SU389468A1 - PHASOMETRIC DEVICE - Google Patents

Description

one

This invention relates to a microwave measurement technique.

A device for studying plasma properties is known, which can be used to measure the phase characteristics of microwave amplifiers. It contains a phase shifter, an amplitude detector, an oscilloscope, and a saw generator (phase modulator). This device does not allow to investigate microwave amplifiers operating in the amplification mode of two harmonic oscillations.

The purpose of the invention is to provide a measuring device for the study of microwave amplifiers operating in the amplification mode of two harmonic signals with increased measurement accuracy.

The proposed phase metering device is characterized in that two hybrid bridge connections and two bandpass filters are introduced, one of the outputs of the input hybrid connection through the device under investigation, a bandpass filter and a phase shifter connected to one of the inputs of the output hybrid connection The bandpass filter and the phase modulator are connected to another input of the output hybrid, the output of which is connected to an oscilloscope via an amplitude detector.

The drawing shows the scheme of the device.

The device contains an input hybrid connection 1, output hybrid connection 2, band-pass filters 3, 4, phase shifter 5, phase modulator 6, amplitude detector 7, oscilloscope 8, absorbing device (load) 9.

Signals with fi and / 2 frequencies arrive at the input hybrid connection. From here both signals go to the reference and measurement channels. In the measuring channel, both signals pass through the amplifier under study 10. The test signal, separated by a band-pass filter 3, is fed through the phase shifter 5 to the input of hybrid 2,

from which a part of the power of this signal arrives at the amplitude detector 7, and everything else is absorbed by the load 9. In the reference channel, the band-pass filter 4 separates the signal under study, which through the phase

the modulator 6 enters the hybrid connection 2. Next, the power of the reference signal falls on the a. amplitude detector 7 and the load 9. Thus, the amplitude detector

Two microwave signals of an arbitrary phase are received, which, after detection, arrive at the oscilloscope 8. The image on the oscilloscope screen with a sawtooth law. Phase modulation in the reference channel depends on

phase ratio of signals arriving at the amplitude detector from the measuring and

reference channel. In the case when the phase modulation index is less than / 2 and only one period of modulating pattern is deployed on the oscilloscope screen, the phase shifter can easily set a symmetric image on the oscilloscope screen. A symmetrical figure on the oscilloscope screen appears at a certain ratio of the phases of the signals arriving at the amplitude detector from the reference and measuring channels, depending on the shape of the modulating voltage. When this ratio changes, the symmetry is violated, and the measurement is reduced to restoring the symmetry of the figure with the phase shifter and reading the differential phase along the slit of the latter.

Subject invention

A phasometric device containing input and output hybrid connections, a measuring channel with a test element and a phase shifter, a reference channel with a phase modulator, an amplitude detector and an indicator, characterized in that in order to increase the measurement accuracy of several harmonic signals, it is additionally introduced with two identical band-pass filters, and in the measuring channel a band-pass filter is connected between the element and the phase shifter, and in the reference channel - between the input ibridnym compound and a phase modulator.