RU2427853C1 - Phase direction finding method and phase direction finder for implementing said method - Google Patents

Abstract

FIELD: physics. ^ SUBSTANCE: phase direction finder which realises the disclosed phase direction finding method has receiving antennae, three receivers, a reference generator, a pulse generator, an electronic switch, two 90 phase changers, three phase detectors, an indicator, a heterodyne, a mixer, an intermediate frequency amplifier, three multipliers, three band-pass filters, a delay line, two squaring devices, a scaling multiplier and a subtractor, connected to each other in certain way. ^ EFFECT: broader functional capabilities of the method and device through accurate and unambiguous determination of the elevation angle of a signal source onboard aircraft. ^ 2 cl, 2 dwg

Description

The proposed method and device relates to the field of electronics and can be used to determine the angular coordinates of the radiation sources of complex signals.

Known phase direction finding methods and phase direction finders (RF patents Nos. 2,003.131, 2.006.872, 2.010.258, 2.012.010, 2.134.429, 2.155.352, 2.175.770, 2.290.658, 2.311.656; German patents No. 2.127.087, 2.710.955; UK patents No. 1.395.599, 1.598.325; Kinkulkin I.E. et al. Phase method for determining coordinates. M: Sov. Radio, 1979; Space radio engineering complexes. Ed. S.I. Bychkova. - M .: Sov. Radio, 1967, p.130-138, and others).

Of the known methods and devices closest to the proposed are the "Phase direction finding method and phase direction finder for its implementation" (RF patent No. 2.290.658, G01S 3/46, 2005), which are selected as prototypes.

Known technical solutions are invariant to instability of the carrier frequency of the received signals, the type of modulation (manipulation) and the width of the spectrum, and the exact and unambiguous measurement of the angular coordinate α is carried out at a frequency Ω of the reference oscillator.

However, the known technical solutions provide accurate and unambiguous measurement of the angular coordinate α (azimuth) of the ground-based signal source in only one horizontal (azimuthal) plane and will not allow determining the elevation angle β of the signal source located on board the aircraft (airplane, helicopter, airship, probe, etc.).

An object of the invention is to expand the functionality of the method and device by accurately and unambiguously determining the elevation angle of the signal radiation source located on board the aircraft.

The problem is solved in that the phase direction finding method, based in accordance with the closest analogue on receiving signals, amplifying and limiting them in amplitude, comparing signals transmitted through two channels, in phase, while the signal of one of the channels is pre-shifted in phase by 90 ° , set in the azimuthal plane n of the receiving antennas around a circle of radius d with the possibility of their electronic rotation with an angular velocity Ω around a receiving antenna located in the center of the circle, receiving antennas are placed along circles, alternately with frequency Ω, the signal received by the antenna located in the center of the circle is converted in frequency, the intermediate frequency voltage is isolated, it is multiplied with signals alternately received by n receiving antennas located around the circle, the phase-modulated voltage is isolated, it is multiplied with the local oscillator voltage , select a low-frequency voltage with a frequency Ω and compare it in phase with the reference voltage, forming an accurate, but ambiguous direction finding scale of the signal source, simultaneously continuously phase-modulated voltage is subjected to autocorrelation processing emit low-frequency voltage with the frequency Ω, comparing its phase with the reference voltage to form a rough but unambiguous scale DF source signal radiation is different from the closest analog that is installed in the elevation plane of a second receiving antenna at a distance d ₂ from the first reception antenna receiving a signal on it, amplify and limit the amplitude is multiplied with the intermediate frequency voltage harmonic isolated voltage at the local oscillator frequency, multiply it with the local oscillator voltage, isolate the voltage proportional to the phase difference between the signals received by the first and second receiving antennas, forming a rough but unambiguous direction finding scale for the signal source in the elevation plane, the voltage indicated is squared, at the same time the initial voltage proportional to the phase difference between the signals received by the first and second antennas, phase shifted by 90 °, squared, multiplied with the original voltage m proportional to the phase difference between the signals received by the first and second antennas using a scaling factor of three and subtract the resulting product from the initial voltage proportional to the phase difference between the signals received by the first and second antennas, forming an accurate but ambiguous source direction finding scale radiation signal in elevation plane.

