SU530312A1 - Measuring non-uniformity group lag time - Google Patents

Description

(54) MEASURING UNEQUAL DIMENSIONS OF THE GROUP TIME

containing a oscillating frequency generator, connected via an amplitude modulator, to a switch, a modulating oscillator, an adjudging detector connected to one short-circuit terminal for connecting the object under study, a phase detector, one of whose inputs is connected to the output of the reference frequency generator, and an output to the indicator , a low-pass filter, a modulating frequency generator is connected to the switch, and the output of the amplitude modulator is connected to another terminal for connecting the object under study, in addition, the output The bulk detector is connected to the input of a phase detector, the output of which is connected to a low-pass filter connected to a reference frequency generator.

The drawing shows a block diagram of the proposed irregularity meter of group I lag time.

The group lag time unevenness meter consists of a generator of oscillating frequency 1 connected to amplitude modulator 2 and a modulating oscillator 3 connected via switch 4 to the input of amplitude modulator 2j which is connected to one clip to connect the object under study, the other clip is connected with amplitude detector 5 e the output of the amplitude detector is connected to one input of the phase detector 6, and the output of the phase detector 6 is connected to the indicator 7 and the low-pass filter 8, the other input of the phase detector 6 is connected to the reference frequency generator 9.

The meter works as follows

The oscillating frequency generator 1 sweeps with a period of T-voltage gene sweep.

A ramping frequency 1 oscillator in an amplitude modulator 2 is modulated in amplitude by the voltage of a modulating oscillator 3, coming through switch 4, which switches with a period

So in one way,

. switch g-

d .-: switching the voltage of the oscillating frequency generator is modulated, in the other half period it is not modulated. With the passage of an amplitude-modulated signal through the object under study, information on phase characteristics is transferred to the signal envelope. The signal from the output of the object under study is demodulated in amplitude detector 5 and fed to the input of the phase detector. P 6. The voltage of the reference frequency generator 9 is applied to the other input of the phase detector, which is adjusted by the output of the Hbnvi output through the low-pass filter 8. At a change in the group delay time of the object under study, at the moment of switching on the mode ;; imbalance, a voltage jump occurs at the output of the phase detector 6 proportional to the difference in the group time of the reserve dyvani. The band (low pass filter 8 is selected from the condition that the switching frequency is outside the transparency band of the filter. Thus, slow changes in the phase of the reference frequency generator 9 and the modulating oscillator 3 are excluded.

Lack of switching devices for high resistivity; allows to measure the unevenness of the group delay time in a wide frequency range, and the absence of switching of the carrier frequencies reduces the measurement error of the group delay time.

Claims (2)

1. The patent of Germany No. 10SO441, cl. 21 Е 36 / 1О, 10.О1.58. 2. The patent of Germany No. 1025072, cl. 21 E 36/10, 21.05,57.   fi