RU2465733C1 - Radio monitoring station - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: radio monitoring station has an antenna device, a receiver, a direction finder, a received signal parameter analyser, a device for storing and processing the obtained information and a telemetering device, three receiving antennae, an adjustment unit, two heterodynes, four mixers, three first intermediate frequency amplifiers, a detector, three delay lines, a switch, a second intermediate frequency amplifier, five multipliers, three narrow-band filters, a phase detector, two phase meters, two 90° phase changers, two low-pass filters, two squaring devices, an adder and a threshold unit, connected to each other in a certain manner.

EFFECT: high reliability of detecting composite signals with unknown carrier frequency, given tolerance range and random initial phase by quadrature signal processing.

Description

The proposed station belongs to the field of radio electronics and allows you to carry out radio-technical control of electronic equipment (RES) (radar, radio communication and control, etc.).

Known stations and radio-electronic control systems of RES (RF patents Nos. 2.150.178, 2.275.746; US patents Nos. 3.806.926, 3.891.989, 3.896.439; German patent No. 3.346.155; British patent No. 1.587.357; French patent No. 2,447.041; Vakin S.A., Shustov L.N. Fundamentals of radio countermeasures and electronic intelligence. M: Sov. Radio, 1968, p. 382, Fig. 10.2, etc.).

Of the known stations and systems, the closest to the proposed one is the Radio Control Station (RF patent No. 2.275.746, Н04К 3/00, 2004), which is chosen as the base one.

The well-known station provides an extension of the control area in terms of area and the number of controlled electronic equipment due to its placement on board a helicopter. In this case, the detector, which is part of the receiver, plays an important role, since the task of detecting a complex signal with an unknown frequency is very relevant in the radio control station located on board the helicopter, where significant frequency uncertainty is due to the large magnitude of the Doppler frequency shift.

An object of the invention is to increase the reliability of detection of complex signals with an unknown carrier frequency, a given region of acceptable values, and a random initial phase by quadrature signal processing.

The problem is solved in that the radio control station, containing, in accordance with the closest analogue, a series-connected antenna device, a receiver, an analyzer of the parameters of the received signal, a device for storing and processing the received information, the second input of which is connected through the direction-finding device to the output of the antenna device, and a telemetry device, the output of which is the output of the station, while the receiver is made in the form of series-connected receiving antenna, the first amplifier, the second input of which through the first local oscillator is connected to the output of the tuning unit, the amplifier of the first intermediate frequency, a detector, the second input of which through the first delay line is connected to its output, a key, the second input of which is connected to the output of the amplifier of the first intermediate frequency, the second mixer, the second the input of which is connected to the output of the second local oscillator, and the amplifier of the second intermediate frequency, the output of which is the output of the receiver, the control input of the tuning unit is connected to the output of the detector, the lengator device is made in the form of two direction-finding channels, each of which consists of a series-connected receiving antenna, a mixer, the second input of which is connected to the output of the first local oscillator, an amplifier of the first intermediate frequency, a multiplier, the second input of which is connected to the output of the amplifier of the second intermediate frequency, and narrowband filter, to the output of the first narrow-band filter, a third multiplier is connected in series, the second input of which is connected to the output of the second narrow-band filter, t the second narrow-band filter and the first phase meter, the second delay line, the phase detector, the second input of which is connected to the output of the second narrow-band filter, and the second phase meter, the second inputs of the phase meters are connected to the output of the reference generator, and the outputs are connected to the memory device to the output of the second narrow-band filter and processing the received information, the antenna device contains three receiving antennas, the receiving antenna of the receiver is located above the helicopter rotor hub, the receiving antennas of the direction-finding device The properties are located at the ends of the rotor blades of the helicopter, the engine is kinematically connected with the helicopter rotor and the reference generator, differs from the closest analogue in that the detector is made in the form of a third intermediate delay line, a fourth multiplier, the second input of which is connected to the output of the amplifier of the first intermediate frequency, the first low-pass filter, the first quad, adder and threshold block, the second input of which through the first line the rzhka is connected to its output, and the output is connected to the control input of the tuning block and to the first input of the key, connected in series to the output of the amplifier of the first intermediate frequency of the first phase shifter by 90 °, the fifth multiplier, the second input of which is connected through the second phase shifter by 90 ° to the output of the third delay lines, a second low-pass filter and a second quadrator, the output of which is connected to the second input of the adder.