Phase direction finder containing, in accordance with the closest analogue, a first receiving antenna connected in series, a first receiver, a mixer, the second input of which is connected to the local oscillator output, an intermediate frequency amplifier, a first multiplier, a first bandpass filter, a delay line, a second phase detector, the second input of which is connected with the output of the first bandpass filter, the first phase shifter 90 °, the first phase detector, the second input of which is connected to the second output of the reference generator, and an indicator, sequentially in a reference generator, a pulse generator, an electronic switch, n inputs of which are connected to the outputs of n receiving antennas arranged around a circle of radius d with the possibility of electronic rotation around the first receiving antenna located at the center of the circle, and a second receiver, the output of which is connected to the second input of the first multipliers, connected in series to the output of the first bandpass filter, a second multiplier, the second input of which is connected to the output of the local oscillator, a second bandpass filter and a third phase detector p, the second input of which is connected to the third output of the reference generator, and the output is connected to the second input of the indicator, differs from the closest analogue in that it is equipped with a second receiving antenna, a third receiver, a third multiplier, a third bandpass filter, a fourth phase detector, two quadrators, a second 90 ° phase shifter, a scaling multiplier and a subtractor, and a third receiver, a third multiplier, the second input of which is connected to the output of intermediate frequency amplifier, third bandpass filter, fourth phase detector, the second input of which is connected to the output of the local oscillator, the first quadrator and subtractor, the output of which is connected to the third input of the indicator, the fourth input of which is connected to the output of the fourth phase detector, are connected to the output of the fourth phase detector in series a second 90 ° phase shifter, a second quadrator and a scaling multiplier, the second input of which is connected to the output of the fourth phase detector, and the output is connected to the second the subtractor, the second receiving antenna is installed in the azimuthal plane at a distance d ₂ from the first receiving antenna.

The structural diagram of the phase direction finder that implements the proposed phase direction finding method, is presented in figure 1. The relative position of the receiving antennas 1, 21, 2i · (i = 1, 2, ..., n) and the radio emission source of the IRI is shown in FIG. 2.

The phase direction finder comprises in series a first receiving antenna 1, a first receiver 3, a mixer 12, a second input of which is connected to the output of the local oscillator 11, an intermediate frequency amplifier 13, a first multiplier 14, a first band-pass filter 15, a delay line 16, a second phase detector 17, and a second the input of which is connected to the output of the first band-pass filter 15, the first phase shifter 8 by 90 °, the first phase detector 9, the second input of which is connected to the second output of the reference generator 5, and the indicator 10. To the first output of the reference generator 5, a pulse generator 6, an electronic switch 7, n inputs of which are connected to the outputs of n receiving antennas 2.i · (i = 1,2, ..., n) arranged in a circle of radius d with the possibility of their electronic rotation with speed Ω around the first receiving antenna 1, located in the center of the circle, and the second receiver 4, the output of which is connected to the second input of the first multiplier 14. The second multiplier 18 is connected in series to the output of the first bandpass filter 15, the second input of which is connected to the output of the local oscillator 11, the second polo oic third filter 19 and phase detector 20, a second input coupled to a third output of the reference oscillator 5 and the output connected to the second input 10 of the indicator.

The third receiver 22, the third multiplier 23, the second input of which is connected to the output of the intermediate frequency amplifier 13, the third pass filter 24, the fourth phase detector 25, the second input of which is connected to the output of the local oscillator 11, the first square 26 and a subtractor 30, the output of which is connected to the third input of the indicator 10, the fourth input of which is connected to the output of the fourth phase detector 25. A second phase rotation is connected in series to the output of the fourth phase detector 25 a device 27 by 90 °, a second quadrator 28 and a scaling multiplier 29, the second input of which is connected to the output of the fourth phase detector 25, and the output is connected to the second input of the subtractor 30.

The proposed method is implemented as follows.

