RU2005994C1 - Indication device - Google Patents

Abstract

FIELD: indication and registration instruments. SUBSTANCE: indication device has sweep generator 1, cathode-ray tubes 2, 33, 34, aerials 3, 42, wide-band amplifiers 4, 43, frequency discriminators 5, 30, differentiation circuits 6, 7, mixers 8, 44, intermediate frequency amplifiers 9, 45, keys 10, 27, scale-of-eight amplifiers 11, 17, 38, band-pass filters 12, 14, 16, 18, 20, scale-of-eight dividers 13, 19, multipliers 15, 48, 49, phase discriminator 21, low-pass filters 22, 50, 51, former 23 of controlling signal, element 24 of controlled delay, detector 25, delay element 26, search unit 28, heterodyne 29, phase inverters 31, 46, 47 of 90 deg, reference voltage generator 32, information input 35, reset input 36, meters 37, 39 of width of spectrum, comparator 40, threshold unit 41, squarers 52, 53, adder 54, unit 55 of extraction of square root, single-polarity valve 56, meter 57 of time intervals and register 58. EFFECT: expanded functional capabilities by accurate and single-sign direction finding of source of emission of complex signals with combined linear frequency modulation and multiple phase-shift keying. 2 cl, 7 dwg

Description

 The invention relates to indicator and recording devices and can be used to indicate rapidly changing processes, in particular for visual analysis and registration of parameters of complex signals with combined linear frequency modulation and multiple phase shift keying (LFM-MFMn).

Of the known devices, the closest to the proposed one is an "indicator device" that contains a sweep generator, three cathode ray tubes, an antenna, a broadband amplifier, two frequency detectors, two differentiating circuits, a mixer, an intermediate frequency amplifier, two keys, two frequency multipliers by eight, two eight-frequency amplifiers, five band-pass filters, a controlled delay element, a detector, a phase detector, a low-pass filter, a control signal shaper, a delay element, a search unit ka, a local oscillator, phase shifter ⁹⁰ and the reference voltage generator.

 This indicator device provides a visual analysis and registration of parameters of complex signals with combined linear frequency modulation (LFM-MFMn).

 However, this device does not allow direction finding of a radiation source of complex LFM-MPSK signals.

 The aim of the invention is to expand the functionality due to the accurate and unambiguous direction finding of the radiation source of complex signals with combined linear frequency modulation and multiple phase shift keying.

This goal is achieved by the fact that a second antenna, a second broadband amplifier, a second mixer, a second intermediate frequency amplifier, a second and third phase shifters of 90 ^° , a second and third multipliers, a second and third low-pass filters, a first and a second quadrator, an adder are introduced into the device , a square root extraction unit, a unipolar valve, a time interval meter, and a recording unit, and a second broadband amplifier, a second mixer, and a second input terminal are connected in series to the output of the second antenna One of which is connected to the local oscillator output, a second intermediate-frequency amplifier, a second multiplier, the second input of which is connected to the first key output, a second low-pass filter, a first quadrator, adder, square root extraction unit, a unipolar valve, a time interval meter, the second input of which is connected a yield of a key, and the recording unit, to the output of the first switch connected in series with a second phase shifter ^90, a third multiplier, the second input of which is via the third phase shifter ⁹⁰ is connected to Exit second intermediate frequency amplifier, a third low pass filter and a second squarer output of which is coupled to a second input of the adder.

 The block diagram of the proposed device is presented in FIG. 1. Structural diagrams of a detector and a time interval meter are shown in FIG. 2 and 3. A view of the possible waveforms is shown in FIG. 4. The principle of direction finding of a radiation source of complex signals with combined linear frequency modulation and multiple phase shift keying in one plane is illustrated in FIG. 5. Timing diagrams explaining the operation of the device are shown in FIG. 6 and 7.