The structural diagram of the proposed radio control station is presented in figure 1, a geometric arrangement of the receiving antennas on a helicopter is shown in figure 2.

The receiver 2 contains a series-connected receiving antenna 7, a first mixer 12, the second input of which through the first local oscillator 11 is connected to the output of the tuning unit 10, the amplifier 17 of the first intermediate frequency, the detector 20, the second input of which is connected to its output through the first delay line 21, the key 22, the second input of which is connected to the output of the amplifier 17 of the first intermediate frequency, the second mixer 24, the second input of which is connected to the output of the second local oscillator 23, and the amplifier 25 of the second intermediate frequency, the output of which is output of the receiver 2 and is connected to the analyzer input signal 4 received parameters.

In this case, the detector 20 is made in the form of series-connected to the output of the amplifier 17 of the first intermediate frequency of the third delay line 37, the fourth multiplier 38, the second input of which is connected to the output of the amplifier 17 of the first intermediate frequency, the first low-pass filter 41, the first quadrator 43, the adder 45 and threshold unit 46, the second input of which is connected through the first delay line 21 to its output, and the output is connected to the control input of the tuning unit 10 and to the input of the key 22, connected in series to the output of the amplifier I 17 of the first intermediate frequency of the first phase shifter 36 by 90 °, the fifth multiplier 40, the second input of which through the second phase shifter 39 by 90 ° is connected to the output of the third delay line 37, the second low-pass filter 42 and the second quadrator 44, the output of which is connected to the second input adder 45.

The direction-finding device 3 contains two direction-finding channels, each of which contains a receiving antenna 8 (9) in series, a mixer 13 (14), the second input of which is connected to the output of the local oscillator 11, an amplifier 18 (19) of the first intermediate frequency, a multiplier 26 (27) , the second input of which is connected to the output of the amplifier 25 of the second intermediate frequency, and a narrow-band filter 28 (29). At the same time, the third multiplier 30, the second input of which is connected to the output of the second narrow-band filter 29, the third narrow-band filter 32 and the first phase meter 34, are connected to the output of the first narrow-band filter 28, the second delay line 31, the phase detector 33 are sequentially connected to the output of the second narrow-band filter , the second input of which is connected to the output of the narrow-band filter 29, and the second phase meter 35. The second inputs of the phase meters 34 and 35 are connected to the output of the reference generator 16, and the outputs are connected to the storage device 5 processing the information received. The antenna device 1 contains three receiving antennas 7-9, the receiving antenna 7 of the receiver 2 is located above the rotor hub of the helicopter, the receiving antennas 8 and 9 of the direction-finding device 3 are located at the ends of the rotor blades of the helicopter (figure 2). The engine 15 is kinetically connected with the helicopter propeller and the reference generator 16.

Radio control station operates as follows.

The station is located on board a helicopter. The presence of the rotor of the helicopter is used to determine the direction of the radiating RES using an antenna device 1, receiving antennas 8 and 9 of which are located at the ends of the rotor blades (figure 2).

Signals received by antennas 7-9, for example with phase shift keying (PSK)

,

,

,

,

, 0≤t≤T_c,

, 0≤t≤T _c ,

where U ₁ , U ₂ , U ₃ - amplitude signal RES,

ω _c is the carrier frequency of the RES signal;

φ _c is the initial phase of the RES signal;

T _c is the duration of the RES signal;

± Δω - instability of the carrier frequency of the signal due to various destabilizing factors;

φ _k (t) = {0, π} is the manipulated component of the phase, which displays the law of phase manipulation in accordance with the modulating code;

R is the radius of the circle on which the receiving antennas 8 and 9 are located;

Ω = 2πR — rotation speed of receiving antennas 8 and 9 around receiving antenna 7 (rotational speed of a helicopter rotor);

α - bearing (azimuth) to the radiating RES,

arrive at the first inputs of the mixers 12-14, the second inputs of which are supplied with the voltage of the first local oscillator 11 linearly measured frequency

0≤t≤T_П,

0≤t≤T _P ,

- скорость изменения частоты гетеродина.Where

- rate of change of the local oscillator frequency.