Received complex signals, for example, with phase shift keying (PSK):

U ₁ (t) = Vc · cos [(ωc ± Δω) · t + φk (t) + φ ₁ ],

U ₂ (t) = Vc · cos [(ωc ± Δω) · t + φk (t) + φ ₁ + 2π (d / λ) · cos (Ω · t-α)],

U ₃ (t) = Vc · cos [(ωc ± Δω) · t + φk (t) + φ ₂ ], 0≤t≤Tc,

where Vc, ωc, φ ₁ , φ ₂ , Tc - amplitude, carrier frequency, initial phases and signal duration;

± Δω - instability of the carrier frequency of the signals due to various destabilizing factors, including the Doppler effect;

φk (t) = {0, π} is the manipulated component of the phase, which displays the law of phase manipulation in accordance with the modulating code, and φk (t) = const for k · τэ <t <(k + 1) · τэ and can change abruptly at t = k · τэ, i.e. at the borders between elementary premises (k = 1, 2, ..., N-1);

τe, N - duration and number of chips that make up a signal of duration Tc · (Tc = N · τe);

d is the radius of the circle on which the receiving antennas are located 2.i · (i = 1, 2, ..., n) (measuring base);

Ω is the speed of electronic rotation of the receiving antennas 2.i- (i = 1, 2, ..., n) around the receiving antenna 1;

α - bearing (azimuth) to the signal source;

from the outputs of the receiving antennas 1, 2.i · (i = 1, 2, ..., n) and 21 directly and through the electronic switch 7 are fed to the inputs of the receivers 3, 4 and 22, and then to the first inputs of the mixer 12, the multipliers 14 and 23 respectively. The second input of the mixer 12 from the output of the local oscillator 11 receives the voltage:

Uг (t) = Vг · cos (ωг · t + φ _г ].

At the output of the mixer 12, voltages of combination frequencies are generated. The amplifier 13 is allocated the voltage of the intermediate (differential) frequency:

Upr (t) = Vpr · cos [(ωpr ± Δω) · t + φk (t) + φpr], 0≤t≤Tc,

where Vpp = _^1/2 Vc · Vr;

ωpr = ωc-ωg - intermediate frequency;

φpr = φc-φg,

which is fed to the second inputs of the multipliers 14 and 23. At the output of the multiplier 14 is formed phase-modulated (FM) oscillation at a frequency ωg of the local oscillator 11:

U ₃ (t) = V ₃ · cos [ωг · t + φг + 2π (d / λ) · cos (Ω · t-α)], 0≤t≤Tc,

wherein V ₃ = _^1/2 Vc · Vpp,

which is allocated by a band-pass filter 15 and supplied to the first inputs of the phase detector 17, delay line 16 and multiplier 18. The second input of the latter is supplied with the voltage Ug (t) of the local oscillator 11. At the output of the multiplier 18, a harmonic voltage is generated:

U ₄ (t) = V ₄ · cos [2π (d / λ) · cos (Ω · t-α)], 0≤t≤Ts,

₄ where V = _^1/2 · V _3, Vg;

which is allocated by the band-pass filter 19 and supplied to the first input of the phase detector 20. The reference voltage is applied to the second input of the phase detector 20 from the third output of the reference generator 5

U ₀ (t) = V ₀ cosΩ t.

The output of the phase detector 20 produces a voltage:

Un ₁ (λ) = Vn ₁ cosλ,

where Vr = _{1 ^1/2} · V V _{4 0,}

which is fixed by indicator 10.

This forms the direction finding scale of the signal source in the azimuthal plane, which is an accurate but ambiguous scale.

At the same time, the phase-manipulated oscillation U ₃ (t) is subjected to autocorrelation processing using an autocorrelator consisting of a delay line 16 and a phase detector 17.

In the phase-manipulated voltage U ₃ (t), the quantity m _φ = 2π · d / λ, called the phase modulation index, characterizes the maximum value of the phase deviation from the zero value that occurs when the receiving antennas are electronically rotated 2.i · (i = 1, 2, ... , n) around the receiving antenna 1.

Receiving antennas 2.i · (i = 1, 2, ..., n) are alternately switched with a frequency Ω using an electronic switch 7 controlled by an n-phase pulse generator 6. The control pulses are generated by the 6 pulse generator from the harmonic voltage generated by the reference generator 5:

U ₀ (t) = V ₀ cosΩ t.

However, when d / λ> _^1/2 ambiguity comes reference angle α. The elimination of this ambiguity by reducing the d / λ ratio usually does not justify itself, since the main advantage of the wide-base direction finder is lost. In addition, in the ranges of meter and especially decimeter waves, it is often not possible to take small d / λ values due to design considerations.

