SU1190307A1 - Apparatus for measuring attenuation of attenuators - Google Patents

Abstract

A DEVICE FOR MEASURING THE ATTENUATOR RELAXATION, containing a high frequency generator, an output connected to the input of an amplitude modulator, the reference input of which is connected to the output of a low frequency generator, an exemplary attenuator, an indicator and a series-connected first adder and detector. The nepBbtfj input of the first adder is connected to the first terminal of the device for connecting the attenuator under investigation, and the second input of the first adder is connected to the output of the high-frequency generator, characterized in that, in order to improve the accuracy and broaden the dynamic measuring range, a series-connected phase-shifting element is added to it the attenuator and the second adder, while the input of the phase-shifting element is connected to the output of the low-frequency generator, the second input of the second adder through the model ttenyuator connected to the output of the detector, the second adder output is connected to the indicator input, the second terminal device for coupling the test output of the attenuator is connected to an amplitude modulator circuit for vtolnennogo ring modulator.

Description

The invention relates to measurement techniques and can be used to measure attenuator attenuation.

The purpose of the invention is to increase the accuracy of measurements to 0.01% and expand the dynamic range of measurements up to 10 times through the use of the compensation method of measurement.

The drawing shows a structural diagram of the device.

The device comprises a high-frequency generator 1, a ring modulator 2, a low-frequency generator 3, an attenuator 4 under investigation, a first adder 5, connected via an output 6 through an input of an exemplary attenuator 7, a phase-shifting element 8, connected via an additional attenuator 9 to an input of a second adder 10 , indicator 11 and the first 12 and second 13 terminals of the device for connecting the studied attenuator ..

The device operates as follows.

Sinusoidal signal from the output of a generator of the 1st type oscillation amplitude; angular frequency; initial phase, (in the future we set Cf ₀ = 0) to the first input of the ring where V _H W _H 10 (1) the modulator 3 arrives, the reference input of which receives a signal from the output of the generator 3 of the form

Η _Μ --νοψΜ _0Ι ), (2)

- amplitude of oscillation;

is the angular frequency, while

Ώ << from n;

is the initial phase (in the future we assume that _{0 <} = 0).

At the output of ring modulator voltage appears proportional to the sum and difference frequency signal generator 1 and 3 _minutes and species where w = 0 ^ - modulation factor.

where v _m

VNIIIPI Order 6975/48

The signal (3) through the attenuator 4 under study with the attenuation introduced to _cd passes to the first input of the adder 5, where it is added to the signal (1) supplied to the second input of the adder 5. The voltage at the output of the adder 5 has the form

And _am L _n С05 0) _m 1 + · / ₄ )

- ^ Τ ^ - [θθ5 (ω _Η -Ώ) 1: + οο5 (ω _Η + 5ΐΗ].

The elements of the adder 5 are selected so that the voltage equal to Vnj, where the coefficient k> 1, with a minimum attenuation of the attenuator 4 does not create an overmodulation of the amplitude-modulated (AM) signal at the output of the adder 5 and does not exceed the voltage Vj,

Signal (4) with level V _h -с os ω _Η £ _? necessary for the detector 6 to operate in linear mode, it enters its input and is detected. An output signal of the form (5) appears on the detector where kj is the transfer coefficient of detector 6.

Next, the signal (5) through the model attenuator 7 with the introduced attenuation K _{Qft is} fed to the first input of the adder 10. Simultaneously, from the output of the generator 3, the signal (2) through the phase-shifting element 8, which forms a 180 ° phase shift, and an additional attenuator 9 with the introduced attenuation equal to. to _AA = ____ * * 0D t

transforms to the form ^M M _t ^{= k} AA ' ^V MCOs (ftb (80 °) s

and enters the second input of the adder 10. In the adder, the signal (5) with the entered attenuation K _{od are} compensated by the signal (b). Indicator 11 should indicate a zero value.

Circulation 747 Subscription

Branch of PPP ’’ Patent ’, Uzhgorod, Project 4,

Claims (1)

DEVICE FOR MEASURING ATTENUATOR ATTENUATOR ATTENUATION, containing. a high-frequency generator output connected to the input of the amplitude modulator, the reference input of which is connected to the output of the low-frequency generator, an exemplary attenuator, an indicator and a series-connected first adder and detector, the first input of the first adder is connected to the first terminal of the device for connecting the studied attenuator, and the second input the first adder is connected to the output of a high-frequency generator, characterized in that, in order to improve accuracy and expand the dynamic range of measurements, the phase-shifting element, the additional attenuator and the second adder are connected in series, while the input of the phase-shifting element is connected to the output of the low-frequency generator, the second input of the second adder is connected to the output of the detector through the model attenuator, the output of the second adder is connected to the indicator input, the second terminal of the device for connecting the the attenuator is connected to the output of the amplitude modulator, made according to the circuit of a ring modulator.