It should be noted that the search for QPSK signals of RES in a given frequency range Df is carried out using tuning block 10, which periodically with a period T _P changes the frequency ω _{Г1 of the} local oscillator 11 according to a sawtooth law. A sawtooth voltage generator can be used as tuning block 10.

At the output of the mixers 12-14, voltages of combined frequencies are generated.

Amplifiers 17-19 distinguish the voltage of the first intermediate frequency:

, 0≤t≤T_c

, 0≤t≤T _c

;Where

;

;

;

;

;

K ₁ - gear ratio of the mixers;

ω _CR1 = ω _with -ω _G1 - the first intermediate frequency;

φ _pr1 = φ _with -φ _G1 .

The voltage u _CR1 (t) can be represented as follows:

where M (t) is the modulating code, in accordance with which the phase of harmonic oscillation is manipulated;

this voltage is applied to the input of the detector 20, namely, to the inputs of the delay line 37, the multiplier 38, and the phase shifter 36 by 90 °. The output of the latter forms a voltage

which is fed to the first input of the multiplier 40.

A voltage is generated at the output of the delay line 37

,

,

where τ ₁ is the delay time of the delay line 37.

The delay time τ _{1 of} the delay line 37 is selected from the following considerations: τ ₁ ≤τ _e , (ω _pr1 ± Δω) τ ₁ = 2πK, K = 1, 2, 3, ..., where τ _e is the duration of the chips (clock period) .

The _delayed voltage u _pr9 (t) is supplied to the input of the second phase shifter 39 by 90 °, at the output of which a voltage is generated

.

.

This voltage is supplied to the second input of the multiplier 40. The result of the multiplication of the voltages u _CR1 (t) and u _CR9 (t), u _CR8 (t) and u _CR10 (t) are complex vibrations, of which the following low-frequency filters are allocated 41 and 42 voltage:

,

,

,

,

Where

K ₂ - multiplier coefficient.

These stresses after squares 43 and 44, respectively, take the following form:

and enter the two inputs of the adder 45, the output of which is formed by the total voltage:

, 0≤t≤τ_c,

, 0≤t≤τ _c ,

which is fed to the input of the threshold block 46, where it is compared with the threshold voltage u _then and if it is exceeded, a decision is made to detect the signal.

When a RES signal is detected, a constant voltage appears at the output of the detector 20, which is supplied to the control input of the tuning unit 10, turning it off, to the control input of the key 22, opening it, and to the input of the delay line 21. The key 22 is always closed in the initial state. The delay time τ _{3 of} the delay line is selected so that it is possible to fix the detected PSK signal and analyze its parameters.

When you turn off the tuning unit 10 amplifiers 17-19 allocated the following voltages:

,

,

,

,

0≤t≤T_c

0≤t≤T _c

The voltage u _CR4 (t) from the output of the amplifier 17 of the first intermediate frequency through the public key 22 is supplied to the first input of the mixer 24, the second input of which is supplied with the voltage of the second local oscillator 23 with a stable frequency ω _Г2

.

.

At the output of the mixer 24, a voltage of combination frequencies is generated. Amplifier 25 isolates the voltage of the second intermediate frequency

, 0≤t≤T_c,

, 0≤t≤T _c ,

;Where

;

ω _CR2 = ω _CR1- ω _G2 - the second intermediate frequency;

φ _CR2 = φ _CR1 -φ _G2 ,

which is fed to the input of the analyzer 4 parameters of the received signal, which determines the duration τ _{3 of the} elementary packages from which the PSK signal is composed, their number N (T _c = N · τ ₃ ) and the law of phase manipulation.