In connection with the stated reason, the problem arises of decreasing the phase modulation index without decreasing the relative size of the measuring base d / λ. This is achieved by autocorrelation processing of the phase-modulated voltage U ₃ (t) using the delay line 16 and the phase detector 17. Moreover, the delay time τ of the delay line 16 is chosen so as to reduce the phase modulation index to the value:

mφ ₁ = 2π · d ₁ / λ,

where d ₁ <d,

in which the inequality is true:

d ₁ / λ ^_<1/2,

providing unambiguous direction finding of the signal source in the azimuthal plane. The output of the phase detector 17 produces a harmonious voltage:

U ₅ (t) = V ₅ · cos (Ω · t-α)], 0≤t≤Tc,

wherein V ₅ = _^1/2 V ^{₂ March,}

which through the phase shifter 8 through 90 ° enters the first input of the phase detector 9, the second input of which from the third output of the reference generator 5 is supplied with a reference voltage U ₀ (t). The output of the phase detector 9 produces a voltage:

Un ₂ (α) = V _{2 2} sinα,

₂ where Vr = _^1/2 · V ₅ V _0,

which is fixed by indicator 10.

This forms a rough but unambiguous scale of direction finding of the signal source in the azimuthal plane.

The second input of the multiplier 23 from the output of the intermediate frequency amplifier 13 is supplied with voltage Uпp (t). The output of the multiplier 23 produces a harmonic voltage at a frequency ωg of the local oscillator 11:

U ₆ (t) = V ₆ · cos (ωг · t + φг + Δφ), 0≤t≤Tc,

₆ where V = _^1/2 Vc · Vpp;

Δφ = φ ₂ -φ ₁ = 2π · d ₂ / λ · cosβ,

d ₂ - the distance between the receiving antennas 1 and 21 (measuring base);

λ is the wavelength;

β is the elevation angle of the IRI radiation source;

which is allocated by the band-pass filter 24 and supplied to the first input of the phase detector 25, the second input of which is supplied with the voltage Ug (t) of the local oscillator 11. A voltage is generated at the output of the phase detector 25

Un ₃ (β) = Vn ₃ · cosΔφ, 0≤t≤Ts,

wherein V ₃ = _^1/2 V ₆ · Vr;

Δφ = 2π · d ₂ / λ · cosβ,

which is fixed by the indicator. 10.

This forms a rough but unambiguous scale of direction finding of the signal source in the elevation plane.

At the same time, the voltage Un ₃ (β) from the output of the phase detector 25 is supplied to the inputs of the first quadrator 26 and the second phase shifter 27 by 90 °. The output of the quadrator 26, which is a multiplier, the two inputs of which are supplied with the same voltage Un ₃ (β), the following voltage is formed:

U ₇ (β) = V ₇ cos ² Δφ,

₇ where V = _^1/2 VH _{March ^2,}

which is fed to the first input of the subtractor 30.

The output of the second phase shifter 27 to 90 ° produces a voltage:

U ₈ (β) = - Vн ₃ · sinΔφ,

which is fed to the two inputs of the second quadrator 28. The voltage is formed at the output of the latter:

U ₉ (β) = V ₉ sin ² Δφ,

₉ where V = _^1/2 VH ^{₂ March.}

This voltage is supplied to the first input of the scaling multiplier 29, the second input of which is supplied with voltage Un ₃ (β) from the output of the phase detector 25. The scaling factor Km of the scaling multiplier 29 is chosen equal to 3 (Km = 3). The output of the scaling multiplier 29 is formed voltage:

U ₁₀ (β) = 3V ₁₀ cosΔφ sin ² Δφ,

where V ₁₀ = _^1/2 · V ₃ Vh ₉

which goes to the second input of the subtractor 30. At the output of the last voltage is formed:

U ₁₁ (β) = V ₁₁ cos3Δβ,

where V ₁₁ = V ₇ -3V ₁₀ ,

Δφ = 2π · d ₂ / λ · cosβ, 3Δφ = 2π · 3d ₂ / λ · cosβ,

which is fixed by indicator 10. This voltage is proportional to the triple value of the phase difference between the signals received by the two receiving antennas 1 and 21, and corresponds to the measuring base 3d ₂ .

Thus, an accurate, but ambiguous, direction-finding scale for the signal source in the elevation plane is formed. Moreover, between the measuring bases establish the following inequality:

.

.