The indicator device comprises a sweep generator 1, a first cathode ray tube (CRT) 2, a first antenna 3, a first broadband amplifier 4, a first frequency detector 5, a first and second differentiating circuit 6 and 7, a first mixer 8, a first intermediate frequency amplifier 9, the first key 10, the first frequency multiplier 11 by eight, the first bandpass filter 12, the first divider 13 by eight frequency, the second bandpass filter 14, the first multiplier 15, the third bandpass filter 16, the second frequency multiplier 17 by eight, the fourth bandpass filter 18, in filled with narrow-band, the second eight frequency divider 19, the fifth band-pass filter 20, made narrow-band, the phase detector 21, the first low-pass filter 22, the driver signal driver 23, the controlled delay element 24, the detector 25, the delay element 26, the second key 27, block 28 search, local oscillator 29, second frequency detector 30, first phase shifter 31 by 90 ^° , reference voltage generator 32, second and third CRT 33 and 34, information input 35, reset input 36, first spectral width meter 37, third frequency multiplier 38 by eight second a spectral width meter 39, a comparison unit 40, a threshold unit 41, a second antenna 42, a broadband amplifier 43, a second mixer 44, a second intermediate frequency amplifier 45, a second and third phase shifters 90 ^° 46 and 47, second and third multipliers 48 and 49 , the second and third low-pass filters 50 and 51, the first and second quadrants 51 and 53, the adder 54, the square root extraction unit 55, the first unipolar valve 56, the time slot meter 57, and the registration unit 58.

 Moreover, the broadband amplifier 4, mixer 8, the second input of which through the local oscillator 29 is connected to the first output of the search unit 28, the intermediate frequency amplifier 9, the second input of which is connected to the output of the delay element 26, the detector 25, and the vertical CRT electrode 33 are serially connected to the output of the antenna 3 the horizontal electrode of which is connected to the second output of the search unit 28. A key 10 is connected in series to the output of the intermediate frequency amplifier 9, the second input of which is connected to the detector 25 output, a frequency multiplier 11 by eight, a band pass filter 12, a frequency divider 13 by eight, a band pass filter 14, a frequency filter 14, a frequency detector 5, a differentiating circuit 7, a sweep generator 1 and a horizontal CRT electrode 2, the vertical electrode of which is connected to the output of the differentiating circuit 6.

A multiplier 15 is connected to the output of the intermediate frequency amplifier 9, the second input of which is connected to the output of the controlled delay element 24, a bandpass filter 16, a frequency multiplier 17 by eight, a bandpass filter 18, a frequency divider 19 by eight, a bandpass filter 20, a phase detector 21, the second input of which is connected to the output of the generator 32 of the reference voltage, the low-pass filter 32, the driver 23 of the control signal and the element 24 controlled delay, the second input of which is connected to the output of the band-pass filter 14. To the output of VAVO filter 16 connected in series with switch 27, a second input coupled to an output of the detector 25, frequency detector 30 and modulating electrode CRT 34, which is directly vertical electrode and the horizontal electrode 31 via the phase shifter 90 connected to the output ^of the generator 32 of the reference voltage. To the output of the antenna 42, a broadband amplifier 43, a mixer 44 are connected in series, the second input is connected to the output of the local oscillator 29, an intermediate frequency amplifier 45, a multiplier 48, the second input of which is connected to the output of the key 10, a low-pass filter 50, a quadrator 52, an adder 54, a block 55 square root extraction, unipolar valve 56, a meter 57 time intervals, the second input of which is connected to the output of the key 10, and the block 58 registration.

To the output switch 10 connected in series with the phase shifter 46 to ^about 90, a multiplier 49, whose second input 47 through a phase shifter 90 connected to the output ^of intermediate frequency amplifier 45, filter 51 and lowpass squarer 53, which output is coupled to a second input of the adder 54.

 The time interval meter 57 comprises a series-differentiating circuit 61, a unipolar valve 62, a counter-divider 67, the second input of which is connected through the coincidence element 66 to the outputs of the unipolar valve 56 and the counter pulse generator 65, and the third input is connected to the amplitude output through a differentiating circuit 64 detector 63.

 The indicator device operates as follows.

The specified range D _f is viewed using the search unit 28, which periodically, according to the sawtooth law, tunes the frequency of the local oscillator 29. At the same time, the search unit 28 forms a horizontal scan of the CRT 33, which is used as the frequency axis and corresponds to the field of view of the specified frequency range. Keys 10 and 27 in the initial state are closed.

Received signals with combined linear frequency modulation and multiple phase shift keying (LFM-MPSK)
U ₁ = U _c ˙cos [ω _c t + πγt ² + φ _к (t) + φ ₁ ] =
= U _c ˙ M (t) ˙cos (ω _c t + πγt ² + φ ₁ ).

