SU958983A1 - Device for measuring phase - Google Patents

Description

The invention relates to a radio metering technique and can be used to measure the phase characteristics of various devices at high and ultrahigh frequencies.

A device for measuring the phase difference is known in which, for improving the accuracy of phase measurement, the reference oscillation channel is made of an optical CMM. This makes it possible to reduce measurement errors due to the absence of reflections in the reference channel and the parasitic connection between the reference and measurement channels 1.

The disadvantage of the device is a narrow operating range. ,

. The closest to the proposed invention in the structure and composition of the communications is a phase measurement device comprising a high-frequency generator connected to a power divider, to the first output of which the microwave element under study is connected in series, the first. the valve, the disposable detector and the indicator, and to the second output - the second valve, the output of which is connected to the control input of the electro-optical modulator, a coherent light source optically coupled

through an electron-optical, modulator and optical phase shifter with a second-, phase detector input.

c In the known device, the phase detector is made in the form of a photoelectric detector. rf multiplier with a high-frequency resonator, and an electron-optical light modulator performs

JQ modulation of the light emission intensity of an optical quantum generator by a reference high-frequency signal. The output of the phase detector (photomultiplier tube) produces a signal proportional to

15 to the phase shift between the support oscillations, which are supplied from the second valve to the electro-optic modulator, and the signal of the measuring channel, which passed through the studied

20 UHF element E.;

Claims (2)

So the measuring device provides greater accuracy in measuring the phase shift, however, it has a significant disadvantage in its narrowband. This is due to the narrow-band phase detector, made in the form of a photomultiplier with a high-quality microwave resonator, and a comparative narrow-band electro-optical light modulator. The aim of the invention is to expand the operating frequency range of the device for measuring the difference. Phases. ; . The goal is achieved by the fact that the device for measuring the phase contains a high-frequency generator connected to a power divider, to the first output of which the microwave element under study is connected, the first gate, the phase detector and the indicator, and the second coherent source is connected to the second output. light, optically coupled through an optical phase shifter to the second input of the phase detector, the coherent light source is made with. a modulating input which is connected to the output of the second valve, and a phase detector in the form of an avalanche photodiode with a matching circuit at the input and a lower filter at the output. The drawing shows a block diagram of the device. The device contains a generator of 1 high-frequency oscillations, a power divider 2, the microwave element 3 being investigated, the first valve .4, the matching circuit 5, the avalanche photodiode 6, the low-pass filter 7, the indicator 8, the second valve 9, the coherent light source 10, the optical phase shifter 11 The matching circuit 5, the avalanche photodiode 6, and the low-pass filter 7 form a phase detector 12. The device works as follows. The high-frequency signal from generator 1 is fed to the input of power divider 2. From the first output of the power divider 2, high-frequency oscillations through the microwave device under study 3 and the first valve 4 arrive at the first input of the phase detector 12. From the second output of the power divider 2, the high-frequency signal goes through the second valve 9 to the coherent light source 10 and modulates the light radiation in intensity by reference high frequency oscillations. The coherent light source 10 generates a high-stability coherent signal in the optical frequency range (light beam), which through the optical phase shifter 11 enters the second input of the phase detector 42. In the phase detector 12, the matching circuit 5 serves to match the complex impedance of the avalanche photodiode in the device’s operating frequency range with measuring channel. Valves 4 and 9. serve to isolate and reduce the influence of reflected waves. The low pass filter 7 serves to isolate a component in the avalanche photodiode 6 current that is proportional to the phase difference between the reference oscillations that the light beam is intensity-modulated and the high-frequency oscillations received on the avalanche photodiode from the measuring channel through the matching circuit 5. The avalanche current the photodiode is determined both by the high-frequency voltage acting on it, received from the matching circuit 5, and by the intensity of its illumination, which is determined by the ray beam received from the optical phase shifter 111. The intensity of the light beam, p according to the above, varies in time with the reference high-frequency oscillations arriving at the coherent light source 10 from the second valve 9. As a result, the avalanche photodiode current contains a component proportional to the phase difference between the reference oscillations the channel and oscillations of the measuring channel passing through the microwave element 3. This current component is selected by the filter 7 of the lower frequencies and is displayed on the indicator 8. The invention formula phase measurement, containing a high-frequency generator connected to a power splitter, to the first output of which the microwave element under study is connected in series, the first valve, phase detector and indicator, and the second output connected to the second output, a coherent light source optically coupled through the optical phase shifter to the second the input of the phase detector, which is called, and so that, in order to expand the operating frequency range, the source of coherent light is made with. a modulating input, which is connected to the output of the second valve, and a phase detector in the form of an avalanche photodiode with a matching circuit at the input and a low-pass filter at the output. Sources of information taken into account in the examination 1.Patent aOA 3319165, cl. 234-83, 1967. 2. USSR author's certificate 720955, cl. C 01 P 25 / 02,26.06,78.,