SU1273833A1 - Method of measuring phase difference - Google Patents

Abstract

The invention can be used to measure the instantaneous phase difference of a radio pulse signal with a short time to access the signals and in a large dynamic range. The purpose of the invention is to improve the accuracy of measurements under conditions of a large dynamic range of their change. To do this, in a known method based on quadrature signal processing, the operations of summing the modules of the constant components of the multiplied signals, dividing the module of one of the constant components, which is selected on the basis of the analysis of the polarities of the selected components, are obtained, the result of dividing is taken with the weight of TT / 2. A device implementing the method contains limiting amplifiers 1 and 2, delay element 3, multipliers 4 and 5, integrators 6 and 7, force worlds 8 and 9, adder 10, switch 11 and weight divider 12, (L 1 Il.

Description

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The invention relates to a radio metering technique and can be used to measure the instantaneous phase difference of signals with a short signal access time and a large dynamic range. The purpose of the invention is to improve the accuracy of measurement of the instantaneous phase difference of radio pulse signals under conditions of a large dynamic range, they are achieved by the fact that, according to the method based on quadrature signal processing, operations are performed which consist in summing the modules of the constant components of multiplied signals, dividing module of one of the constant components, which is selected on the basis of the analysis of the polarities of the selected constant components, the resulting sum, and the result of dividing erets weighing TT / 2. The drawing shows a structural diagram of one of the variants of the device for implementing the proposed method. The device contains two limiter amplifiers 1 and 2, a delay element 3, two multipliers 4 and 5, two integrators 6 and 7, two shapers 8 and 9, an adder 10, a switch 11 and a weight divider 12. The first input of the device is through a series-connected first amplifier limiter 1, multiplier 4, integrator 6 and driver 8 are connected to the first inputs of adder 10 and switch 11. Second device input through a series-connected amplifier limiter 2, delay element 3, multiplier 5, integrator 7, driver 9 is connected with the second inputs of the adder 10 and the switch 11. The outputs of the adder 10 and the switch 11 are connected respectively to the inputs of the weight divider 12, and the output of the first amplifier limiting 1 is connected to the second input of the second multiplier 5, the output of the second amplifier limiting 2 is connected to the second input of the first multiplier 4. The method is carried out as follows. The input measurement signal e (t) U sin (wH - MI) is fed to the input of the amplifier limiter 1. After the amplifier limiter, the signal is branched into two channels and fed to 332 the first inputs of multipliers 4 and 5. The signals on these inputs look like e ( t) e (t) U sign sin ((A) t-tf). (1) LPL Similarly, the reference signal passing the limiting amplifier 2 is fed to the second inputs of these multipliers, and the reference signal by element 3 is delayed by a quarter of the second channel. The reference signals at the second inputs of the multipliers 4 and 5 are of the form e (t) U sign sinuJt; (t) sin (u) t). (3) In equations (1) - (3), the dash is over and means that the signal level indicated by this letter is limited. After multiplying the signals (1) and (2) in multipliers 4 and filtering the constant components of the multiplied signal by the integrator 6, at the output of the latter, we obtain the voltage Uj. , having a linear-broken line dependence of the phase shift and JU / Uo W2 -h) L1 / 2; , lu UpTT / 2 -h) / 1/2; . Similarly, after multiplying the signals (1) and (3) in multiplier 5 and filtering in the integrator 7, the voltage U,, also having a linearly broken line, is obtained at the output of the latter; dependence on I M / 1G / 2; O 7 UhU "(1T-) (5) / -and, and" (2IT -4) / fT / 2; ZTT / 2. Given the expressions (4) and (5), the phase difference s of the various quadrants is obtained in the first quadrant; () I and I 2 IUJ + tU, V in the second quadrant () - TT lUil + u 2 lUn + jUj; 2 in the third quadrant (ITS) JL1Ух1. (ux 2 W, 1 + in the fourth quadrant (3Ti / 2.i h 2 | T) -, r-VTu :,

From expressions (7) - (10) it follows that to determine the phase shift in the prdels of one quadrant, it is necessary to take the ratio of the voltage modulus / Uyj or / Ujl at the output of one of the channels to the sum of the moduli of these voltages. The choice of voltage} uj or during divisions is determined by the ratio of the polarities of these voltages: if the polarities are the same (first and third quadrants), then the voltage is taken, if different (the second and fourth quadrants), then the voltage is taken. In the device, this is accomplished with the help of the formers 8 and 9, the adder 10, the switch 11 and the weight divider 12.

To unambiguously determine the phase shift in the range of 0-2ff, one of the constants must be added to the result of dividing: 0, ft / 2, and W / 2. The choice of the constant is also determined by the following polarity ratio of the voltage U; and u

f

1st quadrant U..Ci U 0-constant L ..

ta 0;

2nd quadrant U О, U О - constant П / 2;

3rd quadrant C, 0, constant TG;

The 4th quadrant U Oh, U Oh is a constant 3/2. one

Thus, the use of the proposed method provides an increase in the accuracy of measuring the phase difference

signals with a short time to access these signals and a wide dynamic range of their change.

Claims (1)

Invention Formula The method of measuring the phase difference, concluded in limiting the measured and reference signals, splitting these signals on two channels, the reference signal in the first channel is delayed relative to the reference signal in the second channel by a quarter of the period, multiplying these signals in each channel, selecting the voltage models the constant components of the multiplied signals at the outputs of each of the channels, characterized in that, in order to increase the accuracy of measurement of the instantaneous difference f of the radio pulse signals under conditions of greater their dynamic range, the sum of the modules of these voltages is summed, the voltage module is divided at the output of one of the channels by the resulting sum and the result of the division is taken with the weight tF / 2, and the voltage of the second channel is selected when dividing; The outputs of the first and second channels are different, and the voltage modulus of the first channel, if the polarities of the voltages at the outputs of the channels are the same.