р \, уй, - amplitude,

initial carrier frequency, duration and

initial phases of signals;

1679645А1

1679645

Δίο

γ = - ==-— rate of change often1 s

you are inside the impulse;

Δί ₀ - frequency deviation, from the output of receivers 1-3 is fed to the first input of mixers 5-7, respectively, to the second input of which the voltage of the local oscillator 4

and _G 1 (ΐ) = \ / _G 1 cos (& n g + rm), where ν _Γ ι ΰ λι, ^ г1 - amplitude, frequency and initial phase of the local oscillator voltage 4.

At the output of the mixers 5-7 formed voltage combinational frequencies. Amplifiers 8-10 stand out voltage only the first intermediate (differential) frequency

p1 and _P (x) = cos Upr1 (ολιρί x + πγ χ ² _{+ ^ ρ ι): υ Π} ρ2 (χ) = cos Upr1 (BDP _R 1 χ + πχχ ² + ^ Πρϋ):

_etc. s (χ) = ν _πρ ι cos (ωπρί X + ² + y Luh great?): O <χ <T _c,

where υ _πρ ι =% Κι and _s and _g :

Κι is the coefficient of performance of the mixers;

£ 0pr1 = bc - <ti first intermediate frequency

Άψΐ - ψ} - ψν:

- ψηρί ⁼ ~~ ψτ;

^ Ρπρ3 - <pg - φτ \

Frequency-converted chirp signal from the output of the mixer 6 is fed to the input of the compression filter 11 and the frequency detector 12. The latter is converted into a voltage of the appropriate form. This voltage is applied to the input of the differentiating unit 13, the output of which produces rectangular pulses. At the output of the shaper 14 pulses, pulses are generated at the instants of time corresponding to the instants of the change in the sign of the slope of the frequency modulation functions of the chirp signal. These pulses together with the information pulses from the output of the compression filter 11 are fed to the corresponding input of the decision block 15, providing clock synchronization when receiving the decision.

The voltage υ _Π ρΐ (χ) from the output of the amplifier 8 of the first intermediate frequency is fed to the first input of the mixer 17, to the second input of which the local oscillator 16 is applied

ΙΛ2 (X) = ΙΛ2 cos (С0г2 X + </> r2). where ig2, <Dg2, and _r2 - amplitude, frequency and initial phase voltage of the local oscillator 16.

At the output of the mixer 17 are formed voltage combinational frequencies. The amplifier 18 selects the voltage only the second intermediate frequency

11pr4 (χ) = ν _πρ 2 · cos (<Upr2X + l; oh ² + y5pr4). O ^ X ^ Tc

one

where ν _πρ 2 - 2 ^{Κι ν} πρΐ ν _Γ 2:

ωπ _Ρ 2 = ιΛιρΐ - ΟΑ-2 ^_ second intermediate frequency;

$ Ρπρ4 ⁼⁼ </ ^ι πρ1 ^- ^ Prg2 »

which arrives at the second inputs of the multipliers 19 and 20, the first inputs of which are supplied with voltage and _П рг (х) and _П Пз (х), respectively. At the outputs of the multipliers 19 and 20 harmonic oscillations are formed

1) 4 (x) = VI POPs (CDg2 X + 90g2 Δ ^ 1),

(x) = VI cos ((U2 x + ad-2 Δί02), o £ X 5 = Tc,

one

where νί - 2 Kg Upr1 ν _Π ρ2:

K ₂ - multiplier multiplication factor:

Lu? 1 - <p2 —φ \ ~ phase shift, which determines the direction to the radiation source in the azimuthal plane;

Δ922 - 923 - φι is the phase shift, which determines the direction to the radiation source in the elevation plane, in which linear frequency modulation is already absent. The harmonic oscillations U (xx) and ib (x) are distinguished by narrow-band filters 21 and 22 and are fed to the first input of phase detectors 23 and 24, to the second input of which voltage is applied and from the output of the local oscillator 16. Low-frequency voltages are generated at the output of phase detectors

_Η ι (x) = ν _Η cos Δ <p; and _H 2 (x) = ν _Η cos Δφι;

where ν „= ^ - Кз νί ν _Γ 2:

Кз is the transmission coefficient of phase detectors, proportional to phase shifts Δφ \ and Δφι.

Claims (1)

Claim A device for receiving broadband signals with linear frequency modulation, containing serially connected a first receiver with an antenna, a first mixer, a frequency detector, a differentiating unit, a pulse shaper and a decision unit whose output is the first output of the device, a compression filter whose output is connected to the second input decision block five 1679645 6 the first local oscillator, the output of which is connected to the second input of the first mixer, and the second local oscillator and the second mixer connected in series, a. the output of the first mixer is connected to the input of a compression filter, characterized in that, in order to expand the volume of received information due to the direction finding of the radiation source in two planes, the first amplifier of the first intermediate frequency, the first, is sequentially connected into it. the multiplier, the first narrow-band filter and the first phase detector ', the output of which is the second output of the device, are successively connected to the second. Receiver with antenna, the third mixer and the second amplifier of the first intermediate frequency, the output of which is connected to the second input of the second mixer, are connected in series to the third receiver with antenna, the fourth mixer, the third amplifier of the first intermediate frequency, the second multiplier, the second narrow5 bandpass filter and the second phase detector, the output of which is the third The output of the first local oscillator is connected to the second inputs of the third and fourth mixers, the output of the first mixer is connected to the input of the first amplifier of the first intermediate frequency, the output of the second mixer is connected to the output of the device, and the amplifier of the second intermediate frequency, whose output is connected to the second inputs of the first and second multipliers. with the input of the amplifier of the second intermediate frequency, and the output of the second local oscillator is connected to the second inputs of the first and second phase detectors. 3 - 7 - - + yu > -> 1 * five - eight four g * 11 > - * 2 ~ * 6 - • -