SU1307386A2 - Phase-meter - Google Patents

Abstract

The invention relates to the field of measurement technology and is a fig. 1 improvement of the invention according to the authors. St. No. 561148. It can be used to implement the phase method of direction finding of radio emission sources. Introduction of an adjustable delay to the phase meter of the block (B) 13, multiplier 14, low-pass filter 15, threshold B 16 and key 17 will increase the measurement accuracy by eliminating the direction finding ambiguity. radiation source of pulsed phase-manipulated signals. 2 Il.

Description

fO

11307386

The invention relates to a measurement technique and can be used to implement the phase method of direction finding radio emission sources .5

The purpose of the invention is to improve the measurement accuracy by eliminating the ambiguity of direction finding of a radiation source of pulsed phase-shift keyed (FMN) signals.

FIG. 1 shows a phase meter diagram; Fig. 2 shows the principle of direction finding of a source of radiation of a PSK signal in one plane with a phase meter.

The phase meter contains two measuring channels, each of which consists of a series-connected mixer 1 (2) and a filter 3 (4) of the total frequency, the outputs of the measurement channels are connected to the input of the mixer 5, the output of which is through the difference frequency filter 6 and the phase detector 7 connected to the indicator input

five

20

tion, and cpc (1;) contests

at t ке „, K ((K-n) x

 may change abruptly, i.e. on the boundaries between the elementary powders (to 1,2,3 ,, N-1),

  - the duration and the number of elementary parcels from which the signal is composed of duration T- (T (

 N;:,) -,

DC - the phase difference of the signals

determining the direction of the radiation source. Voltages are respectively supplied to the second inputs of mixers 1 and 2 from the outputs of generators 11 and 12, respectively.

Ur, (t) Ur, Cos (COr + 5l) t;

and

yy

(t) .cos (.) t.

25

Filters 3 and 4 select the components of voltages having total frequencies OC, -tQ.tSl (),,, + a, 1 $, 8, the mixer 9 is connected to the output of the output; and the minimum of the second filter 10 difference and maximum carrier frequencies of the frequency, and inputs with the outputs of the generators 11 and 12 of the reference frequency, with

VI

In this case, the generator output 11 is the reference frequency with

Tota connected to the second input of the mixer 1,. the output of the reference frequency generator 12 is connected to the second input of the mixer 2, the adjustable delay block 13, 35 multiplier 14, low-pass filter 15, the threshold block 16 and the key 17, the signal input of which is connected to the output of the second difference frequency filter 10, and the output - with the second input of the phase detector 7. The input of the adjustable delay unit 13 is connected to the output of the filter 3 of the total frequency, and the second input of the multiplier 14

input signals.

At the output of filters 3 and 4, they form UJ (t) u, .cos (Y (. + Tor +) (t) -f (and (t) + cOr-S7.) T + q (t),

Uj -k, .i.i.,

where K is the transfer coefficient of the mixer 1,

40

To - the transfer coefficient of the mixer 2, which is fed to the inputs of the mixer

5, to the output of which the filter is connected

6, tuned to the difference voltage frequency l) (t) and 1) 4 (t) is connected to the filter code 4, the total voltage at the filter 6 output frequency.

Phase meter works as follows.

Signals -50 are fed to the inputs of the mixers 1 and 2 from the outputs of the antennas

and, (t) Up Cos cOct + q K (t) + U, (t) Uj, -cos cOct + q) (t) ,,

U (t) U5-cos iQt + bC | r),

where u5) 4

K - transfer coefficient of the mixer 5.

where and ISO ;, is the amplitude and the carrier part- This voltage goes to the signal pertot; spin input of the phase detector 7. (jf (t) 0, - manipulated is - From the second outputs of the generators 11

. phase, mapping and 12 voltage reference frequency

the phase shift key law —U t) and (t) is fed to the mixer

tion, and cpc (1;) contests

at t ке „, K ((K-n) x

 may change abruptly, i.e. on the boundaries between the elementary powders (to 1,2,3 ,, N-1),

  - the duration and the number of elementary parcels from which the signal is composed of duration T- (T (

 N;:,) -,

DC - the phase difference of the signals

determining the direction of the radiation source. Voltages are respectively supplied to the second inputs of mixers 1 and 2 from the outputs of generators 11 and 12, respectively.

Ur, (t) Ur, Cos (COr + 5l) t;

and

yy

(t) .cos (.) t.

Filters 3 and 4 select the components of voltages having the total frequencies OC, -t-Q.tSl (), ", + a, 1 $, g / sE;; - and the values of the minimum and maximum carriers

input signals.

At the output of filters 3 and 4, they form UJ (t) u, .cos (Y (. + Tor +) (t) -f (and (t) + cOr-S7.) T + q (t),

Uj -k, .i.i.,

where K is the transfer coefficient of the mixer 1,

To - the transfer coefficient of the mixer 2, which is fed to the inputs of the mixer

5, to the output of which the filter is connected

6, tuned to the difference frequency of voltages l) (t) and 1) 4 (t) voltage at the output of the filter 6

U (t) U5-cos iQt + bC | r),

where u5) 4

K - transfer coefficient of the mixer 5.

3

9, to the output of which the filter 10 is connected, tuned to the difference frequency of voltages U (t) and

u, (t).

The voltage at the output of the filter 10 is equal to

Ug, (t),

where Ug 4- V W

K - transfer coefficient mixer 9.

At the same time, the voltages Uj (t) and U (t) from the outputs of filters 3 and 4 are fed to a correlator consisting of a multiplier 14, an adjustable delay unit 13 and a low-pass filter 15. The mutually correlation function R (ir) of the signals U (t) and U (t) obtained at the output of the correlator has a maximum at

 t,

Ur

where t and t are the signal travel time of the distance from the radiation source to the first and second antennas (A and B);

C is the propagation velocity of radio waves.

At the same time, the threshold level Unop in the threshold block I 6 is exceeded only at the maximum value of the correlation function RCo) and does not exceed at values С corresponding to the side lobes of the correlation function. When the threshold level Unop is exceeded in the threshold block 16, a voltage is generated, which is fed to the control input of the key 17 and opens it. In the initial state, the key 17 is always closed. In this case, the voltage Ug (t) from the output of the filter 10 through the public key 17 goes to the second input of the phase detector 7,

3073864

the output of which is a voltage

UnCt) IL cosAcf.

ten

where u

K - transfer coefficient of the phase detector 7;

„/ - V

Hr about 2b -r-sinj

The output of the phase detector 7 is connected to an indicator 8, the scale of which is calibrated in terms of the phase shift between the input signals.

Claims (1)

Thus, in the proposed phase meter, the contradiction between the requirements of measurement accuracy and the uniqueness of the angle report is eliminated. In this case, an increase in the measurement accuracy of the phase difference between the QPSK signals received by two separated antennas is achieved by eliminating the ambiguity of the angle reading. Invention Formula Phase meter auth. St. No. 561148, characterized in that, in order to improve measurement accuracy by eliminating the ambiguity of direction finding of a radiation source of pulsed phase-shifting signals, serially connected adjustable delay unit, multiplier, low pass filter, threshold unit and key are entered into it, while the key input signal is connected the output of the second filter of the difference frequency, and the output with the second input of the phase detector, the second input of the multiplier is connected to the output of the total frequency filter of the second measuring channel la, and the input of the variable delay unit coupled to the filter output sum frequency of the first measurement channel. Fi.2