SU1322191A2 - Device for measuring complex reflectance - Google Patents

Abstract

The invention relates to a technique for measuring on microwave and is additional to the invention in a. No. 1125556. The purpose of the invention is to improve the measurement accuracy of small coefficients, reflections. The device contains synthesizers 1, 5 frequencies, measuring probe section (FMC) 2 with a detector, power meter 3, directional coupler 4, key 6, time master unit 7, clock generator 8, two-terminal circuit under study (IDP) 9, computer 10, calibrated regulator of complex coefficient transmission (CR) 11. Synthesizer 1 generates a reference signal, synthesizer 5 - measuring signal. During calibration, the amplitudes of the reference and measurement signal sources are aligned. During the measurement, the PID 9 is connected and the K 11 level is increased modulo the level and the phase of the measuring signal supplied to the PID 9 is changed by a certain value. In FRS, the reference signal and the signal reflected from the PID 9 are summed to form a standing wave. With an increase in module coefficient. transmitting the RC 11, the standing wave amplitude increases. By the formula, taking into account the values of the modulus and the phase of the transmission coefficient KP 11, the complex coefficient is determined. reflections. Due to the introduction of the CU 11, an accurate measurement of small values of the coefficient is carried out. reflection based on the measurement of the amplitude of the shifting standing wave at fixed points in time with a calibrated change in the level of the complex amplitude of the measuring signal supplied to the panel 9. 1 Il. ё (L 00 to yu with MS)

Description

113

The invention relates to a technique for measurements on microwave and is an improvement of the known device according to the author, no. 1125556.

The purpose of the invention is to more accurately measure small reflection coefficients.

The drawing shows the structural electrical circuit of the device for measuring the complex reflection coefficient.

The device contains a first frequency synthesizer 1, a measuring probe section 2 with a 9M detector, a power meter 3, a directional coupler 4, a second frequency synthesizer 5, a key.6, a time master unit 7, a clock generator 8, a two-terminal 9, a computer 10 under investigation , calibrated controller 11 to 1plex gain.

A device for measuring the complex reflection coefficient works as follows.

The signal from the first synthesizer 1 frequency gives, the reference signal U. and sin (+ Q), the signal from the second synthesizer 5 frequency produces a measuring signal Uj and „sin (u) ,, t + d), the sum of the signals in the measuring probe section 2

Ut U-f, fsin (to, t + b) + + sinCwjt + Ы + fx).

where G is the modulus of the complex reflection coefficient from is. the following two-terminal 9; 40 Vv is the phase of the complex reflection coefficient from the two-terminal 9 under study. Under the condition of linear frequency conversion: using the detector of the 45 probe section 2, the power meter 3 fixes the power

G, + 2 Uin.-

s / g - and

X Y, COs (iWt + b - at - I / ;;), (O

where K is the transmission coefficient of the probe

connection, matching device and detector.

For different C; separated in the time interval, get a system of nonlinear equations with four unknowns

12

U, m; Cgl,; V ,,

I

K values; Q-ds are determined by calibrating the And, are remembered. Before calibration, a transient attenuation N is introduced by a calibrated complex gain controller 11, after which the amplitudes of the reference and measurement signal sources are equalized with power regulators. After calibration, a double-ended 9 monitored switch is connected, and using a calibrated regulator 11, the level of the applied measurement signal to the modulo load is increased and the phase is changed to a known value. At the same time, relation (1) takes the form

(i; + UL N

rl + 2 and

-rm

-uirn-t, ...

X N - r cos (/ 3 (xit + 0 - o (- fJ),

where N, / E is the modulus and phase of the transfer coefficient of the calibrated controller I1. Since the amplitude is one hundred

the component is determined

and

rm

+ e

N GU cosUwt +

- (/ v - f, ±),

as W increases, the amplitude of the standing wave increases. After incorporation of N into the measurement and calibration results, the complex reflection coefficient is determined.

Measuring small reflection coefficients based on measuring the amplitude of a shifting standing wave in the measuring probe section at fixed points in time with a calibrated change in the level of the complex amplitude of the measuring signal applied to the device being measured, improves the measurement accuracy by more than an order of magnitude and completely eliminates phase uncertainty.

Claims (1)

Invention Formula A device for measuring the complex reflection coefficient of the author. St. No. 1125556, characterized in that, with the aim of turning 313221914 Neither the accuracy of the measurement of the small coefficient includes a calibrated reflection receptor, between the second signal generator of the complex coefficient by the frequency tester and the directional transmission.