- скорость изменения частоты внутри импульса;
Δf_g - девиация частоты;
φ_и(t) - манипулируемая составляющая фазы, отображающая закон фазовой манипуляции в соответствии с модулирующим кодом M(t), причем φ_и(t) = const при Кτ_э < < t < (К + 1) τ_э и может изменяться скачком при t = К τ_э т. е. на границах между элементарными посылками (К = 1,2, . . . , N-1);
τ_э, N - длительность и количество элементарных посылок, из которых составлены сигналы длительностью τ_и( τ_и = N. τ_э);
M(t) - модулирующая функция, в соответствии с которой манипулируемая фаза сигналов;
τ=

=

- время запаздывания сигнала, приходящего на одну из антенн, по отношению к сигналу, приходящего на другую антенну (фиг. 5);
α - расстояние между антеннами (измерительная база);
β - угол прихода радиоволны;
с - скорость распространения света; с выходов антенн 3 и 42 через широкополосные усилители 4 и 43 соответственно поступают на первые входы смесителей 8 и 44, на вторые входы которых подается напряжение гетеродина 29 линейноизменяющейся частоты
U₁ - (t) = U_г˙cos(ω_гt + πγ_гt + φ_г), o≅t≅T_г где U_г, ω_г, φ_г - амплитуда, начальная частота, начальная фаза и период повторения напряжения гетеродина;
γ_r=

- скорость изменения частоты гетеродина. На выходах смесителей 8 и 44 образуются напряжения комбинационных частот.U ₂ = U _c ˙cos [ω _c (t + τ) + πγ (t + τ) ² +
+ φ _to (t + ρ) + φ ₂ ] = U _c ˙M (t + τ) +
+ πγ (t + τ) ² + φ _к (t + τ) + φ ₂ ],
0 ≅ t ≅ τ _and where U _c , ω _c , φ ₁ , φ _2, τ _and are the amplitude, initial carrier frequency, initial phases and signal duration;
γ =

- rate of change of frequency inside the pulse;
Δf _g - frequency deviation;
φ _and (t) is the manipulated component of the phase, which displays the law of phase manipulation in accordance with the modulating code M (t), and φ _and (t) = const for Kτ _e <<t <(K + 1) τ _e and can change stepwise .. at t = K _e τ ie at the boundaries between the elementary parcels (K = 1,2,, N-1,...);
τ _e , N - the duration and number of chips that make up the signals of duration τ _and (τ _and = N. τ _e );
M (t) is the modulating function, in accordance with which the manipulated phase of the signals;
τ =

=

- the delay time of the signal arriving at one of the antennas with respect to the signal arriving at the other antenna (Fig. 5);
α is the distance between the antennas (measuring base);
β is the angle of arrival of the radio wave;
c is the speed of light propagation; from the outputs of the antennas 3 and 42 through the broadband amplifiers 4 and 43, respectively, go to the first inputs of the mixers 8 and 44, the second inputs of which are supplied with the voltage of the local oscillator 29 of a ramp frequency
U ₁ - (t) = U _g ˙cos (ω _g t + πγ _g t + φ _g ), o≅t≅T _g where U _g , ω _g, φ _g - amplitude, initial frequency, initial phase and repetition period local oscillator voltage;
γ _r =

- rate of change of the local oscillator frequency. At the outputs of the mixers 8 and 44, voltages of combination frequencies are generated.

Amplifiers 9 and 45 are allocated voltage intermediate frequency:
U _pr1 (t) = U _pr ˙cos [ω _pr ˙t + πγt ² + φ _к (t) -
- πγ _g f ² + φ _pr1 ] = U _pr ˙ M (t) ˙cos (ω _pr t +
+ πγt ² - πγ _g f ² + φ _pr1 ].

K₁·U_с·U_г;
К₁ - коэффициент передачи смесителей;
ω_пр = ω_c - ω_г - промежуточная частота:
φ_пр1 = φ₁ - φ_г, φ_пр2 = φ₂ - φ_г. _Np2 U (t) = U _pr ˙cos [ω _ave (t + τ) + πγ ( t +
+ τ) ² + φ _k (t + τ) - πγ _g (t + τ + φ _pr2 ],
0 ≅ t ≅ τ _and where U _pr =

K ₁ · U _s · U _g ;
To ₁ - gear ratio of the mixers;
ω _CR = ω _c - ω _g - intermediate frequency:
φ _CR1 = φ ₁ - φ _g , φ _CR2 = φ ₂ - φ _g .

