SU127710A1 - Dual-channel heterodyne phase meter - Google Patents

Description

The known schemes of wide-range heterodyne two-channel phase meters do not provide measurement accuracy when the amplitudes of the input signals change.

The proposed phase meter is different from the known independence of the readings from changes in signal amplitudes during the measurement process. This is achieved by using two frequency inverters in the first channel of the phase meter, between which the barrier filter tuned to the local oscillator frequency is turned on. The signals from the filter are fed to the converter of the second channel. In the second channel, two phase shifters are included for changing the phase of the input signal; the outputs of the phase shifters are connected to the transducers of the first and second channels.

The block diagram of the phase meter shown in the drawing. The phase meter has two 1 K 2 inputs to which voltage is applied; The phase angle between the voltages is measured by a phase meter. The input / input signal goes to converter 5. It also receives the voltage from the local oscillator 4. From the output of the converter 3, the voltage goes to the barrier filter 5 that does not let the voltage of the local oscillator 4 pass through and then to the converter 6.

The signal from input 2 is fed to the phase shifter 7, from the output of which the voltage goes to the converter 6 and the phase shifter 8. The latter serves to shift the phase of the voltage supplied to the input of the converter 9 by 90 ° relative to the voltage input to the phase E. .

Phase shifter 10 serves to select a parasitic phase shift between voltages taken from amplifiers 11 and 12. Phaser 13 serves to select a parasitic phase shift between voltages from amplifiers 11-12 and a local oscillator voltage 4.

The voltage from the amplifier // (proportional to cos φ) and the amplifier 12 (proportional to z1pf) is fed through the phase shifter 10 to the vertical and horizontal plates of the electron-beam tube, respectively. Since the amplitudes of the voltages are proportional to cos φ and sin φ, and the phases of the voltages are equal, then the beam will deflect at an angle φ from the vertical straight line.

The voltage from the local oscillator 4 is fed to the amplitude discriminator 15, which serves to transform the harmonic-iecKoro oscillations into rectangular pulses fed to the tube modulator. Thus, on the screen of the tube, a beam appears that goes along the radius from the center, and its slope from the vertical is equal to the phase shift angle φ. A scale can be attached to the screen.

For setting the phase meter zero, an input switch 16 is provided.

Subject invention

Dual-channel heterodyne phase meter with a double frequency converter, characterized in that, in order to increase the measurement accuracy when the amplitudes E (of the output signals), in the first channel between the first and second converters, the barrier filter is switched on, the filter output is simultaneously connected to the converter of the second channel , and in the second channel, DE. and consecutive phase shifters are included to change the phase of the input signal, the outputs of which are connected respectively to the second converters ervogo and second channels.