SU1183917A1 - Method of determining phaseamplitude error - Google Patents

Description

The invention relates to a phase-measuring technique and can be used to determine the phase-amplitude error of phase calibrators and attenuators. five

The purpose of the invention is to improve the accuracy of determining the phase-amplitude error of phase calibrators by eliminating the phase-amplitude error of the comparator device (sample (O c phase phase meter), by using the method of

plow equivalent value ', obtained by another independent method.

FIG. 1 shows a block diagram 15 of a device that implements the proposed method in FIG. 2 is a vector diagram explaining the operation of the device.

The device contains a successively connected voltage adder 1 and a voltage divider 2 to two and is equipped with an ungraded phase shifter 3, an exemplary phase meter 4, a voltage meter 5 voltage 25 and a switch 6, while the input of an ungraded phase shifting device 3 is connected to the first input 35

nym clamp (υ _ή), and an output - to the first input 1 and the adder 6 via switch 5 to voltage meter and a first input of an exemplary fazomera 4, which is also connected via the switch 6 to the output voltage 2 divider by two. The second input terminal (and _c ) is connected to the second input of the adder 1 and the reference phase meter 4. The method is as follows.

Let it be necessary to measure the phase-amplitude error when the amplitude difference A (^ B) between the measured and reference channels

A = ---—, hence = ---—. (one)

and _n A "

To do this, initially replace the value of the required difference in the amplitudes of the measured signal and, _{and the} relative reference ϋ _{0, with the} equivalent value ϋ _ρ obtained by another non-dependent method. The switch 6 is set to position a, and the reference and measuring signals of equal amplitude are fed to the input terminals. 55

and ₀ = υ, δίηωΐ ?,

and _n = and ₂ 51pos, (2)

where b, = ni = ϋ

thirty

40

When this signal arrives at the "input phase-shifting device 3, the output of which we have

υή = υ, δίη (ωί О)

The signal and ' _ъ (Fig. 2) is summed with the help of the voltage adder 1 with the reference signal and _p , and the resulting signal 2ϋρ is divided in half by amplitude with the help of the divider 2 _{- the} voltage into two, resulting in

And, 5ΐη (ωί +1?) +1) 1η ωί isoe4 <'( ^ib ^ 1 ·

From expression (4) it can be seen that by changing the value of cp between the reference and measured signals, it is possible to achieve the required difference A between the signals and _e and ϋρ, achieve to iso $ _r - g?

what is done with the help of phase shifting device 3 according to voltage meter 5, after that the first value of phase shift cp (Fig. 2) between the resultant and _p and reference and ₀ signals is recorded using the reference phase meter 4.

Then the switch 6 is set to position B and the second phase shift value (p ₂ (FIG. 2) between the measuring ϋ ¹ and the reference and _o

signals, then change

measured value of the measured signal (1)

amdo

and again fix the shift cf ₃ (Fig. 2)

the value of the phase between the reference ϋ „

and measured signals ϋ _η = ρ.

In this case, we have three measured values of phase shifts.

⁽⁶⁾

(7)

+ ₍₈ )

wheref — phase-amplitude errors of the phase meter and the calibrator, respectively, with the same voltage amplitude differences.

3

Next, the phase-amplitude error value is determined, for which the difference between the first (6) and half of the second (7) measurement results, between the results of the third (8) and second measurements (7) and the difference between the second and first results of calculations, i.e.

. (9)

the absolute value of the phase-amplitude error is assumed to be equal / a <p _to /.

1183917: 4

The proposed method makes it possible to accurately measure the phase – amplitude error of phase 5 calibrators or an attenuator with an error of the reference phase meter. Such accuracy is achieved by eliminating the phase-amplitude error of the comparator device (model phase meter); for this, the method of replacing the amplitude difference between the calibrator or attenuator channels with an equivalent value obtained by ₍ another independent method) is used.

Claims (1)

METHOD FOR DETERMINING PHASE-AMPLITUDE ERROR in measuring phase shifts, characterized in that, in order to improve accuracy, the amplitude signals initially measured and reference are initially summed, the phase shift value of the measured signal is changed relative to the reference signal so that the sum of the result of the addition of these signals is equal to a certain nonzero value, and measure the value of the phase shift of the received signal relative to the reference, then change the amplitude of the measured signal to the desired value, not equal to zero, and again and The value of the phase shift of the measured signal relative to the reference signal is measured, and then the difference between the first and half of the second measurement results, the results of the third and second measurements are calculated and the phase-amplitude error is determined as the difference between the second and first calculations. (rig. 1 51) 1183917 1 1183917