Thus, the proposed method and device in comparison with prototypes and other technical solutions of a similar purpose provide an accurate and unambiguous determination of the elevation angle of the radiation source of a signal placed on board an aircraft (aircraft, helicopter, airship, probe, etc.). In this case, two measuring bases are used: small d ₂ - rough, but unequivocal, and large 3d ₂ - accurate, but ambiguous, between which the following inequality is established:

.

.

Moreover, an accurate but ambiguous measuring base of 3d _{2 is} formed by an indirect method. Thus, the functionality of the method and device is expanded.

Claims (2)

1. The phase direction finding method, based on receiving signals, amplifying and limiting them in amplitude, comparing signals transmitted through two channels in phase, while the signal of one of the channels is pre-phase shifted by 90 ° in phase, set n receiving antennas in the azimuth plane circles of radius d with the possibility of their electronic rotation with an angular velocity Ω around a receiving antenna located in the center of the circle, receive antennas are arranged around the circle, alternately with frequency Ω, the signal received by the antenna is placed at the center of the circle, it is converted in frequency, the intermediate frequency voltage is isolated, it is multiplied with signals alternately received by n receiving antennas located around the circle, the phase-modulated voltage is isolated, it is multiplied with the local oscillator voltage, the low-frequency voltage is isolated with the frequency Ω and the phase is compared in phase with a reference voltage, forming an accurate but ambiguous direction finding scale of the signal radiation source, simultaneously phase-modulated voltage is subjected to autocorrelation processing They select a low-frequency voltage with a frequency Ω, compare it in phase with the reference voltage, forming a rough but unambiguous direction finding scale for the signal source, characterized in that a second receiving antenna is installed in the elevation plane at a distance d ₂ from the first receiving antenna, its signal, amplify and limit it in amplitude, multiply it with an intermediate frequency voltage, emit a harmonic voltage at the local oscillator frequency, multiply it with a local oscillator voltage, emit voltage proportional to the phase difference between the signals received by the first and second receiving antennas, forming a rough but unambiguous direction finding scale of the signal source in the elevation plane, the indicated voltage is squared, at the same time, the initial voltage proportional to the phase difference between the signals received by the first and second antennas , phase shifted by 90 °, squared, multiplied with the initial voltage proportional to the phase difference between the signals received by the first and second antennas, with and using a scaling factor of three, and the resulting product is subtracted from the initial voltage, proportional to the phase difference between the signals received by the first and second antennas, of the second degree, forming an accurate but ambiguous direction finding scale of the signal source in the elevation plane. 2. Phase direction finder containing a first receiving antenna in series, a first receiver, a mixer, the second input of which is connected to the local oscillator output, an intermediate frequency amplifier, a first multiplier, a first bandpass filter, a delay line, a second phase detector, the second input of which is connected to the output of the first band-pass filter, the first phase shifter 90 °, the first phase detector, the second input of which is connected to the second output of the reference oscillator, and an indicator, the reference oscillator connected in series, the generator a pulse torus, an electronic switch, n inputs of which are connected to the outputs of n receiving antennas arranged around a circle of radius d with the possibility of electronic rotation around the first receiving antenna located in the center of the circle, and a second receiver, the output of which is connected to the second input of the first multiplier, connected in series to the output of the first bandpass filter, a second multiplier, the second input of which is connected to the output of the local oscillator, a second bandpass filter and a third phase detector, the second input of which is connected to a third output of the reference generator, and the output is connected to the second input of the indicator, characterized in that it is equipped with a second receiving antenna, a third receiver, a third multiplier, a third bandpass filter, a fourth phase detector, two quadrants, a second 90 ° phase shifter, a scaling multiplier and a subtractor moreover, a third receiver, a third multiplier, a second input of which is connected to an output of an intermediate frequency amplifier, a third bandpass filter, are sequentially connected to the output of the second receiving antenna p, a fourth phase detector, the second input of which is connected to the output of the local oscillator, the first quadrator and subtractor, the output of which is connected to the third input of the indicator, the fourth input of which is connected to the output of the fourth phase detector, the second phase shifter 90 ° is connected in series to the output of the fourth phase detector, a second quadrator and a scaling multiplier, the second input of which is connected to the output of the fourth phase detector, and the output is connected to the second input of the subtractor, the second receiving antenna is installed in azimuthal plane at a distance d ₂ from the first receiving antenna.

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