The voltage u _pr7 (t) from the output of the amplifier 25 of the second intermediate frequency is simultaneously supplied to the second inputs of the multipliers 26 and 27 direction finding channels, the first inputs of which receive the voltage u _pr5 (t) and u _pr6 (t) from the outputs of the amplifiers 18 and 19 of the first intermediate frequencies respectively. At the outputs of the multipliers 26 and 27, phase-modulated (FM) voltages are formed at a stable frequency ω _{Г2 of the} second local oscillator:

, 0≤t≤T_c,

, 0≤t≤T _c ,

;Where

;

;

;

K ₂ - transmission coefficient of the multipliers,

which are distinguished by narrow-band filters 28 and 29 with a tuning frequency of ω _H = ω _G2 .

соответствуют диаметрально противоположным расположениям антенн 8 и 9 на концах лопастей несущего винта вертолета.Signs "+" and "-" before the value

correspond to diametrically opposite locations of the antennas 8 and 9 at the ends of the rotor blades of the helicopter.

Therefore, useful information about the bearing α is transferred to the stable frequency ω _{Г2 of the} second local oscillator 23. Therefore, the instability ± Δω of the carrier frequency caused by various destabilizing factors and the type of modulation (manipulation) of the received RES signal do not affect the direction finding result, thereby increasing the accuracy of positioning RES.

и называемая индексом фазовой модуляции, характеризует максимальное значение отклонения фазы сигналов, принимаемого неподвижной антенной 7.Moreover, the value that is part of these fluctuations

and called the phase modulation index, characterizes the maximum value of the phase deviation of the signals received by the fixed antenna 7.

. Однако с ростом

уменьшается значение угловой координаты α, при котором разность фаз превосходит значение 2π, т.е. наступает неоднозначность отсчета угла α.Direction finding device 3 is the more sensitive to a change in angle α, the larger the relative size of the measuring phase

. However with growth

the value of the angular coordinate α decreases, at which the phase difference exceeds the value 2π, i.e. ambiguity of reading the angle α occurs.

наступает неоднозначность отсчета угла α. Устранение указанной неоднозначности путем уменьшения соотношения

обычно себя не оправдывает, так как при этом теряется основное достоинство широкобазовой системы. Кроме того, в диапазоне метровых и особенно дециметровых волн брать малые значения

часто не удается из-за конструктивных соображений.Therefore, for

ambiguity of reading the angle α occurs. Resolving this ambiguity by reducing the ratio

usually doesn’t justify itself, since the main advantage of the wide-base system is lost. In addition, in the range of meter and especially decimeter waves, take small values

often fails due to design considerations.

To increase the accuracy of the direction finding of the RES in the horizontal (vertical) plane, the receiving antennas 8 and 9 are located at the ends of the rotor blades of the helicopter. The mixing of signals from two diametrically opposite receiving antennas 8 and 9, located at the same distance R from the axis of rotation of the rotor, causes phase modulation, obtained using one receiving antenna rotating in a circle whose radius R is two times larger (R ₁ = 2R )

Indeed, the output of the multiplier 30 produces a harmonic voltage

, 0≤t≤T_c,

, 0≤t≤T _c ,

Where

with phase modulation index

R₁=2R,

R ₁ = 2R,

which is allocated by a narrow-band filter 32 and fed to the first input of the phasemeter 34, the second input of which is supplied with the voltage of the reference oscillator 16

u ₀ (t) = U ₀ cosΩt.

. Это достигается использованием автокоррелятора, состоящего из линии задержки 31 и фазового детектора 33, что эквивалентно уменьшению индекса фазовой модуляции до величиныThe phasometer 34 provides an accurate but ambiguous measurement of the angular coordinate α. To eliminate the ambiguity in reading the angle α, it is necessary to reduce the phase modulation index without decreasing the ratio

. This is achieved by using an autocorrelator consisting of a delay line 31 and a phase detector 33, which is equivalent to reducing the phase modulation index to

,

,

where d ₁ <R.

