SU408235A1 - WIDEBAND PHASOMETER - Google Patents

Description

The invention relates to a phase-measuring technique and can be used to create broadband phase meters.

Phase meters are known that contain attenuators, phase detectors, and generators, however, well-known phase meters do not provide linearity characteristics and do not allow automation of measurement.

The aim of the invention is to obtain a linear characteristic of a phase meter and automate measurements.

For this, the phase meter is equipped with a tunable and reference oscillator, two comparison circuits, an adder, an additional phase detector, a phase shifter, and a control unit.

The drawing shows a block diagram of the phase meter.

The wideband phase meter contains phase detectors / and 2, tunable 3 and reference low frequency 4 oscillators, control element 5, attenuators 5 and 7, comparison circuits 5 and 9, adder 10, fixed phase shifter 11 with switch 12 and phase indicator 13.

The device works as follows.

The control element 5 receives the voltage from the adder 10 of the output signals of the detectors / and 2, which have identical characteristics. With attenuators b and 7,

the comparison circuits 5 and P amplitudes of the signals are set equal. Since attenuators 5 and 7 are installed in low-frequency channels, they can easily be phase-shifted.

Generators 3 and 4 have almost zero initial detuning, since the frequencies of generator 3 can be adjusted before starting measurements. Therefore, in the absence of measured signals, the output voltage at phase detector 2 is zero, and the phase shift between the voltages of the reference and tunable voltage is 90 °. The constant phase shift between these voltages is removed.

the phase shifter of the phase indicator 13 by setting it to zero.

Upon receipt of the measured signals at the phase detector / signal appears, which is fed to the adder 10. Since the initial detuning of the generators 5 and 4 is zero, the system performs this voltage with the opposite sign. To form this voltage, the phase difference between the voltages of the 3 n 4 generators is changed by

equal to the phase difference between the measured signals. This phase difference is measured by a low frequency phase indicator 13, which has a linear scale.

The ambiguity of reference is eliminated by the inclusion of a phase shifter shunt by switch 12 on one of the signal channels. If a negative voltage increment appears at the output of phase detector 1 when opening switch 12, this indicates that the phase difference is within ~ 180 °. If the matching increment is positive, then the phase difference is in the range of 180-360 °.

Subject invention

A wideband phase meter containing a phase detector, two attenuators and a phase indicator, characterized in that, in order to obtain a linear characteristic and automate measurements, it is equipped with a tunable and reference oscillator, two comparison circuits, an adder, an additional phase

a detector, a phase shifter with a shunt key and a control device whose input is connected to the output of the adder, and the output to the control input of a tunable generator; connected to one of the inputs of the adder, and the other input of the adder is connected to the output of the first phase detector, in the input circuit of which the phase shifter with untiruyuschim key, the inputs of comparators are connected respectively to the inputs of phase detectors and vghody - with the control inputs of the attenuators.

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