SU742824A1 - Digital correlation phase meter - Google Patents

Description

one

The device relates to digital equipment used to measure the phase shift of signals in the presence of noise and noise.

A digital correlation phase meter is known, which contains input blocks, a recording unit and a control unit 1.

A digital correlation phase meter is also known, which contains two input blocks whose inputs are connected respectively to the first and second inputs of a digital correlation phase meter, a clock generator, a control unit, a recording unit and a counter, and the input of the control unit and its output are respectively connected to the generator output clock pulses and control input of the registration unit 2.

A disadvantage of the known digital correlation phasemeters is the limited noise immunity.

The purpose of the invention is to increase the noise immunity of the digital correlation phase meter.

This goal is achieved by the fact that a digital phase correlator has a phase meter containing

the first and second input blocks, the clock pulse generator, the control block, the registration block and the counter, the input of the control block and its output connect 1, respectively, to the output of the clock pulse generator and the control input of the registration block, equipped with a code converter, first and second multipliers, adder , desch {tele, first, second, third, and fourth difference-difference counters, and the inputs of difference counters are connected to the outputs of the transformers of code bodies, whose information inputs are connected to the outputs of input b shackles, a clock input connected to the output of the divider and counter input, the outputs of the two MSBs

15 of which are connected to the control inputs of the code converter, the input of the divider is connected to the output of the clock pulse generator, the outputs of the first and second difference chips are connected to the first and second inputs of the first multiplier, the second switches are connected to the outputs of the third and fourth difference counters, multiply first outputs

The connectors are connected respectively to the first and second inputs of the adder, the output of which is connected to the input of the registration unit, and the second inputs of the multipliers are connected to the additional output of the control unit.

The drawing shows the structure of the digital circuit of the digital phase meter.

The digital correllor phase meter, contains the first 1 and second 2 input blocks, input: d1e1 which are connected respectively with the first. and the second inputs of the digital correlation phase meter, the generator of 3 clock pulses, control block 4, recording block 5,: counter 6, code converter 7, first 8 I and second 9 multipliers, adder 10, divider 11, first, second, third and fourth and differential meters 12-15.

The device works as follows.

The code converter provides switching of pulses coming from the input of counter 6 to the inputs of differential meters 12-15, depending on the output signals of input blocks 1 and 2 and two high-order bits of counter 6. Since counter 6 is completely filled in during the time equal to one period studied signal component, the signal from the input of the counter 6 is added or subtracted from the code recorded in the difference counters 12-15 in accordance with the table, where the + and - signs indicate the subtraction of the pulse, respectively.

The inputs to the divider 11 are supplied with a code defining the period of the signal component being studied. Thus, the pulses with a frequency f from the clock generator 3, the passage through the de-shtel 11, have a frequency f / T, where T is the period under study. Thus, a constant number of pulses are placed at the output of divider 11 during the period under study, and these pulses completely fill the counter 6 over the period. Consequently, during the first quarter of the period, the output state of the two most significant bits of the counter is 6 00, the second quarter is 01, the third - 10 and fourth - I. The input test signals are fed to inputs 3 and 4 and, passing through input 1 blocks 1 and 2, take i values O or 1 depending on whether the threshold value is greater or not (if the signal is bipolar then the threshold value can be be zero). After the counter 6 is filled, the block 4 generates a signal that provides above multipliers 8 and 9 multiplying the codes recorded by the difference counters 12-15, respectively. The resulting product codes are summed by adder 1, converted and recorded by block 5. Since the codes recorded by difference counters 12-15 are proportional to the sign correlation of the signals under study with sin-cos and sin-period T, the components of the noise, arriving at both inputs, but not correlated with respect to the equivalent harmonic signal with frequency T, do not contribute to the codes fixed by the difference counters and are suppressed. Thus, a digital correlation phase meter provides, using relatively simple instrumental means, the determination of the phase shift with suppression of noise coming in at both inputs.

Claims (2)

1. Phase measuring systems and devices. Tomsk, 1974, p. 102, fig. eight. . 2. USSR author's certificate number 423066, cl. G 01 R 25/00, 11.04.72.