The voltage U _pr1 (t) from the output of the intermediate frequency amplifier 9 is fed to the input of the detector 25. At the output of the frequency multiplier 38, a voltage is generated by eight
U ₃ (t) = U _pr ˙cos (8ω _pr ˙t + 8πγt ² - 8πγ _g t ² +
+ 8φ _pr1 ), 0 ≅ t ≅ τ _and , in which phase manipulation is already absent.

f₈=

), тогда как ширина спектра Δ f_c принимаемого сигнала определяется длительностью τ_э его элементарных посылок (

f_с=

), т. е. ширина спектра восьмой гармоники сигнала в N раз меньше ширины спектра входного сигнала

= N.The width of the spectrum Δ f _{8 of the} eighth harmonic of the signal is determined by the duration τ _{and the} signal (

f ₈ =

), while the width of the spectrum Δ f _{c of the} received signal is determined by the duration τ _{e of} its elementary premises (

f _c =

), i.e., the spectrum width of the eighth harmonic of the signal is N times smaller than the spectrum width of the input signal

= N.

 Consequently, when the frequency of the LFM-MPSM signal is multiplied by eight, its spectrum “folds” N times. This circumstance makes it possible to detect the LFM-MFMn signal even when its power at the input of the device is less than the power of noise and interference.

The spectral width Δ f _{c of the} input signal is measured using a meter 37, the spectral width Δ f _{8 of the} eighth harmonic of the signal is measured using a meter 39. The voltages U and U8 are proportional to Δ f _c and Δ f _8, respectively, from the outputs of the meters 37 and 39 of the spectrum width arrive at two inputs of the block 40 comparison. Since U >> U ₈ , a positive pulse is generated at the output of the comparison unit 40, which is fed to the input of the threshold unit 41, where it is compared with the threshold voltage U _then . The threshold voltage U _then is chosen so that this level does not exceed random interference. The threshold voltage U _{then is} exceeded only when the LFM-MPSK signal is detected. When the threshold voltage U _then is exceeded, a constant voltage is generated in the threshold block 41, which is supplied to the control input of the search unit 28, putting it into stop mode, to the input of the delay line 25, to the control inputs of the keys 10 and 27, opening them, and to the vertical electrode CRT 33 with linear sweep. From this point in time, viewing the specified frequency range D _f and searching for LFM-MFMn signals stops for the time of visual analysis of the main parameters of the detected LFM-MFMn signal, which is determined by the delay time of the delay line 26. In this case, a pulse (frequency mark) is generated on the CRT screen 33, the horizontal position of which unambiguously determines the initial carrier frequency ω _{c of the} detected LFM-MPSK signal (Fig. 4a).

When you stop viewing a given frequency range D _f (when the search unit 28 stops), the following voltages are allocated by the amplifiers 9 and 45 of the intermediate frequency:
U _pr3 (t) = U _pr ˙cos [ω _pr ˙t + πγt ² + φ _к (t) +
+ φ _pr1 ] = U _pr ˙ M (t) ˙cos (ω _pr t +
+ πγt ² + φ _pr1 ].

U _pr4 (t) = U _pr ˙cos [ω _pr (t + τ) + πγ t ² + φ _к (t + τ) + φ _pr1 ] =
_Ave = U ˙M (t + τ) cos [ ω _ave (t + τ) + πγ ( t + τ) + φ _np2]
0 ≅ t ≅ τ _and Voltage U _CR3 (Fig. 6b) through the public key 10 is supplied from the output of the intermediate frequency amplifier 9 to the input of the frequency multiplier 11 by eight, at the output of which a voltage is generated
U ₄ (t) = U _pr ˙cos (8ω _pr ˙t + 8πγt ² + 8φ _pr1 ),
0 ≅ t ≅ τ _and , This voltage is allocated by the band-pass filter 12 and supplied to the input of the frequency divider 13 by eight, the output of which is generated by voltage (Fig. 6c).

U ₅ (t) = U _pr ˙cos (ω _pr t + πγ t ² + φ _pr1 ), o≅t≅τ _and which is an LFM signal at an intermediate frequency, is allocated by a band-pass filter 14 and fed to the input of the frequency detector 5. A video pulse is formed at the output of the latter (Fig. 6d), the shape of which corresponds to the law of linear frequency modulation. The specified video pulse from the output of the frequency detector 5 is fed to the input of the differentiating circuit, the output pulse (Fig. 6e) of which is supplied to the vertical electrode of the CRT 2 and to the input of the differentiating circuit 7. At the output of the latter, short bipolar pulses are generated (Fig. 6e). Moreover, a positive short pulse starts, and a negative short pulse closes the generator 1 sweep. The generated sawtooth voltage (Fig. 6g) is used as a sweep voltage and is supplied to a horizontal CRT electrode 2. A pulse is generated on the CRT 2 screen (Fig. 4b), the duration of which is proportional to the duration τ _{and the} received LFM-MPSK signal, the amplitude is proportional to the rate of change of frequency γ inside the pulse, and the waveform area is proportional to the frequency deviation Δf _g (Δf _g = γ˙τ _и ) of the received LFM-MPSM signal.

