SU1422177A2 - Method of checking two-phase generator - Google Patents

Abstract

The invention relates to a radio metering technique and allows for improved calibration accuracy. With the help of a phase meter, a comparison of the output shifts of the calibrated and exemplary generators at each controlled point of its phase scale is carried out. The outputs of the generator being turned, converted to signals of a fixed frequency, are compared in phase over two cycles. The novelty consists in performing the third measurement cycle, at which an additional phase shift is introduced into the reference channel of the generator being turned. In this case, the signals from the reference channels of the tuned and model generators are connected to the phase meter and the fourth measurement cycle is performed. In the process of the fourth measurement cycle, an additional phase shift is introduced into the measuring channel of the generator being turned, and the signals of the measuring channels of both generators are connected to the phase meter. 1 il. S (l

Description

N)

The invention relates to a radio metering technique, may be used in estimating the error of phase calibrators, and is an improvement of the invention according to the author. St. No. 596890.

The purpose of the invention is to improve the accuracy of the verification of two-phase generators

In the method of two-phase generator calibration, based on the phase meter comparing the phase shifts of the calibrated and exemplary generators at each controlled point of its phase scale, the output signals of the calibrated generator are alternately fed to the frequency converter, where they are converted into fixed signals frequencies that are compared in phase during two measurement cycles with coherent signals from the reference generator; in the first measurement cycle, signals from reference channels are connected to the phase meter and the Exemplary Generators, in the second cycle - from the measuring channels of both generators, the error is determined from the difference in the measured values, an additional phase shift is entered only into the reference channel of the Rotating Generator and the third measurement cycle is performed, at which the signals from the reference channels are connected to the phase meter the calibrated and exemplary generators, establish the initial phase shift in the reference channel, introduce an additional, equal to the specified phase shift only to the measuring channel of the tunable generator and you the fourth measurement cycle is complete, in which signals from the measuring channels of both generators are connected to the phase meter, the error is determined from the difference in measured values in the third and fourth measurement cycles, the resulting error of the generator being turned on is determined by the difference in the results of calculating the error of phase shift for the first and second measurement cycles and the dependence of the error on the phase shift for the third and fourth measurement cycles. .

The drawing shows a block diagram of the device, using the proposed method of calibration.

The device contains an exemplary two-phase generator 1, the local oscillator 2, a multiplier 3 frequencies, a phase meter 4, switches 5 and 6, mixers 7-9, a control unit 10, a rotatable two-phase generator 11 and phase shifters 12 and 13. The exemplary two-phase generator 1 is connected via switch 6 with one input of the phase meter 4, a rotatable two-phase generator 11 with its outputs through phase shifters 12 and 13 is connected to the inputs of the switch 5, the output of which is connected through the mixer 8 to the second input of the phase meter 4, the output of the reference channel of the sample generator

1 is connected via a frequency multiplier 3 to the first input of the mixer 9, the output of which is connected to the second input of the mixer 8, the output of the reference channel of the rotating generator 11 is connected to the first input of the mixer 7, the output of which is connected to the input of the reference generator 1, the output of the local oscillator 2 is connected to the second inputs mixers 7 and 9, the outputs of the control unit 10 are connected to the control inputs of the switches 5 and 6.

To ensure the coherence of the input signals of the phase meter 4 (frequency F) when converting the output signals of the tuned generator 11 (frequency) Frequencies of the output signals of the local oscillator

2 (fp) and multiplier 3 frequencies (f.) Should be chosen, for example, from the ratios "

f „f, + F.

  I-F-; f

F.-1)

a

where fo - discrete phase shift generator 1.

The measurement of the accuracy of the two-phase generator being tested 11 is carried out as follows.

Set the phase shift of the output signals of the generator being turned on, 11, equal to the first calibrated point of its phase scale. A similar phase shift is established between the output signals of the reference generator 1. The phase shifters 12 and 13 introduce equal (taken as zero) phase shifts (0 °, t / fi o).

By means of the control unit 10, the signals of the reference channels of the exemplary 1 and of the 11 generators being turned on are connected to the phase meter 4. The phase shift of the signals of the reference channels C / O) is measured with a phase meter 4 — the first measurement cycle. With the help of the control unit, the signals of the measuring channels of the model 1 and 11 generators being turned on are connected to the phase meter 4. A second phase meter measurement cycle is performed.