A voltage is generated at the output of the autocorrelator

, 0≤t≤T_c,

, 0≤t≤T _c ,

with the phase modulation index Δφ _m2 , which is supplied to the first input of the phasemeter 35, the voltage u ₀ (t) of the reference generator 16 is supplied to the second input. The phase meter 35 provides a rough but unambiguous measurement of the angle α.

The minimum distance R ₀ from the RES to the helicopter propeller is determined from the expression

,

,

where F _q (t) is the Doppler frequency shift;

V = Ω · R;

λ is the wavelength.

The Doppler frequency shift is measured in the analyzer 4 parameters of the received signal, which also determines R ₀ . The latter are recorded in the device 5 for storing and processing the received information.

The location of the RES is determined in the device 5 by the measured values of α and R ₀ .

The telemetry device 6 is designed to transmit the received information to the control point.

After the time τ _{3, the} constant voltage from the output of the delay line 21 is supplied to the control input of the detector 20 (threshold block 46) and resets its contents to zero. In this case, the key 22 is closed, and the tuning unit 10 is turned on, i.e. they are translated into their original positions.

When a signal of the next RES is detected, the operation of the radio control station occurs in a similar way.

The proposed radio control station provides an expansion of the field of intelligence in terms of area and number of controlled electronic equipment. This is achieved by placing a radio monitoring station on board the helicopter, the flight route of which is laid in the border areas of the distribution zone.

The proposed radio control station provides accurate and unambiguous determination of the location of the RES. In this case, the direction-finding device is invariant to the form of modulation (manipulation) and instability of the carrier frequency of the received signals.

Thus, the proposed radio control station in comparison with the base provides an increase in the reliability of detection of complex signals with an unknown carrier frequency, a given region of permissible values, and a random initial phase. This is achieved by quadrature signal processing, which eliminates a priori uncertainty about the value of the carrier frequency and other parameters of the received signal.

Claims (1)

A radio control station comprising an antenna device, a direction-finding device, a receiver connected in series, an analyzer of parameters of the received signal, a device for storing and processing the received information, and a telemetry device whose output is the output of the station, the receiver being made in the form of a series-connected receiving antenna, a first mixer, the second input of which through the first local oscillator is connected to the output of the tuning unit, the amplifier of the first intermediate frequency, will detect For the key, the second input of which is connected to the output of the amplifier of the first intermediate frequency, the second mixer, the second input of which is connected to the output of the second local oscillator, and the amplifier of the second intermediate frequency, the output of which is the output of the receiver, the direction-finding device is made in the form of two direction-finding channels, each of which consists of a series-connected receiving antenna, a mixer, the second input of which is connected to the output of the first local oscillator, an amplifier of the first intermediate frequency, a multiplier, the second input to which is connected to the output of the amplifier of the second intermediate frequency, and a narrow-band filter, while the third multiplier is connected in series to the output of the first narrow-band filter, the second input of which is connected to the output of the second narrow-band filter, the third narrow-band filter and the first phase meter, the second is connected in series to the output of the second narrow-band filter a delay line, a phase detector, the second input of which is connected to the output of the second narrow-band filter, and the second phase meter, the second inputs of the first and second phase meters are connected to the output of the reference generator, and the outputs are connected to a device for storing and processing the received information, the antenna device contains three receiving antennas, the receiving antenna of the receiver is located above the rotor hub of the helicopter, the receiving antennas of the direction-finding device are located at the ends of the rotor blade of the helicopter, the engine is kinematically connected with helicopter rotor and reference generator, characterized in that the detector is made in the form of a first intermediate connected in series to the output of the amplifier The frequency of the third delay line, the fourth multiplier, the second input of which is connected to the output of the amplifier of the first intermediate frequency, the first low-pass filter, the first quad, adder and threshold block, the second input of which is connected to its output through the first delay line and the output is connected to the control input tuning unit and to the first input of the key, connected in series to the output of the amplifier of the first intermediate frequency of the first phase shifter by 90 °, the fifth multiplier, the second input of which is through the second phase a 90 ° rotator is connected to the output of the third delay line, the second low-pass filter and the second quadrator, the output of which is connected to the second input of the adder.

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