 For a visual assessment of the main parameters of the received signal, a coordinate frequency-time grid is applied to the CRT 2 screen.

cos[ωδ˙t + φ_к(t) + φδ] ,
0 ≅ t ≅ τ_и где U_δ=

·K₂·U $\genfrac{}{}{0ex}{}{\text{2}}{\text{п}}$ _р;
К₂ - коэффициент передачи перемножителя;
ωδ = 2πγτ - частота биений;
φδ = ω_пр˙τ - πγτ² - начальная фаза биений, которое представляет собой сигнал с многократной фазовой манипуляцией на частоте биений. Причем частота биений определяется скоростью изменения частоты γ сигнала и величиной задержки. Напряжение биений U δ₁(t) выделяется полосовым фильтром 16 и поступает на вход умножителя 17 частоты на восемь, на выходе которого образуется гармоническое колебание
U δ₂(t) = Uδ ˙ cos(8ωδt + 8φδ), 0 ≅ t ≅ τ_и . Напряжение U δ₂(t) выделяется узкополосным фильтром 18 и поступает на вход делителя 19 частоты на восемь, на выходе которого образуется напряжение (фиг. 6и)
Uδ₃(t) = Uδ ˙ cos(ωδt + φδ), 0 ≅ t ≅ τ_и, которое представляет собой гармоническое колебание на частоте биений.The voltage U ₅ (t) (Fig. 6c) emitted by the band-pass filter 14 is also supplied to the information input of the controlled delay element 24, the output of which is voltage
₆ U (t) = U ₅ (t - τ) = U _pr ˙cos [ω _ave (t - τ) +
+ πγ (t - τ) ² + φ _CR1 ], 0 ≅ t ≅ τ _and This voltage is supplied to the second input of the multiplier 15, the first input of which receives voltage U _CR3 (t) (Fig. 6b) from the output of the intermediate frequency amplifier 9 . At the output of the multiplier 15, a beat voltage is generated (Fig. 6h)
Uδ ₁ (t) = U

cos [ωδ˙t + φ _к (t) + φδ],
0 ≅ t ≅ τ _and where U _δ =

K ₂ U $\genfrac{}{}{0ex}{}{\text{2}}{\text{P}}$ _p ;
K ₂ is the transmission coefficient of the multiplier;
ωδ = 2πγτ is the beat frequency;
φδ = ω _pr ˙τ - πγτ ² is the initial phase of the beats, which is a signal with multiple phase shift keying at the beat frequency. Moreover, the beat frequency is determined by the rate of change of the γ signal frequency and the delay value. The beat voltage U δ ₁ (t) is allocated by a band-pass filter 16 and is fed to the input of a frequency multiplier 17 by eight, at the output of which a harmonic oscillation is generated
U δ ₂ (t) = Uδ ˙ cos (8ωδt + 8φδ), 0 ≅ t ≅ τ _and . The voltage U δ ₂ (t) is allocated by a narrow-band filter 18 and is fed to the input of a frequency divider 19 by eight, at the output of which a voltage is generated (Fig. 6i)
Uδ ₃ (t) = Uδ ˙ cos (ωδt + φδ), 0 ≅ t ≅ τ _and , which is a harmonic oscillation at the beat frequency.

The voltage Uδ ₃ (t) is allocated by a narrow-band filter 20 and is supplied to the first input of the phase detector 21, the second input of which is supplied with voltage from the output of the reference voltage generator 32
U _o (t) = U _o cos (ω _o t + φ _o ), where U _o , ω _o , φ _o are the amplitude, frequency, and initial phase of the local oscillator voltage.