3U221

4 phase shifts (V () of signals of measuring channels. According to the difference of measured values determine the measurement error for the first turnable, point of the scale of the GB Nerator P.

oh -V

 P1

Then again, using the control unit 10, the signals of the reference channels of the generators 1 and 11 are connected to the phase meter 4. The phase shifter 12 introduces an additional phase shift Y, - H o. the reference signal generator II, whose magnitude is set on the indicator of the phase meter 4 times the phase shift bias of the two-phase generator II (the phase shift in the measuring signal remains unchanged

% h 0)

Make the third measurement cycle

phase meter 4 -. Using the control unit 10, signals from the primary channels of generators 1 and II are connected to the phase meter 4. Phaser 12 is set to zero (V / d O), and phase shifter 13 introduces an additional phase shift (Vy) into the measuring channel of generator 11 and performs the fourth measurement cycle with a phase meter 4 - Y. From the difference of the measured values for the first point to be checked, the measurement error is determined

(/ I

W (/ - W 1 - o / jh

Establish the phase shift of the output signals of the generator 11, equal to the second adjustable point of its phase scale, and a similar phase shift between the output signals of the reference generator 1.

Phases 15 and 12 and 13 introduce zero phase shifts (V ,, O,

  0 °).

Phase shifts of output signals of generator II in the second, third, and so on up to the last k-th turning point of its phase scale, proposed by the device, reduce the experimental data and calculate the values of%,%; V,, U / G ..

{a j

 Hj n

The obtained measurement result can be represented as two control systems:.

774

, g, + / nFti.M);

. g Vu -) /

 H 3 yr-Z (JtH) V, ,, + Y,, r. / I-r; where fr% b / t, respectively, phase phase and the accuracy of the jty generator j1 and phase-. Va error due to the conversion of the output signals of the oscillator 11 to coherent signals of a fixed frequency for the kth measurement point;

 - the error due to the conversion for the k-th measurement point when the additional phase shift is entered, H d - nth -th and If - the interval between the turning points of the phase scale of the generator 11. In addition, the measurement results can be represented as two dependences from phase shift

(Y), W ();

f w g (+ fnt (+ P,

the last of my transforms to the form 1 / (h; .. vfj,) V-.CV-f) + Vnf. (“f);

where Vnp (4 +) is the dependence „f, (PR, shifted to the left by the angle%.

f с J - Pj) is the dependence r (f), shifted to the right by the angle v ,.

The difference between the measured dependences. The 4 (f) and (4 -V) functions contain information only about the error of the povorovitem, generator of II in all k poverkhovaemye points of its scale.

The result of the error value of the turned-on generator 1Гв each k-th point of its scale 4V-. () Vni. can be determined, for example, by the decomposition in the Fourier series of the difference W - f (V -) by the formula g

H d h;) I

W.-i l

(

 KC,

X cos m. H,

k).

where m is the harmonic number of the error

generator to be turned on 11 m 1, D, 3, ..., g;

respectively, the amplitudes of the sinusoidal and cosine-harmonic harmonic components of decomposition in the Fourier series of 15 are the errors of the generator being turned 11. The beats are calculated from

JO

20

 0.5

AT

KV)

 0.5 With ctg

;

C 0.5 C, - 0.5 V ,,,

4. I ctg where B, C are, respectively, the amplitudes of the sinusoidal and cosine-like harmonic components of the decomposition in the Fourier series of the difference

V W - (- f).

The resulting error values of the tunable generator 11 can be determined for each kth point of its scale by solving these two systems of equations. Thus, an increase in the accuracy of error determination is achieved.

a two-phase generator due to phase error compensation due to the conversion of the output signals of the generator being turned into coherent signals of a fixed frequency and only the error of the two-phase generator being turned on.

Claims (1)

Invention Formula five 0 five thirty 35 Method of verification of a two-phase generator according to ed. St. No. 596890, characterized in that, in order to improve the verification accuracy at each measured point of its phase scale, a third measurement cycle is performed, at which an additional phase shift is entered only into the reference channel of the generator being turned, and signals connected to the phase meter are reference channels of the calibrated and reference oscillators; a fourth measurement cycle is carried out, during which an additional phase shift is entered only into the measuring channel of the calibrated oscillator, and signals from the measuring channels of both oscillators are connected to the phase meter c, then the error is determined by the difference of the measured values in the third and fourth measurement cycles, the resulting error of the generator being tested is determined by the difference of the results of calculating the dependence of the error on the phase shift for the first and second measurement cycles and the dependence of the error on the phase shift for the third and fourth measurement cycle.