If these voltages differ from each other in frequency or phase, then a control voltage is generated at the output of the phase detector 21. Moreover, the amplitude and polarity of this voltage depends on the degree and direction of deviation of the beat frequency ωδ from the frequency ω _{o of} the reference voltage generator 32. The control voltage is allocated by the low-pass filter 22 and, using the control signal generator 23, acts on the controlled delay element 24, changing the delay value τ so that the equality
ωδ = 2 π γ τ = ω _o .

To visually assess the magnitude of the phase jumps Δφ and the multiplicity m of phase manipulation of the received LFM-MPSK signal, a circular CRT 34 is used. Moreover, the circular scan is formed using the generator 32 of the reference voltage, the frequency ω _o which is maintained equal to the beat frequency ωδ (ω _o = ωδ) using a phase-locked loop.

The voltage Uδ ₁ (t) (Fig. 6h) from the output of the bandpass filter 16 through the open key 27 is fed to the input of the frequency detector 30, the output of which is formed by a sequence of short bipolar pulses (Fig. 6k), the temporary position of which corresponds to the moments of the abrupt change in the signal phase (Fig. 6h).

Voltage U _o (t) output from the reference voltage generator 32 is supplied directly to the vertical electrode, and through a phase shifter 31 for ⁹⁰ - on the horizontal electrode 34 of the CRT to form at its circumferential screen scan. The formed sequence of short-lived bipolar pulses (Fig. 6k) from the output of the frequency detector 30 enters the modulating electrode of the CRT 34 and modulates its electron beam in brightness. On the screen of the CRT 34, an image is formed in the form of several bright points located on a circle (Fig. 4c, d, e). The number of points determines the multiplicity m of phase manipulation, and the angular distance between them is equal to the phase jump Δφ of the received LFM-MPSM signal. With a frequency inequality (ωδ ≠ ω _o ), the luminance marks will move around the circle with a difference frequency, and the reliability of the visual estimation of the multiplicity m of phase manipulation and the magnitude of the phase jumps Δφ of the received LFM-MPSM signal decreases sharply. To eliminate this drawback, a phase-locked loop is used.

(t) = U_p˙M(t)˙M(t + τ)cos(ω

t +
+ φ

+ U_pM(t)˙M(t + τ)˙cos(2ω_прt +
+ 2πγt² + 2φ_пр1 + ωδt + πγτ²),
0 ≅ t ≅ τ_и где U_р=

K₂U $\genfrac{}{}{0ex}{}{\text{2}}{\text{п}}$ _р. Из результирующего колебания U

(t) фильтром 50 нижних частот выделяется напряжение разностной частоты
U_р1(t) = Uδ˙M(t)˙M(t + τ)cos(ωδt + φδ + Δφ),
0 ≅ t ≅ τ_и, где Δφ = φ₂ - φ₁; пропорциональное корреляционной функции.Voltages U _CR3 (t) and U _CR4 (t) from the outputs of the dividers 9 and 45 of the intermediate frequency through the public key 10 are fed to two inputs of the multiplier 48, the output of which is the resulting oscillation
U

(t) = U _p ˙ M (t) ˙ M (t + τ) cos (ω

t +
+ φ

+ U _p M (t) ˙ M (t + τ) ˙cos (2ω _pr t +
+ 2πγt ² + 2φ _pr1 + ωδt + πγτ ² ),
0 ≅ t ≅ τ _and where U _р =

K ₂ U $\genfrac{}{}{0ex}{}{\text{2}}{\text{P}}$ _r . From the resulting oscillation U

(t) a differential frequency voltage is allocated by the low pass filter 50
U _p1 (t) = Uδ˙M (t) ˙M (t + τ) cos (ωδt + φδ + Δφ),
0 ≅ t ≅ τ _and , where Δφ = φ ₂ - φ ₁ ; proportional to the correlation function.

(t) = U _p1 ²(t) + U _p2 ²(t) = [Uδ˙M(t) x
M(t + τ)] ² x [cos²(ωδt + φδ + Δφ) + + sin²(ωδt + φδ + Δφ)] = [Uδ˙M(t) x x M(t + τ)] ² . Суммарное напряжение U

(t) поступает на вход блока 55 извлечения квадратного корня, на выходе которого образуется низкочастотное напряжение
U_н(t) = U δ˙ M(t). M(t + τ), представляющее собой произведение двух модулирующих функций M(t) (фиг. 7а) и M(t + +τ) (фиг. 7в), сдвинутых друг относительно друга на величину задержки τ.The maximum value of the correlation function is provided when the following condition is met
/ cos (ωδt + φδ) / = 1. To fulfill this condition, the voltages U _CR3 (t) and U _CR4 (t) from the outputs of the amplifiers 9 and 45 of the intermediate frequency simultaneously arrive at the inputs of the phase shifters 46 and 47 by 90 ^° , at the outputs of which stresses are formed:
U _pr5 (t) = U _pr ˙ M (t) ˙sin (ω _pr t + πγt ² + φ _pr1 ),
_Pr6 U (t) = U _pr ˙M (t + τ) sin [ ω _ave (t + τ) +
+ πγ (t + τ) ² + φ _pr2 ], which are supplied to the two inputs of the multiplier 49. The output oscillator 49 generates the resulting oscillation, from which the difference frequency voltage is extracted from the low-pass filter 51
U _p2 (t) = Uδ˙M (t) ˙M (t + τ) sin (ωδt + φδ + Δφ). Voltages U _p1 (t) and U _p2 (t) from the outputs of the low-pass filters 50 and 51 are supplied through the squares 52 and 53 to the two inputs of the adder 54
U

(t) = U _p1 ² (t) + U _p2 ² (t) = [Uδ˙M (t) x
M (t + τ)] ² x [cos ² (ωδt + φδ + Δφ) + sin ² (ωδt + φδ + Δφ)] = [Uδ˙M (t) xx M (t + τ)] ² . Total voltage U

(t) enters the input of the square root extraction unit 55, at the output of which a low-frequency voltage is generated
U _n (t) = U δ˙ M (t). M (t + τ), which is the product of two modulating functions M (t) (Fig. 7a) and M (t + + τ) (Fig. 7c), shifted relative to each other by the delay value τ.

/n, где τ_i - длительность i-го временного интервала (i = 1,2, . . . n);
n - объем выборки (количество измерений). Напряжение U_пр3(t) с выхода усилителя 9 промежуточной частоты через открытый ключ 10 одновременно поступает на второй вход (вход 60) измерителя 57 временных интервалов (на вход амплитудного детектора 63). Амплитудный детектор 63 выделяет огибающую напряжения U_пр3(t) (фиг. 7д), которая поступает на вход дифференцирующей цепи 64. На выходе последней образуются два коротких разнополярных импульсов, поступающих на третий вход счетчика-делителя 67. Причем положительным коротким импульсом счетчик-делитель 67 приводится в исходное (нулевое) состояние, т. е. подготавливается к работе. А отрицательным коротким импульсом измеренное среднее значение τ_сp в цифровом коде переписывается в блок 58 регистрации. По измеренному среднему значению времени задержки τ_срможно однозначно определить угол прихода β радиоволны.The voltage U _n (t) (Fig. 7f) is supplied to the input of a unipolar valve 56, at the output of which negative pulses of duration τ are formed (Fig. 7g). These pulses are fed to the input of the meter 57 time intervals (input 59). At the output of the differentiating circuit 61, a sequence of short bipolar pulses is formed (Fig. 7h), which, through a unipolar valve 62 (Fig. 7i), are fed to the first input of the counter-divider 67. Unipolar valves 56 and 62 pass only negative pulses. Negative pulses (Fig. 7) from the output of the unipolar valve 56 simultaneously arrive at the first input of the coincidence element 66, the second input of which is supplied with counting pulses from the output of the generator 65 (Fig. 7k). At the output of the coincidence element 66, counting pulses proportional to τ are formed, which are fed to the second input of the counter-divider 67. In the counter-divider 67, the pulses proportional to τ are sequentially added and the resulting sum is divided by the number n of measurements
τ _avg =

/ n, where τ _i is the duration of the ith time interval (i = 1,2,... n);
n is the sample size (number of measurements). The voltage U _pr3 (t) from the output of the intermediate frequency amplifier 9 through the public key 10 is simultaneously supplied to the second input (input 60) of the meter 57 time intervals (to the input of the amplitude detector 63). The amplitude detector 63 selects the voltage envelope U _{pr3 (} t) (Fig. 7d), which is fed to the input of the differentiating circuit 64. At the output of the latter, two short bipolar pulses are generated, which arrive at the third input of the counter-divider 67. Moreover, the counter-divider is a positive short pulse 67 is restored to its initial (zero) state, i.e., it is being prepared for work. And with a negative short pulse, the measured average value of τ _cp in the digital code is written to the registration unit 58. From the measured average value of the delay time τ _sr, we can uniquely determine the angle of arrival β of the radio wave.

The delay time τ _{s of} the delay line 26 is selected so that it is possible to visually evaluate the main parameters of the received LFM-MPSK signal by observing oscillograms on CRT screens 2.33 and 34.

 After this time, the voltage from the output of the delay line 26 is supplied to the reset input of the detector 25 (threshold block 41) and resets its contents to zero values. In this case, the search unit 28 is transferred to the tuning mode, and the keys 10 and 27 are closed, i.e., are transferred to their initial states. From this moment in time, viewing a given frequency range and searching for LFM-MPSK signals continues.

 In case of detection of the next LFM-MPSK signal, the device operates in a similar way.

Thus, the proposed device in comparison with the prototype provides accurate and unambiguous direction finding of the radiation source of signals with combined linear frequency modulation and multiple phase shift keying. Moreover, accurate direction finding is achieved by increasing the measuring base α. And the resulting ambiguity in reading the angular coordinate is eliminated by correlation quadrature processing of the received LFM-MPSK signals, at which the average value of the delay time τ _cf is measured. Therefore, the functionality of the device is expanded.

 In addition, the presentation of direction finding results in digital code ensures their long-term storage, long-distance transmission via communication channels and interfacing with computer technology. (56) Copyright certificate of the USSR N 1606859, cl. G 01 D 7/10, 1989.

 USSR copyright certificate N 1682788, cl. G 01 D 7/10, 1991.

Claims (2)

1. INDICATOR DEVICE containing a first antenna in series, a first wideband amplifier, a first mixer, a second input of which is connected through a local oscillator to the first output of the search unit, a first intermediate frequency amplifier, a first key, the second input of which is connected to the detector output, the first frequency multiplier by eight, the first band-pass filter, the first frequency divider by eight, the second band-pass filter, the first frequency detector, the first differentiating circuit, the second differentiating circuit, an oscillator wraps and a horizontal electrode of the first cathode ray tube, the vertical-deflecting electrode of which is connected to the output of the first differentiating circuit, a detector is connected in series to the output of the first intermediate-frequency amplifier, the second input of which is connected to the output of the delay element, and the vertical-deflecting electrode, which is connected through the search unit with the detector output, the first multiplier is connected in series to the output of the first intermediate frequency amplifier, the second input of which is connected through without a controlled delay element with the output of a second bandpass filter, a third bandpass filter, a second frequency multiplier by eight, a fourth bandpass filter, a second frequency divider by eight, a fifth bandpass filter, a phase detector, the second input of which is connected to the output of the reference voltage generator, the first lower filter frequencies and a driver of the control signal, the output of which is connected to the second input of the controlled delay element, the second key is connected in series to the output of the third band-pass filter, the second input otorrhea connected to the output of the detector, the second frequency detector and a modulation electrode of the third cathode ray tubes, vertical deflection electrode connected to the output reference voltage generator directly and horizontal deflection electrode - through the first phase shifter 90 ^o, characterized in that in it entered the second antenna, the second wide-band amplifier, a second mixer, the second intermediate-frequency amplifier, the second and third phase shifters 90 ^o, the second and third multipliers, second and third phi Low frequencies, the first and second quadrants, the adder, the square root extraction unit, a unipolar valve, a time interval meter and a recording unit, while the second antenna, a second broadband amplifier, and a second mixer, the second input of which is connected to the local oscillator output, are connected to the output , a second intermediate frequency amplifier, a second multiplier, the second input of which is connected to the output of the first key, a second low-pass filter, a first quadrator, adder, a quad extraction unit Nogo root unipolar valve time-interval meter, a second input coupled to an output of the first key and the registration unit serially connected second phase shifter 90 ^o, the second input of which is connected to the output of the first switch, the third phase shifter 90 ^o, the third multiplier, a second whose input through the third phase shifter is 90 ^° connected to the output of the second intermediate-frequency amplifier, the third low-pass filter and the second quadrator, the output of which is connected to the second input of the adder.  2. The device according to p. 1, characterized in that the time interval meter is made in the form of a series-connected first differentiating circuit, the input of which is the first input of the meter, a unipolar valve and a counter-divider, the output of which is the output of the meter, series-connected amplitude detector, input which is the second input of the meter, the second differentiating circuit, the output connected to the second input of the counter-divider, series-connected counting pulse generator and element And that, the other input of which is connected to the input of the first differentiating circuit, and an output - to the third input amplifier counter.

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